<PAGE>

                                                                    EXHIBIT 10.2
                                                                    ------------

Confidential treatment has been requested for portions of this exhibit. The copy
filed herewith omits the information subject to the confidentiality request.
Omissions are designated as **. A complete version of this exhibit has been
filed separately with the Securities and Exchange Commission.



                         OPTION AND LICENSE AGREEMENT
                         ----------------------------

THIS AGREEMENT (the "Agreement") is made and is effective the 10th day of June,
1998 (the "Effective Date") by and between:

           Adolor Corporation, a Delaware corporation having its principal place
           of business at 371 Phoenixville Pike, Malvern, Pennsylvania 19355
           ("ADOLOR")

     and

           Roberts Laboratories Inc., a New Jersey corporation, having its
           principal place of business at 4 Industrial Way West, Eatontown, New
           Jersey 07724 ("ROBERTS").

                                   RECITALS
                                   --------

1.   ADOLOR is engaged in the development and marketing of therapeutic products
     utilizing opiate receptor-mediated pathways.

2.   ROBERTS has acquired from Eli Lilly and Company ("Lilly"), in an agreement
     dated November 5, 1996 (the "Lilly License"), an exclusive, world-wide
     license to make, have made, use or sell (+)-[2(S)-[4(R)-(3-hydroxyphenyl)-
     3(R),4-dimethyl-1-piperidinyl]methyl]-1-oxo-3-phenylpropyl]amino]-acetic
     acid and all pharmaceutically acceptable salts and solvates thereof (the
     "Compound"), with the right to sublicense, which Lilly License and its
     Appendices A and B are appended hereto as Exhibit A.

3.   An Investigational new Drug Application ("IND"), made to the United States
     Food and Drug Administration ("FDA"), was initiated for the Compound, but
     currently there is no activity pursuant to this Application.

4.   As ADOLOR believes the Compound may provide the basis for a therapeutic
     product utilizing opiate receptor-mediated pathways, ADOLOR desires to
     obtain and ROBERTS desires to provide an exclusive, world-wide license
     including (a) a "Phase A" during which ADOLOR will seek to establish the
     therapeutic index of the Compound, and (b), provided the therapeutic index
     is satisfactory to ADOLOR at its sole discretion, a "Phase B" during which
     ADOLOR will pursue development and commercialization of the Compound.

5.   Assuming ADOLOR proceeds to Phase B, ADOLOR further desires to seek to
     convert the license to an assignment of the Lilly License to ADOLOR subject
     to the same duties as between ADOLOR and ROBERTS as are set forth below,
     and ROBERTS desires to deliver such assignment to ADOLOR and to exert best
     efforts to obtain for ADOLOR the required permission from Lilly, though in
     the absence of such an assignment the license provided herein shall be
     maintained.

NOW THEREFORE, in consideration of the mutual covenants and obligations
hereinafter set forth the parties agree to be legally bound as follows:
<PAGE>

ARTICLE I      - DEFINITIONS
----------------------------

     Section 1.1.   "Affiliate," "Compound," "End User," "Lilly Intellectual
     ------------
Property Rights," "Net Sales" and "Product" shall have the meanings,
respectively, set forth in the Lilly License.

     Section 1.2.   "First Commercial Sale" shall mean the first time sales are
     ------------
made of Product by ADOLOR to an unrelated third party on a country by country
basis.

     Section 1.3.   "Lilly Know-How" shall have the meaning set forth for "Know-
     ------------
How" in the Lilly License.

     Section 1.4.   "NDA" shall mean an application filed with the FDA for the
     ------------
approval of the manufacturing, marketing or importation of a therapeutic product
for use in humans. The references below to "similar filing" shall encompass, for
example, Product License Applications ("PLAs") and Pre-Marketing Applications
("PMAs").

     Section 1.5.   "Technical Information" shall mean Technology which is
     ------------
owned, discovered or developed by or licensed to ROBERTS which is embodied or
employed in the composition, manufacture or use of the Compound or Product, or
components, reagents, parts or elements thereof. "ADOLOR Technical Information"
shall mean Technology which is owned, discovered or developed by ADOLOR which is
embodied or employed in the composition, manufacture or use of the Compound or
Product, or components, reagents, parts or elements thereof.

     Section 1.6.   "Technology" shall mean know-how, protocols, processes,
     ------------
instruments, machines, materials, compositions, tests procedures, manufacturing
procedures, techniques, formulations, methodologies and data, inventions,
observations and information, related to the Compound or the Product.

ARTICLE II     LICENSE
----------------------

Pursuant to the Lilly Intellectual Property Rights or any ROBERTS Technical
Information, ROBERTS grants ADOLOR an exclusive, world-wide license to make,
have made, use, sell or import Product pursuant to the Lilly Intellectual
Property Rights or any other ROBERTS Technical Information. The term of the
license shall be either the term of Phase A or, if ADOLOR elects to proceed with
Phase B, the sum of the terms of Phase A and Phase B.

The rights acquired hereunder shall include all rights licensed to ROBERTS
pursuant to the Lilly License.
<PAGE>

ARTICLE III    - PHASE A
------------------------

     Section 3.1.   - Phase A Consideration
     --------------------------------------

     In consideration for Phase A, ADOLOR shall deliver to ROBERTS a non-
refundable payment of $300,000 on the Effective Date.

     Section 3.2.   - Phase A Term
     -----------------------------

The term of Phase A shall be from the Effective date until the earlier of (a)
the date on which ADOLOR delivers to ROBERTS notice of ADOLOR's completing
studies sufficient to establish the therapeutic index of the Compound and of
whether ADOLOR intends to initiate Phase B and (b) July 31, 1999. The parties
acknowledge that there are areas of risk to ADOLOR's ability to meet this
timetable including:

     .     the risk that the pharmaceutical composition of the Compound or
           Product provided by ROBERTS be insufficient in quality or quantity to
           conduct the studies necessary to establish the therapeutic index; and

     .     the risk that the FDA will suspend or place on hold any activity
           pursuant to the IND for the Compound.

The parties further acknowledge that the above exemplified risks, should they
become realities, would provide cause for the July 31, 1999 term expiration date
to be extended. Should an event outside of ADOLOR's control give rise to a
reasonable basis to extend the July 31, 1999 term expiration date, meaning that
it is reasonable to expect that ADOLOR acting with commercially reasonable
diligence shall not have completed studies to establish the therapeutic index of
the Compound by July 31, 1999, an extension of time will be provided to enable
ADOLOR to complete the studies and the parties shall negotiate in good faith and
arrive at a reasonable period of extension.

     Section 3.3.   - ADOLOR's Phase A Duties
     ----------------------------------------

     In addition to any other duties imposed by this Agreement, during the term
of Phase A, ADOLOR shall use commercially reasonable efforts to conduct studies,
including Phase I clinical studies, to establish the therapeutic index of the
Compound. All costs associated therewith shall be borne by ADOLOR. While the
Phase A is in effect, ADOLOR agrees to undertake the obligations incumbent on
ROBERTS under the Lilly License, with the exception of the milestone payments
set forth in Section 3.01 of the Lilly License and the costs associated with
prosecuting or maintaining patents under the Lilly Intellectual Property Rights,
which shall continue to be borne by ROBERTS.
<PAGE>

     Section 3.4.   - ROBERTS' Phase A Duties
     ----------------------------------------

     In addition to any other duties imposed by this Agreement, ROBERTS shall:

     (a)   provide ADOLOR its stocks of the Compound, in the amount ROBERTS
           possesses in whatever condition that such Compound may be as of the
           Effective Date; and

     (b)   during the term of Phase A, refrain from discussing, negotiating or
           agreeing to, with a third party, a license or assignment of rights in
           the Compound, or its use, manufacture, sale or import.

ARTICLE IV     - PHASE B
------------------------

     Section 4.1.   - Term and Contingency
     -------------------------------------

     The term of Phase B begins on the last day of Phase A through to the end of
the term defined in Section 8.01 of the Lilly License. Entrance into Phase B is
contingent on ADOLOR delivering to ROBERTS during the term of Phase A notice of
ADOLOR's intent to proceed with Phase B.


     Section 4.2.   - Phase B Consideration
     --------------------------------------

Subject to the foregoing, in consideration for Phase B, ADOLOR shall pay
ROBERTS:

     .     $300,000 payable within five (5) business days of the expiration of
           Phase A;
     .     $** payable within five (5) business days of the filing of a first
           application for a NDA or similar filing in the United States, Canada,
           Japan or the European Community that seeks permission to market a
           Product;
     .     $** payable within five (5) business days of receiving notice of
           acceptance of a first NDA or similar filing in the United States,
           Canada, Japan or the European Community that seeks permission to
           market a Product; and
     .     a royalty equal to **% of Net Sales.

ADOLOR shall pay Lilly, on behalf of ROBERTS, $** upon acceptance of a first NDA
or similar filing in the United States, Canada, Japan or the European Community
that seeks permission to market a Product, in accordance with Section 3.01(v)
the Lilly License. ADOLOR agrees to pay Lilly, on behalf of ROBERTS, a royalty
equal to ** % of Net Sales in accordance with the Lilly License. For any payment
made on behalf of ROBERTS, ADOLOR shall deliver proof of such payment to
ROBERTS.

**=Certain information on this page has been omitted and filed separately with
   the Commission. Confidential treatment has been requested with respect to
   the omitted portions.

<PAGE>

     Section 4.3.   - ADOLOR's Phase B Duties
     ----------------------------------------

While Phase B is in effect, ADOLOR agrees to undertake the obligations incumbent
on ROBERTS under the Lilly License and accruing during Phase B, with the
exception of the execution milestone payment set forth in Section 3.01(a)(i) of
the Lilly License. Except for costs associated with Robert's duties under this
Agreement, all costs associated with developing and commercializing the Compound
or Product shall be borne by ADOLOR.

ARTICLE V      - SUBLICENSES OF THIS AGREEMENT
----------------------------------------------

     (a)   ADOLOR shall have the right to grant sublicenses hereunder consistent
           with the terms of the Lilly License, provided, however, that should
                                                -----------------
           ADOLOR grant a sublicense hereunder within seventy-five (75) days of
           the Effective Date, ROBERTS shall receive 25% of any payments made to
           ADOLOR in consideration of such sublicense.

     (b)   Should ADOLOR decide to actively seek to sublicense marketing rights
           in the Compound or seriously consider a good faith offer by a third
           party to sublicense such marketing rights, ADOLOR shall notify
           ROBERTS of its intention to seriously seek to sublicense the
           marketing rights and shall provide ROBERTS with an opportunity to
           negotiate in good faith for a sublicense to the marketing rights.
           However, nothing herein shall imply that ROBERTS has a right of
           priority or preference in such negotiations, or imply any restraints
           whatsoever on ADOLOR's business judgment as to partners in marketing
           the Compound.

ARTICLE VI     - TECHNOLOGY TRANSFER
------------------------------------

     Section 6.1.   - From ROBERTS to ADOLOR
     ---------------------------------------

     Following execution and payment under Section 3.1 ROBERTS shall deliver to
ADOLOR copies of the Lilly Know-how, ROBERTS Technical Information, and its
inventory of Compound and intermediates for the production of Compound.

     Section 6.2.   - From ADOLOR to ROBERTS
     ---------------------------------------

     (a)   Should ADOLOR establish the therapeutic index of the Compound but
           nonetheless decline to initiate Phase B, ADOLOR shall deliver to
           ROBERTS copies of ADOLOR data on the therapeutic index of the
           Compound and any other ADOLOR data on the therapeutic efficacy of the
           Compound as well as any dosage forms containing the Compound.
<PAGE>

     (b)   Should ADOLOR fail to establish the therapeutic index and should
           ADOLOR not dispute that the term of Phase A, taking into
           consideration any extensions thereto under Section 3.2, has expired,
           then ADOLOR shall deliver to ROBERTS copies of ADOLOR data on the
           therapeutic index of the Compound and any other ADOLOR data on the
           therapeutic efficacy of the Compound as well as any dosage forms
           containing the Compound.

     (c)   All such materials delivered to ROBERTS pursuant to this Section 6.2
           shall thus become the sole and exclusive property of ROBERTS.

ARTICLE VII    - REPORTS, RECORDS, PAYMENTS
-------------------------------------------

     Section 7.1.   - Quarterly Reports
     ----------------------------------

     (a)   ADOLOR shall give ROBERTS prompt written notice of-the first
           acceptance of a NDA or similar filing in the United States, Canada,
           Japan or the European Community that seeks permission to market a
           Product.

     (b)   Within forty five (45) days after the end of each calendar quarter
           following the First Commercial Sale in any country, whether or not a
           royalty payment is due for that period, ADOLOR shall provide ROBERTS
           with a written statement with respect to such period, specifying the
           gross sales, the calculation of Net Sales and Net Sales of Product
           during the period, and the amount of royalty due, if any, together
           with the payment of royalties due.

     Section 7.2.   - Records
     ------------------------

     (a)   ADOLOR shall keep complete and accurate records pertaining to the
           manufacture, use and sale of Product appropriate to determine
           royalties payable under Section 4.2 of this Agreement.

     (b)   At the request and expense of ROBERTS, an independent certified
           public accountant, selected by ROBERTS and reasonably approved by
           ADOLOR, shall have access limited to once per calendar year, at
           ADOLOR's principal place of business during ordinary business hours,
           to such records maintained by ADOLOR as may be necessary to:

           (i)   determine, with respect to any of the two (2) preceding years
     the correctness of any report or payment made under this Agreement, or

           (ii)  obtain information with respect to any of the two (2) preceding
     years as to the royalty payable in the case of ADOLOR's failure to report
     or pay such royalty pursuant to this Agreement.
<PAGE>

     (c)   If deemed necessary or desirable in the sole opinion of the
           accountant, the accountant shall at ROBERTS' expense be permitted to
           consult with and obtain the assistance of consultants selected by the
           accountant and reasonably acceptable to ADOLOR. Neither the
           accountant nor the selected consultants shall disclose to ROBERTS or
           any third pasties any information relating to the business of ADOLOR
           other than information relating solely to the accuracy of the reports
           and payments under this Agreement.

     Section 7.3.   - Payment of Royalty
     -----------------------------------

     (a)   ADOLOR shall pay the royalty due under Section 4.2 for sales of
           Product in each calendar quarter within forty five (45) days after
           the end of such calendar quarter.

     (b)   All royalty due hereunder shall be paid in same day United States
           funds.

     (c)   Any sum required under the laws of any governmental authority to be
           withheld by ADOLOR from payment of royalties for the account of
           ROBERTS under Section 4.2 shall be promptly paid by ADOLOR for and on
           behalf of ROBERTS to the appropriate tax or other governmental
           authorities and ADOLOR shall furnish ROBERTS with copies of official
           tax receipts or other appropriate evidence issued by the appropriate
           tax or other governmental authorities.

     (d)   Should an audit under Section 7.2(b) identify a delinquency in
           royalties due. ADOLOR shall pay, in addition to such delinquent
           amount, liquidated damages of 1 1/2% of the delinquency per month of
           the delinquency. Should such delinquency in any year exceed five
           percent (5%), ADOLOR shall pay for the audit fees and expenses
           incurred by ROBERTS.

ARTICLE VIII   - CONFIDENTIALITY
--------------------------------

     Section 8.1.   - Nondisclosure and Nonuse
     -----------------------------------------

     (a)   ROBERTS and ADOLOR shall each retain in confidence information
           obtained from the other under this Agreement and shall not disclose
           such information to any third party except:

           (i)   consultants and Affiliates who are obligated to maintain it in
     confidence pursuant to written agreements which incorporate the terms of
     this Article VIII.

           (ii)  as necessary to obtain approval from a governmental agency in
     order to market the Product; or

           (iii) as otherwise may be required by law, regulation or judicial
     order, and shall not use such information for any purposes other than those
     contemplated by this Agreement. Each party shall take all reasonable
     precautions to safeguard the confidentially of the information.
<PAGE>

     Section 8.2.   - Exceptions
     ---------------------------

The obligations of nondisclosure and nonuse of this Article VIII shall not apply
to information which:

     (a)   is known to the receiving party, as evidenced by written records
           maintained by the receiving party, or to the public, or is in the
           public domain, prior to its disclosure under this Agreement;

     (b)   is hereafter lawfully disclosed to the receiving party by a third
           party not- under an obligation of confidence to the other party;

     (c)   subsequently enters the public domain or becomes known to the public
           by some means other than a breach of this Agreement;

     (d)   is required by law to be disclosed; or

     (e)   becomes the property of the property of the disclosing party pursuant
           to this Agreement.

     Section 8.3.   - Purpose of Article
     -----------------------------------

Each party acknowledges that the restrictions contained in this Article VIII are
necessary and reasonable to protect the legitimate interests of the parties and
a violation of this Article by a party may result in irreparable harm to the
other party.

     Section 8.4.   - Term
     ---------------------

The provisions of this Article VIII shall survive the expiration or termination
of this Agreement and continue for five (5) years thereafter.

     Section 8.5.   - Merger
     -----------------------

Upon execution, all confidential information relating to the Compound disclosed
under any previous confidentially agreements between ROBERTS and ADOLOR shall be
governed by this Agreement instead of such prior agreement.

ARTICLE IX     - INVENTIONS AND PATENTS
---------------------------------------

     (a)   While licensed under Phase B, ADOLOR shall make the payments for
           prosecuting and maintaining patent applications set forth in Section
           4.03 of the Lilly License.
<PAGE>

     (b)   While ADOLOR is licensed under Phase B, should Lilly elect, in any
           country, to not prosecute or maintain an application or not to
           maintain or defend an issued patent, ADOLOR shall be given timely
           notice and shall have the right to direct that such prosecution,
           maintenance or defense be conducted at ADOLOR's expense. If (1)
           ADOLOR declines to undertake such expense, (2) the application or
           patent at issue is the only Lilly patent or Application covering the
           Compound, its synthesis, use or formulation in the given country, and
           (3) such prosecution, maintenance or defense is conducted at ROBERTS'
           expense, the license granted by this Agreement shall no longer apply
           with respect to such county.

     (c)   While ADOLOR is licensed under Phase B, Lilly may, pursuant to
           Section 4.03 of the Lilly License, send notice to ROBERTS of a cost
           associated with prosecuting, maintaining or defending an application
           or patent in a given country, a copy of which notice shall be timely
           forwarded to ADOLOR. If ADOLOR elects not to pay such costs, ROBERTS
           may on its own account, without compensation from ADOLOR, undertake
           the costs payable to Lilly. If (1) ADOLOR elects not to pay such
           costs, (2) the application or patent at issue is the only Lilly
           patent or application covering the Compound, its synthesis, use or
           formulation in the country, and (3) the costs payable to Lilly for
           such prosecution, maintenance or defense are undertaken by ROBERTS,
           the license granted by this Agreement shall no longer apply with
           respect to such county.

     (d)   An official of ADOLOR designated by ADOLOR shall receive copies from
           ROBERTS of all significant correspondence to and from the U.S. Patent
           and Trademark Office or other, foreign patent administrative body
           relating to Licensed Patents.

     (e)   ROBERTS shall consult with ADOLOR on any matters arising under
           Section 4.06 of the Lilly License (regarding reexamination, reissue
           other proceedings relating to granted patents), and ROBERTS shall
           provide no Consent under that Section 4.06 without the prior consent
           of ADOLOR.

     Section 9.2.   - Third-Party Infringement
     -----------------------------------------

     (a)   If either ADOLOR or ROBERTS learns of an infringement or threatened
           infringement of Lilly Intellectual Property Rights or ADOLOR or
           ROBERTS Technical Information wherein the infringement or threatened
           infringement involves a third party's manufacture, or sale of
           Compound or Product, the party who so learns shall notify the other
           party within a reasonable time.
<PAGE>

     (b)   While ADOLOR is licensed under Phase B, ADOLOR shall have the rights
           allocated to ROBERTS in Section 4.05 of the Lilly License to
           participate in actions to terminate an infringement of Lilly
           Intellectual Property Rights. ROBERTS will execute (and cause its
           Affiliates to execute) all documents necessary to effect this
           provision. While ADOLOR is licensed under Phase B, ADOLOR shall have
           the same rights to participate in actions to terminate an
           infringement of ROBERTS Technical Information as ROBERTS has with
           respect to Lilly Intellectual Property Rights under the Lilly
           License.

     (c)   With respect to an action involving Lilly, the parties shall endeavor
           to have recoveries allocated in proportion to reasonable costs
           incurred by the parties. With respect to actions not involving Lilly,
           recoveries shall be so allocated.

ARTICLE X      - EXPIRATION AND TERMINATION
-------------------------------------------

     Section 10.1.  - Expiration
     ---------------------------

Unless terminated earlier under other provisions of this Agreement will expire
at the end of the term set forth Section 8.01 of the Lilly License.

     Section 10.2.  - Surviving Rights
     ---------------------------------

The provisions of 10.3 (Termination) and 12.5 (Governing Law) and Article VIII
(CONFIDENTIALITY) of this Agreement shall survive the expiration or termination
of this Agreement.

     Section 10.3.  - Termination
     ----------------------------

     (a)   ADOLOR may terminate this agreement with respect to Phase A by
           delivering notice of such termination to ROBERTS at least thirty (30)
           days prior to the effective date of such termination.

     (b)   Either party may terminate this Agreement upon (60) days prior
           written notice in the event of the other party's breach of any other
           material provision of this Agreement, if such default or breath is
           not remedied within sixty (60) days from the date of such notice.

     (c)   Any failure to terminate shall not be construed as a waiver by the
           aggrieved party of its right to terminate for future defaults or
           breaches.

     (d)   Upon termination of this Agreement, each party shall upon the request
           of the other party return all books, records, documents and data
           which it shall have received from the other party pursuant to this
           Agreement.
<PAGE>

     (e)   Termination of this Agreement by either party shall not prejudice the
           right of ROBERTS to recover any royalty or other payments due at the
           time of termination or which become due after termination based upon
           rights vested prior to termination and shall not prejudice any cause
           of action or claim of ROBERTS or ADOLOR accruing under this
           Agreement.

     (f)   ADOLOR shall not make, have made, use or sell the Compound or Product
           following termination of this Agreement, except that if termination
           occurs during Phase B ADOLOR may sell such stocks of the Compound or
           Product as it shall have on hand at the time of termination. This
           provision shall not exempt ADOLOR from the duty to pay royalty at the
           rates and times provided under this Agreement.

     (g)   ROBERTS shall not terminate this Agreement during Phase A and any
           term extensions pursuant to Section 3.2, provided that ADOLOR is
           proceeding in good faith to seek to establish the therapeutic index
           of the Compound.

ARTICLE XI     - REPRESENTATIONS, WARRANTIES, COVENANTS
-------------------------------------------------------

     (a)   ROBERTS represents and warrants that it is not in breach of the Lilly
           License and that it has the right to grant the licenses provided this
           Agreement

     (b)   ROBERTS represents and warrants that it shall not take any action or
           refrain from any action so as to give Lilly cause to terminate the
           Lilly License.

     (c)   ROBERTS represents and warrants that it has undertaken no action, and
           that it knows of no action or other change of circumstances, that has
           diminished the value of the Lilly Intellectual Property Rights
           relative to the Lilly Intellectual Property Rights as they existed,
           or as ROBERTS understood them, on the fifth (5th) day of November,
           1996, when the Lilly License was executed.

     (d)   ROBERTS shall use best efforts to obtain from Lilly permission to
           assign the Lilly License to ADOLOR, and, on obtaining such permission
           and receiving notice from ADOLOR of ADOLOR's intent to initiate Phase
           B, shall assign the Lilly License to ADOLOR subject to the same
           duties as between ROBERTS and ADOLOR as set forth in this Agreement.
           Accordingly, this Agreement shall be, with respect to Phase B,
           converted to an agreement to assign.

     (e)   ROBERTS shall make available to ADOLOR personnel reasonably
           appropriate to help ADOLOR understand and implement the Lilly Know-
           how and the ROBERTS Technical Information. Such personnel shall
           include Phil Lange and shall be made available on ADOLOR's request
           for a period not to exceed five (5) working days.
<PAGE>

ARTICLE XII    - MISCELLANEOUS PROVISIONS
-----------------------------------------

     Section 12.1.  - Entire Understanding
     -------------------------------------

This Agreement sets forth the entire understanding between ROBERTS and ADOLOR
pertaining to its subject mailer and supersedes and replaces all prior oral or
written agreements between ROBERTS and ADOLOR pertaining to such subject matter.

     Section 12.2.  - Amendment
     --------------------------

This Agreement may not be amended, supplemented or otherwise modified except by
an instrument in writing signed by both parties.

     Section 12.3.  - Assignment
     ---------------------------

Neither party may assign this Agreement without the prior written approval of
the other party except in connection with the sale or merger of the entire
business or in connection with an assignment to an Affiliate. Such approval
shall not unreasonably be withheld. Notwithstanding such approval, the assigning
party shall be responsible to the party jointly or severally, with the assignee
for any obligations under this Agreement.

     Section 12.4.  - Waiver
     -----------------------

No provision of this Agreement shall be waived by any act, omission or knowledge
of a party or its agents or employees, except by an instrument in writing
expressly waving such provision and signed by the waiving party.

     Section 12.5.  - Governing Law
     ------------------------------

The Agreement shall be governed by and interpreted in accordance with the laws
of the Commonwealth of Pennsylvania, exclusive of its conflict of laws
provisions, and the parties consent to the jurisdiction and to venue at, a court
within the District of the United States Federal Courts in which the defendant
shall be found.

     Section 12.6.  - Restriction of Distribution of this Agreement
     --------------------------------------------------------------

This Agreement shall not be distributed to persons other than those personnel of
ROBERTS and ADOLOR who shall have a need to know its contents and to those whose
knowledge of its contents will facilitate performance of the obligations of the
parties under this Agreement, except as may be required by law, regulation or
judicial order.

     Section 12.7.  - Publicity
     --------------------------

Notwithstanding the provisions of Section 12.6, either party may publicly
announce the existence of this Agreement and the nonfinancial terms contained
herein, provided such announcement is consented to by Lilly. The parties shall
consult with each other prior to any press release or other public disclosure.
<PAGE>

     Section 12.8.  - Consents Not Unreasonably Withheld or Delayed
     --------------------------------------------------------------

Whenever a provision is made in this Agreement for either party to secure the
consent, approval or acceptance of the other, such consent, approval or
acceptance shall not unreasonably be withheld or delayed.

     Section 12.9.  - Construction
     -----------------------------

The captions appearing in this Agreement are for reference purposes only and
shall not be considered for the purpose of interpreting or construing this
Agreement. The plural shall be substituted for singular numbers in any place in
which the context may require such substitution.

     Section 12.10. - Invalidity of Particular Provisions
     ----------------------------------------------------

If any provision of this Agreement is invalid or unenforceable by reason of any
rule of law, administrative order or judicial decision, all other provisions of
this Agreement shall remain in full force and effect.

     Section 12.11. - Notices
     ------------------------

Any notice or report required or permitted hereunder shall be given in writing
by personal delivery or by registered or certified mail, return receipt
requested, postage prepaid, and, if sent by mail, shall be effective upon
delivery to the following addresses:

          ROBERTS LABORATORIES INC.
          4 Industrial Way West
          Eatontown, New Jersey 07724
          ATTN: A.A. Rascio, Vice President

          ADOLOR CORPORATION
          371 Phoenixville Pike
          Malvern, Pennsylvania 19355
          ATTN: President

or such other address as a party may designate by prior written notice to the
other party.

     Section 12.12. - Payment Method
     -------------------------------

All payments by ADOLOR to ROBERTS under this Agreement shall be by wire transfer
of same day funds to ROBERTS' bank account. ROBERTS shall supply ADOLOR with the
bank, routing and account information needed for such a wire transfer.

     Section 12.13. - Late Payments
     ------------------------------

All payments due ROBERTS under this Agreement which are received later than the
due date, shall be subject to an additional payment of one and one-half percent
(1.5%) per month or portion thereof as liquidated damages for payments received
later than the due date.
<PAGE>

     Section 12.14. - Currency
     -------------------------

All references to currency and payments shall be in U.S. dollars.

     Section 12.15. - Force Majeure
     ------------------------------

Each party hereto shall be relieved of its obligations hereunder to the extent
that fulfillment of such obligations shall be prevented by acts of war, labor
difficulties, riot, fire, flood, hurricane, wind storm, acts of defaults of
common carriers, governmental laws, act or regulations (including withdrawal or
suspension of governmental approval of sale of Product), shortages of materials
or any other occurrence beyond the control of the party affected thereby.


(Any Remainder of this page beyond this line is intentionally left blank.)
<PAGE>

IN WITNESS WHEREOF, the parties have caused this Agreement to be executed in
duplicate by their duly authorized representatives.

                                        ADOLOR CORPORATION


                                        By:  /s/ John J. Farrar
                                             -----------------------------------

                                        Title:  President and Chief Executive
                                                --------------------------------
                                                Officer
                                                -------

                                        Date:   June 8, 1998
                                                --------------------------------


                                        ROBERTS LABORATORIES INC.


                                        By:  /s/ Anthony A. Rascio
                                             -----------------------------------

                                        Title:  VP
                                                --------------------------------

                                        Date:   6/10/98
                                                --------------------------------

In order to induce Adolor Corporation to execute this Agreement, Robert
Pharmaceutical Corporation, the parent company of Robert Laboratories Inc.,
hereby unconditionally guarantees the due payment and performance of all
obligations of Roberts Laboratories Inc. contained in this Agreement.

                                        ROBERTS PHARMACEUTICAL CORPORATION


                                        By:  /s/ Anthony A. Rascio
                                             -----------------------------------

                                        Title:  VP
                                                --------------------------------

                                        Date:   6/10/98
                                                --------------------------------