Exhibit 10.1

     STOCK  PURCHASE  AGREEMENT,  dated March 25, 1998,  between  Pharmaceutical
Resources,  Inc., a New Jersey  corporation  (the  "Company"),  whose  principal
offices are located at One Ram Ridge Road,  Spring Valley,  New York 10977,  and
Lipha Americas, Inc., a Delaware corporation (the "Purchaser"),  whose principal
offices are located at 1209 Orange Street, Wilmington, Delaware 19801.

     WHEREAS,  the Company  desires to issue and sell to the Purchaser,  and the
Purchaser  desires to purchase from the Company,  10,400,000  restricted  shares
(the "Shares") of the Company's  common stock, par value $.01 per share ("Common
Stock");

     WHEREAS,  concurrently  with the execution and delivery of this  Agreement,
Merck KGaA, an affiliate of the  Purchaser  ("Merck"),  and Clal  Pharmaceutical
Industries,  Ltd. ("Clal") are entering into a stock purchase agreement pursuant
to which  Merck (or its  designees)  will,  subject to the terms and  conditions
thereof, purchase from Clal certain shares of Common Stock beneficially owned by
Clal  (the  "Clal  Stock  Purchase   Agreement"),   the  consummation  of  which
transaction  shall  occur at the time of the  consummation  of the  transactions
contemplated by this Agreement;

     WHEREAS, concurrently with the execution and delivery of this Agreement and
as an  inducement to the Company to enter into this  Agreement,  the Company and
Genpharm, Inc. ("Genpharm"),  an affiliate of the Purchaser, are entering into a
distribution  agreement  pursuant  to  which,  and  subject  to  the  conditions
contained  therein,  the Company shall distribute  certain products of Genpharm,
substantially in the form of Exhibit A hereto (the "Distribution Agreement");

     WHEREAS, at the Closing (as defined in Section 1.2 hereof), the Company and
Genpharm and Merck shall enter into  services  agreements  substantially  in the
form  of  Exhibit  B  hereto  (collectively,  the  "Services  Agreements";  each
individually  referred  to herein as a "Services  Agreement")  pursuant to which
Merck and Genpharm shall render certain significant  services to the Company, in
consideration  of, among other things,  the issuance by the Company to Merck and
Genpharm of certain five-year stock options  exercisable  commencing in the year
2001 to acquire up to an  aggregate  of  1,171,040  additional  shares of Common
Stock  (the  "Option  Shares"),  substantially  in the form of  Exhibit C hereto
(collectively,  the  "Options";  each  individually  referred  to  herein  as an
"Option");

     WHEREAS,  the Company has  received a fairness  opinion from Gruntal & Co.,
L.L.C.  ("Gruntal") to the effect that the Purchase Price (as defined in Section
1.1  hereof)  and  the   transactions   contemplated  by  this  Agreement,   the
Distribution Agreement,  the Services Agreements and the Options are, taken as a
whole, from a financial point of view, fair to the holders of Common Stock;

     WHEREAS,  the  Company's  Board of Directors has approved the execution and
performance  of  this  Agreement,   the  Distribution  Agreement,  the  Services
Agreements  and  the  Options,   and  has  determined   that  the   transactions
contemplated hereby and thereby are in the best interests of the Company and its
shareholders; and

     WHEREAS,  the Company and the  Purchaser  desire to set forth their  mutual
agreements  with  respect to the sale and  purchase  of the Shares and as to the
other matters set forth herein.

                                        1





         NOW,  THEREFORE,  in  consideration  of the  premises and of the mutual
agreements set forth herein, the parties hereto agree as follows:

         SECTION 1.        Closing Transactions.

         1.1 Purchase and Sale of Shares. At the Closing, the Company shall sell
to the  Purchaser,  and the  Purchaser  shall,  or shall cause its  designee to,
purchase  from the  Company,  upon  the  terms  and  subject  to the  conditions
hereinafter  set forth,  the  Shares for an  aggregate  cash  purchase  price of
$20,800,000 (the "Purchase Price"), or $2.00 per Share.

         1.2 The Closing.  The closing of the transactions  contemplated by this
Agreement (the "Closing") shall take place at the offices of Hertzog, Calamari &
Gleason,  100 Park Avenue, 23rd Floor, New York, New York, at 10:00 A.M., on the
second  business day following the date on which all of the conditions set forth
in  Sections  4 and 5  hereof  shall  have  been  satisfied  or,  to the  extent
permitted,  waived,  or at such other place, time and/or date as the parties may
agree (the  "Closing  Date");  provided,  that the Closing  Date shall not occur
before June 1, 1998.

     1.3 Closing  Deliveries.  (a) At the Closing,  the Company shall deliver to
the Purchaser, Merck and Genpharm, as applicable:

                           (i) a stock certificate or certificates  representing
         the Shares,  registered  in the name of the  Purchaser  or,  subject to
         Section 13.2 hereof, its designee on the Company's books and containing
         no  legends  other  than as set  forth in  Section  9.2  hereof  and as
         required  under the  Rights  Agreement  (as  defined  in  Section  7.11
         hereof);

                           (ii) a registration  rights agreement,  duly executed
         by the  Company,  substantially  in the form of  Exhibit D hereto  (the
         "Registration Rights Agreement");

                           (iii)    the certificates of officers of the Company 
         referred to in Sections 5.1 and 5.2 hereof;

                           (iv)     the agreements covering the Options, duly 
         executed by the Company;

                           (v)      the opinion of counsel referred to in 
         Section 5.3 hereof;

                           (vi)      the Services Agreements, duly executed by 
         the Company;

                           (vii)     the agreement of the Chairman of the 
         Company referred to in Section 7.10 hereof; and

                           (viii) the agreement of Kenneth Sawyer referred to in
         Section 7.3(e) hereof.


                                        2





         (b) At the Closing, the Purchaser,  Merck and Genpharm,  as applicable,
shall deliver to the Company:

             (i)  the  Purchase  Price,  in  the  form  of a  wire  transfer  of
                  immediately  available  funds to an account  designated by the
                  Company;

             (ii) the  Registration  Rights  Agreement,  duly  executed  by  the
                  Purchaser, Merck and Genpharm;

             (iii) the certificates of officers of the Purchaser  referred to in
                  Sections 4.1 and 4.2 hereof;

             (iv) the opinion of counsel referred to in Section 4.3 hereof;

             (v)  the Services  Agreements,  duly executed by Merck or Genpharm,
                  as applicable;

             (vi) the agreements covering the Options, duly executed by Merck or
                  Genpharm, as applicable; and

             (vii) the agreement of the Purchaser (and its  Affiliates) referred
                  to in Section 7.3(e) hereof.

     SECTION 2.  Representations  and  Warranties  of the  Company.  The Company
hereby represents and warrants to the Purchaser as follows:

     2.1 Organization.  Each of the Company, and any corporation with respect to
which the Company owns a majority of the common stock,  or has the power to vote
or direct  the  voting  of  sufficient  securities  to elect a  majority  of the
directors,  or  has  the  power  to  control  or  direct  the  actions  of  such
corporation,  all of which are set forth on Schedule 2.11 hereto  (collectively,
the "Subsidiaries",  each individually referred to herein as a "Subsidiary"), is
a corporation  duly organized,  validly  existing and in good standing under the
laws of the  jurisdiction of its  incorporation,  as set forth on Schedule 2.11.
Each of the Company and its Subsidiaries  has all necessary  corporate power and
authority  to own or lease its  properties  and to conduct  its  business as now
being  conducted.  Each of the Company and its Subsidiaries is duly qualified to
do  business  and  is  in  good  standing  as  a  foreign  corporation  in  each
jurisdiction  in which the  property  owned,  leased or  operated  by it, or the
nature of the  business  conducted  by it,  requires  such  qualification  under
applicable  law, except where the failure to be so qualified would not result in
a Material Adverse Effect (as defined in Section 2.10 hereof).

                                        3



     2.2  Authorization.  The execution,  delivery and, subject to obtaining the
approval (the "Shareholders'  Approval") of the holders of (i) a majority of the
outstanding  shares of Common Stock for the issuance of the Shares, the delivery
of the Options and the  issuance  of the Option  Shares,  (ii) a majority of the
outstanding   shares  of  Common  Stock  for  the  amendment  of  the  Company's
certificate  of  incorporation  in order to  increase  the number of  authorized
shares of Common Stock and (iii) a plurality of the shares of Common Stock voted
at a meeting for the election of the Nominees (as defined in Section 7.3 hereof)
(the preceding clauses (i), (ii) and (iii) to be individually referred to herein
as a "Proposal" and  collectively  as the  "Proposals"),  the performance by the
Company  of this  Agreement,  the other  agreements  referred  to herein and the
transactions  contemplated  hereby and thereby have been duly  authorized by all
requisite corporate action by the Company. This Agreement constitutes,  and each
other  agreement  referred to herein,  upon due  execution  and  delivery,  will
constitute, the valid and binding obligation of the Company, enforceable against
the Company in accordance with its terms,  except as such  enforceability may be
limited by (i)  bankruptcy  laws and other  similar  laws  affecting  creditors'
rights  generally and (ii) general  principles of equity,  regardless of whether
asserted in a proceeding in equity or at law.

     2.3  Non-contravention.  Neither the execution,  delivery or performance of
this Agreement and the other agreements  referred to herein nor the consummation
of the transactions  contemplated  hereby or thereby will,  subject to obtaining
the Shareholders' Approval,  violate or be in conflict with any provision of the
certificate  of  incorporation  or  by-laws  of  any  of  the  Company  and  its
Subsidiaries; subject to obtaining the Shareholders' Approval, and except as set
forth on Schedule 2.3 hereto,  violate or be in conflict with any material note,
bond, lease, mortgage,  indenture,  license,  contract,  commitment,  franchise,
permit, instrument or other material agreement or obligation to which any of the
Company and its  Subsidiaries is a party or by which it is bound;  violate or be
in conflict with any law, judgment,  decree,  order,  regulation or ordinance by
which any of the Company and its Subsidiaries is bound or affected; or result in
the creation or imposition of any liens, charges,  pledges or other encumbrances
("Liens") in favor of any third party upon any property or assets of the Company
and its Subsidiaries.

     2.4  Authorization  of the Shares.  Subject to obtaining the  Shareholders'
Approval, all corporate action necessary for the issuance,  sale and delivery of
the Shares has been taken by the Company  and,  when issued and  delivered  upon
payment in full of the Purchase Price, the Shares will be validly issued,  fully
paid  and  nonassessable,  free  and  clear  of any and all  Liens.  Subject  to
obtaining  the  Shareholders'  Approval,  the  Option  Shares  will  be  validly
authorized  for  issuance  and,  when and if issued upon  payment in full of the
exercise  price  for the  Option  Shares  in  accordance  with the  terms of the
Options, the Option Shares will be validly issued, fully-paid and nonassessable,
free and clear of any and all Liens.

     2.5 Capitalization. The authorized capital stock of the Company consists of
60,000,000  shares of Common Stock, of which no more than 18,923,000  shares are
issued and outstanding as of the date hereof,  and 6,000,000 shares of preferred
stock, par value $.0001 per share, of which no shares are issued and outstanding
as of the date hereof.  The Company holds no treasury  shares.  All  outstanding
shares of Common Stock have been duly and validly  issued and are fully-paid and
nonassessable.  There are no outstanding securities  exchangeable or convertible
into,  or options,  warrants,  or rights to subscribe  for, or to  purchase,  or
commitments to issue, any unissued shares of capital stock of any of the Company
and its Subsidiaries, except as set forth on Schedule 2.5 hereto.

                                        4



     2.6 Reports  Under the Exchange Act.  Since October 1, 1994,  except as set
forth on Schedule  2.6 hereto,  the  Company has filed with the  Securities  and
Exchange  Commission  (the "SEC") in timely  fashion all reports  required to be
filed by the Company pursuant to the Securities Exchange Act of 1934, as amended
(the "Exchange Act") (as such reports may have been amended or supplemented, the
"SEC  Reports").  The Common  Stock is  registered  under  Section  12(b) of the
Exchange Act. As of their respective  filing dates with the SEC, the SEC Reports
did not  contain  any untrue  statement  of a  material  fact or omit to state a
material  fact  required to be stated  therein or necessary in order to make the
statements made therein,  in light of the circumstances in which they were made,
not misleading.

     2.7 No Brokers or Finders. No person, firm or corporation has or will have,
as a result of any act or omission  by any of the Company and its  Subsidiaries,
any right,  interest or valid claim  against the Purchaser or any of the Company
and its Subsidiaries for any commission,  fee or other  compensation as a finder
or broker,  or in any similar  capacity,  other than with respect to the opinion
referred  to in  Section  4.9  hereof  (the  costs of which will be borne by the
Company), in connection with the transactions contemplated by this Agreement.

     2.8  Governmental   Authorizations;   Third-Party  Consents.  No  approval,
consent,  authorization  or other  action by, or notice to or filing  with,  any
governmental  authority or any other person or entity, and no lapse of a waiting
period,  is necessary or required in connection with the execution,  delivery or
performance by the Company of this Agreement,  the other agreements  referred to
herein or the transactions  contemplated hereby or thereby,  except for (i) such
filings  or  approvals  required  pursuant  to the  Hart-Scott-Rodino  Antitrust
Improvements Act of 1976, as amended, and the regulations promulgated thereunder
(the "HSR  Act"),  (ii) such  filings  or  approvals  as may be  required  to be
obtained in connection with the manufacture and sale of products pursuant to the
Distribution Agreement, (iii) the Shareholders' Approval of the Proposals by the
requisite votes, (iv) such filings or approvals  required to list the Shares and
the Option Shares on the New York Stock  Exchange and the Pacific Stock Exchange
and (v) the matters set forth on Schedule 2.8 hereto.

     2.9 Financial  Statements.  The audited financial statements of the Company
included in the  Company's  Annual Report on Form 10-K for the fiscal year ended
September  30,  1997 (the  "Audited  Statements")  and the  unaudited  financial
statements  of the Company  included in the Company's  Quarterly  Report on Form
10-Q for the fiscal quarter ended December 31, 1997 (the "Unaudited Statements")
complied  as to form with the  requirements  of the  Exchange  Act and except as
disclosed  therein or in the  footnotes  thereto and,  except for the absence of
notes  and  subject  to  year-end  adjustments  in the  case  of  the  Unaudited
Statements,  were prepared in accordance with United States  generally  accepted
accounting  principles.  The Audited  Statements  and the  Unaudited  Statements
fairly present, in all material respects,  the consolidated  financial condition
and the  consolidated  results of  operations of the Company as of the dates and
for the periods indicated therein.

     2.10  Absence of Material  Adverse  Effect.  Except as disclosed in the SEC
Reports, since January 1, 1998, the business of the Company and its Subsidiaries
has been operated in the ordinary

                                        5



course and substantially  consistent with past practice.  Since January 1, 1998,
there has been no event or circumstance  resulting in a material  adverse effect
on the properties,  business and assets,  liabilities,  condition  (financial or
otherwise) or operations  of the Company and its  Subsidiaries,  considered as a
whole (a "Material  Adverse  Effect").  There has been no event or circumstance,
since January 1, 1998,  which would  materially  adversely affect the ability of
the Company to perform its obligations under this Agreement, or any of the other
agreements  to  be  entered  into  in  connection  with  this  Agreement,  or to
consummate the transactions contemplated hereby and thereby.

     2.11 Subsidiaries;  Other Equity Interests.  Each Subsidiary of the Company
and each other  person in which the  Company or any of its  Subsidiaries  has an
equity interest is set forth on Schedule 2.11 hereto.  Each Subsidiary is wholly
(100%) owned by the Company.  The authorized,  issued and outstanding  shares of
the capital stock of each Subsidiary, and the record and beneficial ownership of
the outstanding  shares thereof,  is as set forth on Schedule 2.11. There are no
agreements or  arrangements to which any Subsidiary is a party or by which it is
bound for the  redemption,  repurchase or issuance of, and there are no options,
warrants,  puts,  calls or other rights to subscribe for or purchase,  shares of
such Subsidiary's capital stock.

     2.12 No Third-Party Options. Except as contemplated hereby, as set forth on
Schedule 2.12 hereto, or as disclosed in the SEC Reports,  there are no existing
agreements,  contracts,  commitments, options, warrants or rights with, of or to
any person which are binding on the Company or its  Subsidiaries  to acquire any
of the  Company's and its  Subsidiaries'  assets,  properties,  or rights or any
interest  therein  (whether  real,  personal or mixed,  tangible or  intangible,
wherever  located  and  whether  in  the  possession  of  the  Company  and  its
Subsidiaries or any other person), except for those entered into in the ordinary
course of  business  consistent  with past  practice  for the sale of  inventory
and/or which could not  reasonably  be expected to result in a Material  Adverse
Effect.

     2.13 Employee Matters.

     (a)  The  Company  has  delivered  to the  Purchaser  a list of its and its
Subsidiaries' current employees (the "Employees"). This list, attached hereto as
Schedule  2.13(a),  sets forth the current  compensation,  commissions or hourly
rate of pay, date of birth,  date and location of  employment  and job title for
each Employee. Schedule 2.13(a) lists all agreements between the Company and its
Subsidiaries  and  any  Employee(s)  with  respect  to  the  employment  of  any
Employee(s).  Except as set forth on Schedule 2.13(a),  there are no outstanding
loans with outstanding  principal  amounts in excess of $50,000 from the Company
or any of its  Subsidiaries  to any  Employees.  Except as set forth on Schedule
2.13(a),  no Employee is on disability or other leave of absence and the Company
is not  aware of the  intent of any  officer,  executive  employee  or head of a
department  of any of the  Company and its  Subsidiaries  to  terminate  his/her
employment.

     (b) Schedule 2.13(b) hereto lists each "employee  benefit plan", as defined
in Section  3(3) of the Employee  Retirement  Income  Security  Act of 1974,  as
amended ("ERISA"),  whether or not covered by ERISA, that any of the Company and
its Subsidiaries sponsors or has

                                        6



sponsored to which the Company or any of its  Subsidiaries is or has been in the
past three years required to make  contributions,  including without  limitation
any pension,  profit-sharing,  retirement or deferred  compensation  plan,  each
other benefit plan,  policy,  arrangement or practice,  whether  covering one or
more employees,  which provides deferred  compensation,  bonus,  stock purchase,
stock  option,  vacation,  severance,   disability,   hospitalization,   medical
insurance or life insurance payments or benefits and any other material employee
benefit plans,  agreements,  arrangements or  understandings  maintained for the
benefit of the  Employees  or former  employees  of any of the  Company  and its
Subsidiaries  ("Former  Employees")  (collectively,  together  with any  related
trusts, the "Employee Benefit Plans").  Except as set forth on Schedule 2.13(b),
no Employee  Benefit Plan  constitutes a  multi-employer  plan (as defined under
Section  400(a)(3)  of  ERISA).  Except as set forth on  Schedule  2.13(b),  all
participants in the Employee Benefit Plans are Employees or Former Employees (or
their dependents or beneficiaries). The Company has previously delivered or made
available  to the  Purchaser  true  and  complete  copies  of all  documents  or
instruments establishing or constituting each such Employee Benefit Plan and all
summary  plan  descriptions  or other  descriptive  materials  relating  thereto
distributed  by the Company and its  Subsidiaries  to  Employees.  Except as set
forth  on  Schedule  2.13(b),  all  Employee  Benefit  Plans  are  currently  in
compliance with all applicable funding  requirements under law. Schedule 2.13(b)
also  sets  forth a list of those  Former  Employees  (or  their  dependents  or
beneficiaries)  who are receiving  continuation  coverage under the Company's or
any of its  Subsidiaries'  medical plans  pursuant to the  Consolidated  Omnibus
Budget  Reconciliation  Act of 1985  ("COBRA")  and the dates upon  which  those
individuals commenced receiving such continuation coverage.  Except as set forth
on Schedule 2.13(b), none of the Company, its Subsidiaries or the Purchaser will
incur any  liability  under  any  Employee  Benefit  Plan or  agreement  with an
Employee solely as a result of the transactions contemplated by this Agreement.

     (c) Except as set forth on  Schedule  2.13 (c)  hereto,  (i) each  Employee
Benefit Plan which is an "employee  pension benefit plan", as defined in Section
3(2) of ERISA,  meets the  requirements  of  Section  401(a) of the Code and any
related trust is exempt from U.S. federal income tax under Section 501(a) of the
Code and (ii) the Company and its Subsidiaries are in compliance in all material
respects with the terms of such Employee Benefit Plans and with the requirements
of the Internal  Revenue Code of 1986,  as amended  (the  "Code"),  and ERISA in
respect  thereto.  None of the Company or its  Subsidiaries  has any  obligation
under any Employee Benefit Plan or otherwise to provide  post-retirement  health
benefits  (exclusive  of  obligations  under  COBRA) with  respect to any of the
Employees or Former Employees.

     (d) The Employees are not and have not in the past three years been covered
by any labor or  collective  bargaining  agreement.  No strike,  work  stoppage,
picketing,  slowdown,  lockout or material labor dispute involving the Company's
or its Subsidiaries'  operations has occurred during the past three years or, to
the Company's knowledge,  is threatened.  To the Company's knowledge, no attempt
at the  organization  of a union involving the Company or its  Subsidiaries  has
occurred during the past three years or is threatened.

     (e) None of the  Company or its  Subsidiaries  has  incurred  any  material
liability  under,  and has complied in all material  respects  with,  the Worker
Adjustment Retraining and

                                        7



Notification  Act and the  regulations  promulgated  thereunder  and any similar
state  laws and does not  reasonably  expect  to incur any such  liability  as a
result of actions taken or not taken prior to the date hereof.

     (f) Except as set forth on Schedule  2.13(f)  hereto or as disclosed in the
SEC  Reports,  the Company and its  Subsidiaries  have  complied in all material
respects with all  applicable  laws,  rules,  regulations  and executive  orders
governing the terms and conditions of employment,  discriminatory practices with
respect to  employment,  hiring and  discharge,  the  employment of aliens,  the
payment of minimum wages and overtime,  workplace health and safety or otherwise
relating to the conduct of employers  with respect to  employees  and  potential
employees,  and except as set forth on Schedule 2.13,  there have been no claims
made or, to the  Company's  knowledge,  threatened  against  the  Company or its
Subsidiaries  arising out of, relating to or alleging any material  violation of
the foregoing.

     2.14 Permits. The Company and its Subsidiaries have all licenses,  permits,
orders, certificates, authorizations, consents and approvals of all governmental
and regulatory authorities and bodies, whether federal, state or local, domestic
or foreign,  which are  necessary for the operation of its business as currently
conducted  ("Permits"),  except for the failure to have such  Permits that could
not,  individually  or in the  aggregate,  reasonably be expected to result in a
Material Adverse Effect.  Except as could not, individually or in the aggregate,
reasonably be expected to result in a Material  Adverse Effect,  the Permits are
in full force and effect and no  suspension  or  cancellation  of any of them is
pending or, to the Company's knowledge, threatened.

     2.15  Intellectual  Property.  Schedule  2.15  hereto sets forth all of the
patents,  registered copyrights and registered trademarks of the Company and its
Subsidiaries,   all of which are owned by the Company or its  Subsidiaries  free
and clear of any Liens.  None of the Company or its  Subsidiaries  has infringed
upon or unlawfully used, in any material respect, any patent, trademark, service
mark, tradename,  copyright, or trade secret ("Intellectual  Property") owned by
another person. None of the Company or its Subsidiaries has received any written
notice of any claim of  infringement  or other material claim relating to any of
its Intellectual  Property. No shareholder of the Company or its Subsidiaries or
member of any such shareholder's family or any entity controlled by them, or any
Employee or Former  Employee  owns or has any  proprietary,  financial  or other
material interest,  directly or indirectly,  in any Intellectual  Property which
the  Company or its  Subsidiaries  owns,  possesses  or  materially  uses in its
operations.  Schedule  2.15 sets  forth all  confidentiality  or  non-disclosure
agreements  to  which  either  the  Company  or its  Subsidiaries  or any of its
Employees or Former  Employees  is a party and which relate to the  Company's or
its Subsidiaries' business and were executed in the past seven years.

     2.16 No Pending Litigation or Proceedings.  Except as set forth on Schedule
2.16 hereto or as disclosed in the SEC Reports,  there are no material  actions,
suits,  proceedings  (including arbitral proceedings) or investigations  pending
or,  to  the  Company's  knowledge,   threatened  against  the  Company  or  its
Subsidiaries  or  directly  relating  to or  otherwise  directly  affecting  the
business,  assets or properties of the Company and its  Subsidiaries.  Except as
set forth on Schedule 2.16 or as

                                        8



disclosed  in  the  SEC  Reports,  there  is  no  outstanding  judgment,   writ,
injunction,  decree,  award  or  order  of  any  court  or any  governmental  or
regulatory authority or body against or directly affecting the business,  assets
or properties of the Company and its Subsidiaries.

     2.17  Insurance  Coverage.  Each of the  Company and its  Subsidiaries  has
during the past three years maintained  liability,  casualty,  property loss and
other  insurance  policies  with  respect to the conduct of its business in such
amounts,  of such kinds and with such  insurance  carriers as the Company and it
Subsidiaries, as applicable, has deemed appropriate and sufficient for companies
of a similar  size  engaged  in  similar  types of  businesses  and  operations.
Schedule  2.17 hereto sets forth a summary  description  of each such  insurance
policy, listing for each policy the risks insured against,  coverage limits, any
deductible  amounts,  any pending  claims  thereunder  and the term of each such
policy.  Each such policy is in full force and effect,  and no written notice of
cancellation  has been  received  with respect to any such policy,  nor will the
consummation  of the  transactions  contemplated  by this  Agreement  cause  the
cancellation  of, or the right to cancel,  any such policy pursuant to the terms
of such  policy.  The  Company  and its  Subsidiaries  have filed all notices or
reports  required under such policies,  except such filings the failure of which
to make could not reasonably be expected to result in a Material Adverse Effect.

     2.18 Compliance  with Laws.  Except as set forth on Schedule 2.18 hereto or
as disclosed in the SEC Reports,  each of the  Company's  and its  Subsidiaries'
business and  operations are being  conducted in compliance  with all applicable
laws, statutes,  rules, regulations,  ordinances,  codes, orders, franchises and
Permits  of all  governmental  entities,  including  without  limitation,  those
relating  to  occupational  safety and health  and equal  employment  practices,
except for such instances of  noncompliance  that could not,  individually or in
the aggregate, reasonably be expected to result in a Material Adverse Effect. No
notice,  citation,  summons or order has been assessed and no  investigation  or
review is pending or, to the Company's knowledge, threatened by any governmental
or other  entity with  respect to any alleged  material  violation by any of the
Company and its Subsidiaries of any of the foregoing.

     2.19 Environmental Matters.  Except as set forth on Schedule 2.19 hereto or
as  disclosed  in the SEC  Reports,  and except for such matters that could not,
individually or in the aggregate, reasonably be expected to result in a Material
Adverse Effect, (a) there are no investigations,  inquiries or other proceedings
pending or, to the Company's knowledge, threatened with regard to the current or
prior   conduct  of  the  business  and   operations  of  the  Company  and  its
Subsidiaries, or relating to (x) any properties owned or previously owned by the
Company and its Subsidiaries, (y) any properties at which any of the Company and
its Subsidiaries  has conducted  operations or (z) any sites at which any of the
Company and its  Subsidiaries  has disposed of, or arranged for the disposal of,
waste materials, and arising out of or relating to any actual or alleged failure
to comply with any requirement of any law, statute,  rule,  regulation,  code or
ordinance relating to air or water quality, waste management, hazardous or toxic
substances,  or the  protection  of  health or the  environment  ("Environmental
Laws");  (b) the  Company  and  its  Subsidiaries  are in  compliance  with  the
requirements  of  all  Environmental  Laws  in  connection  with  its  business,
operations and otherwise; and (c) none of the properties or sites referred to in
clauses (x), (y) or (z) above is contaminated with

                                        9



any  hazardous  waste or  substance  as a result of any act or  omission  of the
Company and any of its Subsidiaries,  or, to the Company's knowledge, any agent,
servant or bailee of the Company and any of its  Subsidiaries,  to a degree that
poses a risk to health or the  environment  or could  impose a liability  on the
Company.  With regard to compliance with Environmental Laws, the representations
and warranties set forth in this Section 2.19 shall  supersede the provisions of
Section 2.18 hereof.

     2.20 Tax Returns and Taxes.

     (a) The  Company  and its  Subsidiaries  have  filed  all Tax  Returns  (as
hereinafter  defined)  required to be filed by it.  Except  with  respect to any
contested liability for Taxes (as hereinafter defined), as set forth on Schedule
2.20  hereto,  all such Tax Returns  were  correct and  complete in all material
respects.  All Taxes owed by the Company and any of its Subsidiaries (whether or
not shown on any Tax Return) have been paid except for (i) Taxes accrued but not
yet  payable,  (ii) Taxes which are being  contested  in good  faith,  and (iii)
Taxes,  the non-payment of which could not reasonably be expected to result in a
Material  Adverse  Effect.  Except as set forth on  Schedule  2.20,  none of the
Company and its Subsidiaries has received any notice of assessment of additional
Taxes that is currently  pending.  Except as set forth on Schedule 2.20, none of
the  Company  and its  Subsidiaries  has waived any  statute of  limitations  in
respect of Taxes or executed or filed with any Tax  authority  any  agreement or
document  extending the period of  assessment of any Taxes,  and the Company and
its  Subsidiaries  are not  currently the  beneficiary  of any extension of time
within which to file any Tax Return. Except as set forth on Schedule 2.20, there
are no claims, examinations, audits, proceedings or proposed deficiencies for or
in respect of Taxes pending or, to the Company's  knowledge,  threatened against
the  Company  or its  Subsidiaries.  No claim  has been made in  writing  to the
Company  or its  Subsidiaries  in the  past  three  years by an  authority  in a
jurisdiction where the Company and its Subsidiaries do not file Tax Returns that
it is or may be subject to taxation by that jurisdiction.  There are no recorded
Tax Liens on any of the  assets of the  Company  and its  Subsidiaries,  nor are
there  any  security  interests  on any of the  assets  of the  Company  and its
Subsidiaries  that arose in connection with any failure (or alleged  failure) of
the  Company or any of its  Subsidiaries  to pay any Tax  (other  than Liens and
security  interests  for Taxes  not yet due and  payable  or for Taxes  that the
Company  (or any of its  Subsidiaries,  as  applicable)  is  contesting  in good
faith).

     (b) The Company (and each of its Subsidiaries,  as applicable) has withheld
and paid all Taxes  required by applicable law to have been withheld and paid in
connection  with  amounts  paid or owing to any  Employee  or  Former  Employee,
independent contractor, creditor, stockholder or other third party, except where
the  failure to do so could not  reasonably  be expected to result in a Material
Adverse Effect.

     (c)  Except as set forth on  Schedule  2.20,  there is no  dispute or claim
concerning  any Tax  liability  of the Company (or any of its  Subsidiaries,  as
applicable)  either  (i)  claimed  or raised by any  governmental  authority  in
writing or (ii) as to which the  Company or any of its  executive  officers  (or
employees  principally  responsible  for Tax matters) has  knowledge  based upon
personal  contact with any agent of such  authority.  Schedule  2.20 lists those
federal, state, local, and foreign

                                       10



income  Tax  Returns   filed  with  respect  to  the  Company  (or  any  of  its
Subsidiaries, as applicable) that have been audited in the past three years, and
indicates those Tax Returns that currently are the subject of audit.

     (d) The Company (or any of its Subsidiaries, as applicable) has not filed a
consent under Section 341(f) of the Code  concerning  collapsible  corporations.
Except as set forth on  Schedule  2.20(f)  hereto,  the  Company  (or any of its
Subsidiaries,  as applicable) has not made any payments,  nor is it obligated to
make  any  payments,  nor is it a party  to any  agreement  that  under  certain
circumstances could obligate it to make any payments that will not be deductible
under Section 280G of the Code.  The Company has disclosed on its federal income
Tax Returns all  positions  taken  therein that could give rise to a substantial
understatement  of federal  income Tax within the meaning of Section 6662 of the
Code. The Company (or any of its Subsidiaries,  as applicable) is not a party to
any Tax allocation or sharing agreement. The Company has not been a member of an
Affiliated  Group filing a consolidated  federal income tax return (other than a
group the common parent of which is the Company).

     (e) The Company (or any of its  Subsidiaries,  as applicable) does not have
(i)  income   reportable  for  a  period  ending  after  the  Closing  Date  but
attributable  to a transaction  (e.g.,  an installment  sale)  occurring in or a
change in accounting  method made for a period ending on or prior to the Closing
Date which resulted in a deferred  reporting of income from such  transaction or
from such  change in  accounting  method  (other  than a  deferred  intercompany
transaction);  or  (ii)  deferred  gain  or  loss  arising  out of any  deferred
intercompany  transaction.  No "ownership change" (within the meaning of Section
382(g) of the Code) has, to the Company's knowledge,  occurred prior to the date
hereof which currently limits the Company's ability to utilize any net operating
loss carryovers under Section 382 of the Code.

     For purposes of this Agreement,  "Tax" or "Taxes" means any federal, state,
local, or foreign income, gross receipts, license, payroll, employment,  excise,
severance,   stamp,  occupation,   premium,   windfall  profits,   environmental
(including  taxes  under Code  Section  59A),  customs  duties,  capital  stock,
franchise,  profits,  withholding,  social security (or similar),  unemployment,
disability,   real  property,   personal   property,   sales,   use,   transfer,
registration,  value added,  alternative or add-on minimum,  estimated, or other
tax of any kind  whatsoever,  including  any  interest,  penalty,  deficiency or
addition  thereto,  whether  disputed or not, and "Tax Return" means any return,
declaration,  report,  claim for  refund,  or  information  return or  statement
relating to Taxes,  including any schedule or attachment thereto,  and including
any amendment thereof.

     2.21 Outstanding  Registration Rights. Except as set forth on Schedule 2.21
hereto or as disclosed in the SEC Reports, the Company has not in the past three
years  granted (or  incurred any  obligations  or  commitments  to grant) to any
holder or holders of any capital stock (or rights to acquire any capital  stock)
of the  Company  (i) any  rights to request  or demand  registration  of, or the
filing of an offering  circular with respect to,  outstanding  shares of capital
stock of the  Company  under any  securities  laws or rules,  (ii) any rights to
include  any  outstanding  shares  of  capital  stock  of  the  Company  in  any
registration or filing  effected by the Company  pursuant to any securities laws
or

                                       11



rules,  or (iii) any rights to require  the  Company  to take  action  under any
securities laws or rules in order to permit or otherwise facilitate  disposition
of any outstanding shares of the Company's capital stock.

     2.22 Certain Beneficial Owners.

     (a)  Schedule  2.22(a)  hereto  sets  forth  an  analysis  prepared  by the
Company's  auditors  stating the stock ownership of 5-percent  shareholders  (as
such term is defined in Section  382 of the Code) in the Company as of the dates
indicated  therein.  To the Company's  knowledge,  such Schedule  correctly sets
forth in all material  respects the stock ownership of such shareholders and the
changes in such stock ownership as of each fiscal year-end indicated therein.

     (b) Schedule  2.22(b)  lists all options,  warrants,  or other stock rights
issued by the  Company  and  outstanding  as of the date  hereof to any  person,
whether or not a 5-Percent  Shareholder,  that have not yet been exercised as of
the date  hereof,  together  with  the  exercise  dates,  exercise  prices,  any
consideration paid therefor and expiration dates.

     2.23 FDA  Compliance.  The  products  manufactured,  sold,  distributed  or
supplied by each of the Company and its  Subsidiaries,  as  applicable,  are not
adulterated or misbranded  within the meaning of the United States Federal Food,
Drug and Cosmetic Act, as amended ("USFFDCA"),  and comply with any monograph or
other  requirements  of the United States Food and Drug  Administration  ("FDA")
applicable  to the  products  or their  manufacture,  except  for  instances  of
noncompliance  that could not,  individually or in the aggregate,  reasonably be
expected to result in a Material  Adverse  Effect.  Such  products have been and
continue  to  be  manufactured  in  compliance  with  all  applicable  statutes,
ordinances  and  regulations,  including but not limited to, the USFFDCA and the
regulations thereunder, including the current Good Manufacturing Practices which
have been adopted by the FDA, except for instances of  noncompliance  that could
not,  individually  or in the  aggregate,  reasonably be expected to result in a
Material Adverse Effect.  Current Good Manufacturing Practice means current good
manufacturing  practice regulations  established in 21 C.F.R. Parts 210 and 211,
as amended and in effect from time to time,  and other  applicable  FDA policies
relating thereto. Except as set forth on Schedule 2.23 hereto or as disclosed in
the SEC Reports,  none of the Company and its Subsidiaries has in the past three
years  received  any notice or summons  in  respect of a material  violation  or
alleged  material  violation of any statute or regulation  from the FDA or other
similar authorities.

     2.24 Reliance. The representations, warranties, covenants and agreements of
the Company  contained herein and in the certificates and schedules  required to
be delivered in accordance  with the terms of this Agreement  shall,  subject to
Section 11 hereof,  survive any investigation made by the Purchaser and are made
by the Company with the  expectation  that the  Purchaser is relying  thereon in
entering  this  Agreement  and  the  same  shall  not be  deemed  waived  by any
investigation conducted by the Purchaser or its employees, advisors, consultants
or representatives, whether before or after the consummation of the transactions
contemplated hereby.


                                       12



     SECTION 3.  Representations and Warranties of the Purchaser.  The Purchaser
hereby represents and warrants to the Company as follows:

     3.1 Organization. The Purchaser is a corporation duly organized and validly
existing and in good standing  under the laws of Delaware and is a  wholly-owned
subsidiary  of  Merck.  The  Purchaser  has all  necessary  corporate  power and
authority  to own or lease its  properties  and to conduct  its  business as now
being conducted.

     3.2 Authorization. The execution, delivery and performance by the Purchaser
of this Agreement,  the other agreements referred to herein and the transactions
contemplated  hereby and  thereby  have been duly  authorized  by all  requisite
corporate action by the Purchaser and, in the case of the Distribution Agreement
and the Services Agreement to which it is a party, by Merck and Genpharm, as the
case  may be.  This  Agreement  constitutes,  and each of the  other  agreements
referred to herein,  upon execution and delivery,  will constitute,  a valid and
binding  obligation  of the  Purchaser  and,  in the  case  of the  Distribution
Agreement  and the  Services  Agreement  to which it is a  party,  of Merck  and
Genpharm,  enforceable against the Purchaser, Merck or Genpharm, as the case may
be, in accordance with its terms,  except as such  enforceability may be limited
by (i)  bankruptcy  laws and other  similar  laws  affecting  creditors'  rights
generally and (ii) general principles of equity,  regardless of whether asserted
in a proceeding in equity or at law.

     3.3 Non-contravention.  Neither the execution,  delivery and performance of
this Agreement and the other agreements  referred to herein nor the consummation
of the  transactions  contemplated  hereby  or  thereby  will  violate  or be in
conflict with any provision of the articles of organization of the Purchaser or,
in the case of the Distribution Agreement and the Services Agreement to which it
is a party, of Merck or Genpharm,  as the case may be; violate or be in conflict
with any material note, bond, lease,  mortgage,  indenture,  license,  contract,
commitment,  franchise,  permit,  instrument  or  other  material  agreement  or
obligation  to which the  Purchaser,  Merck or  Genpharm  is a party or by which
either of them is  bound;  violate  or be in  conflict  with any law,  judgment,
decree, order, regulation or ordinance by which the Purchaser, Merck or Genpharm
is bound or affected;  or result in the creation or  imposition  of any Liens in
favor of any third party upon any property or assets of the Purchaser,  Merck or
Genpharm.

     3.4 No Brokers or Finders. No person, firm or corporation has or will have,
as a result of any act or  omission by the  Purchaser,  Merck or  Genpharm,  any
right,  interest or valid claim against the Company for any  commission,  fee or
other  compensation  as a finder  or  broker,  or in any  similar  capacity,  in
connection with the transactions contemplated by this Agreement.

     3.5  Governmental   Authorizations;   Third-Party  Consents.  No  approval,
consent,  authorization  or other  action by, or notice to or filing  with,  any
governmental  authority or any other person or entity, and no lapse of a waiting
period,  is necessary or required in connection with the execution,  delivery or
performance by the Purchaser or, in the case of the  Distribution  Agreement and
the Services Agreement to which it is a party, by Merck or Genpharm, as the case
may be, of this

                                       13



Agreement,   the  other  agreements  referred  to  herein  or  the  transactions
contemplated  hereby or  thereby,  except  for such  filings  or  approvals  (a)
required pursuant to the HSR Act and (b) as may be required (by the FDA or other
governmental  authorities)  to be obtained in connection  with the  Distribution
Agreement.

     3.6  Investment  Representations.  (a) The Purchaser and its Affiliates (as
defined in Rule 405 of the Securities  Act of 1933, as amended (the  "Securities
Act")) are  acquiring  the Shares and the  Options  and,  upon  exercise  of the
Options,  will be acquiring  the Option Shares solely for their own accounts and
not with a view to, or for resale in connection with, any  distribution  thereof
within the  meaning of the  Securities  Act.  Each of the  Purchaser,  Merck and
Genpharm is an "accredited  investor" (as defined in Rule 501(a) of Regulation D
promulgated under the Securities Act).

     (b) The Purchaser, on behalf of itself and its Affiliates, understands that
(i) the Shares and the Option have not been  registered,  and the Option Shares,
when issued,  will not be registered  under the Securities Act or any applicable
state  securities  laws,  by  reason  of  their  issuance  by the  Company  in a
transaction exempt from the registration  requirements of the Securities Act and
applicable state securities laws and (ii) the Shares, the Options and the Option
Shares  must be held by the  Purchaser  (or Merck or  Genpharm,  as  applicable)
indefinitely  unless a subsequent  disposition  thereof is registered  under the
Securities  Act and  applicable  state  securities  laws or is exempt  from such
registrations.

     (c) The  Purchaser,  on behalf of itself and its  Affiliates,  acknowledges
that no  representations or warranties have been made or furnished to, or relied
on by,  the  Purchaser  or any of its  representatives  in  connection  with its
purchase of the Shares except as expressly  provided  herein.  The Purchaser has
such  knowledge  and  experience  in financial  and business  matters that it is
capable of evaluating the risks and merits of this investment.

     (d) The  Purchaser,  on behalf of itself and its  Affiliates,  acknowledges
that,  following  its  acquisition  of the  Shares,  the  Purchaser  will  be an
Affiliate  of  the  Company  and  will  be  subject  to  all   requirements  and
restrictions  applicable to Affiliates under the Securities Act and the Exchange
Act (including the rules and regulations promulgated thereunder).

     SECTION 4. Conditions to the Company's Obligation.

     The obligation of the Company to consummate the  transactions  contemplated
hereby shall be subject to the  satisfaction or waiver (other than in respect of
Sections 4.4, 4.6 and 4.8 hereof) by the Company, at or prior to the Closing, of
all the following conditions:

     4.1 Representations  and Warranties.  The representations and warranties of
the  Purchaser  set forth in this  Agreement  shall be true and  correct  in all
material respects on and as of the date hereof and on and as of the Closing Date
(with the same effect as though such  representations  and  warranties  had been
made on and as of such Closing Date),  and officers of the Purchaser  shall have
certified to such effect to the Company in writing.

                                       14



     4.2  Performance  of  Obligations.  The  Purchaser  shall  have  performed,
satisfied and complied with all covenants, agreements and conditions required by
this  Agreement to be  performed,  satisfied or complied with by it on or before
the Closing  Date,  and officers of the Purchaser  shall have  certified to such
effect to the Company in writing.

     4.3  Opinion of Counsel.  The  Company  shall have  received  from  Coudert
Brothers,  counsel for the Purchaser, an opinion addressed to the Company, dated
the Closing Date, in form and substance reasonably  satisfactory to the Company,
it being  understood  that  Coudert  Brothers  may  rely  upon  the  opinion  of
Klaus-Peter  Brandis,  Head of the Legal Department of Merck, for all matters of
German law, if applicable.

     4.4 No  Litigation  or  Legislation.  No federal,  state,  local or foreign
statute,  rule or regulation shall have been enacted after the date hereof,  and
no  litigation,  proceeding,  governmental  inquiry  or  investigation  shall be
pending,  which  prohibits  or seeks to prohibit  or  materially  restricts  the
consummation  of the  transactions  contemplated  by this Agreement or the other
agreements provided for herein.

     4.5 Clal Sale of Shares. Merck (or its designee) shall have purchased those
certain shares of Common Stock beneficially owned by Clal in accordance with the
terms of the Clal Stock Purchase Agreement,  and all agreements between Clal and
the Company  relating to or arising out of Clal's  acquisitions  of Common Stock
shall be  terminated  by the  parties  thereto  and be of no  further  force and
effect.

     4.6 HSR Act. All  applicable  waiting  periods under the HSR Act shall have
expired or been terminated with respect to the transactions contemplated by this
Agreement.

     4.7 Distribution  Agreement in Effect. The Distribution  Agreement shall be
in full force and effect and there shall exist no facts or circumstances  which,
with the giving of notice or the  passage of time or both,  would  constitute  a
material default thereunder by Genpharm.

     4.8  Shareholders'  Approval.  The  Shareholders'  Approval  of each of the
Proposals  shall  have been  obtained  and all of the  Nominees  (as  defined in
Section 7.3 hereof) shall have been elected.

     4.9  Fairness  Opinion.  The  fairness  opinion of Gruntal,  the  Company's
financial  advisor,  rendered  with  regard  to this  Agreement  and  the  other
agreements  to be  entered  into in  connection  herewith  and the  transactions
contemplated hereby and thereby shall have been reconfirmed by Gruntal as of the
date of mailing to the Company's  shareholders of the definitive proxy statement
(the "Proxy  Statement") in respect of the Company's meeting of its shareholders
to be held in connection with the Proposals (the "Meeting").

     4.10 Purchase Price and Other Closing Deliveries.  The Purchaser shall have
paid the Purchase Price and delivered, or cause to be delivered, the agreements,
instruments and certificates specified in Section 1.3(b) hereof.

                                       15



     4.11  Consents and Waivers.  The Company  shall have  obtained all material
consents  and waivers  necessary  or  appropriate  for its  consummation  of the
transactions  contemplated by this Agreement, as specified in Section 2.8 hereof
and Schedule 2.8 hereto, and the other agreements referred to herein after using
its reasonable best efforts to obtain them.

     4.12 Services  Agreements.  Merck and Genpharm shall have duly executed and
delivered to the Company the Services Agreements.

     4.13 Purchaser Board  Approval.  The Board of Directors of Merck shall have
approved this Agreement and the transactions  contemplated hereby prior to April
3, 1998.

     SECTION 5. Conditions to the Purchaser's Obligation.

     The obligation of the Purchaser to consummate the transactions contemplated
hereby shall be subject to the  satisfaction or waiver (other than in respect of
Sections 5.4, 5.5 and 5.9 hereof) by the Purchaser,  at or prior to the Closing,
of all the following conditions:

     5.1 Representations  and Warranties.  The representations and warranties of
the  Company  set  forth in this  Agreement  shall be true  and  correct  in all
material respects on and as of the date hereof and on and as of the Closing Date
(with the same effect as though such  representations  and  warranties  had been
made on and as of such Closing  Date),  and  officers of the Company  shall have
certified to such effect to the Purchaser in writing.

     5.2 Performance of Obligations. The Company shall have performed, satisfied
and complied with all  covenants,  agreements  and  conditions  required by this
Agreement to be  performed,  satisfied  or complied  with by it on or before the
Closing Date, and officers of the Company shall have certified to such effect to
the Purchaser in writing.

     5.3 Opinion of Counsel.  The  Purchaser  shall have  received from Hertzog,
Calamari  & Gleason,  counsel  for the  Company,  an  opinion  addressed  to the
Purchaser, dated the Closing Date, in form and substance reasonably satisfactory
to the Purchaser.

     5.4 No  Litigation  or  Legislation.  No federal,  state,  local or foreign
statute,  rule or regulation shall have been enacted after the date hereof,  and
no  litigation,  proceeding,  governmental  inquiry  or  investigation  shall be
pending,  which  prohibits  or seeks to prohibit  or  materially  restricts  the
consummation  of the  transactions  contemplated  by this Agreement or the other
agreements  provided for herein, or materially  restricts or impairs the ability
of the Purchaser to own an equity interest in the Company.

     5.5 HSR Act. All  applicable  waiting  periods under the HSR Act shall have
expired or been terminated with respect to the transactions contemplated by this
Agreement.


                                       16



     5.6 Board Resignations.  The Purchaser shall have received the resignations
of the current  members of the Board of  Directors  of the  Company,  subject to
their re-election in accordance with Section 7.3 hereof.

     5.7 No Material Adverse Effect. Since the date hereof, there shall not have
occurred a condition or event constituting a Material Adverse Effect (other than
in respect of the matter set forth on Schedule 2.10 hereto).

     5.8 ISRA. The Company shall have delivered to the Purchaser evidence of the
Company's having obtained an ISRA Clearance (as defined in Section 7.4 hereof).

     5.9  Shareholders'  Approval.  The  Shareholders'  Approval  of each of the
Proposals  shall  have been  obtained  and all of the  Nominees  shall have been
elected.

     5.10 Closing  Deliveries.  The Company shall have delivered the Shares, the
Options and the agreements,  instruments and  certificates  specified in Section
1.3(a) hereof.

     5.11  Distribution  Agreement.  There shall exist no facts or circumstances
which,  with  the  giving  of  notice  or the  passage  of time or  both,  would
constitute a material default by the Company under the Distribution Agreement.

     5.12 Services Agreements; Options. The Company shall have duly executed and
delivered to Merck and Genpharm the Services Agreements and the Options.

     5.13 Board  Approval.  The Board of Directors of Merck shall have  approved
this Agreement and the transactions contemplated hereby prior to April 3, 1998.

     5.14 Option  Standstill  Agreements.  At least  fifteen  (15) days prior to
Closing,  the Company  shall have duly  executed and  delivered to the Purchaser
agreements in writing,  in form reasonably  satisfactory to the Purchaser,  from
(i) the four persons listed on Schedule 5.14(a) hereto that, notwithstanding the
terms of any stock option plan or any option heretofore granted, not to exercise
or seek to  exercise  such  options  until  three  (3)  years  and ten (10) U.S.
business days from the Closing Date and (ii) substantially all other persons who
then hold unexercised options, warrants or other stock rights to purchase Common
Stock,  other than those  persons set forth on  Schedule  5.14(b)  hereto,  not,
notwithstanding  the terms of any stock  option  plan or any option  theretofore
granted,  to exercise or seek to exercise such options,  warrants or other stock
rights, except to the extent indicated on Schedule 5.14(b).

     5.15 Section 7.10 Agreement. The Company shall have delivered the agreement
of the Chairman of the Company referred to in Section 7.10 hereof.


                                       17



     5.16 Clal Share Purchase.  The Purchaser shall have purchased,  after using
its  reasonable  best  efforts to do so,  those  certain  shares of Common Stock
beneficially  owned  by Clal in  accordance  with the  terms  of the Clal  Stock
Purchase Agreement.

     5.17  Consent.  The Company  shall have obtained the approvals set forth on
Schedule 2.3, Item 1, hereto.


     SECTION 6. Covenants of the Parties.

     The Company and the Purchaser hereby covenant as follows:

     6.1  Hart-Scott-Rodino  Notification.  As soon  as  practicable  after  the
execution of this  Agreement,  the Company and the Purchaser shall each file, or
cause to be filed, with the Federal Trade Commission and the Antitrust  Division
of the  United  States  Department  of  Justice,  pursuant  to the HSR Act,  the
notifications  and  documentary   materials  required  in  connection  with  the
transactions  contemplated  by this Agreement.  Thereafter,  the Company and the
Purchaser will file any additional  information requested as soon as practicable
after  any  receipt  of a  request  for  additional  information  and  shall use
reasonable  best efforts to obtain early  termination of the applicable  waiting
period under the HSR Act. The Company and the  Purchaser  shall  coordinate  and
cooperate  with each other in exchanging  such  information  and providing  such
reasonable  assistance as may be requested in connection with such filings.  All
filing fees in connection with the HSR Act shall be paid by the Purchaser.

     6.2 Publicity. The Company and the Purchaser shall consult with each other,
to the extent reasonably practicable,  as to the form and substance of any press
releases and other  third-party  communications  or disclosures  relating to the
negotiation,  execution,  delivery and consummation of this Agreement, the other
agreements  referred  to herein,  and the  transactions  contemplated  hereby or
thereby.  No party shall be prohibited  from issuing or filing any press release
or other third-party communication or disclosure which, upon advice of its legal
counsel,  shall be deemed  necessary or appropriate  under applicable law or the
applicable rules of any stock exchange; provided, however, that such party shall
have first  consulted  with the other  party as to the form and  content of such
disclosure.  This covenant shall survive the Closing or any  termination of this
Agreement.

     6.3 Confidentiality.  All information to which access is given or furnished
by one  party  to the  other in  connection  with  the  negotiation,  execution,
delivery and consummation of this Agreement,  the other  agreements  referred to
herein,  and the  transactions  contemplated  hereby  or  thereby  shall be kept
confidential  by each  party  and  shall be used  only in  connection  with this
Agreement,  such other agreements and the transactions  contemplated  hereby and
thereby;  provided,   however,  that  the  foregoing  shall  not  apply  to  any
information  that (a) shall be publicly  available  as of the date  hereof,  (b)
shall become publicly available other than as a result of prohibited  disclosure
by such party, (c) shall be disclosed to such party by any person or entity that
is not known to such  party to be subject  to any  confidentiality  restrictions
imposed by the other party or (d) shall be

                                       18



required to be disclosed by law, the  applicable  rules of any stock exchange or
by order of any court of competent jurisdiction. Without limiting the foregoing,
the Purchaser  shall not disclose,  and shall use its reasonable best efforts to
cause its Affiliates not to disclose,  any such confidential  information to any
person or entity  that is not an  Affiliate  or a  director  or  officer of such
Affiliate or any advisor thereto. This covenant shall survive the Closing or any
termination of this Agreement.

     6.4  Further  Assurances.  Upon  reasonable  request of a party and without
further  consideration,  the other party, whether prior to or after the Closing,
shall execute, acknowledge and deliver all such other instruments and documents,
and  shall  take all  such  other  actions  for the  purpose  of  effecting  and
evidencing the consummation of the  transactions  contemplated by this Agreement
and the other agreements referred to herein.  Without limiting the generality of
the foregoing,  the Company shall, and shall cause its Subsidiaries to, from the
date hereof  until the earlier of the Closing  Date or the  termination  of this
Agreement  pursuant  to  Section  13.11  hereof,  provide  all  information  and
documents  reasonably  requested by the Purchaser relating to a determination of
the Company's  status as a United States real property holding  corporation,  as
defined under the Code.

     SECTION 7. Covenants of the Company.

     The Company (and the Purchaser,  to the extent  expressly  provided in this
Section 7) hereby covenants as follows:

     7.1  Exchange  Act  Filings.  From and after the date hereof to the Closing
Date or the earlier  termination  of this  Agreement  pursuant to Section  13.11
hereof,  the Company  shall use its best efforts to file in a timely  manner all
reports  required  to be filed by it with the SEC  under  the  Exchange  Act and
shall, promptly upon filing, deliver copies of such reports to the Purchaser.

     7.2 Proxy Statement;  Meeting; Listing Applications.  (a) The Company shall
prepare,  review with the Purchaser  and its counsel,  and file with the SEC the
Proxy Statement as soon as reasonably  practicable  after the date hereof.  Each
party shall furnish all information  concerning itself and related persons which
is required or  customary  for  inclusion  in the Proxy  Statement.  The Company
shall,  as soon as reasonably  practicable  after the date hereof,  (i) take all
steps  necessary to duly call, give notice of, convene and hold a meeting of its
shareholders  for the  purpose of  securing  the  Shareholders'  Approval to the
Proposals  (such meeting is presently  contemplated by the parties to be held in
June  1998);  (ii)  distribute  to  its  shareholders  the  Proxy  Statement  in
accordance  with  applicable  Federal and state laws and with its Certificate of
Incorporation  and By-Laws;  and (iii) recommend (in the Proxy Statement and, if
deemed  appropriate by the Company,  otherwise) to its shareholders  approval of
the Proposals. Notwithstanding anything to the contrary contained herein, if the
Agreement shall be terminated (or is subject to termination) pursuant to Section
13.11 hereof, the Company may postpone,  adjourn or cancel the Meeting, withdraw
or change  its  recommendation  to its  shareholders  and/or  withdraw  or delay
distribution of the Proxy Statement.

     (b) The Company  shall use its  commercial  best efforts to have the Shares
and the Option  Shares  listed on The New York Stock  Exchange  and The  Pacific
Stock Exchange.

                                       19



     7.3 Board  Representation.  (a) Subject to the conditions set forth herein,
the Company shall  nominate,  and the Company and the Purchaser  shall use their
best  efforts to cause the  election at the Meeting  of,  certain  persons to be
designated  by  each  of  the  Purchaser  and  the  Company  (collectively,  the
"Nominees"), as provided herein, to serve as directors on the Board of Directors
of the Company such that:

          (i) a majority of the members of such Board shall be  comprised of the
     Purchaser's designated representatives; and

          (ii)  three of the  members of such Board  shall be  comprised  of the
     Company's  designated  representatives  consisting  of  Kenneth  I.  Sawyer
     ("Sawyer")  and two  additional  representatives  designated by the current
     Board of Directors of the Company (collectively, the "Company Designees").

Notwithstanding  anything to the contrary contained herein,  each representative
designated by the Purchaser in  accordance  with Section  7.3(f) hereof shall be
nominated  for  election  to  serve  on  the  Board  of  Directors  unless  such
representative  shall not be  satisfactory  to the  Company's  current  Board of
Directors for good faith reasons and each Company Designee shall be nominated to
serve on the Board of Directors  unless such Designee  (other than Sawyer) shall
not be satisfactory to the Purchaser for good faith reasons. All current members
of the  Company's  Board of  Directors  not  nominated  as set forth above shall
resign  effective upon the Closing.  Any current members of such Board nominated
as set forth above shall resign  effective  upon the  Closing,  subject to their
renomination and re-election as set forth herein. All Nominees shall take office
if, and only if, the Closing shall occur.

     (b) Any director  designated  hereunder shall serve subject to the terms of
the Company's Certificate of Incorporation and By-laws, each as in effect on the
Closing Date, and the provisions of applicable law.

     (c) The Company  Designees and the Purchaser shall jointly designate two of
the Company's directors to comprise the audit committee of the Company.  Each of
such directors must qualify as independent, outside directors in accordance with
the rules and regulations of The New York Stock Exchange.

     (d) The directors  designated  by the Purchaser  shall serve as Class I and
Class III directors of the Company (as allocated by the  Purchaser)  whose terms
shall  expire in the years 2000 and 1999,  respectively.  The Company  Designees
shall serve as Class II directors of the Company whose terms shall expire in the
year 2001. There shall be no Class II directors other than the Company Designees
(and their respective successors selected in accordance with Section 8.1 hereof)
through May 31, 2001.

     (e) The Company shall include in the Proxy Statement distributed in respect
of the Meeting the Proposals  and shall  recommend its approval of each Proposal
(including approval of all

                                       20



Nominees) by the shareholders of the Company.  Sawyer and the Purchaser (and its
Affiliates) agree to vote any shares of Common Stock which they own or otherwise
have the power to vote in favor of each of the Proposals  (including approval of
all Nominees).

     (f) The Company  shall give the Purchaser  written  notice not less than 10
days prior to the filing  with the SEC of the  preliminary  Proxy  Statement  in
respect of the Meeting to allow the  Purchaser  to  designate  its  nominees for
director  for  inclusion  in such Proxy  Statement.  The  Company  shall have no
obligation  to include such nominees in the Proxy  Statement  unless the Company
receives written notice from the Purchaser setting forth its designated nominees
(along with all  biographical and other  information  necessary for inclusion in
the Proxy  Statement) not later than five days after the Company's notice to the
Purchaser.

     7.4 Environmental Matters. For each parcel of real property which is owned,
operated, leased or used by the Company and any of its Subsidiaries in the State
of New Jersey,  the Company shall,  and shall cause each of its Subsidiaries to,
as applicable,  comply with the obligations imposed by the New Jersey Industrial
Site Recovery Act and any regulations promulgated thereunder, at or prior to the
Closing,  by  either  (a)  securing  any  of  the  following:  (i) a  letter  of
nonapplicability  from the New Jersey  Department  of  Environmental  Protection
("NJDEP");  (ii)  approval by NJDEP of a negative  declaration  submitted by the
Company;  (iii)  a no  further  action  letter  from  NJDEP;  (iv) a  letter  of
authorization  for the  transfer of  ownership  from NJDEP  without any material
conditions  thereto;  or (v)  approval  from  NJDEP of a  remediation  agreement
reasonably  acceptable  to the  Purchaser;  or (b) filing a De Minimis  Quantity
Exemption  Affidavit  with NJDEP (any of the items listed in clauses (a) and (b)
above being an "ISRA Clearance").

     7.5 Conduct of Business Prior to Closing. From and after the date hereof to
the  Closing  Date or the  earlier  termination  of this  Agreement  pursuant to
Section  13.11 hereof,  except as set forth on Schedule 7.5 hereto,  neither the
Company nor its Subsidiaries shall (a) conduct their respective businesses other
than in the ordinary course, except as contemplated by this Agreement; (b) amend
its charter or by-laws;  (c) sell,  lease or  otherwise  dispose of any material
assets  or  properties  owned  or  used in the  operation  of  their  respective
businesses,  except  for the  sale of  inventory  and  disposition  of  obsolete
equipment  in the  ordinary  course  of  business;  (d)  dissolve,  or  agree to
dissolve,  or merge or consolidate  with, or agree to merge or consolidate with,
or purchase or agree to purchase all or  substantially  all of the assets of, or
otherwise acquire, any other business entity; (e) authorize for issuance,  issue
or sell  any  additional  shares  of its  capital  stock  or any  securities  or
obligations  convertible  into shares of its capital stock or issue or grant any
option,  warrant or other  right to purchase  any shares of its  capital  stock,
except for (i) the granting of options,  warrants or rights under the  Company's
existing  stock or other plans (as such are set forth on Schedule  2.13  hereto)
and (ii) the issuance or sale of capital  stock  pursuant to the exercise of any
options,  warrants,  or rights  granted  prior to the date  hereof to any of the
Company's  employees,  directors,  independent  contractors  or other agents and
listed on Schedule  2.12  hereto;  (f) redeem,  buy back,  or cancel any shares,
securities, options, warrants or other stock rights in the Company; or (g) other
than in the  ordinary  course of business,  enter into any material  contract or
agreement,  or  incur  any  material  capital  expenditure,  which  has not been
approved by the Purchaser.

                                       21



     7.6 Options, Warrants or Other Stock Rights. From and after the date hereof
to the Closing Date or the earlier  termination  of this  Agreement  pursuant to
Section  13.11 hereof,  the Company  shall issue options and warrants,  or other
stock rights under the Company's  existing  stock option or stock purchase plans
only if the  exercise  date is no earlier than three years from the Closing Date
and the options,  warrants or other stock rights are issued in  connection  with
the  performance  of  services  for the  Company  and  qualify as  "compensatory
options" within the meaning of Treas. Reg. Sec. 1.382-4(d)(8)(iii).

     7.7 Other Agreements. At the Closing, upon satisfaction or permitted waiver
of the conditions  set forth in Section 4 hereof,  the Company shall execute and
deliver the agreements, instruments and certificates specified in Section 1.3(a)
hereof.

     7.8  Right of First  Refusal.  (a)  Subject  to the  conditions  and  other
provisions set forth in this Section 7.8 and in Section 8.4 hereof, the Company,
for a period  of six years  following  the  Closing,  shall  give the  Purchaser
written  notice (the  "Transaction  Notice") of the Company's  intention to sell
equity  securities  of the Company in any offering  not subject to  registration
under the  Securities Act (or, if subject to  registration  under the Securities
Act, in any offering for cash only)  specifying the terms and conditions of such
offering,  including the type and amount of  consideration to be received by the
Company.  Subject  to the  conditions  and  other  provisions  set forth in this
Section  7.8 and in Section  8.4  hereof,  the  Purchaser  shall have the right,
exercisable by giving written notice to the Company within 30 days after receipt
of the Transaction Notice, to purchase all, but not less than all, of the equity
securities  described in the Transaction  Notice on substantially the same terms
and conditions as specified in such  Transaction  Notice.  In the event that the
Purchaser   shall  not  provide  notice  of  its  election  to  consummate  such
transaction  within  such  30-day  period,  the  Company  may  sell  the  equity
securities  to any third  party or  parties  (a  "Third-Party  Transaction")  on
substantially  the same terms and  conditions  as specified  in the  Transaction
Notice at any time within 90 days after the expiration of such 30-day period. If
the Company shall not  consummate a Third-Party  Transaction  within such 90-day
period,   the  consummation  of  such  Transaction  or  any  other   Third-Party
Transaction shall again be subject to the Purchaser's  rights under this Section
7.8(a).

     (b) The closing of any  transaction  to be  consummated  with the Purchaser
pursuant  to this  Section 7.8 shall take place at the offices of the Company or
its counsel on a date designated by the Company and reasonably acceptable to the
Purchaser  not  later  than  60  days  after  the  Purchaser's  receipt  of  the
Transaction Notice.

     7.9 Appointment of COO. As soon as practicable  following the Closing,  the
Board of Directors of the Company  shall duly elect a designee of the  Purchaser
as the  President and Chief  Operating  Officer (COO) of the Company and each of
its Subsidiaries.

     7.10 Agreement of the Chairman of the Company. At the Closing,  the Company
shall  deliver  a  fully   executed   agreement  to  the  Purchaser   reasonably
satisfactory  to the Purchaser  whereby the Chairman of the Company,  Kenneth I.
Sawyer,  shall expressly (i) agree to the appointment referred to in Section 7.9
above; (ii) agree that he shall serve as the Chairman and Chief Executive

                                       22



Officer of the Company and each of its Subsidiaries;  and (iii) acknowledge that
Section 7.9 hereof and this Section 7.10 hereof do not  constitute a breach or a
violation  by the  Employer  (as  such  term  is  used  in the  below  mentioned
Employment  Agreement) of the terms of his employment pursuant to the Employment
Agreement  between  the  Company  and  Sawyer,  dated as of October 4, 1992,  as
amended.

     7.11 Rights Agreement.  Each of the Company and First City Transfer Company
(as successor rights agent) shall, prior to the Closing,  execute and deliver an
amendment to the Rights Agreement, dated August 6, 1991, as amended (the "Rights
Agreement"),   exempting   from  operation   under  the  Rights   Agreement  the
acquisitions  of shares of  Common  Stock  pursuant  to this  Agreement  and the
Options. Such amendment shall be in full force and effect and constitute a valid
and  binding  agreement  of the  Company  enforceable  against  the  Company  in
accordance with its terms.

     7.12 U.S. Real Property Holding Corporation. From and after the date hereof
to the Closing Date or the earlier  termination  of this  Agreement  pursuant to
Section 13.11  hereof,  the Company  shall (a) use  reasonable  efforts to avoid
making  any  changes in the  composition  of its assets  which  would  cause the
Company to be classified as a United  States real property  holding  corporation
within the meaning of Section  897(c)(2)  of the Code and (b) obtain the consent
of the  Purchaser  prior to the  acquisition  of any United States Real Property
Interest (as defined in Section 897 of the Code).

     SECTION 8. Covenants of the Purchaser.

     The  Purchaser  (and the  Company  following  the  Closing,  to the  extent
expressly provided in this Section 8) hereby covenants as follows:

     8.1 Company  Designees.  For a period of three years following the Closing,
the Purchaser shall not cause, and shall use its best efforts not to permit, (i)
the removal, except for cause (as such term is defined and used under New Jersey
corporate  law),  of any of the Company  Designees  serving as  directors of the
Company prior to the scheduled  expiration of their terms or (ii) the shortening
of any of such  Designees'  terms as  directors.  In the event that any  Company
Designee shall resign or cannot otherwise  continue to serve as a director,  the
remaining Company  Designee(s) shall designate a replacement  therefor and, upon
such designation,  unless such designee shall not be reasonably  satisfactory to
the Purchaser,  the Company and the Purchaser  shall use their  reasonable  best
efforts to cause the appointment and/or election of such designated  replacement
to the Company's Board of Directors.  Such replacement directors shall be deemed
to be Company Designees for the purpose of this Agreement.

     8.2 No Modification. For a period of three years following the Closing, the
Purchaser  shall not cause,  and shall use its  reasonable  best  efforts not to
permit, the Company to agree to any amendment, modification or waiver of or take
any action in respect of this Agreement, the Distribution Agreement or the other
agreements referred to herein, including,  without limitation, in respect of any
agreement  or  settlement  relating  to a dispute  or claim for  indemnification
hereunder

                                       23



or thereunder,  without the prior written  consent of at least a majority of the
Company  Designees  (including any replacements  therefor as provided in Section
8.1 hereof).

     8.3 Other Agreements. At the Closing, upon satisfaction or permitted waiver
of the  conditions  set forth in Section 5 hereof,  the Purchaser  shall pay the
Purchase  Price  and  execute  and  deliver  the  agreements,   instruments  and
certificates specified in Section 1.3(b) hereof.

     8.4 Related Party  Transactions.  For a period of three years following the
Closing, except as expressly permitted by this Agreement or any other agreements
referred to herein,  the Purchaser  shall not cause or permit the Company or its
Subsidiaries existing on the date of the Agreement,  directly or indirectly,  to
engage in or enter into any, or to amend or terminate any then validly existing,
transaction,  arrangement  or agreement  with,  or to make any  distribution  or
dividend of property or monies to, the  Purchaser or any  Affiliate or associate
(as defined in Rule 405 of the  Securities Act  ("Associate")  of the Purchaser,
without  the prior  written  consent  of a  majority  of the  Company  Designees
(including any replacements therefor as provided in Section 8.1 hereof).

     8.5  Business  Combinations.  For a period  of three  years  following  the
Closing,  neither the Purchaser nor any of its  Affiliates or Associates  shall,
without  the prior  written  consent  of a  majority  of the  Company  Designees
(including any replacements  therefor as provided in Section 8.1 hereof) and the
prior receipt from an independent  nationally  recognized  investment  bank of a
written  fairness  opinion to the effect that the proposed  transaction  is fair
(from a financial point of view) to all shareholders of the Company, (i) propose
that the Company, or cause or permit the Company to, merge, consolidate or enter
into any other  business  combination  with or into another  entity  (including,
without limitation,  any "short-form" merger), (ii) propose that the Company, or
cause or permit the Company to, sell, lease,  pledge or otherwise dispose of all
or any material portion of the assets of the Company,  (iii) propose or make, or
cause or permit the  Company to propose or make,  any  exchange  offer or tender
offer for, or repurchase  of, any securities of the Company or (iv) propose that
the  Company,  or cause or  permit  the  Company  to,  recapitalize,  liquidate,
dissolve  or, to the extent it would cause the Company not to be  publicly-held,
reorganize.

     8.6 Executive Committee. For a period of three years following the Closing,
the Purchaser shall cause the Company to, and the Company shall,  constitute and
maintain an executive  committee of the  Company's  Board of Directors to manage
the fundamental  matters  concerning the Company in the intervals  between Board
meetings, and each shall use its reasonable best efforts to cause Sawyer (or his
designee who shall be a member of the  Company's  Board of Directors) to be, and
remain for such period, a duly appointed, full member of such committee.

     SECTION 9. Transfer of Securities.  The  Purchaser,  for itself and each of
its Affiliates, agrees as follows:

     9.1 Transfer  Restrictions.  The  Purchaser  and its  Affiliates  shall not
transfer any of the Shares or the Option Shares unless such transfer shall be in
full  compliance  with all  applicable  provisions of the Securities Act and all
applicable provisions of state securities laws.

                                       24



     9.2 Legends. Each certificate for the Shares and the Option Shares shall be
endorsed with the following legend:

         "THE SECURITIES  REPRESENTED  HEREBY HAVE NOT BEEN REGISTERED UNDER THE
         SECURITIES ACT OF 1933 OR UNDER ANY STATE  SECURITIES LAWS, AND MAY NOT
         BE SOLD,  TRANSFERRED,  PLEDGED OR OTHERWISE DISPOSED OF IN THE ABSENCE
         OF AN EFFECTIVE  REGISTRATION  STATEMENT UNDER  APPLICABLE  FEDERAL AND
         STATE SECURITIES LAWS OR AN OPINION OF COUNSEL REASONABLY  SATISFACTORY
         TO THE COMPANY  THAT THE  TRANSFER IS EXEMPT  FROM  REGISTRATION  UNDER
         APPLICABLE FEDERAL AND STATE SECURITIES LAWS."

     SECTION  10.  Exchanges;  Lost,  Stolen  or  Mutilated  Certificates.  Upon
surrender by the Purchaser (or Merck or Genpharm,  as applicable) to the Company
of any certificates  representing the Shares or the Option Shares,  the Company,
at its expense,  shall issue in exchange therefor,  and deliver to the Purchaser
(or  Merck or  Genpharm,  as  applicable),  a new  certificate  or  certificates
representing  such  Shares or Option  Shares,  in such  denominations  as may be
requested in writing by the  Purchaser  (or Merck or Genpharm,  as  applicable).
Every surrendered certificate representing the Shares or the Option Shares shall
be duly endorsed or be  accompanied by a written  instrument of the  Purchaser's
(or Merck's or Genpharm's,  as applicable)  attorney duly authorized in writing.
Upon  receipt  of  evidence  satisfactory  to the  Company  of the loss,  theft,
destruction or mutilation of any certificate  representing  any Shares or Option
Shares, and in case of any such loss, theft or destruction,  upon delivery of an
indemnity  agreement  satisfactory  to the  Company,  or in  case  of  any  such
mutilation,  upon surrender and  cancellation of such  certificate,  the Company
shall issue and deliver to the Purchaser (or Merck or Genpharm, as applicable) a
new  certificate  for such Shares or Option Shares of like tenor and in the same
amount and name in lieu of such lost, stolen or mutilated certificate.

     SECTION 11. Survival of  Representations,  Warranties and  Agreements.  The
representations  and warranties  (including the Schedules hereto) of the parties
contained herein and the agreements and covenants  contained in Section 7 hereof
(excluding Sections 7.3, 7.8 and 7.9 hereof) shall survive the date hereof for a
period  of 12  months  following  the  Closing  Date  (the  "Survival  Period");
provided, that (i) a party shall not be liable to the other party hereto for any
claim for  indemnification  under  Section 12 hereof in respect of a breach of a
representation  or warranty unless written notice thereof  describing such claim
with reasonable  specificity shall be delivered to the Indemnitor (as defined in
Section 12.1 hereof) prior to the expiration of the Survival Period and (ii) the
representations  and  warranties  relating to Taxes  contained  in Section  2.20
hereof  shall  survive  until  the  expiration  of the  appropriate  statute  of
limitation.

     SECTION 12. Indemnification.

     12.1  Indemnitors;  Indemnified  Persons.  For purposes of this Section 12,
each party  which,  pursuant to this Section 12,  agrees to indemnify  any other
person or entity shall be referred to as the

                                       25



"Indemnitor"  with  respect to such  person or entity,  and each such  person or
entity who is indemnified shall be referred to as the "Indemnified  Person" with
respect to such Indemnitor.

     12.2 Company  Indemnity.  The Company  hereby  agrees to indemnify and hold
harmless each of the Purchaser and it Affiliates,  and its directors,  officers,
employees,  agents and controlling  persons (within the meaning of Section 15 of
the Securities  Act or Section 20(a) of the Exchange Act),  from and against any
and all claims,  liabilities,  losses, damages and expenses (including,  without
limitation,  reasonable  attorneys' fees and disbursements)  asserted against or
incurred by any such Indemnified Person which are caused by or are related to or
arise out of (a) subject to Section 11 hereof,  the Company's material breach of
any of its  representations,  warranties,  covenants or agreements  contained in
this  Agreement,  (b) any untrue  statement  or alleged  untrue  statement  of a
material  fact  contained  in the Proxy  Statement  or the  omission  or alleged
omission to state a material fact required to be stated  therein or necessary to
make the  statements  therein  not  misleading  (a  "Violation")  or (c) (i) any
material violation by the Company or any Subsidiary thereof of any Environmental
Laws,  or the  disposal,  discharge or release of solid  wastes,  pollutants  or
hazardous  substances,  whether in compliance  with  Environmental  Laws or not,
other than in respect of those  matters set forth on  Schedule  12.2 hereto (ii)
the ownership, operation or use of any landfill, wastewater treatment plant, air
pollution  control  equipment,  storage  lagoon  or other  waste  management  or
pollution control  facility,  whether in compliance with  Environmental  Laws or
not,  other than in respect of those  matters set forth on Schedule 12.2 hereto,
or (iii) exposure of any person to any chemical substances, noises or vibrations
generated by the Company,  any of its  Subsidiaries,  or any of their respective
predecessors,  whether in compliance with  Environmental Laws or not, other than
in  respect  of those  matters  set forth on  Schedule  12.2  hereto;  provided,
however, that no indemnification shall be provided hereunder for any decrease in
the  market  price of the  shares  of  Common  Stock  purchased  or owned by the
Purchaser  or  any  of  its   Affiliates;   and  provided,   further,   that  no
indemnification shall be provided hereunder with respect to the preceding clause
12.2(b) to the extent an untrue or  alleged  untrue  statement  or  omission  or
alleged omission was made by the Company in reliance upon and in conformity with
information  furnished  by or on  behalf of the  Purchaser  for use in the Proxy
Statement. The Company shall reimburse any such Indemnified Person for all costs
and expenses  (including,  without  limitation,  reasonable  attorneys' fees and
disbursements and costs of investigation)  incurred in connection with preparing
for,  bringing or  defending  any action,  claim,  investigation,  suit or other
proceeding,  whether or not in connection with pending or threatened litigation,
which shall be caused by or related to or arise out of the foregoing, whether or
not such Indemnified Person shall be named as a party thereto.

     12.3 Purchaser Indemnity. The Purchaser hereby agrees to indemnify and hold
harmless each of the Company, and its directors, officers, employees and agents,
from and against any and all claims,  liabilities,  losses, damages and expenses
(including, without limitation, reasonable attorneys' fees and disbursements and
costs of  investigation)  asserted  against or incurred by any such  Indemnified
Person  which are  caused by or are  related  to or arise out of (a)  subject to
Section  11  hereof,  the  Purchaser's  material  breach of any  representation,
warranty,  covenant or agreement of the Purchaser contained in this Agreement or
(b) a  Violation  to the extent  that such  Violation  shall occur in respect of
information furnished to the Company by or on behalf of the Purchaser for use in
the

                                       26



Proxy Statement.  The Purchaser shall reimburse any such Indemnified  Person for
all costs and expenses  (including,  without limitation,  reasonable  attorneys'
fees and disbursements  and costs of investigation)  incurred in connection with
preparing for, bringing or defending any action, claim,  investigation,  suit or
other  proceeding,  whether or not in  connection  with  pending  or  threatened
litigation,  which  shall  be  caused  by or  related  to or  arise  out  of the
foregoing,  whether  or not such  Indemnified  Person  shall be named as a party
thereto.

     12.4 Defense.  Promptly after receipt by an Indemnified Person of notice of
any claim or demand or the commencement of any suit, action or proceeding by any
third party with respect to which indemnification may be sought hereunder,  such
Indemnified  Person  shall  notify in writing  the  Indemnitor  of such claim or
demand or the commencement of such suit, action or proceeding, but failure so to
notify the Indemnitor  shall not relieve the Indemnitor from any liability which
the Indemnitor may have hereunder or otherwise,  unless the Indemnitor  shall be
actually  prejudiced  by such failure.  If the  Indemnitor  shall so elect,  the
Indemnitor  shall  assume the defense of such  claim,  demand,  action,  suit or
proceeding,  including the employment of counsel reasonably satisfactory to such
Indemnified Person, and shall pay the fees and disbursements of such counsel. In
the event, however, that such Indemnified Person shall reasonably determine that
having common  counsel would present such counsel with a conflict of interest or
alternative  defenses  shall be  available  to an  Indemnified  Person or if the
Indemnitor shall fail to assume the defense of the claim,  demand,  action, suit
or  proceeding  in a timely  manner,  then such  Indemnified  Person  may employ
separate  counsel to  represent  or defend such  Person  against any such claim,
demand,  action,  suit or proceeding and the Indemnitor shall pay the reasonable
fees and disbursements of such counsel;  provided,  however, that the Indemnitor
shall  not be  required  to pay the  fees  and  disbursements  of more  than one
separate  counsel for all Indemnified  Persons in any jurisdiction in any single
action, suit or proceeding.  For any claim,  demand,  action, suit or proceeding
the defense of which the Indemnitor shall assume,  the Indemnified  Person shall
have the right to  participate  therein  and to retain  its own  counsel at such
Indemnified Person's own expense (except as otherwise  specifically  provided in
this Section 12.4),  so long as such  participation  does not interfere with the
Indemnitor's  control of such claim,  demand,  action,  suit or proceeding.  The
Indemnitor  shall not,  without  the prior  written  consent of the  Indemnified
Person,  settle or  compromise  or consent to the entry of any  judgment  in any
pending or  threatened  claim,  action,  suit or  proceeding in respect of which
indemnification  may be sought hereunder  unless such settlement,  compromise or
consent shall include an unconditional  release of such Indemnified  Person from
all liability arising out of such claim, demand,  action, suit or proceeding and
would not prohibit,  restrict or impair the Indemnified  Person from engaging in
any business.

     12.5 Purchaser Claims. If there shall be any claim for  indemnification  by
the Purchaser  under this Section 12 or under the  Distribution  Agreement,  all
determinations by the Company relating thereto,  including,  without limitation,
the choice and  engagement of counsel,  the defense  and/or  prosecution  of any
action and the terms and  conditions of any  settlement  or compromise  thereof,
shall be made solely by the Company Designees (by majority vote thereof).

     12.6 Exclusive Remedy. The parties hereto agree that the sole and exclusive
remedy and recourse with respect to any and all claims, suits, actions, demands,
liabilities, losses, expenses and

                                       27



damages  relating  to or arising  out of the  subject  matter of this  Agreement
(excluding  the  Distribution  Agreement and the Services  Agreements)  shall be
pursuant,  and  subject,  to the  indemnification  provisions  set forth in this
Section 12, subject to the provisions of Section 13.11 hereof and except for the
remedy of injunctive relief set forth in Section 13.12 hereof.

     SECTION 13. Miscellaneous.

     13.1  Expenses.  The  parties  shall  bear  their own  respective  expenses
(including,  but not  limited to, all fees and  expenses  of counsel,  financial
advisers  and   independent   accountants)   incurred  in  connection  with  the
preparation,   negotiation  and  execution  of  this  Agreement  and  the  other
agreements   referred  to  herein  and  the  consummation  of  the  transactions
contemplated  hereby and thereby. To the extent that a Company Designee shall be
required  to make any  determination  or take any action  hereunder  (including,
without limitation,  with respect to indemnification  under Section 12 hereof or
reviewing  the  compliance of the  Purchaser  with its covenants and  agreements
contained herein) in his/her capacity as a Company Designee, the Purchaser shall
cause the Company to, and the Company shall,  promptly  reimburse and/or pay any
reasonable  out-of-pocket expenses incurred by the Company Designee in acting in
such capacity.  The Company Designees are intended third-party  beneficiaries of
this provision.

     13.2 Assignment; Binding Effect. All terms and provisions of this Agreement
shall be binding  upon and inure to the benefit of the parties  hereto and their
respective  successors and permitted assigns, but neither this Agreement nor any
of the rights,  interests or obligations  hereunder may be assigned or delegated
by any party  hereto  without  the prior  written  consent  of the other  party;
provided,  that the Purchaser  shall have the right to designate an Affiliate of
the  Purchaser  to  purchase  and take  delivery  of the  Shares at the  Closing
pursuant to Section 1.1 hereof.  The obligations and agreements of the Purchaser
hereunder shall succeed to and bind any purchaser or transferee,  whether or not
such  purchaser or  transferee  shall be an Affiliate of the  Purchaser,  of the
Shares and/or the Option Shares,  but shall also remain binding on the Purchaser
if the transferee is an Affiliate thereof.  Notwithstanding  the foregoing,  the
Options shall be at all times nontransferable and nonassignable by the Purchaser
or Genpharm.

     13.3 Entire Agreement. This Agreement (including the Exhibits and Schedules
hereto) and the other agreements referred to herein or delivered pursuant hereto
contain the entire  agreement  between the parties  with  respect to the subject
matter   hereof  and   thereof  and   supersede   all  prior   arrangements   or
understandings,  written  or oral,  with  respect  thereto,  including,  without
limitation,  the  Confidentiality  Agreement,  dated  December 16, 1997,  by and
between the parties.  The parties hereto agree that the only representations and
warranties  made in connection  with the  transactions  contemplated  hereby and
thereby are those  expressly  made in writing in this  Agreement.  The Purchaser
expressly  disclaims reliance upon any  representations or warranties other than
those expressly made in writing by the Company in this Agreement.  The Purchaser
acknowledges  and agrees  that it is  sophisticated  in matters  concerning  the
subject  matter of this  Agreement  and the  business of the  Company,  that the
Purchaser and the Company have an ordinary business relationship

                                       28



of seller-purchaser and that no special relationship of trust exists between the
Purchaser and the Company which could give rise to a special duty of care.

     13.4 Notices. All notices hereunder shall be in writing and shall be given:
(a) if to the  Company,  at One Ram Ridge Road,  Spring  Valley,  New York 10977
(attention:  Kenneth I. Sawyer,  President), fax number: (914) 425-5097, or such
other address or fax number as the Company  shall have  designated in writing to
the  Purchaser in  accordance  with this Section  13.4,  with a copy to Hertzog,
Calamari &  Gleason,  100 Park  Avenue,  New York,  New York  10017  (attention:
Stephen  Ollendorff,  Esq.  and Stephen R.  Connoni,  Esq.),  fax number:  (212)
213-1199,  or (b) if to the Purchaser,  at c/o Merck KGaA,  Frankfurter  Strasse
250, 64271 Darmstadt Germany (attention:  Dr. Rudi Neirinckx), fax number 011 49
6151 72 3435, or such other  address or fax number as the  Purchaser  shall have
designated in writing to the Company in accordance  with this Section 13.4, with
a copy to Coudert  Brothers,  1114 Avenue of the  Americas,  New York,  New York
10036-7703  (attention:  Edwin  S.  Matthews,  Jr.,  Esq.),  fax  number:  (212)
626-4120.  Any notice shall be deemed to have been given if personally delivered
or sent by express  commercial  courier  or  delivery  service  or by  telegram,
telefax, telex or facsimile  transmission.  Any notice given in any other manner
shall be deemed given when actually received.

     13.5 Amendments;  Waiver.  Prior to the Closing,  this Agreement may not be
amended or, subject to Section 13.11 hereof, terminated, and no provision hereof
may be waived,  except pursuant to a written instrument  executed by the Company
and the Purchaser.  For a period of three years  following the Closing,  neither
this Agreement nor the Distribution  Agreement may be amended,  and no provision
hereof or thereof may be waived, without the prior written consent of at least a
majority of the Company Designees (on behalf of the Company) and except pursuant
to a written instrument executed by both parties.

     13.6 Counterparts. This Agreement may be executed in counterparts, and each
such  counterpart  shall be deemed to be an  original  instrument,  but all such
counterparts together shall constitute but one agreement.

     13.7  Headings.  The headings of the sections of this  Agreement  have been
inserted for  convenience of reference only and shall not be deemed to be a part
of this Agreement. As used herein, the phrase "to the Company's knowledge" shall
mean the actual knowledge of any of the executive officers of the Company only.

     13.8 Governing  Law. This  Agreement  shall be governed by and construed in
accordance  with the laws of the State of New York  applicable to contracts made
and to be performed wholly therein.

     13.9  Severability.  If any term or  provision  hereof  shall be invalid or
unenforceable,   (i)  the  remaining  terms  and  provisions   hereof  shall  be
unimpaired,  (ii) any such invalidity or  unenforceability  in any  jurisdiction
shall not invalidate or render unenforceable such term or provision in any other
jurisdiction and (iii) the invalid or  unenforceable  term or provision shall be
deemed replaced by a term

                                       29



or  provision  as  determined  by a court to be  valid  and  enforceable  and to
express, to the fullest extent legally permissible, the intention of the parties
with respect to the invalid or unenforceable term or provision.

     13.10 Consent to  Jurisdiction.  In  connection  with any dispute which may
arise  under this  Agreement  or under any other  agreement  referred  to herein
(except for the Distribution Agreement),  each of the parties hereby irrevocably
submits to, consents to, and waives any objection to the exclusive  jurisdiction
of the courts of the State of New York  located in the County of New York and of
the United  States  District  Court for the Southern  District of New York,  and
waives  any  objection  to the laying of venue in such  courts.  Each such party
admits that any such dispute may be resolved at least as  conveniently in such a
court as in any other court,  and shall not seek  dismissal or a change of venue
on the ground that  resolution  of such a dispute in any such court shall not be
convenient or in the interests of justice. The Purchaser hereby appoints Coudert
Brothers  as its agent upon whom  service  of process  may be made with the same
force and effect as if such  service  shall have been made  personally  upon the
Purchaser. The Company hereby appoints Hertzog,  Calamari & Gleason as its agent
upon whom  service of  process  may be made with the same force and effect as if
such service shall have been made personally upon the Company.

     13.11 Termination.

     (a) This  Agreement may be  terminated  and the  transactions  contemplated
hereby  may be  abandoned  at any time prior to the  Closing:  (i) by the mutual
written  consent of the Purchaser and the Company,  (ii) by either party to this
Agreement,  if the  Shareholders'  Approval  shall not have been  obtained  with
respect to each of the  Proposals at the  Meeting,  including  any  adjournments
thereof,  (iii) by either  party to this  Agreement,  if there shall have been a
material breach of a representation  or warranty  contained in this Agreement by
the other  party,  or a material  breach by the other  party of any  covenant or
agreement  set forth herein and such breach shall not have been cured within ten
(10) days following the occurrence thereof,  and such shall not have been waived
by the other  party  hereto,  (iv) by  either  party to this  Agreement,  if the
Closing shall not have  occurred by July 15, 1998 or (v) by the Company,  if the
Board of Directors of the Company  determines in good faith,  after consultation
with outside  counsel,  that failure to terminate this Agreement  would create a
substantial  risk  of  liability  for  breach  of its  fiduciary  duties  to the
Company's shareholders under applicable law.

     Upon any such  termination,  all further  obligations  of the parties shall
become null and void and no party shall have any  liability  to the other party,
except that the  obligations of the parties hereto pursuant to Sections 6.2, 6.3
and 13,  including  Section  13.11(b),  hereof shall  survive  such  termination
indefinitely.

     (b)  Notwithstanding  anything to the contrary  contained  herein,  if this
Agreement (i) is terminated by either party  pursuant to Section  13.11(a) (iii)
hereof,  then the breaching party shall promptly pay to the non-breaching  party
in cash an amount equal to $750,000, or (ii) is

                                       30



terminated  by the Company  pursuant to Section  13.11(a)  (v) hereof,  then the
Company  shall  promptly  pay to the  Purchaser  in  cash  an  amount  equal  to
$1,000,000.  The  parties  acknowledge  and agree  that the  provisions  of this
Section 13.11(b) provide for liquidated damages (and not a penalty) and shall be
the sole and exclusive remedy and recourse of the parties hereto in respect of a
termination of this Agreement pursuant to Sections 13.11(a)(iii) or (v) hereof.

     13.12 Injunctive Relief.

     (a) The Purchaser hereby acknowledges and agrees that a breach by it of its
covenants or agreements  hereunder will cause  irreparable  harm to the Company.
Accordingly,  the Purchaser  acknowledges  and agrees that a remedy at law for a
breach  of its  obligations  hereunder  (including,  but  not  limited  to,  its
obligations under Sections 6.3, 7.3 and 8 hereof) will be inadequate and agrees,
in the event of a breach or threatened breach by the Purchaser of the provisions
of this Agreement  (including,  but not limited to, its obligations  pursuant to
Sections  6.3, 7.3 and 8 hereof),  that the Company and, in the case of Sections
7.3, 8.1, 8.5 and 8.6 hereof,  the  shareholders  of the Company (other than the
Purchaser)  and the Company  Designees,  shall be  entitled,  in addition to all
other available remedies, to an injunction  restraining any actual or threatened
breach and/or the remedy of specific performance.

     (b) The Company hereby  acknowledges  and agrees that a breach by it of its
covenants or agreements  hereunder will cause irreparable harm to the Purchaser.
Accordingly,  the  Company  acknowledges  and agrees  that a remedy at law for a
breach  of its  obligations  hereunder  (including,  but  not  limited  to,  its
obligations  under Sections 6.3 and 7 hereof) will be inadequate and agrees,  in
the event of a breach or threatened  breach by the Company of the  provisions of
this  Agreement  (including,  but not  limited to, its  obligations  pursuant to
Sections  6.3, 7.3 and 7.8 hereof),  that the  Purchaser  shall be entitled,  in
addition to all other  available  remedies,  to an  injunction  restraining  any
actual or threatened breach and/or the remedy of specific performance.


                                       31





     IN WITNESS WHEREOF, each of the undersigned has caused this Agreement to be
executed as of the date first written above.



                                                  PHARMACEUTICAL RESOURCES, INC.


                                                  
                                                  By: /s/ Kenneth I. Sawyer
                                                     ___________________________
                                                     Name: Kenneth I. Sawyer 
                                                     Title: President


                                                  LIPHA AMERICAS, INC.


                                                  By: /s/ Rudi Neirinckx
                                                     ___________________________
                                                     Name: Rudi Neirinckx
                                                     Title: Head, New Business
                                                            Merck KGaA



                                       32





                                   Exhibit A

                             Distribution Agreement


                            [Intentionally Omitted]





                                   Exhibit B

                              Services Agreements

                            [Intentionally Omitted]



                                   Exhibit C

                                     Options

                            [Intentionally Omitted]



                                   Exhibit D

                          Registration Rights Agreement

                            [Intentionally Omitted]