Exhibit 10.7


     REGISTRATION RIGHTS AGREEMENT,  dated June 30, 1998, between PHARMACEUTICAL
RESOURCES, INC., a New Jersey corporation (the "Company"), Lipha Americas, Inc.,
a Delaware corporation ("Lipha") Merck KGaA, a Kommanditgesellschaft  auf Aktien
organized under the laws of Germany ("Merck"), and Genpharm, Inc., a corporation
organized  and  existing  under  the laws of the  Province  of  Ontario,  Canada
("Genpharm", together with Merck and Lipha, the "Holders" and each a "Holder").

     WHEREAS,  Lipha  concurrently  herewith is purchasing  10,400,000 shares of
common stock, par value $.01 per share, of the Company ("Common Stock") pursuant
to a Stock Purchase Agreement, dated March 25, 1998, between the Company and the
Holder (the "Stock Purchase Agreement");

     WHEREAS,  Lipha  concurrently  herewith is purchasing  2,313,000  shares of
Common Stock owned by Clal Pharmaceutical  Industries Ltd., pursuant to the Clal
Stock  Purchase  Agreement  (as  such  term is  defined  in the  Stock  Purchase
Agreement);
 
     WHEREAS,  the Holders  may  purchase an  aggregate  of up to an  additional
1,171,040  shares of Common Stock upon exercise of the separate Options (as such
term is defined in the Stock Purchase Agreement); and

     WHEREAS,  the Stock  Purchase  Agreement  provides  that the  execution and
delivery  of  this  Agreement  is  a  condition   precedent  to  the  respective
obligations of the Company and Lipha to consummate the transactions contemplated
by such Stock Purchase Agreement.

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

     SECTION 1. DEMAND REGISTRATIONS.

     1.1 The Company  agrees that,  commencing  on the date nine (9) months from
the date  hereof,  upon  receiving a written  request (the  "Request")  from any
Holder to register under the Securities Act of 1933, as amended (the "Securities
Act"), and under the securities laws of a reasonable  number of states specified
by the Holder in the Request (the  "Specified  States"),  a specified  number of
shares of Subject Stock (as hereinafter  defined),  which number may be all or a
material part of the Subject Stock then owned by the Holders, the Company shall,
as soon  thereafter  as  practicable,  file  with the  Securities  and  Exchange
Commission (the "Commission") on the appropriate form a registration  statement,
together with any requisite  registration  statements or applications  under the
securities  laws of the  Specified  States,  covering  the  number  of shares of
Subject Stock  specified in the Request.  The Company,  under no  circumstances,



shall be required to make more than three  effective  filings of a  registration
statement under this Section 1; provided,  however, that beginning at such time,
if ever, as any Holder shall exercise the Options, in whole or in material part,
the Company shall be obligated to effect two additional  registrations  pursuant
to this  Section 1  following  any  Holder's  delivery  of a Request;  provided,
further,  that the Holders may not deliver more than one Request in total during
any  12-month  period.  For the  purpose  of the  preceding  sentence,  Requests
delivered  at the same time by the  Holders  together  shall be  counted  as one
Request.  The Company may, in its sole discretion,  include additional issued or
unissued shares of Common Stock in such registration  statement;  provided, that
the  inclusion  of any such  shares  shall not  reduce  the  number of shares of
Subject Stock  contained in the Request  which are covered by such  registration
statement.

     1.2 The term  "Subject  Stock",  as used  herein,  shall mean the number of
shares of Common Stock owned by the Holders  which shall have been  purchased by
any Holder (a) under the Stock  Purchase  Agreement at the Closing (as such term
is defined therein), (b) under the Clal Stock Purchase Agreement or (c) upon any
exercise  of  the  Options.  "Registration  statement"  means  all  registration
statements,  including all prospectuses  contained therein and all amendments or
supplements  thereto, or any related applications filed under the Securities Act
or under the securities laws of the applicable states.

     1.3 The  Company  shall  use  its  best  efforts  to  cause a  registration
statement  including the shares of Subject Stock to become  effective  under the
Securities  Act and, if necessary,  under the  securities  laws of the Specified
States.  The  Company  shall  further  use its  best  efforts  to  maintain  the
effectiveness  of  such  registration  statement  for  such  period  as  may  be
reasonably  necessary to complete the  distribution of the Subject Stock covered
thereby, subject to the limitations set forth in Sections 3 and 4 hereof.

     1.4 If the method of  disposition  requested  by a Holder  pursuant to this
Section 1 shall be an underwritten  public offering,  such Holder shall have the
right to designate the underwriter of such offering. Any underwriter selected by
such Holder  shall be subject to the  approval of the  Company,  which  approval
shall not be unreasonably  withheld (the  "Underwriter").  The Company will join
the Holders in entering into an  underwriting  agreement and related  agreements
with  the  Underwriter,   which  shall  be  in  form  and  substance  reasonably
satisfactory  to the  Company  and its  counsel  and  shall  contain  terms  and
provisions customarily contained in the underwriting agreements utilized by such
Underwriter  in  connection  with  comparable  public  offerings,  including  an
indemnification of the Underwriter by the Company and the Holders.

     1.5 All expenses,  disbursements,  fees (filing fees and others), legal and
accounting expenses,  and other costs of every kind and nature incurred or borne
by the Company and the Holders in connection with a registration requested under
this Section 1 (both under the Securities  Act and under the securities  laws of
the Specified States) shall be paid and/or reimbursed by the Holders;  provided,
however,  that if the Company  shall  include any shares of Common  Stock in any

                                       2


such registration,  then the Company shall reimburse the Holders, within 10 days
following the Holders'  written request,  for all such expenses,  disbursements,
fees and other costs using the ratio of net cash received by the Company and any
other sellers of shares of Common Stock under such registration statement to the
total amount of net cash  received by the Holders  unless the Holders shall have
otherwise agreed to bear such expenses,  disbursements,  fees and other costs on
behalf of any other  stockholder  of the Holders for whom shares of Common Stock
are being included in such registration.

     SECTION 2. PIGGYBACK REGISTRATIONS.

     2.1 The Company agrees that, on each occasion that it shall propose to file
a registration  statement  covering  shares of Common Stock,  whether on its own
behalf or at the request of any other  stockholder  of the Company (other than a
registration  statement on Form S-4 or Form S-8 under the Securities  Act), with
the  Commission or under the laws of any state  jurisdiction,  the Company shall
give written notice ("Piggyback  Notice") of such proposed filing to the Holders
at least 40 days prior to such filing.  Upon the written  request of any Holder,
given within 10 days after the date of the Piggyback  Notice,  the Company shall
use its best  efforts  to include in any such  filing  such  number of shares of
Subject Stock that shall be requested by the Holders, subject to any limitations
as to the number of shares of Subject Stock that may be imposed by the Company's
underwriter (if any); provided,  however, that if such registration statement is
being  filed at the  request of another  stockholder  of the  Company,  then the
maximum number of shares of Subject Stock included in such registration shall be
equal to the lesser of (a) the aggregate number of shares of the Common Stock to
be included in such  registration  multiplied  by a fraction,  the  numerator of
which shall be the number of shares of Common  Stock owned by the Holders on the
date of the Piggyback Notice and the denominator of which shall be the aggregate
number of shares of Common Stock that are issued and  outstanding  on such date,
or (b) the number of shares of the  Common  Stock  that the  Holders  shall have
requested to have included in such registration.

     2.2 The  Company  agrees  that it shall use its best  efforts  to cause the
registration statement including the shares of Subject Stock to become effective
under the Securities Act and under the securities laws of Specified States.  The
Company shall further use its best efforts to maintain the effectiveness of such
registration  statement  for  such  period  as may be  reasonably  necessary  to
complete the distribution of the Subject Stock covered  thereby,  subject to the
limitations set forth in Section 4 hereof.

     2.3 The  Holders  shall  pay all  fees  and  expenses  of its  counsel  and
accountants who shall not also be representing the Company,  and shall reimburse
the Company for certain additional expenses incurred by the Company as set forth
in this Section 2.3. The Company  shall pay all  expenses,  disbursements,  fees
(filing  and  others),  legal and  accounting  and other costs of every kind and
nature  incurred or borne by the Company in connection  with such a registration
requested under this Section 2 (both under the Securities Act and under the laws

                                       3


of the  Specified  States in which shares of the Subject  Stock are being sold),
except  that the  Holders  shall  promptly  reimburse  the  Company for all such
expenses,  disbursements,  fees and  other  costs  using  the  ratio of net cash
received by the Holders to the total amount of net cash  received by the Company
and any  other  sellers  of  shares  of Common  Stock  under  such  registration
statement  unless the Company shall have otherwise agreed to bear such expenses,
disbursements,  fees and other costs on behalf of any other  stockholder  of the
Company for whom shares of Common Stock are being included in such registration.

     SECTION 3. HOLDBACK AGREEMENT; LIMITATION ON RESALES. If the Company at any
time shall register  shares of Common Stock under the Securities Act for sale to
the public, neither Holder shall sell publicly, make any short sale of, or grant
any option for the  purchase of, or  otherwise  dispose  publicly of, any of the
shares of Subject  Stock (other than Subject  Stock  included in a  registration
statement pursuant to Sections 1 or 2 hereof), without the prior written consent
of the  Company,  for a period  designated  by the  Company  in  writing  to the
Holders,  which  period  shall  begin not more  than ten (10) days  prior to the
effectiveness  of the  registration  statement  pursuant  to which  such  public
offering shall be made and shall terminate at such time as similar  restrictions
imposed by law and/or Company policy on directors and executive  officers of the
Company generally shall terminate;  provided,  however, that, in no event, shall
such  restrictions  last more than 180 days  after  the  effective  date of such
registration statement.


     SECTION 4.  PREPARATION AND FILING.  Whenever the Company shall be under an
obligation  pursuant  to this  Agreement  to use its best  efforts to effect the
registration  of the shares of Subject Stock,  the Company and the Holders agree
as follows:

          (a)  The  Company  shall,  in no  event,  be  required  to  keep  such
     registration effective for longer than nine months after the effective date
     thereof or during  any period in which the  trading of any shares of Common
     Stock shall be suspended for any reason by the Commission.

          (b) The  Company  shall use its best  efforts  to cause all  shares of
     Subject  Stock  registered  pursuant to Sections 1 or 2 hereof to be listed
     for trading on each securities exchange or other securities market on which
     the Common Stock shall then be listed.

          (c) The Company may require each Holder to promptly furnish in writing
     to the Company such information  regarding such Holder, the distribution of
     the shares of Subject Stock as the Company may from time to time reasonably
     request and such other information as may be legally required in connection
     with such registration.

                                       4



          (d) The Company shall supply the Holders with such number of copies of
     registration  statements,  and amendments and supplements  thereto, and any
     prospectus relating thereto as may be reasonably  requested by the Holders,
     and will  supply  the  Holders  with  copies of any  preliminary  and final
     prospectus  filed in connection  therewith that may be reasonably  required
     and, if necessary,  with copies of a prospectus meeting the requirements of
     Section  10(a)(3) of the Securities Act;  provided,  however,  that no such
     prospectus  need be supplied more than nine months after the effective date
     of any such registration statement.

          (e)  The  Company  shall  not  be  required  in  connection  with  any
     qualification  of the shares of Subject  Stock to be sold  within any state
     jurisdiction  to qualify to do  business  as a foreign  corporation  in any
     state,  to  execute a general  consent  to service of process or to subject
     itself to taxation,  registration as a broker-dealer or to any unreasonable
     regulatory  requirements  or unreasonable  expenses,  but shall execute and
     deliver  consents  to  service of  process  in the  Specified  States as to
     matters relating to the sale of the shares of Subject Stock in such States.

          (f) The Company  shall  promptly  notify the Holders of any stop order
     issued or threatened by the  Commission or any state  regulatory  authority
     with respect to any registration  statement  covering the shares of Subject
     Stock and shall take all reasonable  actions  required to prevent the entry
     of such stop order or to remove it if entered.

          (g) Each of the  Company  and each Holder  shall  promptly  notify the
     other party of the  occurrence  of any event which shall require the filing
     of an amendment or supplement to any registration  statement and prospectus
     covering the shares of Subject  Stock.  Upon  receipt of such notice,  each
     party shall refrain from the sale of any shares of Subject  Stock  pursuant
     to such  registration  statement and  prospectus  until the receipt by such
     party of copies of the supplemented or amended  registration  statement and
     prospectus.

     SECTION 5. INFORMATION.  Each Holder agrees that, promptly upon the request
of the  Company,  it shall  furnish to the Company  such  information  regarding
itself  and  its  Affiliates,  as such  term is  defined  in Rule  12b-2  of the
Securities Exchange Act of 1934 (the "Exchange Act"), and its holdings of shares
of the Subject  Stock as the Company  shall specify in such request and as shall
be  required  in  connection  with any  registration  statement,  proxy or other
reporting  requirements of the Company.  Each Holder further agrees to cooperate
with  the  Company  in any way  reasonably  necessary  to  accomplish  any  such
registration  hereunder and, when  participating  in any such  registration,  to
comply with all of the  requirements  of the  Securities  Act and the securities
laws of the  states  in which  the  shares of  Subject  Stock  are  being  sold,
including delivery by the Holder to any purchaser of the shares of Subject Stock
of a copy of any required  prospectus.  Notwithstanding  anything  herein to the

                                       5


contrary,  each Holder  further  agrees that it shall  indemnify the Company and
hold it harmless from and against,  and pay or reimburse it for, any  liability,
loss, cost or damage,  including  attorneys' fees,  incurred by the Company as a
result  of any  failure  on such  Holder's  part  to  carry  out  the  foregoing
agreement.


     SECTION 6. INDEMNIFICATION.

     6.1 INDEMNITORS;  INDEMNIFIED PERSONS. For purposes of this Section 6, each
party which, pursuant to this Section 6, agrees to indemnify any other person or
entity shall be referred to, as applicable,  as the "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.

     6.2 COMPANY  INDEMNITY.  The Company  hereby  agrees to indemnify  and hold
harmless  each Holder,  and their  respective  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  reasonable
attorneys'  fees and  disbursements)  asserted  against or  incurred by any such
Indemnified  Person which shall be caused by any untrue  statement of a material
fact  contained  in any  registration  statement or  prospectus  relating to the
Subject Stock, including any amendment or supplement thereto, or shall be caused
by any omission to state therein a material  fact required to be stated  therein
or necessary to make the statements  therein not  misleading,  except insofar as
such losses,  claims,  damages,  liabilities and expenses shall be caused by any
untrue statement or omission based upon information  furnished in writing to the
Company  by  such  Holder  or  on  such   Holder's   behalf  for  use   therein.
Notwithstanding  anything to the contrary contained herein, the  indemnification
agreement  contained  in this  Section 6.2 shall not inure to the benefit of any
Indemnified  Person  from whom a person or entity  asserting  a claim  purchased
shares if an untrue  statement  or omission of material  fact in any  prospectus
shall have been  corrected  by the  Company on a timely  basis,  such  person or
entity shall have failed to utilize such corrected prospectus and such corrected
prospectus would have cured the defect giving rise to such claim.

     6.3 HOLDER  INDEMNITY.  Each Holder  hereby  agrees to  indemnify  and hold
harmless each of the Company, 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 reasonable attorneys' fees
and  disbursements)  asserted against or incurred by any such Indemnified Person
to the same extent as the foregoing  indemnity  from the Company to the Holders,
but only with  respect to  information  relating  to such  Holder  furnished  in
writing by such Holder or on such  Holder's  behalf for use in any  registration
statement  or  prospectus  relating to the  Subject  Stock or any  amendment  or
supplement  thereto.  The total amount  payable by such Holder  pursuant to this
Section 6.3 shall not exceed an amount equal to the number of shares proposed to
be sold by such Holder in the  registered  offering  that shall give rise to any
such claim for indemnity multiplied by the selling price per share.

                                       6



     6.4 Defense.  Promptly after receipt by an Indemnified  Person of notice of
any claim or demand or the commencement of any action or proceeding with respect
to which indemnification may be sought hereunder,  such Indemnified Person shall
notify the Indemnitor of such claim or demand or the commencement of such 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 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  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 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 or related action or proceeding.  For any claim,
demand,  action 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 6.4), so long as such participation shall
not interfere with the  Indemnitor's  control of such claim,  demand,  action 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 or proceeding.

     6.5 Contribution. If the indemnification in this Section 6 shall be held by
a court of competent  jurisdiction  to be unavailable  to an Indemnified  Person
with  respect to any claim,  liability,  loss,  damage or  expense  referred  to
herein,  then the Indemnitor  shall contribute to the amounts paid or payable by
such Indemnified  Person as a result of such claim,  liability,  loss, damage or
expense in such  proportion as is appropriate  to reflect the relative  benefits
and  also  the  relative  fault  of the  Indemnitor,  on the one  hand,  and the
Indemnified Party, on the other, in connection with the transactions giving rise
to such claim, liability, loss, damage or expense, as well as any other relevant
equitable  considerations.  The relative benefits received by the Indemnitor, on
the one hand, and the Indemnified  Party, on the other, shall be deemed to be in

                                       7


the same  proportion  as the total net  proceeds  from the sale of Common  Stock
under the  registration  statement or  prospectus  (before  deducting  expenses)
received by the  Indemnitor  shall bear to the total net proceeds from such sale
received by the Indemnified  Person. The relative fault of the Indemnitor and of
the Indemnified  Person shall be determined by reference to, among other things,
whether  the untrue  statement  of a material  fact or the  omission  to state a
material fact shall relate to  information  supplied by the Indemnitor or by the
Indemnified  Person  and the  parties'  relative  intent,  knowledge,  access to
information  and  opportunity  to correct or prevent such statement or omission.
The  Company and each Holder  agree that it would not be just and  equitable  if
contribution  were  determined by any other method of allocation  which does not
take account of the equitable considerations referred to above.  Notwithstanding
the foregoing, (a) the total amount payable by a Holder pursuant to this Section
6.5 shall not exceed an amount equal to the number of shares sold by such Holder
in the  registered  offering  that give rise to any such claim for  contribution
multiplied  by the selling price per share and (b) no person or entity guilty of
or liable for fraudulent  misrepresentation (within the meaning of Section 11(f)
of the  Securities  Act) will be  entitled  to  contribution  from any person or
entity who was not guilty of fraudulent misrepresentation.

     6.6 HOLDER-RELATED  CLAIMS. If there shall be any claim for indemnification
by or against any Holder or any of its related persons under this Section 6, all
determinations by the Company relating thereto,  including,  without limitation,
the choice and  engagement  of counsel,  the  prosecution  of any action and the
terms and conditions of any  settlement or  compromise,  shall be made solely by
the "Company Designees" (as defined in the Stock Purchase Agreement) by majority
vote thereof.

     SECTION 7.  TERMINATION.  This Agreement  shall  terminate upon the sale or
disposition of beneficial  ownership by the Holders of all shares of the Subject
Stock;  provided,  however,  this  Agreement  shall continue in effect as to any
indemnification and payment or reimbursement obligations herein.

     SECTION 8. MISCELLANEOUS.

     8.1 ASSIGNMENT. 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.

     8.2 ENTIRE AGREEMENT.  This Agreement and the other agreements  referred to
herein or  delivered  pursuant  hereto  contain the entire  agreement  among the
parties  with  respect to the  subject  matter  hereof and  supersede  all prior
arrangements or understandings with respect thereto.

                                       8


     8.3 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),  fax  number:  (914)  425-5097,  or such other
address or fax number as the  Company  shall have  designated  in writing to the
Holders in accordance with this Section 8.3, with a copy to Hertzog,  Calamari &
Gleason,  100 Park  Avenue,  New York,  New York  10017  (attention:  Stephen A.
Ollendorff,  Esq. and Stephen R. Connoni, Esq.), fax number: (212) 213-1199, (b)
if to Merck, at Frankfurter  Strasse 250, 64271 Darmstadt,  Germany  (attention:
Dr.  Rudi  Neirinckx),  fax  number:  011 49 6151 72 3435 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,  (c) if to Genpharm,
at 85  Advance  Road,  Etobicoke,  Ontario  M8Z 2S9,  Canada  (attention:  Chief
Financial Officer), fax number: (416) 236-2940, with a copy to Coudert Brothers,
at 1114 Avenue of the Americas,  New York, New York 10036  (attention:  Edwin S.
Matthews,  Jr., Esq.), fax number:  (212) 626-4120,  or (d) if to Lipha, at [ ],
with a copy to Coudert Brothers,  at 1114 Avenue of the Americas,  New York, New
York 10036 (attention: Edwin S. Matthews, Jr., Esq.), fax number: (212) 626-4120
or such other  address(es) or fax number(s) as a Holder shall have designated in
writing to the Company in accordance  with this Section 8.3. 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.

     8.4  AMENDMENTS;  WAIVER.  This Agreement may not be amended or terminated,
and no provision  hereof 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 the Company and the Holders.  Each
Holder  shall not  cause,  and shall use its best  efforts  not to  permit,  the
Company to agree to any amendment,  modification or waiver or take any action in
respect of this  Agreement,  including,  without  limitation,  in respect of any
agreement  or  settlement  relating  to a dispute  or claim for  indemnification
hereunder,  without  the prior  written  consent of at least a  majority  of the
Company  Designees,  as such term is  defined  in the Stock  Purchase  Agreement
(including any  replacement(s)  therefor as provided in Section 8.1 of the Stock
Purchase Agreement).

     8.5  COUNTERPARTS.  This  Agreement  may  be  executed  in  any  number  of
counterparts,  and each  such  counterpart  shall be  deemed  to be an  original
instrument,  but  all  such  counterparts  together  shall  constitute  but  one
agreement.

     8.6  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.

                                       9


     8.7  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.

     8.8  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  provision  in any other
jurisdiction and (iii) the  invalid or unenforceable  term or provision shall be
deemed  replaced by a term 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.

     8.9 EXPENSES.  Except as otherwise specifically provided in this Agreement,
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   consummation   of  the   transactions
contemplated  hereby. 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 6 hereof) in his/her
capacity as a Company Designee,  the Holders shall cause the Company to, and the
Company shall, promptly reimburse and/or pay any reasonable expenses incurred by
the Company  Designee in acting in such  capacity.  The  Company  Designees  are
intended third-party beneficiaries of this provision.

                                       10



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

                                             PHARMACEUTICAL RESOURCES, INC.




                                             By:  /s/  Kenneth I.  Sawyer 
                                                --------------------------------
                                                Name: Kenneth  I.  Sawyer  
                                                Title:   Chief Executive Officer
                                                          & Chairman


                                             LIPHA AMERICAS, INC.




                                             By: /s/ Edwin S. Matthews
                                                --------------------------------
                                                Name:  Edwin S. Matthews
                                                Title:  Asst. Secretary


                                             MERCK KGaA




                                             By: /s/ Bernhard Scheuble
                                                --------------------------------
                                                Name:  Bernhard Scheuble
                                                Title:  Chief Executive Officer
                                                          Pharma



                                             GENPHARM, INC.




                                             By: /s/ J.N. Tabatznik 
                                                --------------------------------
                                                Name:  J.N. Tabatznik
                                                Title:  Chairman

                                       11