CANADIAN ASSET PURCHASE AGREEMENT

         THIS CANADIAN ASSET PURCHASE AGREEMENT (this "Agreement") is made as of
the  19th  day of  December  1997  between  Connetics  Corporation,  a  Delaware
corporation  ("Connetics")  and  Pharmascience,  Inc.,  a  Canadian  corporation
("Pharmascience").


                                    Recitals

         A.  Connetics  sells  certain  prescription   pharmaceutical  products,
specifically Ridaura(R) capsules (auranofin 3 mg) (the "Products") in the United
States and Canada;

         B. Pharmascience  desires to purchase and Connetics desires to sell the
rights to sell the Products in Canada and the Intellectual  Property (as defined
below).


                                    Agreement

         Therefore,  in consideration of the premises and the mutual  covenants,
agreements  and  representations  herein  contained  and intending to be legally
bound, Connetics and Pharmascience agree as follows:


                                    SECTION 1
                                 INTERPRETATION

         1.1  Definitions.  Where used in this Agreement the following  words or
phrases shall have the meanings set forth below unless the context  specifically
indicates:

                  (a) "Affiliate" of an entity means,  for so long as one of the
following relationships is maintained,  any corporation or other business entity
controlled by,  controlling,  or under common control with another entity;  with
"control"  meaning  direct or indirect  beneficial  ownership of more than fifty
percent  (50%) of the  voting  stock of such  corporation,  or more  than  fifty
percent  (50%)  interest  in  the   decision-making   authority  of  such  other
unincorporated business entity;

                  (b) "Business  Day" means any day excluding  Saturday,  Sunday
and any other day which in the United States is a national  legal holiday or any
day on which U.S. national banking institutions are authorized by law to close;

                  (c)  "Intellectual  Property"  means all  trademarks  (whether
registered or unregistered), trade names and applications therefor, brand names,
logotypes and symbols  unique to the Products to the extent owned by or licensed
to and used by Connetics in the Territory in the sale of Products, all renewals,
modifications  and  extensions  thereof,  together with the goodwill  associated
therewith, including, without limitation, such of the foregoing as are listed or
described in Exhibit A, all  copyrights  (whether  registered or  unregistered),
trade secrets,  trade dress  relating to the size,  shape and color of packaging
and  capsules,  formulations,  designs,  discoveries,  processes,  manufacturing
techniques,  improvements, ideas, or copyrightable works, to the extent owned by
or licensed to and used by Connetics uniquely in the sale of the Products in the






Territory,  including,  without limitation,  those that are listed in Exhibit A;
provided,  however, that "Intellectual  Property" does not include the Connetics
name or any  variation  thereof,  the  SmithKline  Beecham name or any variation
thereof,  or the corresponding  logos of the Products (except for the trademarks
listed in Exhibit A);

                  (d) "NDS" means Canadian NDS File No. 9427-S1376/4-27, Control
No. 7HN906405, issued on September 12, 1985;

                  (e)  "Purchase  Price"  means the  purchase  price  payable to
Connetics for the Purchased Assets provided for in Section 3;

                  (f) "Purchased Assets" means the property and assets described
in Section 2.1;

                  (g)  "SmithKline"  means  SmithKline  Beecham  Corporation,  a
Pennsylvania corporation;

                  (h) "Supply  Agreement" means the agreement  between Connetics
and Pharmascience substantially in the form of Exhibit B hereto;

                  (i) "Territory" means Canada; and

                  (j) "Time of  Closing"  means 1:00  o'clock  in the  afternoon
(California  time) on December 17, 1997 or such other date as the parties  shall
mutually  agree at which time the parties  are to deliver the closing  documents
described in Section 9.

         1.2 Currency.  All dollar amounts  referred to in this Agreement are in
U.S. Dollars.

         1.3 Headings, etc. The division of this Agreement into Sections and the
insertion of headings are for convenience of reference only and shall not affect
the interpretation hereof.


                                    SECTION 2
                                PURCHASED ASSETS

         2.1  Assets  to be  Sold  and  Purchased.  Subject  to  the  terms  and
conditions  of this  Agreement,  Connetics  shall sell,  assign and  transfer to
Pharmascience  and Pharmascience  shall purchase from Connetics,  at the Time of
Closing,  all rights,  title and interest of Connetics in the Purchased  Assets.
The "Purchased Assets" shall consist of:

                  (a) the Intellectual Property and the NDS;

                  (b) Connetics' existing lists of current, past and prospective
customers in the  Territory  for the  Products,  records of volumes of sales and
actual selling price by customer by month in the Territory for the eleven months
ending November 30, 1997 and written  contracts and  documentation in Connetics'
possession pertaining to the same; provided, however, that Connetics retains its
rights to such information with respect to sales of Connetics' other products;

                                      -2-




                  (c)  Connetics'  existing  files  pertaining  to the  Products
(whether  in  written  or machine  readable  form) and  unique to the  Territory
including,  without  limitation,  Canadian  regulatory  files  pertaining to the
Products  (including  applications  and  registrations,  as applicable),  market
studies,  marketing plans, key physician  records,  copies of consumer complaint
files, sales histories, quality control histories, and all other information and
data  pertaining to the Products owned by Connetics and unique to the Territory,
which is in the  possession of Connetics  and is  accessible  by Connetics  with
reasonable efforts;

                  (d) all work in  progress  with  respect  to the  improvement,
planning, promotion, production, development and distribution of the Products in
the  Territory,  including,  without  limitation,  all  papers  and  promotional
materials on hand, all original art  mechanicals  and artwork for the production
of  packaging  components,   television  masters,  agreements  with  advertising
agencies  and other  materials  associated  with the  Products and unique to the
Territory; and

                  (e) all  unfilled  customer  orders  for the  Products  in the
Territory  as of the Time of Closing (a list of such  orders to be  provided  to
Pharmascience promptly after the Time of Closing).

                  In addition,  at the Time of Closing,  Connetics shall provide
to  Pharmascience  (i)  copies of all  existing  information  in its  possession
relating to the  stability  and shelf life of the  Products  and (ii) fifty (50)
copies of each item of printed marketing or promotional materials currently used
by Connetics for the Products.

         2.2      Liabilities.

                  (a)  Subject  to  the   provisions   of  Section  13.1  below,
Pharmascience  shall be liable for all liabilities  relating to actions taken or
omissions  to act from and after the Time of Closing  related  to the  Purchased
Assets,  including any cost, claim,  expense, loss or liability arising from any
product  liability  claim  or  lawsuit  or any  governmental  agency  action  or
notification  relating to actions  taken or  omissions to act from and after the
Time of Closing  (the  foregoing  liabilities  being  assumed  by  Pharmascience
hereinafter referred to as the "Assumed Liabilities");  provided,  however, that
in the event the Closing does not occur and  Pharmascience  does not acquire the
Purchased Assets as contemplated by this Agreement, then Pharmascience shall not
assume,  and shall not be liable for, the Assumed  Liabilities for any period of
time.

                  (b) Prior to and after the Time of  Closing,  Connetics  shall
promptly pay and discharge all liabilities  arising prior to the Time of Closing
in respect of the Purchased Assets as such liabilities come due.

                  (c)  Except for the  Assumed  Liabilities  and  subject to the
provisions  of Section 13.1 below,  Pharmascience  shall not assume or be liable
for  any  liabilities  whatsoever,   including,   without  limitation,   product
liability,  liability  in  tort  (including  unripened  liabilities  due to past
actions or sales), indebtedness for money borrowed, tax liabilities, obligations
to employees,  and  liabilities  for trade  promotions  related to the Purchased
Assets and to acts or omissions occurring prior to the Time of Closing.

                                      -3-




                  (d)  Pharmascience  shall  assume  all  responsibilities  with
regard to protecting and  maintaining the  Intellectual  Property and the NDS in
the  Territory  after  the Time of  Closing.  Without  limiting  the  foregoing,
Pharmascience  shall be  responsible  for the  maintenance  of trademarks in the
Territory from the Time of Closing, including all costs associated therewith.

         2.3  No  Rights  Outside  the  Territory.  No  rights  are  granted  to
Pharmascience by this Agreement to use,  promote,  sell or otherwise  distribute
the Products, directly or indirectly, outside the Territory. Notwithstanding the
sale of the  Purchased  Assets,  Connetics  retains  the  right to  utilize  the
Intellectual  Property  (other than  trademarks  unique to the  Territory)  with
respect to the marketing and sale outside the Territory of Products.


                                    SECTION 3
                                 PURCHASE PRICE

         3.1 Purchase  Price.  The Purchase  Price  payable to Connetics for the
Purchased  Assets  shall be $1,000 and shall be payable to Connetics by check or
wire transfer at the Closing.

         3.2 Transfer Taxes. Pharmascience shall be liable for and shall pay all
Canadian,  provincial and local sales, use, and international  withholding taxes
imposed by law on  Pharmascience  in connection with the conveyance and transfer
of the Purchased Assets by Connetics to Pharmascience.


                                    SECTION 4
                   REPRESENTATIONS AND WARRANTIES OF CONNETICS

         Connetics  hereby  represents and warrants to  Pharmascience as follows
and  acknowledges  that  Pharmascience  is relying on such  representations  and
warranties in connection with the transactions contemplated by this Agreement:

         4.1  Incorporation,  Organization  and  Qualification.  Connetics  is a
corporation duly  incorporated,  validly existing and in good standing under the
law of the jurisdiction of its incorporation, and has the corporate power to own
or lease its property and to carry on its business as now being conducted by it.
Connetics is duly  qualified to do business as a foreign  corporation  and is in
good standing in every  jurisdiction  where the nature of the business conducted
by it  with  respect  to  the  Purchased  Assets  or  the  Products  makes  such
qualification  necessary,  except in such jurisdictions  where the failure to so
qualify does not in the aggregate  have a material  adverse effect on Connetics'
business taken as a whole.

         4.2  Authorization  and  Validity  of  Agreement.   Connetics  has  the
corporate  power to enter into this  Agreement and to carry out its  obligations
hereunder. The execution and delivery of this Agreement and any other agreements
or  instruments  executed in  connection  herewith  and the  performance  of its
obligations hereunder has been duly authorized by all necessary corporate action
by the Board of Directors of Connetics,  and no other  corporate  proceedings on
the part of Connetics are necessary to authorize  such  execution,  delivery and
performance.  The Agreement has been duly executed by Connetics and  constitutes
the valid and binding obligation of Connetics,  enforceable against Connetics in
accordance with its terms.  Execution of this

                                      -4-




Agreement and consummation of the  transactions  contemplated  hereby,  will not
result in the violation of, or conflict with, any of the terms and provisions of
the  certificate  of  incorporation  or  by-laws of  Connetics  or of any law or
regulation or any  applicable  order of any court,  arbitrator  or  governmental
authority  having  jurisdiction  over  Connetics,  the Products or the Purchased
Assets or of any indenture or other written  agreement to which Connetics may be
a party.

         4.3  Title to  Purchased  Assets.  Connetics  is the sole  owner of the
Purchased  Assets with good title thereto free and clear of any mortgage,  lien,
charge,  security interest (except for the security interests  presently held by
SmithKline  and  Silicon  Valley  Bank,  which  must be  released  prior  to the
Closing),   adverse  claim  or  other  encumbrance   whatsoever   (collectively,
"Encumbrances"),  and at the Time of Closing  will have the right to transfer to
Pharmascience good title thereto, free and clear of all Encumbrances.

         4.4  Litigation.  To the best of  Connetics'  knowledge,  there  are no
actions, suits,  proceedings,  investigations,  arbitration proceedings or other
proceedings  pending or threatened  against or affecting the Purchased Assets at
law or in  equity  or by or  before  any  federal,  state,  municipal  or  other
governmental department,  commission,  board, bureau, agency or instrumentality,
domestic or foreign,  or by or before any  arbitrator  which  actions,  suits or
arbitration proceedings or other proceedings relate to the Purchased Assets, and
Connetics is not aware of any existing grounds on which any such action, suit or
proceeding  might be commenced  and there is not currently  outstanding  against
Connetics any judgment, decree,  injunction,  rule, order or award of any court,
governmental  department,  commission,  board, bureau, agency,  instrumentality,
domestic or foreign, or arbitrator and relating to the Purchased Assets.  During
the time that Connetics has owned the Purchased  Assets,  there has not been any
occurrence of, nor is there under  consideration  or  investigation by Connetics
of, any  product  recall,  or  post-sale  warning  conducted  by or on behalf of
Connetics concerning any Product or any product recall conducted by or on behalf
of any entity as a result of any alleged defect in any Product.

         4.5  Regulatory  Issues.  Connetics  has  previously  delivered or made
available  to  Pharmascience  all  material  regulatory  issues,  to the best of
Connetics' knowledge, with respect to the Products in the Territory.

         4.6  Compliance  with  Law.  To  the  best  of  Connetics'   knowledge,
SmithKline has conducted and is currently conducting the sale of the Products in
the Territory in compliance  with all applicable  laws,  rules,  regulations and
court or administrative orders and processes.

         4.7 No Default Under Agreements.  To the best of Connetics'  knowledge,
there are no  contracts  that relate to the  Products in the  Territory.  To the
extent  any  such  contracts   exist,   Connetics  will  (upon  the  request  of
Pharmascience)  use  its  best  efforts  to  facilitate  the  transfer  of  such
contracts,  and the rights and  responsibilities  thereunder  from SmithKline or
Connetics, as the case may be, to Pharmascience.

         4.8 Intellectual Property Rights.

                  (a) Connetics is the beneficial owner of all right,  title and
interest in the  Intellectual  Property and the  registered  owner of all right,
title and  interest in the items  listed on

                                      -5-




Exhibit  A,  and has the  right  to  use,  license,  sublicense  or  assign  the
Intellectual  Property  without  liability to, or any  requirement to obtain the
consent of, any other  person,  except as  described in Exhibit A. Except as set
forth  in  Exhibit  A  there  are no  agreements,  understandings,  instruments,
contracts,  trade  secrets  or other  proprietary  rights  to or from  Connetics
affecting the Intellectual Property.

                  (b)  Except  as  otherwise  set  forth  therein,  all  of  the
Intellectual  Property  listed in Exhibit C as registered or filed has been duly
registered or filed in the Canadian Trademark Office and is currently valid.

                  (c)  To  the  best  of  Connetics'  knowledge,  there  are  no
infringements,  threats of  infringements  or asserted or  unasserted  claims by
Connetics  of  infringements  or  misappropriation  of any  of the  Intellectual
Property in the  Territory  nor are there any asserted or  unasserted  claims by
Connetics  contesting or challenging the right,  title, or interest of any other
person in any of the Intellectual Property in the Territory.

                  (d)  To  the  best  of  Connetics'  knowledge,  there  are  no
outstanding  threatened or actual claims asserted against Connetics alleging the
infringement or  misappropriation  by Connetics of any intellectual  property of
any other party that may affect the  Purchased  Assets in the  Territory  or the
revocation, withdrawal,  expiration,  abandonment, or breach of any right to use
the Intellectual  Property in the Territory.  Connetics has not been notified of
any such  claim of any  person  nor does  Connetics  know of any  basis  for the
existence of any such claim in the Territory.

         4.9 Health, Safety, Employment and Environmental Matters. To the extent
that the failure to do so or be so would have a material adverse effect upon the
Purchased Assets,  to the best of its knowledge  Connetics is in compliance with
all federal,  state,  local and foreign laws related to health and  occupational
safety,  environment and hazardous materials and employment practices,  that are
applicable  to Connetics or its business  related to the Purchased  Assets,  and
Connetics  has  conducted  its  business  relating  to the  Purchased  Assets in
compliance with the foregoing laws.

         4.10 Ordinary  Course.  From December 31, 1996 through the date of this
Agreement, Connetics has conducted the business relating to the Purchased Assets
in the  Territory  only in the ordinary  course and there have been no events or
circumstances  of any kind that  have  materially  and  adversely  affected  the
business related to Purchased Assets.

         4.11  Governmental  Approvals.  Except  for  compliance  with  the U.S.
Securities  Exchange  Act of  1934,  as  amended  (the  "Exchange  Act"),  or as
disclosed in the  Schedules to this  Section 4, no  governmental  authorization,
consent,  approval,  license,  exemption of or filing or  registration  with any
court  or  governmental  department,   commission,   board,  bureau,  agency  or
instrumentality,  domestic  or  foreign,  under any  applicable  laws,  rules or
regulations  currently in effect,  is or will be necessary for, or in connection
with, the execution or delivery by Connetics of this Agreement.

                                      -6-




                                    SECTION 5
                             COVENANTS OF CONNETICS

         5.1  Conduct of the  Business  Until  Closing.  Except for the steps or
actions taken pursuant to the prior consent of  Pharmascience,  Connetics,  from
the date of this Agreement until the Time of Closing,  will conduct its business
with respect to the Purchased  Assets in good faith and in  accordance  with the
same  practices  previously  followed  by it except to the  extent  specifically
contemplated by this Agreement and during that period Connetics shall:

                  (a) conduct the  business  relating to the  Purchased  Assets,
including  without  limitation  marketing  of the  Products,  only in the normal
course;

                  (b) not transfer any of the Purchased Assets;

                  (c) not enter into any  trademark  or  tradename  or  know-how
licenses, or any other leases, licenses, contracts or other commitments relating
to the Purchased Assets, unless each such lease, license, contract or commitment
(other than purchase  orders for raw materials and Products placed in the normal
course of business) is disclosed to and approved by Pharmascience;

                  (d) continue to meet the  contractual  obligations  of, and to
pay obligations  relating to, the Purchased  Assets as they mature in the normal
course;

                  (e) preserve the good  relations  with respect to the Products
with suppliers,  business  customers and others with whom Connetics has business
relations relating to the Products in the Territory; and

                  (f) not  implement  in the  Territory  any price  increases or
decreases for any of the Products or any new trade or consumer  promotions,  and
not change the terms or  conditions  or any such  promotion  in existence on the
date hereof.

         5.2 Records  and  Retained  Product.  Connetics  shall  continue to the
extent of its  current  practice to  preserve  its books and records  (including
financial  information)  relating to the Products and the  Purchased  Assets and
retain product  samples from each batch of the Products  produced for Connetics,
and during such periods and upon reasonable  notice,  shall grant  Pharmascience
and its  agents  and  representatives  reasonable  access  to such  records  and
retained product samples during normal business hours.

         5.3 Post Closing  Orders.  Connetics  shall  promptly  (but in no event
later than five  Business  Days after  receipt by  Connetics'  customer  service
department) deliver any purchase orders and refer all inquiries it shall receive
with respect to the Products in the Territory to Pharmascience.

         5.4  Confidentiality.  From and after the date hereof,  Connetics shall
use the same  efforts to maintain  the  confidentiality  of any  proprietary  or
confidential  information  regarding the  manufacture or sale of the Products in
the  Territory  as  Connetics  uses with  respect to the  Products

                                      -7-




outside  the  Territory;  provided,  however,  that  any  such  confidential  or
proprietary   information  (a)  may  be  shared,   subject  to  execution  of  a
confidentiality  agreement,  with  potential  third party  manufacturers  of the
Products,  (b) may be  disclosed,  subject  to  execution  of a  confidentiality
agreement,  with potential purchasers of rights outside the Territory to product
lines for which auranofin is an active ingredient;  provided that no information
specific to  Pharmascience  shall be disclosed in such  context,  and (c) may be
disclosed to the extent  required by law  (including  without  limitation  under
securities law disclosure requirements).

         5.5 Post-Closing  Cooperation.  From and after the Time of Closing,  in
order to assist  Pharmascience  sell and market  the  Products  in an  effective
manner, Connetics shall use its best efforts to:

                  (a) permit Pharmascience to have one marketing  representative
present at  Connetics'  booths at trade  shows and  conferences  so long as such
Pharmascience   representative   adheres   to  the   protocol,   etiquette   and
communications  guidelines  that  apply to  Connetics'  representatives  at such
events;

                  (b)  provide,  at  Pharmascience's  request and at cost (e.g.,
printing and pro rata production costs),  reasonable  quantities of marketing or
promotional materials regarding the Products;

                  (c)  provide to  Pharmascience  any  information  it  receives
regarding sales leads in the Territory;

                  (d) permit up to three Pharmascience sales  representatives to
attend any Product training  sessions and national sales meetings that Connetics
conducts  for  Connetics'  sales  representatives,  with the direct costs (e.g.,
travel,  hotel,  out-of-pocket  expenses,  and pro rata  amounts  of  meals  and
entertainment)  to be paid by Pharmascience and with such training to be held at
a location reasonably determined by Connetics;

                  (e) inform  Pharmascience  of any ongoing or planned  clinical
studies pertaining to the Products.


                                    SECTION 6
                 REPRESENTATIONS AND WARRANTIES OF PHARMASCIENCE

         Pharmascience   hereby   represents   and  warrants  to  Connetics  and
acknowledges that Connetics is relying on such representations and warranties in
connection with the transactions contemplated by this Agreement that:

         6.1  Incorporation,  Organization and  Qualification of  Pharmascience.
Pharmascience is a corporation duly  incorporated,  validly existing and in good
standing under the law of the  jurisdiction  of its  incorporation,  and has the
corporate power to own or lease its property and to carry on its business as now
being  conducted  by it.  Pharmascience  is duly  qualified  to do business as a
foreign  corporation  and is in good  standing in every  jurisdiction  where the
nature of the business conducted by it makes such qualification necessary except
in such jurisdictions

                                      -8-




where the  failure  to so  qualify  does not in the  aggregate  have a  material
adverse effect on Pharmascience's business taken as a whole.

         6.2  Corporate  Action.  This  Agreement and any other  agreements  and
instruments   executed  in  connection   herewith  are  the  valid  and  binding
obligations of  Pharmascience,  enforceable in accordance with their  respective
terms, subject to bankruptcy,  insolvency or similar laws of general application
affecting  the  enforcement  of rights of  creditors,  and subject to  equitable
principles limiting rights to specific  performance or other equitable remedies,
and  subject  to  the  effect  of  federal  and  state  securities  laws  on the
enforceability of  indemnification  provisions  relating to liabilities  arising
under such laws. The execution,  delivery and  performance of this Agreement has
been duly authorized by all necessary corporate action of Pharmascience.

         6.3  Governmental  Approvals.  No  authorization,   consent,  approval,
license,  exemption of or filing or registration  with any court or governmental
department,  commission,  board, bureau, agency or instrumentality,  domestic or
foreign, under any applicable laws, rules or regulations presently in effect, is
or will be necessary for, or in connection with,  execution and delivery of this
Agreement, or for the performance by it of its obligations hereunder.


                                    SECTION 7
                           COVENANTS OF PHARMASCIENCE

         7.1 Insurance.

                  (a)  Pharmascience.  At all times from the Time of Closing for
as long as  Pharmascience  promotes and distributes the Products,  Pharmascience
shall maintain product liability insurance written on a claims made form in such
amounts as are customary in the industry in the Territory for similar  products;
provided however, that notwithstanding the foregoing,  such amounts shall be not
less than $1,000,000 per occurrence,  $2,000,000 annual aggregate. At Connetics'
request,  Pharmascience  shall provide Connetics with a certificate of insurance
as evidence of such  insurance at any time. In the event that any such insurance
shall be significantly reduced or restricted,  terminated or shall otherwise not
be renewed, Pharmascience shall immediately notify Connetics.

                  (b)  Connetics.  At all times from the Time of Closing  for as
long as  Connetics  promotes  and  distributes  Products  in the United  States,
Connetics shall maintain product  liability  insurance  written on a claims made
form in such amounts as are  customary in the industry in the United  States for
similar products;  provided however,  that  notwithstanding the foregoing,  such
amounts shall be not less than  $1,000,000  per  occurrence,  $2,000,000  annual
aggregate.  At Pharmascience's  request,  Connetics shall provide  Pharmascience
with a  certificate  of insurance as evidence of such  insurance at any time. In
the event that any such insurance shall be significantly  reduced or restricted,
terminated or shall otherwise not be renewed, Connetics shall immediately notify
Pharmascience.

         7.2  Confidentiality.  From and after the date hereof until the Time of
Closing,   Pharmascience   shall  use  the  same   efforts   to   maintain   the
confidentiality  of any  proprietary or confidential  information  regarding the
Purchased   Assets  and   Products  as   Pharmascience   uses  to

                                      -9-




maintain the  confidentiality of its own proprietary  information.  In the event
that  there is no Time of  Closing  under this  Agreement,  Pharmascience  shall
return all information regarding the Purchased Assets and Products to Connetics,
retaining  no  copies,   excerpts  or  other  analysis  or  redactions  of  such
information  and covenants  that no such  information  shall be disclosed to any
third party or utilized  in any way by  Pharmascience  in the conduct of its own
business.


                                    SECTION 8
                                MUTUAL COVENANTS

         8.1 Right to Investigate. After the date hereof, Connetics shall afford
to  representatives  of  Pharmascience  reasonable  access to  offices,  plants,
properties,  books and records of  Connetics  relating to the  Products,  during
normal business hours, in order that  Pharmascience may have full opportunity to
make such  investigations  as it desires  with respect to the  Products.  In the
event of termination of this Agreement prior to the Closing, Pharmascience shall
deliver to Connetics all documents,  work papers and other material  obtained by
Pharmascience,  or on its behalf, from Connetics and all copies thereof, whether
so  obtained  before or after the  execution  of this  Agreement,  and shall not
itself use directly or  indirectly  or through any  subsidiary  or affiliate any
information so obtained,  or otherwise obtained from Connetics,  hereunder or in
connection  herewith (unless such information is generally known in the industry
or was acquired by Pharmascience  prior to the receipt thereof from Connetics or
was  acquired  after the date hereof from a third party having a bona fide right
to  provide  the same to  Pharmascience),  and shall  endeavor  to have all such
information kept confidential and not used in any manner.

         8.2 Supply Arrangements.  On or prior to the Closing, the parties shall
enter into the Supply Agreement.

         8.3  Trade  returns.  For the  period  prior  to the  Time  of  Closing
Connetics shall bear the cost of all returns,  governmental  reimbursements  and
chargebacks  for  Products  regardless  of the  date of  sale,  in each  case in
accordance with Connetics' then-current  practices.  Pharmascience will not take
any action to encourage any returns of such goods to  Connetics.  From and after
the Time of Closing,  Pharmascience  shall be responsible  for all  governmental
reimbursements  and chargebacks for Products  regardless of the date of sale and
shall be responsible  for returns of Products from the trade in accordance  with
Pharmascience's return policy.

         8.4 Brokers.  Pharmascience  represents to Connetics that Pharmascience
has not  employed any  investment  banker,  broker,  finder or  intermediary  in
connection with the transactions  contemplated hereby who might be entitled to a
fee or commission  upon the execution of this Agreement or the  consummation  of
such transactions.  Connetics represents to Pharmascience that Connetics has not
employed any investment  banker,  broker,  finder or  intermediary in connection
with the  transactions  contemplated  hereby who might be  entitled  to a fee or
commission  upon the  execution of this  Agreement or the  consummation  of such
transactions.  Each party agrees to indemnify and hold the other party  harmless
with  respect to any  action,  claim or demand  with  respect to any third party
claiming  any  such fee or  commission  by  reason  of its  relationship  to the
indemnifying party.

                                      -10-




         8.5 Best  Efforts.  Each party shall use its best efforts to close,  to
comply with all covenants herein and to consummate the transactions contemplated
hereby as expeditiously as possible.

         8.6 Best Efforts to Obtain  Satisfaction  of Conditions.  Connetics and
Pharmascience  covenant  and  agree to use their  best  efforts  to  obtain  the
satisfaction of the conditions specified in this Agreement.

         8.7 Adverse Event Reports.  Pharmascience  shall assume  responsibility
for  compliance  with  Canadian  governmental  regulations,   including  without
limitation  adverse event reporting  requirements.  To the extent that Connetics
receives any adverse event reports  (distinguished as serious and non-serious by
U.S. Food and Drug Administration  (FDA) regulations),  Connetics shall promptly
(but in no event later than (i) five  Business Days for serious  adverse  events
after  receipt by Connetics of complete  information  regarding  such events and
(ii) thirty  calendar  days for  non-serious  adverse  events  after  receipt by
Connetics of complete information  regarding such events) forward copies of such
reports to Pharmascience at the address set forth in Section 16.3. To the extent
that  Pharmascience  receives any adverse  event  reports,  Pharmascience  shall
promptly (but in no event later than (i) five Business Days for serious  adverse
events after receipt by  Pharmascience  of complete  information  regarding such
events and (ii)  thirty  calendar  days for  non-serious  adverse  events  after
receipt by  Connetics of complete  information  regarding  such events)  forward
copies of such reports to Connetics at the address set forth in Section 16.3.

         8.8 Transfer of Registrations, etc. Upon Pharmascience's request and to
the extent  legally  permissible,  Connetics will transfer to  Pharmascience  or
facilitate the transfer from SmithKline any health  registrations  in Connetics'
possession necessary to enable uninterrupted manufacture,  marketing and sale of
the Products in the Territory.  Connetics will cooperate with  Pharmascience  in
disclosing and copying any relevant records and reports which are required to be
made, maintained and reported pursuant to law.

         8.9  Transfer  of  Regulatory  Responsibility.  Pharmascience  shall be
responsible  for  transferring  the  Canadian   registrations  and  permits  and
transferring regulatory  responsibilities for the Products in the Territory from
Connetics or SmithKline to Pharmascience  as expeditiously as possible.  Without
limiting the foregoing,  Pharmascience  shall be  responsible  for effecting the
transfer of all Health  Protection Branch (HPB)  registrations and permits,  and
Connetics will provide reasonable assistance to Pharmascience in such transfer.

         8.10 Sales and Marketing Cooperation. Connetics and Pharmascience shall
exchange,  on  a  regular  basis,  information  regarding  sales  and  marketing
initiatives for the Products.  In addition,  representatives of each party shall
meet at least  once  per  calendar  year (at a  mutually  agreed  upon  time and
location) to discuss  sales and  marketing  strategies,  assess the state of the
arthritis market, and review historical and projected sales levels.

                                      -11-




                                    SECTION 9
                              CLOSING ARRANGEMENTS

         9.1  Closing  Arrangements.  At or  before  the  Time of  Closing  upon
fulfillment of all the  conditions  hereof which have not been waived in writing
by Pharmascience or Connetics respectively:

                  (a) Connetics' Delivery of Closing Documents.  Connetics shall
deliver to Pharmascience:

                           (i) a bill of sale and  assignment  substantially  in
the form of Exhibit C;

                           (ii)  all  technical  data,   formulations,   product
literature and other documentation related to the Purchased Assets;

                           (iii) such  certificates  of Connetics'  officers and
such other  documents  evidencing  satisfaction  of the conditions  specified in
Section 10 as Pharmascience shall reasonably request; and

                           (iv)   such   other   documents,    instruments   and
certificates as Pharmascience may reasonably request.

                  (b)    Pharmascience's    Delivery   of   Closing   Documents.
Pharmascience shall deliver to Connetics:

                           (i) such certificates of Pharmascience's officers and
such other  documents  evidencing  satisfaction  of the conditions  specified in
Section 11 as Connetics shall reasonably request; and

                           (ii)   such   other   documents,    instruments   and
certificates as Connetics may reasonably request.

                  (c)  Payment of  Purchase  Price.  On the  fulfillment  of the
foregoing  terms of Section 9 and upon the  fulfillment of all the conditions of
this Agreement,  which have not been specifically waived in writing by Connetics
or Pharmascience,  as the case may be,  Pharmascience  shall pay and satisfy the
Purchase Price as provided in Section 3 hereof.

                  (d)  Physical  Delivery.  Pursuant  to  delivery  arrangements
specified  by  Pharmascience  to  Connetics  prior to the Time of  Closing,  and
reasonably acceptable to Connetics,  Connetics shall deliver to Pharmascience at
Pharmascience's  premises those tangible assets included in the Purchased Assets
at the Time of Closing or as soon  thereafter as reasonably  practical but in no
event later than ten Business Days after the Time of Closing.

                  (e) Transfer Expenses. At Pharmascience's  request,  Connetics
shall deliver to Pharmascience such trademark assignment documents in recordable
form  necessary  to effect  the  transfer  to  Pharmascience  of all  trademarks
included in the Intellectual  Property.  Pharmascience  shall be responsible for
the recordation of same and Pharmascience  shall bear any costs and fees

                                      -12-




related  thereto.  Pharmascience  shall be responsible for all costs  associated
with maintenance of trademarks from the Time of Closing.


                                   SECTION 10
                      PHARMASCIENCE'S CONDITIONS OF CLOSING

         The sale and purchase of the Purchased  Assets in  accordance  with the
terms of this Agreement are subject to the following terms and conditions,  each
of which is included for the exclusive benefit of Pharmascience, to be fulfilled
and/or performed at or prior to the Time of Closing:

         10.1 Representations and Warranties at Closing. The representations and
warranties  of  Connetics  to  Pharmascience  contained  in this  Agreement  and
Exhibits  hereto shall be true and correct in all material  respects at the Time
of  Closing  with the same  force  and  effect  as if such  representations  and
warranties  were  made at and as of such time and  Connetics  shall  deliver  to
Pharmascience at the Time of Closing  certificate(s)  by an officer of Connetics
to such effect provided that the receipt of such evidence and the closing of the
transaction herein provided for shall not be nor be deemed to be a waiver of the
representations and warranties contained in this Agreement and Schedules hereto.

         10.2 Compliance with Terms and Conditions.  All of the terms, covenants
and  conditions of this  Agreement to be complied with or performed by Connetics
at or before the Time of Closing  shall have been  complied with or performed in
all material respects.

         10.3  Necessary  Consents.  There  shall  have been  obtained  from all
appropriate  federal,  state,  municipal or other governmental or administrative
bodies  such  approvals  or  consents  as are  required  to permit the change of
ownership of the Purchased Assets contemplated hereby.

         10.4 No Actions Taken  Restricting Sale. No action or proceeding in the
Territory  by law or in equity  shall be pending or  threatened  by any  person,
firm, corporation, government, governmental authority, regulatory body or agency
to enjoin,  restrict or prohibit the purchase and sale of the  Purchased  Assets
contemplated hereby.

         10.5 Non-Performance of Conditions for the Benefit of Pharmascience. In
the event that any of the  conditions  set forth in this Section 10 shall not be
fulfilled and/or performed at or before the Time of Closing,  Pharmascience  may
rescind this  Agreement  by notice in writing to  Connetics,  and  Pharmascience
shall thereupon be released from all obligations under this Agreement unless the
condition or conditions  for the  non-fulfillment  of  non-performance  of which
Pharmascience  has  rescinded  this  Agreement are  reasonably  capable of being
fulfilled  and/or performed or caused to be fulfilled or performed by Connetics,
then Connetics shall also be released from all obligations under this Agreement,
provided  any of the  said  conditions  may be  waived  in  whole  or in part by
Pharmascience  at any time without  prejudice to its rights of rescission in the
event of  non-fulfillment  and/or  non-performance  of any  other  condition  or
conditions, any such waiver to be binding upon Pharmascience only if the same is
in writing.

                                      -13-




         10.6 Supply  Agreement.  The parties shall have entered into the Supply
Agreement.

         10.7 Release of Security  Interests.  Connetics shall have obtained all
required releases from third parties (including, without limitation,  SmithKline
and Silicon Valley Bank) who hold any security interest in the Purchased Assets.


                                   SECTION 11
                        CONNETICS' CONDITIONS OF CLOSING

         The sale and purchase of the Purchased  Assets in  accordance  with the
terms of this Agreement is subject to the following terms and  conditions,  each
of which is  included  for the  exclusive  benefit  of  Connetics.  Each of such
conditions  is to be  fulfilled  and/or  performed  at or  prior  to the Time of
Closing.

         11.1 Compliance with Terms. All the terms,  covenants and conditions of
this  Agreement to be complied with or performed by  Pharmascience  at or before
the Time of  Closing  shall have been duly  complied  with or  performed  in all
material respects.

         11.2 No Action Taken  Restricting  Sale. No action or proceeding in the
United  States or Canada at law or in equity shall be pending or  threatened  by
any person, firm, corporation,  government,  governmental authority,  regulatory
body or agency to enjoin,  restrict or prohibit the sale of the Purchased Assets
contemplated hereby or the right of Connetics to sell the Purchased Assets.

         11.3 Non-Performance of Conditions for the Benefit of Connetics. In the
event  that any of the  conditions  set  forth in this  Section  11 shall not be
fulfilled  and/or  performed  at or before the Time of  Closing,  Connetics  may
rescind this Agreement by notice in writing to Pharmascience and Connetics shall
thereupon  be  released   from  all   obligations   under  this   agreement  and
Pharmascience  shall also be released from all obligations under this Agreement,
provided  any of the  said  conditions  may be  waived  in  whole  or in part by
Connetics at any time without  prejudice to its respective  rights of rescission
in the event of a non-fulfillment  and/or non-performance of any other condition
or conditions,  any such waiver to be binding upon Connetics only if the same is
in writing

         11.4 Supply  Agreement.  The parties shall have entered into the Supply
Agreement.


                                   SECTION 12
                  CONDITIONS TO THE OBLIGATIONS OF ALL PARTIES

         The  obligations  of each of the  parties  hereto  are  subject  to the
condition that at the Time of Closing,  there shall exist no injunction or other
order issued by a court of competent  jurisdiction which would make unlawful the
consummation of the transactions contemplated by this Agreement.

                                      -14-




                                   SECTION 13
                                 INDEMNIFICATION

         13.1  Connetics'  Indemnification.  Connetics  will  indemnify and hold
harmless Pharmascience and each of its directors, officers, employees, advisors,
affiliates,  agents  and  shareholders  from  and  against  any and all  losses,
damages,  liabilities,  costs, claims and expenses, including but not limited to
attorney's fees, arising out of, based upon or resulting from:

                  (a) any claims  against,  or liabilities  or  obligations  of,
Connetics or against the Purchased Assets other than the Assumed Liabilities;

                  (b)  any  inaccuracy  of any  representation  or  warranty  or
schedule of Connetics which is contained in or made pursuant to this Agreement;

                  (c) any tax  liability of Connetics  (other than sales and use
taxes  referred  to  in  Section  3.2  of  this  Agreement)  including,  without
limitation,  any tax  liability  arising  out of the  failure  of  Connetics  or
Pharmascience  to  comply  with any  provisions  of the tax laws of the State of
California;

                  (d)  any  breach  by  Connetics  of  any  of  its  agreements,
covenants,  warranties  or  obligations  contained  in or made  pursuant to this
Agreement; or

                  (e) any claims,  liabilities or  obligations  arising from the
sale of  Products in the  Territory  by  Connetics  or  SmithKline  prior to the
Closing.

         Connetics  shall have no  obligation to indemnify  Pharmascience  under
this Section 13.1 for any breach of Connetics'  representations  and  warranties
made in or pursuant to this Agreement, until such time, if any, as the aggregate
amount of the liabilities,  losses,  damages,  claims costs and expenses arising
out of such breach exceeds $50,000 and then only to the extent of such excess.

         13.2 Pharmascience's Indemnification.  Pharmascience will indemnify and
hold  harmless  Connetics  and  each  of  its  directors,  officers,  employees,
advisors,  affiliates,  agents and  shareholders  from and  against  any and all
losses,  damages,  liabilities,  costs,  claims and expenses  including  but not
limited to attorney's fees arising out of, based upon or resulting from:

                  (a)  any  inaccuracy  of any  representation  or  warranty  of
Pharmascience which is contained in or made pursuant to this Agreement;

                  (b) any  breach  by  Pharmascience  of any of its  agreements,
covenants,  warranties  or  obligations  contained  in or made  pursuant to this
Agreement;

                  (c)  any  of  the  Assumed  Liabilities,   excluding  damages,
liabilities, costs and claims arising out of or related to returns to the extent
that Connetics has retained liability pursuant to Section 8.4; or

                                      -15-




                  (d) the  Products  ordered  by  Connetics  on  Pharmascience's
behalf pursuant to Section 8.2 above.

         Pharmascience  shall have no  obligation to indemnify  Connetics  under
this  Section  13.2  for  any  breach  of  Pharmascience's  representations  and
warranties  made in or pursuant to this  Agreement,  until such time, if any, as
the  aggregate  amount of the  liabilities,  losses,  damages,  claims costs and
expenses  arising out of such breach exceeds $50,000 and then only to the extent
of such excess.  For the  avoidance of doubt this  limitation  does not apply to
Pharmascience's obligations to pay the Purchase Price.

         13.3 Claims  Procedures.  (a)  Promptly  after the receipt by any party
hereto of notice or upon any party becoming  otherwise aware of (x) any claim or
(y) the  commencement  of any action or proceeding,  such party (the  "Aggrieved
Party")  will,  if a claim with respect  thereto is to be made against any party
obligated to provide indemnification (the "Indemnifying Party") pursuant to this
Section 13, give such  Indemnifying  Party  written  notice of such claim or the
commencement  of such action or  proceeding  and shall  permit the  Indemnifying
Party to assume the defense of any such claim or any  litigation  resulting from
such claim.  Failure by the Indemnifying  Party to notify the Aggrieved Party of
its election to defend any such action within a reasonable time, but in no event
more than  thirty  days  after  notice  thereof  shall  have  been  given to the
Indemnifying  Party,  shall be deemed a waiver by the Indemnifying  Party of its
right to defend such action.

                  (b) If the Indemnifying  Party assumes the defense of any such
claim or litigation  resulting  therefrom,  the obligations of the  Indemnifying
Party as to such claim  shall be limited  to taking all steps  necessary  in the
defense or  settlement of such claim or  litigation  resulting  therefrom and to
holding  the  Aggrieved  Party  harmless  from and  against  any and all losses,
damages and liabilities  caused by or arising out of any settlement  approved by
the  Indemnifying  Party  or any  judgment  in  connection  with  such  claim or
litigation  resulting  therefrom.  The Aggrieved Party may  participate,  at its
expense,  in  the  defense  of  such  claim  or  litigation  provided  that  the
Indemnifying  Party  shall  direct  and  control  the  defense  of such claim or
litigation.  The  Indemnifying  Party shall not, in the defense of such claim or
any litigation  resulting  therefrom,  consent to entry of any judgment,  except
with the written  consent of the Aggrieved  Party, or enter into any settlement,
except with the written consent of the Aggrieved  Party,  which does not include
as an unconditional  term thereof the giving by the claimant or the plaintiff to
the Aggrieved  Party of a release from all liability in respect of such claim or
litigation.

                  (c) If the Indemnifying  Party shall not assume the defense of
any such claim or litigation resulting therefrom, the Aggrieved Party may defend
against such claim or litigation in such manner as it may deem  appropriate and,
unless the  Indemnifying  Party shall  deposit  with the  Aggrieved  Party a sum
equivalent to the total amount  demanded in such claim or  litigation,  or shall
deliver to the Aggrieved Party a surety bond or an irrevocable  letter of credit
in form and  substance  reasonably  satisfactory  to the  Aggrieved  Party,  the
Aggrieved Party may settle such claim or litigation on such terms as it may deem
appropriate,  and the Indemnifying  Party shall promptly reimburse the Aggrieved
Party for the amount of all reasonable expenses,  including, without limitation,
attorneys' fees,  incurred by the Aggrieved Party in connection with the defense

                                      -16-




against or  settlement  of such claims or  litigation.  If no settlement of such
claim or litigation is made, the Indemnifying Party shall promptly reimburse the
Aggrieved  Party for the amount of any  judgment  rendered  with respect to such
claim or in such litigation and of all expenses,  including, without limitation,
attorneys'  fees,  incurred by the Aggrieved  Party in the defense  against such
claim or litigation.

         13.4 Nature of Survival of  Representations,  Etc. All  representations
and warranties and agreements  made by the parties hereto shall survive the Time
of  Closing  and any  investigation  at any time  made by or on behalf of either
party, provided,  however, that no suit or action may be commenced in respect of
a representation or warranty after twelve (12) months from the Time of Closing.


                                   SECTION 14
                                     CLOSING

         The completion of the transactions contemplated by this agreement shall
take place at the Time of Closing at the offices of Venture Law Group, 2800 Sand
Hill Road,  Menlo  Park,  California,  U.S.A.  or at such other  place as may be
agreed upon by the parties hereto.


                                   SECTION 15
                CONDUCT OF BUSINESS PRIOR TO THE TIME OF CLOSING

         It is expressly  understood by the parties that in the event that there
is  no  closing  under  this  Agreement,  Pharmascience  shall  have  no  rights
whatsoever to the revenues  from the  Products,  and shall have no liability for
the Assumed  Liabilities  or for any costs or expenses  incurred or accrued with
respect to the business related to the Products.


                                   SECTION 16
                                  MISCELLANEOUS

         16.1 Further Assurances. Each of the parties hereto upon the request of
the other party hereto,  whether before or after the Time of Closing and without
further consideration, shall do, execute, acknowledge and deliver or cause to be
done,  executed   acknowledged  or  delivered  all  such  further  acts,  deeds,
documents,   assignments,   transfers,   conveyances,  powers  of  attorney  and
assurances  as may be  reasonably  necessary  or  desirable  to effect  complete
consummation of the transactions contemplated by this Agreement.

         16.2  Announcements.  The parties  hereto agree that no  disclosure  or
public  announcement  with respect to this Agreement or any of the  transactions
contemplated  by this  Agreement  shall be made by any party hereto  without the
prior  consent of Connetics or  Pharmascience  provided,  however,  that nothing
herein  contained  shall  restrict  Connetics or  Pharmascience  from making any
public  announcement of the  transactions  contemplated by this Agreement to the
extent that it, in its sole discretion reasonably exercised, is of the view that
such  announcement  is  required  or  deemed  advisable  in  order  to meet  its
obligations  under the securities laws or stock exchange  requirements in Canada
or the United States. Notwithstanding the foregoing, Connetics may disclose this
Agreement and the transactions  contemplated  hereby,  to

                                      -17-




the extent reasonably  necessary,  in connection with (a) a private placement of
securities for the purpose of obtaining  financing and/or (b) Connetics'  filing
and disclosure  obligations under the Exchange Act, including the filing of this
Agreement and all exhibits with the Securities and Exchange Commission.

         16.3 Notices.  Any notice,  direction or other  instrument  required or
permitted  to be given to  Connetics  hereunder  shall be in writing  and may be
given by delivering the same to Connetics via internationally-recognized courier
as follows:

              To:               Connetics Corporation
                                3400 W. Bayshore Road
                                Palo Alto, CA  94303
                                Attn:  Chief Executive Officer


              Copy to:          Venture Law Group
                                2800 Sand Hill Road
                                Menlo Park, CA  94025
                                Attn:  Joshua L. Green


         Any notice,  direction or other instrument  required or permitted to be
given  to  Pharmascience  hereunder  shall  be in  writing  and may be  given by
delivering  the same to  Connetics  via  internationally-recognized  courier  as
follows:

              To:               Pharmascience, Inc.
                                8400 Darnley Road
                                Montreal, Quebec
                                H4T 1M4
                                Attn:  Chairman of the Board

                  Any such notice, direction or other instrument,  if delivered,
shall be deemed to have been given on the date on which it was  delivered and if
transmitted  by  telecommunication  shall be deemed  to have  been  given at the
opening of  business in the office of the  addressee  on the  Business  Day next
following the transmission thereof.

         Any party  hereto may change its address for service  from time to time
by notice given to the other parties hereto in accordance with the foregoing.

         16.4 Termination.

         (a) This  Agreement  may be terminated at any time prior to the Time of
Closing:

                  (i) by mutual consent of Connetics and Pharmascience; and

                                      -18-




                  (ii)  by  either   Connetics  or  Pharmascience  if  the  sale
contemplated  hereby shall not have been  consummated  on or before  January 31,
1998.

         (b) In the event of termination  of this  Agreement in accordance  with
this Section 16.4,  neither party shall be liable to the other,  because of such
termination,  for compensation,  reimbursement or damages on account of the loss
of  prospective  profits or  anticipated  sales or on  account of  expenditures,
inventory, investments, leases or commitments in connection with the business or
goodwill of Connetics or Pharmascience.  Termination shall not, however, relieve
either party of any obligations incurred prior to the termination.

         16.5 Time of the Essence. Time shall be of the essence.

         16.6  Applicable Law. This Agreement shall be construed and enforced in
accordance  with, and the rights of the parties hereto shall be governed by, the
laws of the State of California, U.S.A.

         16.7 Entire  Agreement.  This  Agreement,  including  the  Exhibits and
Schedules  hereto,  constitutes the entire agreement  between the parties hereto
with  respect to the  transactions  provided  for herein  and,  except as stated
herein  and in the  instruments  and  documents  to be  executed  and  delivered
pursuant hereto,  contains all of the agreements  between the parties hereto and
there are no verbal agreements or understandings  between the parties hereto not
reflected in this  Agreement.  This  Agreement may not be amended or modified in
any respect except by written instrument executed by each of the parties hereto.

         16.8  Counterparts.  This  Agreement  may be  executed  in two or  more
counterparts,  each of which shall be deemed to be an original  and all of which
together shall constitute one and the same Agreement.

         16.9 Parties in Interest.  This Agreement shall inure to the benefit of
and be binding upon the parties hereto and their  respective  heirs,  executors,
successors,  administrators, and assigns; provided, however, that this Agreement
shall not be assignable by Connetics or  Pharmascience  hereto prior to the Time
of Closing without the written consent of the other party.


                            [Signature Page Follows.]


                                      -19-




                                  

         IN WITNESS  WHEREOF  this  Agreement  has been  executed by the parties
hereto as of the date first above written.


                                             PHARMASCIENCE, INC.



                                             By: /s/ Pharmascience, Inc.
                                                --------------------------------
                                             Title:
                                                   -----------------------------


                                             CONNETICS CORPORATION



                                             By: /s/ Thomas G. Wiggans
                                                --------------------------------
                                             Title:  President and Chief 
                                                   -----------------------------
                                                     Executive Officer
                                                   -----------------------------






                                  

                                    EXHIBIT A

                          Intellectual Property Rights

TRADEMARKS

Canadian Trademark Registration

Registration No. TMA316,242

Trademark Oppositions/Litigation

No known  pending  oppositions  or  litigation,  or threats  thereof,  affecting
RIDAURA trademarks in Canada.

COPYRIGHTS

No known registrations/applications.








                                    EXHIBIT B


                                SUPPLY AGREEMENT

[Filed as Exhibit 10.55 to Connetics'  Registration  Statement on Form S-1 (File
No. 333-41195).]






                                         

                                    EXHIBIT C

                           BILL OF SALE AND ASSIGNMENT


         Bill of Sale and  Assignment,  dated December __, 1997,  from Connetics
Corporation,  a Delaware  corporation  ("Connetics") to  Pharmascience,  Inc., a
Canadian corporation ("Pharmascience").

         1. Pursuant to the Canadian Asset Purchase  Agreement between Connetics
and Pharmascience dated December __, 1997 (the "Agreement"), incorporated herein
by  reference,  and for  valuable  consideration  therein  recited,  including a
purchase  price  payable as set forth in Section 3 of the  Agreement,  and other
good and valuable  consideration  recited  therein,  Connetics has  respectively
sold,  conveyed,  assigned,  transferred,  set over and  delivered  and by these
presents does hereby sell, convey,  assign,  transfer, set over and deliver unto
Pharmascience,  and to its  successors  and assigns  forever,  all and  singular
rights,  title and  interest  in and to the  Purchased  Assets as  described  in
Section 2 of the Agreement, all of which is incorporated herein by reference.

         2. Connetics hereby covenants and agrees to and with Pharmascience, its
successors  and  assigns,  to execute  and  deliver  all such other and  further
instruments of  conveyance,  assignment and transfer and all such other notices,
releases,  acquittances,  powers of attorney and other documents,  and to do all
such other acts and things as may be  necessary  more fully to convey and assign
to  Pharmascience or its successors or assigns,  all and singular rights,  title
and  interest  in and to the  Purchased  Assets  therein  and  hereby  conveyed,
assigned and  transferred to or acquired by  Pharmascience  by any such specific
conveyances and assignments;  and in case of conflict,  such specific instrument
shall  control with  respect to the  properties  or assets  assigned or conveyed
thereby.






         3.  Connetics   represents  and  warrants  to  Pharmascience  that  (i)
Connetics is the sole owner of all the Purchased  Assets with good title thereto
free and clear of any mortgage,  lien, charge, security interest,  adverse claim
or other encumbrance  whatsoever  (collectively,  the "Encumbrances"),  and (ii)
Connetics has the right to transfer to Pharmascience good title to the Purchased
Assets, free and clear of all Encumbrances, and to execute this Bill of Sale and
Assignment.


                            [Signature page follows]

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         IN  WITNESS  WHEREOF,  Connetics  has  caused  this  Bill of  Sale  and
Assignment to be executed as of the date first above written.


                                               Connetics Corporation


                                               By:  _________________________

                                               Title:  _________________________

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