<PAGE>

                                                                    EXHIBIT 4.18

                           STOCK PURCHASE AGREEMENT

Adolor Corporation
620 Pennsylvania Avenue
Exton, PA  19341

The undersigned (the "Investor"), hereby confirms its agreement with you as
follows:

1. This Stock Purchase Agreement (the "Agreement") is made as of the date set
forth below between Adolor Corporation, a Delaware corporation (the "Company"),
and the Investor.

2. The Company has authorized the sale and issuance of up to 3,000,000 shares
(the "Shares") of common stock of the Company, $.0001 par value per share (the
"Common Stock"), subject to adjustment by the Company's Board of Directors, to
certain investors in a private placement (the "Offering").

3. The Company and the Investor agree that the Investor will purchase from the
Company and the Company will issue and sell to the Investor ____________ shares,
for a purchase price of $20.00 per share, or an aggregate purchase price of
$____________________, pursuant to the Terms and Conditions for Purchase of
Shares attached hereto as Annex I and incorporated herein by this reference as
if fully set forth herein. Unless otherwise requested by the Investor,
certificates representing the Shares purchased by the Investor will be
registered in the Investor's name and address as set forth below.

4. The Investor represents that, except as set forth below, (a) it has had no
position, office or other material relationship within the past three years with
the Company or its affiliates, (b) neither it, nor any group of which it is a
member or to which it is related, beneficially owns (including the right to
acquire or vote) any securities of the Company and (c) it has no direct or
indirect affiliation or association with any NASD member. Exceptions:

________________________________________________________________________________
 (If no exceptions, write "none." If left blank, response will be deemed to be
                                   "none.")

Please confirm that the foregoing correctly sets forth the agreement between us
by signing in the space provided below for that purpose.

                                          Dated as of: ___________________, 2001

                                          ______________________________________
                                          "INVESTOR"

                                          By:___________________________________
                                          Print Name:___________________________
                                          Title:________________________________
                                          Address:______________________________
                                          ______________________________________

AGREED AND ACCEPTED:
ADOLOR CORPORATION

By:_______________________________
Title:____________________________
<PAGE>

                                    ANNEX I

                  TERMS AND CONDITIONS FOR PURCHASE OF SHARES

     1.   Authorization and Sale of the Shares. Subject to the terms and
conditions of this Agreement, the Company has authorized the sale of the Shares.

     2.   Agreement to Sell and Purchase the Shares; Subscription Date.

          2.1. At the Closing (as defined in Section 3), the Company will sell
to the Investor, and the Investor will purchase from the Company, upon the terms
and conditions hereinafter set forth, the number of Shares set forth on the
signature page to which these Terms and Conditions for Purchase of Shares are
attached as Annex I (the "Signature Page") at the purchase price set forth on
such Signature Page.

          2.2. The Company proposes to enter into this same form of Stock
Purchase Agreement with certain other investors (the "Other Investors") and
expects to complete sales of Shares to them. (The Investor and the Other
Investors are hereinafter sometimes collectively referred to as the "Investors,"
and this Agreement and the Stock Purchase Agreements executed by the Other
Investors are hereinafter sometimes collectively referred to as the
"Agreements.") The Company will, in its sole discretion, accept executed
Agreements from Investors for the purchase of Shares commencing upon the date on
which the Company provides the Investors with the proposed purchase price per
Share and concluding upon the date (the "Subscription Date") on which the
Company has received and accepted executed Agreements with Investors for the
purchase of Shares in the aggregate amount of at least $45,000,000.

     3.   Delivery of the Shares at Closing. The completion of the purchase and
sale of the Shares (the "Closing") shall occur at a place and time (the "Closing
Date") to be specified by the Company, and of which the Investors will be
notified in advance by the Company. After receipt of payment therefor, at the
Closing, the Company shall direct the transfer agent of the Company to deliver
to the Investor within three (3) business days one or more stock certificates
representing the number of Shares set forth on the signature page hereto, each
such certificate to be registered in the name of the Investor or, if so
indicated on the Stock Certificate Questionnaire attached hereto as Exhibit A,
in the name of a nominee designated by the Investor.

     The Company's obligation to issue the Shares to the Investor shall be
subject to the following conditions, any one or more of which may be waived by
the Company: (a) Investors shall have executed Agreements for the purchase of
Shares in the aggregate of at least $45,000,000 (b) receipt by the Company of
the purchase price in same day funds for the Shares being purchased hereunder as
set forth on the Signature Page hereto; (c) completion of purchases and sales
under the Agreements with the Other Investors; and (d) the accuracy of the
representations and warranties made by the Investors and the fulfillment of
those undertakings of the Investors to be fulfilled prior to the Closing.
<PAGE>

     The Investor's obligation to purchase the Shares shall be subject to the
following conditions: (a) the Investors shall have executed Agreements for the
purchase of Shares in the aggregate amount of at least $45,000,000; (b) the
accuracy of the representations and warranties made by the Company and the
fulfillment of those undertakings of the Company to be fulfilled prior to
Closing; (c) the delivery of a legal opinion pursuant to Section 6.1(c) hereof;
and (d) the delivery by the Company of an Officer's Certificate in form
reasonably satisfactory to the Investor. Subject to the immediately preceding
sentence, the Investor's obligations are expressly not conditioned on the
purchase by any or all of the other Investors of the Shares that they have
agreed to purchase from the Company.

     4.   Representations and Warranties of the Company. Except as otherwise
described in the Company's regular reports on Form 10-Q, 10-K and 8-K as filed
by the Company with the Securities and Exchange Commission in 2001 (the "SEC
Documents") and in the Company's press releases issued since March 31, 2001 and
available on the Company's web site (including the documents incorporated by
reference therein, the "Company Information"), which qualifies the following
representations and warranties in their entirety, the Company hereby represents
and warrants to the Investor, as follows:

          4.1. Organization. The Company is duly incorporated and validly
existing in good standing under the laws of the jurisdiction of its
organization. The Company has full power and authority to own, operate and
occupy its properties and to conduct its business as presently conducted and is
registered or qualified to do business and in good standing in each jurisdiction
in which it owns or leases property or transacts business and where the failure
to be so qualified would have a material adverse effect upon the business,
financial condition, properties, prospects or operations of the Company
("Material Adverse Effect"), and no proceeding has been instituted in any such
jurisdiction revoking, limiting or curtailing, or seeking to revoke, limit or
curtail, such power and authority or qualification.

          4.2. Due Authorization. The Company has all requisite power and
authority to execute, deliver and perform its obligations under the Agreements,
and the Agreements have been duly authorized and validly executed and delivered
by the Company and constitute legal, valid and binding agreements of the Company
enforceable against the Company in accordance with their terms, except as rights
to indemnity and contribution may be limited by state or federal securities laws
or the public policy underlying such laws, except as enforceability may be
limited by applicable bankruptcy, insolvency, reorganization, moratorium or
similar laws affecting creditors' and contracting parties' rights generally and
except as enforceability may be subject to general principles of equity
(regardless of whether such enforceability is considered in a proceeding in
equity or at law).

          4.3. Non-Contravention. The execution and delivery of the Agreements,
the issuance and sale of the Shares to be sold by the Company under the
Agreements, the fulfillment of the terms of the Agreements and the consummation
of the transactions contemplated thereby will not (A) conflict with or
constitute a violation of, or default (with or without the giving of notice or
the passage of time or otherwise) under, (i) any bond, debenture, note or other
evidence

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of indebtedness, or any lease, contract, indenture, mortgage, deed of trust,
loan agreement, joint venture or other agreement or instrument to which the
Company is a party or by which it or its property is bound, where such conflict,
violation or default is likely to result in a Material Adverse Effect, (ii) the
charter, by-laws or other organizational documents of the Company, or (iii) any
law, administrative regulation, ordinance or order of any court or governmental
agency, arbitration panel or authority binding upon the Company or its property,
where such conflict, violation or default is likely to result in a Material
Adverse Effect, or (B) result in the creation or imposition of any lien,
encumbrance, claim, security interest or restriction whatsoever upon any of the
material properties or assets of the Company or an acceleration of indebtedness
pursuant to any obligation, agreement or condition contained in any material
bond, debenture, note or any other evidence of indebtedness or any material
indenture, mortgage, deed of trust or any other material agreement or instrument
to which the Company is a party or by which it is bound or to which any of the
material property or assets of the Company is subject. No consent, approval,
authorization or other order of, or registration, qualification or filing with,
any regulatory body, administrative agency, self-regulatory organization, stock
exchange or market or other governmental body in the United States is required
for the execution and delivery of the Agreements and the valid issuance and sale
of the Shares to be sold pursuant to the Agreements, other than such as have
been made or obtained, and except for any other securities filings required to
be made under federal or state securities laws.

          4.4. Capitalization. The capitalization of the Company is described in
the Company's SEC Documents. The Company has not issued any capital stock since
March 31, 2001 other than certain shares issued pursuant to employee benefit
plans (the "Benefit Plans") disclosed in the Company's SEC Documents. The Shares
to be sold pursuant to the Agreements have been duly authorized, and when issued
and paid for in accordance with the terms of the Agreements, will be duly and
validly issued, fully paid and nonassessable. The outstanding shares of capital
stock of the Company have been duly and validly issued and are fully paid and
nonassessable, have been issued in compliance with all federal and state
securities laws, and were not issued in violation of any preemptive rights or
similar rights to subscribe for or purchase securities. There are no outstanding
rights (including, without limitation, preemptive rights), warrants or options
to acquire, or instruments convertible into or exchangeable for, any unissued
shares of capital stock or other equity interest in the Company, or any
contract, commitment, agreement, understanding or arrangement of any kind to
which the Company is a party and relating to the issuance or sale of any capital
stock of the Company, any such convertible or exchangeable securities or any
such rights, warrants or options, other than those issued pursuant to the
Benefit Plans and those arising under predetermined stock disposition plans put
in place under Rule 10b5-1 promulgated under the Exchange Act. Without limiting
the foregoing, no preemptive right, co-sale right, registration right, right of
first refusal or other similar right exists with respect to the issuance and
sale of the Shares. There are no stockholders agreements, voting agreements or
other similar agreements with respect to the Common Stock to which the Company
is a party.

          4.5. Legal  Proceedings.  There is no material  legal or  governmental
proceeding pending or, to the knowledge of the Company, threatened, to which the
Company is a

                                      -3-
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party or of which the business or property of the Company is subject that is not
disclosed in the Company's SEC Documents under the heading "Legal Proceedings."
There are no requests for confidential treatment of information currently
pending before the SEC. There is no investigation, inquiry or proceeding by the
SEC of or against the Company currently pending, and, to the Company's
knowledge, no such investigation, inquiry or proceeding has been threatened.

          4.6. No Violations. The Company is not in violation of its charter,
bylaws or other organizational documents, or in violation of any law,
administrative regulation, ordinance or order of any court or governmental
agency, arbitration panel or authority applicable to the Company, which
violation, individually or in the aggregate, would be reasonably likely to have
a Material Adverse Effect, and is not in default (and there exists no condition
which, with or without the passage of time or giving of notice or otherwise,
would constitute a default) in the performance of any bond, debenture, note or
any other evidence of indebtedness in any indenture, mortgage, deed of trust or
any other agreement or instrument to which the Company is a party or by which
the Company is bound or by which the property of the Company is bound, which
would be reasonably likely to have a Material Adverse Effect.

          4.7. Governmental Permits, Etc. With the exception of the matters
which are dealt with separately in Sections 4.12, and 4.13, the Company has all
necessary franchises, licenses, certificates and other authorizations from any
foreign, federal, state or local government or governmental agency, department
or body that are currently necessary for the operation of the business of the
Company as currently conducted except where the failure to currently possess
could not reasonably be expected to have a Material Adverse Effect.

          4.8. Intellectual Property.

               (a) The Company has ownership or license or legal right to use
all patent, copyright, trade secret, trademark, customer lists, designs,
manufacturing or other processes, computer software, systems, data compilation,
research results or other proprietary rights used in the business of the Company
and material to the Company (collectively, "Intellectual Property") other than
Intellectual Property generally available on commercial terms from other
sources. All of such patents, trademarks and registered copyrights owned by the
Company have been duly registered in, filed in or issued by the United States
Patent and Trademark Office, the United States Register of Copyrights or the
corresponding offices of other jurisdictions and have been maintained and
renewed in accordance with all applicable provisions of law and administrative
regulations in the United States and all such jurisdictions, except where the
failure to do so would not reasonably be expected to have a Material Adverse
Effect.

               (b) All material licenses or other material agreements under
which (i) the Company is granted rights in Intellectual Property, other than
Intellectual Property generally available on commercial terms from other
sources, and (ii) the Company has granted rights to others in Intellectual
Property owned or licensed by the Company, are, to the knowledge of the Company,
in full force and effect and, to the knowledge of the Company, there is no
material default by the Company thereto.

                                      -4-
<PAGE>

                (c) The Company believes it has taken all steps required in
accordance with sound business practice and business judgment to establish and
preserve its ownership of all material Intellectual Property.

                (d) To the knowledge of the Company, the present business,
activities and products of the Company do not infringe any intellectual property
of any other person, except where such infringement would not have a Material
Adverse Effect on the Company. Except as described in the Company's SEC
Documents, no proceeding charging the Company with infringement of any adversely
held Intellectual Property has been filed. To the knowledge of the Company, the
Company is not making unauthorized use of any confidential information or trade
secrets of any person. Neither the Company nor, to the knowledge of the Company,
any of its employees have any agreements or arrangements with any persons other
than the Company related to confidential information or trade secrets of such
persons other than such agreements that would not materially restrict the
Company from conducting its business as currently conducted.

          4.9.  Financial Statements. The financial statements of the Company
and the related notes contained in the Company's SEC Documents present fairly,
in accordance with generally accepted accounting principles, the financial
position of the Company as of the dates indicated, and the results of its
operations and cash flows for the periods therein specified. Such financial
statements (including the related notes) have been prepared in accordance with
generally accepted accounting principles applied on a consistent basis
throughout the periods therein specified, except as disclosed in the Company's
SEC Documents.

          4.10. No Material Adverse Change. Since March 31, 2001, there has not
been (i) any Material Adverse Effect in the financial condition or in the
earnings, assets or business affairs of the Company, whether or not arising in
the ordinary course of business, (ii) any obligation, direct or contingent, that
is material to the Company, incurred by the Company, except obligations incurred
in the ordinary course of business consistent with past practice, (iii) any
dividend or distribution of any kind declared, paid or made on the capital stock
of the Company, or (iv) any loss or damage (whether or not insured) to the
physical property of the Company which has been sustained which has had a
Material Adverse Effect.

          4.11. NASDAQ Compliance. The Company's Common Stock is registered
pursuant to Section 12(g) of the Securities Exchange Act of 1934, as amended
(the "Exchange Act"), and is listed on The Nasdaq National Market (the "Nasdaq
Stock Market"), and the Company has taken no action designed to, or likely to
have the effect of, terminating the registration of the Common Stock under the
Exchange Act or delisting the Common Stock from the Nasdaq Stock Market.

          4.12. Reporting Status. The Company has filed in a timely manner all
documents that the Company was required to file under the Exchange Act, during
the period during which the Company's Common Stock has been registered pursuant
to Section 12(g) of the Exchange Act. The following documents complied in all
material respects with the SEC's requirements as of their respective filing
dates, and the information contained therein as of the

                                      -5-
<PAGE>

date thereof did not contain an untrue statement of a material fact or omit to
state a material fact required to be stated therein or necessary to make the
statements therein in light of the circumstances under which they were made not
misleading:

                (a) The Company's Annual Report on Form 10-K for the year ended
December 31, 2000 (the "10-K");

                (b) The Company's  Quarterly Report on Form 10-Q for the quarter
ended March 31, 2001; and

                (c) All other documents, if any, filed by the Company with the
SEC since November 14, 2000 pursuant to the reporting requirements of the
Exchange Act.

          4.13. No Manipulation of Stock. The Company has not taken any action
outside the ordinary course of business designed to or that might reasonably be
expected to cause or result in stabilization or manipulation of the price of the
Common Stock to facilitate the sale or resale of the Shares.

          4.14. Investment Company.  The Company is not an "investment company"
or an "affiliated  person" of, or "promoter" or "principal  underwriter"  for an
investment company, within the meaning of the Investment Company Act of 1940, as
amended.

          4.15. Insurance. The Company maintains insurance of the types and in
the amounts that the Company reasonably believes is adequate for its business,
including, but not limited to, insurance covering all real and personal property
owned or leased by the Company against theft, damage, destruction, acts of
vandalism and all other risks customarily insured against by similarly situated
companies, all of which insurance is in full force and effect.

          4.16. Real Property  Holding  Corporation.  The Company is not a real
property holding corporation within the meaning of Internal Revenue Code Section
897(c)(2) and any regulations promulgated thereunder

          4.17. Environmental.  Except as would not, singly or in the aggregate,
reasonably  be  expected  to have a  material  adverse  effect on the  financial
condition or in the earnings, assets or business affairs of the Company,

                (a) the Company is in compliance with all applicable
Environmental Laws (as defined below);

                (b) the Company has all permits, authorizations and approvals
required under any applicable Environmental Laws and is in compliance with the
requirements of such permits authorizations and approvals;

                (c) there are no pending or, to the best knowledge of the
Company, threatened Environmental Claims (as defined below) against the Company;
and

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<PAGE>

                (d) under applicable law, there are no circumstances with
respect to any property or operations of the Company that are reasonably likely
to form the basis of an Environmental Claim against the Company.

     For purposes of this Agreement, the following terms shall have the
following meanings: "Environmental Law" means any United States (or other
applicable jurisdiction's) Federal, state, local or municipal statute, law,
rule, regulation, ordinance, code, policy or rule of common law and any judicial
or administrative interpretation thereof, including any judicial or
administrative order, consent decree or judgment, relating to the environment,
health, safety or any chemical, material or substance, exposure to which is
prohibited, limited or regulated by any governmental authority. "Environmental
Claims" means any and all administrative, regulatory or judicial actions, suits,
demands, demand letters, claims, liens, notices of noncompliance or violation,
investigations or proceedings relating in any way to any Environmental Law.

          4.18. Properties. The Company has good and marketable title to its
properties, free and clear of all material security interests, mortgages,
pledges, liens, charges, encumbrances and claims of record. The properties of
the Company are, in the aggregate, in good repair (reasonable wear and tear
excepted), and suitable for their respective uses. To the Company's knowledge,
any real property held under lease by the Company is held under valid,
subsisting and enforceable leases with such exceptions as are not material and
do not interfere with the conduct of the business of the Company. The Company
owns or leases all such properties as are necessary to its business or
operations as now conducted.

          4.19. Taxes. The Company has filed all material tax returns required
to be filed, which returns are true and correct in all material respects, and
the Company is not in default in the payment of any taxes, including penalties
and interest, assessments, fees and other charges, shown thereon due or
otherwise assessed, other than those being contested in good faith and for which
adequate reserves have been provided or those currently payable without interest
which were payable pursuant to said returns or any assessments with respect
thereto.

          4.20. Governmental Consents. No registration, authorization, approval,
qualification or consent of any court or governmental authority or agency is
necessary in connection with the execution and delivery of this Agreement or the
offering, issuance or sale of the Shares under this Agreement, other than any
filings required by a Purchaser under the Hart-Scott-Rodino Antitrust
Improvement Act of 1976.

     5.   Representations and Warranties of the Investor.

          5.1.  The Investor represents and warrants to the Company that: (i)
the Investor is an "accredited investor" as defined in Regulation D under the
Securities Act of 1933, as amended (the "Securities Act"), and the Investor is
also knowledgeable, sophisticated and experienced in making, and is qualified to
make decisions with respect to, investments in shares presenting an investment
decision like that involved in the purchase of the Shares, including investments
in securities issued by the Company and investments in comparable companies, and
has requested, received, reviewed and considered all information it deemed
relevant in making

                                      -7-
<PAGE>

an informed decision to purchase the Shares; (ii) the Investor is acquiring the
number of Shares set forth on the Signature Page hereto in the ordinary course
of its business and for its own account for investment only and with no present
intention of distributing any of such Shares in violation of the Securities Act
or any arrangement or understanding with any other persons regarding the
distribution of such Shares; (iii) the Investor has answered all questions on
the Signature Page hereto and the Investor Questionnaire attached hereto as
Exhibit B for use in preparation of the Registration Statement and the answers
thereto are true and correct in all material respects as of the date hereof;
(iv) the Investor has, in connection with its decision to purchase the number of
Shares set forth on the signature page hereto, relied only upon the Company
Information provided to the Investor by the Company in contemplation of this
offering, the representations and warranties of the Company contained herein and
other publicly available information; and (v) there are no suits, pending
litigation or claims against the Investor that could materially affect the net
worth of the Investor. Investor understands that its acquisition of the Shares
has not been registered under the Securities Act, or registered or qualified
under any state securities law in reliance on specific exemptions therefrom,
which exemptions may depend upon, among other things, the bona fide nature of
the Investor's investment intent as expressed herein. Investor has completed or
caused to be completed and delivered to the Company the Investor Questionnaire
attached hereto Exhibit B, which questionnaire is true and correct in all
material respects.

          5.2. The Investor acknowledges, represents and agrees that the Company
has represented that no action has been taken in any jurisdiction outside the
United States by the Company that would permit an offering of the Shares, or
possession or distribution of offering materials in connection with the issue of
the Shares, in any jurisdiction outside the United States where action for that
purpose is required.

          5.3. The Investor further represents and warrants to the Company that
(i) the Investor has full right, power, authority and capacity to enter into
this Agreement and to consummate the transactions contemplated hereby and has
taken all necessary action to authorize the execution, delivery and performance
of this Agreement, and (ii) this Agreement constitutes a valid and binding
obligation of the Investor enforceable against the Investor in accordance with
its terms, except as enforceability may be limited by applicable bankruptcy,
insolvency, reorganization, moratorium or similar laws affecting creditors' and
contracting parties' rights generally and except as enforceability may be
subject to general principles of equity (regardless of whether such
enforceability is considered in a proceeding in equity or at law) and except as
the indemnification agreements of the Investors herein may be legally
unenforceable.

          5.4. The Investor understands that nothing in this Agreement or any
other materials presented to the Investor in connection with the purchase and
sale of the Shares constitutes legal, tax or investment advice. The Investor has
consulted such legal, tax and investment advisors as it, in its sole discretion,
has deemed necessary or appropriate in connection with its purchase of Shares.

                                      -8-
<PAGE>

          5.5. The Investor acknowledges that there may occasionally be times
when the Company, based on the advice of its counsel and subject to the
limitations set forth in Section 7.2 hereof, determines that it must suspend the
use of the Prospectus forming a part of the Registration Statement until such
time as an amendment to the Registration Statement has been filed by the Company
and declared effective by the SEC or until the Company has amended or
supplemented such Prospectus. The Investor is aware that, in such event, the
Shares will not be subject to ready liquidation, and that any Shares purchased
by the Investor would have to be held during such suspension. The overall
commitment of the Investor to investments which are not readily marketable is
not excessive in view of the Investor's net worth and financial circumstances,
and any purchase of the Shares will not cause such commitment to become
excessive. The Investor is able to bear the economic risk of an investment in
the Shares.

     6.   Covenants.

          6.1. Covenants of the Company.

               (a) Transfer Taxes. On the Closing Date, all stock transfer or
other taxes (other than income taxes) which are required to be paid in
connection with the sale and transfer of the Shares to be sold to the Investor
hereunder will be, or will have been, fully paid or provided for by the Company
and all laws imposing such taxes will be or will have been fully complied with.

               (b) Insurance. The Company will continue to maintain insurance
of the types and in the amounts that the Company reasonably believes is adequate
for its business, including, but not limited to, insurance covering all real and
personal property owned or leased by the Company against theft, damage,
destruction, acts of vandalism and all other risks customarily insured against
by similarly situated companies, all of which insurance is in full force and
effect.

               (c) Legal Opinion. The Company shall cause to be delivered to
the Investors by Dechert, counsel to the Company, a customary legal opinion
substantially in such form as such counsel and the Investor may agree upon.

               (d) Listing; Requests for Confidential Treatment of Information.
The Company shall comply with all requirements of the National Association of
Securities Dealers, Inc. with respect to the issuance of the Shares and the
listing thereof on the Nasdaq National Market. Prior to the date that the
Registration Statement becomes effective, the Company will use its best efforts
to promptly file with the SEC and resolve any requests for the confidential
treatment of information.

               (e) Rule 144. The Company covenants that it will file the reports
required to be filed by it under the Securities Act and the Exchange Act and the
rules and regulations adopted by the SEC thereunder (or, if the Company is not
required to file such reports, it will, upon the request of any Investor holding
Shares purchased hereunder made after the second anniversary of the Closing
Date, make publicly available such information as

                                      -9-
<PAGE>

necessary to permit sales pursuant to Rule 144 under the Securities Act), and it
will take such further action as any such Investor may reasonably request, all
to the extent required from time to time to enable such Investor to sell Shares
purchased hereunder without registration under the Securities Act within the
limitation of the exemptions provided by (a) Rule 144 under the Securities Act,
as such Rule may be amended from time to time, or (b) any similar rule or
regulation hereafter adopted by the SEC. Upon the request of any such Investor,
the Company will deliver to such holder a written statement as to whether it has
complied with such information and requirements.

     6.2. Covenants of the Investor.

          (a)  The Investor will not, directly or indirectly, offer, sell,
pledge, transfer or otherwise dispose of (or solicit any offers to buy, purchase
or otherwise acquire or take a pledge of) any of the Shares except in compliance
with the Securities Act, applicable state securities laws and the respective
rules and regulations promulgated thereunder.

          (b)  The Investor will notify the Company promptly of any change in
any of the information pertaining to the Investor herein, on the Signature Page
hereto and the Investor Questionnaire attached hereto as Exhibit B until such
time as the Investor has sold all of its Shares or until the Company is no
longer required to keep the Registration Statement effective. Such information
will be true and correct as of the Closing Date.

          (c)  Each Investor outside the United States will comply with all
applicable laws and regulations in each foreign jurisdiction in which it
purchases, offers, sells or delivers Shares or has in its possession or
distributes any offering material, in all cases at its own expense.

          (d)  The Investor hereby covenants with the Company not to make any
sale of the Shares without complying with the provisions of this Agreement,
including Section 7.2 hereof, and without effectively causing the prospectus
delivery requirement under the Securities Act to be satisfied, if applicable,
and the Investor acknowledges that the certificates evidencing the Shares will
be imprinted with a legend that prohibits their transfer except in accordance
therewith. The Investor acknowledges that there may occasionally be times when
the Company, based on the advice of its counsel, and following consultation with
its Board of Directors and subject to the limitations set forth in Section 7.2
hereof, determines that it must suspend the use of the Prospectus forming a part
of the Registration Statement until such time as an amendment to the
Registration Statement has been filed by the Company and declared effective by
the SEC or until the Company has amended or supplemented such Prospectus.

          (e)  Investor will not, prior to the effectiveness of the Registration
Statement, directly or indirectly, sell, offer to sell, solicit offers to buy,
dispose of, loan, pledge or grant any right with respect to (collectively, a
"Disposition"), the Shares in violation of the Securities Act, nor will Investor
engage in any hedging or other transaction in violation of the Securities Act
which is designed to or could reasonably be expected to lead to or result in a
Disposition of the Shares by the Investor or any other person or entity. Such
prohibited hedging

                                      -10-
<PAGE>

or other transactions would include, without limitation, effecting any short
sale or having in effect any short position (whether or not such sale or
position is against the box and regardless of when such position was entered
into) or any purchase, sale or grant of any right (including, without
limitation, any put or call option) with respect to the Common Stock of the
Company or with respect to any security (other than a broad-based market basket
or index) that includes, relates to or derives any significant part of its value
from the Common Stock of the Company.

     7.   Registration of the Shares; Compliance with the Securities Act.

          7.1. Registration Procedures and Expenses. The Company shall:

               (a)  subject to receipt of necessary information from the
Investors, prepare and file with the SEC, as soon as practicable, but in no
event later than thirty (30) days after the Closing Date, a registration
statement on Form S-1 (or at any time after the Closing Date in the event that
the Company is able to use Form S-3, then the Company shall use its best efforts
to promptly prepare and file with the SEC a registration statement on Form S-3)
(the "Registration Statement") to enable the resale of the Shares by the
Investors from time to time through the automated quotation system of the Nasdaq
Stock Market or in privately-negotiated transactions;

               (b)  use its best efforts, subject to receipt of necessary
information from the Investors, to cause the Registration Statement to become
effective as soon as practicable, but in no event later than seventy-five (75)
days after the Registration Statement is filed by the Company;

               (c)  notify the Investor promptly upon the Registration Statement
being declared effective by the SEC;

               (d)  use its best efforts to prepare and file with the SEC such
amendments and supplements to the Registration Statement and the Prospectus used
in connection therewith and take all such other actions as may be necessary to
keep the Registration Statement current and effective for a period not
exceeding, with respect to each Investor's Shares purchased hereunder, the
earlier of (i) the second anniversary of the Closing Date, (ii) the date on
which the Investor may sell all Shares then held by the Investor without
restriction by the volume limitations of Rule 144(e) of the Securities Act or
(iii) such time as all Shares purchased by such Investor in this Offering have
been sold pursuant to a registration statement;

               (e)  furnish to the Investor with respect to the Shares
registered under the Registration Statement such number of copies of the
Registration Statement, Prospectuses and Preliminary Prospectuses in conformity
with the requirements of the Securities Act and such other documents as the
Investor may reasonably request, in order to facilitate the public sale or other
disposition of all or any of the Shares by the Investor, provided, however, that
the obligation of the Company to deliver copies of Prospectuses or Preliminary
Prospectuses to the Investor shall be subject to the receipt by the Company of
reasonable assurances from the Investor that the Investor will comply with the
applicable provisions of the Securities Act and of

                                      -11-
<PAGE>

such other securities or blue sky laws as may be applicable in connection with
any use of such Prospectuses or Preliminary Prospectuses;

               (f)  file documents required of the Company for normal blue sky
clearance in states specified in writing by the Investor, provided, however,
that the Company shall not be required to qualify to do business or consent to
service of process in any jurisdiction in which it is not now so qualified or
has not so consented;

               (g)  bear all expenses in connection with the procedures in
paragraph (a) through (f) of this Section 7.1 and the registration of the Shares
pursuant to the Registration Statement, other than fees and expenses, if any, of
counsel or other advisors to the Investors; and

               (h)  advise the Investors, promptly after it shall receive notice
or obtain knowledge of the issuance of any stop order by the SEC delaying or
suspending the effectiveness of the Registration Statement or of the initiation
of any proceeding for that purpose; and it will promptly use its best efforts to
prevent the issuance of any stop order or to obtain the withdrawal of any stop
order at the earliest possible moment if such stop order should be issued.

     It shall be a condition precedent to the obligations of the Company to take
any action pursuant to this Section 7.1 that the Investor shall furnish to the
Company such information regarding itself, the Shares to be sold by Investor,
and the intended method of disposition of such securities as shall be required
to effect the registration of the Shares.

     The Company understands that the Investor disclaims being an underwriter,
but the Investor being deemed an underwriter by the SEC shall not relieve the
Company of any obligations it has hereunder, provided, however, that if the
Company receives notification from the SEC that the Investor is deemed an
underwriter, then the period by which the Company is obligated to submit an
acceleration request to the SEC shall be extended to the earlier of (i) the
60/th/ day after such SEC notification, or (ii) 90 days after the initial filing
of the Registration Statement with the SEC.

     7.2. Transfer of Shares After Registration; Suspension.

          (a)  The Investor agrees that it will not effect any Disposition of
the Shares or its right to purchase the Shares that would constitute a sale
within the meaning of the Securities Act except as contemplated in the
Registration Statement referred to in Section 7.1 and as described below, and
that it will promptly notify the Company of any changes in the information set
forth in the Registration Statement regarding the Investor or its plan of
distribution.

          (b)  Except in the event that paragraph (c) below applies, the Company
shall: (i) if deemed necessary by the Company, prepare and file from time to
time with the SEC a post-effective amendment to the Registration Statement or a
supplement to the related Prospectus or a supplement or amendment to any
document incorporated therein by reference or file any other required document
so that such Registration Statement will not contain an untrue statement

                                      -12-
<PAGE>

of a material fact or omit to state a material fact required to be stated
therein or necessary to make the statements therein not misleading, and so that,
as thereafter delivered to purchasers of the Shares being sold thereunder, such
Prospectus will not contain an untrue statement of a material fact or omit to
state a material fact required to be stated therein or necessary to make the
statements therein, in light of the circumstances under which they were made,
not misleading; (ii) provide the Investor copies of any documents filed pursuant
to Section 7.2(b)(i); and (iii) inform each Investor that the Company has
complied with its obligations in Section 7.2(b)(i) (or that, if the Company has
filed a post-effective amendment to the Registration Statement which has not yet
been declared effective, the Company will notify the Investor to that effect,
will use its reasonable efforts to secure the effectiveness of such post-
effective amendment as promptly as possible and will promptly notify the
Investor pursuant to Section 7.2(b)(i) hereof when the amendment has become
effective).

          (c)  Subject to paragraph (d) below, in the event: (i) of any request
by the SEC or any other federal or state governmental authority during the
period of effectiveness of the Registration Statement for amendments or
supplements to a Registration Statement or related Prospectus or for additional
information; (ii) of the issuance by the SEC or any other federal or state
governmental authority of any stop order suspending the effectiveness of a
Registration Statement or the initiation of any proceedings for that purpose;
(iii) of the receipt by the Company of any notification with respect to the
suspension of the qualification or exemption from qualification of any of the
Shares for sale in any jurisdiction or the initiation of any proceeding for such
purpose; or (iv) of any event or circumstance which necessitates the making of
any changes in the Registration Statement or Prospectus, or any document
incorporated or deemed to be incorporated therein by reference, so that, in the
case of the Registration Statement, it will not contain any untrue statement of
a material fact or any omission to state a material fact required to be stated
therein or necessary to make the statements therein not misleading, and that in
the case of the Prospectus, it will not contain any untrue statement of a
material fact or any omission to state a material fact required to be stated
therein or necessary to make the statements therein, in the light of the
circumstances under which they were made, not misleading; then the Company shall
deliver a certificate in writing to the Investor (the "Suspension Notice") to
the effect of the foregoing and, upon receipt of such Suspension Notice, the
Investor will refrain from selling any Shares pursuant to the Registration
Statement (a "Suspension") until the Investor's receipt of copies of a
supplemented or amended Prospectus prepared and filed by the Company, or until
it is advised in writing by the Company that the current Prospectus may be used,
and has received copies of any additional or supplemental filings that are
incorporated or deemed incorporated by reference in any such Prospectus. In the
event of any Suspension, the Company will use its best efforts to cause the use
of the Prospectus so suspended to be resumed as soon as reasonably practicable
within 30 calendar days after delivery of a Suspension Notice to the Investors.
In addition to and without limiting any other remedies (including, without
limitation, at law or at equity) available to the Investor, the Investor shall
be entitled to specific performance in the event that the Company fails to
comply with the provisions of this Section 7.2(c).

                                      -13-
<PAGE>

          (d)  Notwithstanding the foregoing paragraphs of this Section 7.2, the
Investor shall not be prohibited from selling Shares under the Registration
Statement as a result of Suspensions on more than four occasions of not more
than 30 days each (20 days each in the case of a Registration Statement on Form
S-3) in any twelve month period.

          (e)  If a Suspension is not then in effect, the Investor may sell
Shares under the Registration Statement, provided that the Investor arranges for
delivery of a current Prospectus to the transferee of such Shares. Upon receipt
of a request therefor, the Company has agreed to provide an adequate number of
current Prospectuses to the Investor and to supply copies to any other parties
requiring such Prospectuses.

          (f)  In the event of a sale of Shares by the Investor, the Investor
shall deliver to the Company's transfer agent, with a copy to the Company, a
Certificate of Subsequent Sale substantially in the form attached hereto as
Exhibit C, so that the shares may be properly transferred.

     7.3. Indemnification. For the purpose of this Section 7.3:

          (a)  the term "Selling Stockholder" shall include the Investor and any
officer, director, trustee or affiliate of such Investor, and "affiliate" shall
mean any person who controls the Investor within the meaning of Section 15 of
the Securities Act;

          (b)  the term "Registration Statement" shall include any final
Prospectus, exhibit, supplement or amendment included in or relating to the
Registration Statement referred to in Section 7.1; and

          (c)  the term "untrue statement" shall include any untrue statement or
alleged untrue statement, or any omission or alleged omission to state in the
Registration Statement a material fact required to be stated therein or
necessary to make the statements therein, in the light of the circumstances
under which they were made, not misleading.

               (i)  The Company agrees to indemnify and hold harmless each
Selling Stockholder from and against any losses, claims, damages or liabilities
to which such Selling Stockholder may become subject (under the Securities Act
or otherwise) insofar as such losses, claims, damages or liabilities (or actions
or proceedings in respect thereof) arise out of, or are based upon (i) any
untrue statement of a material fact contained in the Registration Statement, or
(ii) any failure by the Company to fulfill any undertaking included in the
Registration Statement, and the Company will promptly reimburse such Selling
Stockholder for any reasonable legal or other expenses reasonably incurred in
investigating, defending or preparing to defend any such action, proceeding or
claim; provided, however, that the Company shall not be liable in any such case
to the extent that such loss, claim, damage or liability arises solely out of,
or is based solely upon, an untrue statement made in such Registration Statement
in reliance upon and in conformity with written information furnished to the
Company by or on behalf of such Selling Stockholder specifically for use in
preparation of the Registration Statement or the failure of such Selling
Stockholder to comply with its covenants and agreements

                                      -14-
<PAGE>

contained in Sections 5.1, 5.2, 5.3 or 7.2(a) hereof or any statement or
omission in any Prospectus that is corrected in any subsequent Prospectus that
was delivered to the Investor at least two business days prior to the pertinent
sale or sales by the Investor; and provided further, however, that the Company
shall not be liable in any such case to the extent that such loss, claim, damage
or liability arises out of, or is based upon, the failure of such Selling
Stockholder to deliver any Prospectus in connection with a sale of the Shares as
required by the prospectus delivery requirement under the Securities Act.

               (ii)  The Investor agrees to (severally and not jointly with any
other Investor) indemnify and hold harmless the Company (and each person, if
any, who controls the Company within the meaning of Section 15 of the Securities
Act, each officer of the Company who signs the Registration Statement and each
director of the Company) from and against any losses, claims, damages or
liabilities to which the Company (or any such officer, director or controlling
person) may become subject (under the Securities Act or otherwise), insofar as
such losses, claims, damages or liabilities (or actions or proceedings in
respect thereof) arise solely out of, or are solely based upon, (i) any failure
to comply with the covenants and agreements contained in Section 5.1, 5.2, 5.3
or 7.2 hereof, or (ii) any untrue statement of a material fact contained in the
Registration Statement if such untrue statement was made in reliance upon and in
conformity with written information furnished by or on behalf of the Investor
specifically for use in preparation of the Registration Statement; provided,
                                                                   --------
however, that the Investor shall not be liable for any such untrue or alleged
-------
untrue statement or omission or alleged omission of which the Investor has
delivered to the Company in writing a correction before the occurrence of the
transaction from which such loss was incurred, and the Investor will reimburse
the Company (or such officer, director or controlling person), as the case may
be, for any legal or other expenses reasonably incurred in investigating,
defending or preparing to defend any such action, proceeding or claim; and
provided further that the aggregate liability of the Investor under this Section
-------- -------
shall not exceed an amount equal to the net amount received by the Investor from
the sale of the Shares unless such liability is the result of willful misconduct
on the part of the Investor.

               (iii) Promptly after receipt by any indemnified person of a
notice of a claim or the beginning of any action in respect of which indemnity
is to be sought against an indemnifying person pursuant to this Section 7.3,
such indemnified person shall notify the indemnifying person in writing of such
claim or of the commencement of such action, but the omission to so notify the
indemnifying party will not relieve it from any liability which it may have to
any indemnified party under this Section 7.3 (except to the extent that such
omission materially and adversely affects the indemnifying party's ability to
defend such action) or from any liability otherwise than under this Section 7.3.
Subject to the provisions hereinafter stated, in case any such action shall be
brought against an indemnified person, the indemnifying person shall be entitled
to participate therein, and, to the extent that it shall elect by written notice
delivered to the indemnified party promptly after receiving the aforesaid notice
from such indemnified party, shall be entitled to assume the defense thereof,
with counsel reasonably satisfactory to such indemnified person. After notice
from the indemnifying person to such indemnified person of its election to
assume the defense thereof, such indemnifying person shall

                                      -15-
<PAGE>

not be liable to such indemnified person for any legal expenses subsequently
incurred by such indemnified person in connection with the defense thereof,
provided, however, that if there exists or shall exist a conflict of interest
that would make it inappropriate, in the reasonable opinion of counsel to the
indemnified person, for the same counsel to represent both the indemnified
person and such indemnifying person or any affiliate or associate thereof, the
indemnified person shall be entitled to retain its own counsel at the expense of
such indemnifying person; provided, however, that no indemnifying person shall
be responsible for the fees and expenses of more than one separate counsel
(together with appropriate local counsel) for all indemnified parties. In no
event shall any indemnifying person be liable in respect of any amounts paid in
settlement of any action unless the indemnifying person shall have approved the
terms of such settlement; provided that such consent shall not be unreasonably
withheld. No indemnifying person shall, without the prior written consent of the
indemnified person, effect any settlement of any pending or threatened
proceeding in respect of which any indemnified person is or could have been a
party and indemnification could have been sought hereunder by such indemnified
person, unless such settlement includes an unconditional release of such
indemnified person from all liability on claims that are the subject matter of
such proceeding.

               (iv)  If the indemnification provided for in this Section 7.3 is
unavailable to or insufficient to hold harmless an indemnified party under
subsection (i) or (ii) above in respect of any losses, claims, damages or
liabilities (or actions or proceedings in respect thereof) referred to therein,
then each indemnifying party shall contribute to the amount paid or payable by
such indemnified party as a result of such losses, claims, damages or
liabilities (or actions in respect thereof) in such proportion as is appropriate
to reflect the relative fault of the Company on the one hand and the Investors
on the other in connection with the statements or omissions or other matters
which resulted in such losses, claims, damages or liabilities (or actions in
respect thereof), as well as any other relevant equitable considerations. The
relative fault shall be determined by reference to, among other things, in the
case of an untrue statement, whether the untrue statement relates to information
supplied by the Company on the one hand or an Investor on the other and the
parties' relative intent, knowledge, access to information and opportunity to
correct or prevent such untrue statement. The Company and the Investors agree
that it would not be just and equitable if contribution pursuant to this
subsection (iv) were determined by pro rata allocation (even if the Investors
were treated as one entity for such purpose) or by any other method of
allocation which does not take into account the equitable considerations
referred to above in this subsection (iv). The amount paid or payable by an
indemnified party as a result of the losses, claims, damages or liabilities (or
actions in respect thereof) referred to above in this subsection (iv) shall be
deemed to include any legal or other expenses reasonably incurred by such
indemnified party in connection with investigating or defending any such action
or claim. Notwithstanding the provisions of this subsection (iv), no Investor
shall be required to contribute any amount in excess of the amount by which the
net amount received by the Investor from the sale of the Shares to which such
loss relates exceeds the amount of any damages which such Investor has otherwise
been required to pay by reason of such untrue statement. No person guilty of
fraudulent misrepresentation (within the meaning of Section 11(f) of the
Securities Act) shall be entitled to contribution from any person who was not
guilty of such fraudulent misrepresentation. The Investors' obligations in this
subsection to

                                      -16-
<PAGE>

contribute are several in proportion to their sales of Shares to which such loss
relates and not joint.

                    (v)  The parties to this Agreement hereby acknowledge that
they are sophisticated business persons who were represented by counsel during
the negotiations regarding the provisions hereof including, without limitation,
the provisions of this Section 7.3, and are fully informed regarding said
provisions.

          7.4. Termination of Conditions and Obligations. The conditions
precedent imposed by Sections 5, 6.2 or this Section 7 upon the transferability
of the Shares shall cease and terminate as to any particular number of the
Shares when such Shares shall have been effectively registered under the
Securities Act and sold or otherwise disposed of in accordance with the intended
method of disposition set forth in the Registration Statement covering such
Shares or at such time as an opinion of counsel reasonably satisfactory to the
Company shall have been rendered to the effect that such conditions are not
necessary in order to comply with the Securities Act. No such opinion of counsel
shall be required in connection with transfers pursuant to Rule 144 promulgated
under the Securities Act except in unusual circumstances.

          7.5. Information Available. So long as the Registration Statement is
effective covering the resale of Shares owned by the Investor, the Company will
furnish to the Investor:

               (a)  as soon as practicable after it is available, one copy of
(i) its Annual Report to Stockholders (which Annual Report shall contain
financial statements audited in accordance with generally accepted accounting
principles by a national firm of certified public accountants) and (ii) if not
included in substance in the Annual Report to Stockholders, its Annual Report on
Form 10-K (the foregoing, in each case, excluding exhibits);

               (b)  upon the reasonable request of the Investor, all exhibits
excluded by the parenthetical to subparagraph (a)(ii) of this Section 7.5 as
filed with the SEC and all other information that is made available to
shareholders; and

               (c)  upon the reasonable request of the Investor, an adequate
number of copies of the Prospectuses to supply to any other party requiring such
Prospectuses; and the Company, upon the reasonable request of the Investor, will
meet with the Investor or a representative thereof at the Company's headquarters
to discuss all information relevant for disclosure in the Registration Statement
covering the Shares and will otherwise cooperate with any Investor conducting an
investigation for the purpose of reducing or eliminating such Investor's
exposure to liability under the Securities Act, including the reasonable
production of information at the Company's headquarters; provided, that the
Company shall not be required to disclose any confidential information to or
meet at its headquarters with any Investor until and unless the Investor shall
have entered into a confidentiality agreement in form and substance reasonably
satisfactory to the Company with the Company with respect thereto.

     8.   Notices. All notices, requests, consents and other communications
hereunder shall be in writing, shall be mailed (A) if within the domestic United
States by first-class

                                      -17-
<PAGE>

registered or certified airmail, or nationally recognized overnight express
courier, postage prepaid, or by facsimile, or (B) if delivered from outside the
United States, by International Federal Express or facsimile, and shall be
deemed given (i) if delivered by first-class registered or certified mail
domestic, three (3) business days after so mailed, (ii) if delivered by
nationally recognized overnight carrier, one (1) business day after so mailed,
(iii) if delivered by International Federal Express, two (2) business days after
so mailed, (iv) if delivered by facsimile, upon electric confirmation of receipt
and shall be delivered as addressed as follows:

               (a)   if to the Company, to:

                     Adolor Corporation
                     620 Pennsylvania Avenue
                     Exton, PA 19341

                     Attn: Chief Financial Officer
                     Phone: 484.595.1500
                     Telecopy: 484.595.1520

               (b)   with a copy mailed to:

                     Dechert
                     1717 Arch Street
                     4000 Bell Atlantic Tower
                     Philadelphia, PA 19103

                     Attn: James A. Lebovitz, Esq.
                     Phone: 215.994.4000
                     Telecopy: 215.994.2222

               (c)   if to the Investor, at its address on the Signature Page
hereto, or at such other address or addresses as may have been furnished to the
Company in writing.

     9.   Changes. This Agreement may not be modified or amended except pursuant
to an instrument in writing signed by the Company and the Investor.

     10.  Headings. The headings of the various sections of this Agreement have
been inserted for convenience of reference only and shall not be deemed to be
part of this Agreement.

     11.  Severability. In case any provision contained in this Agreement should
be invalid, illegal or unenforceable in any respect, the validity, legality and
enforceability of the remaining provisions contained herein shall not in any way
be affected or impaired thereby.

     12.  Governing Law. This Agreement shall be governed by, and construed in
accordance with, the internal laws of the State of Delaware, without giving
effect to the principles of conflicts of law.

                                      -18-
<PAGE>

     13.  Succession and Assignment. This Agreement shall be binding upon and
inure to the benefit of the parties named herein and their respective successors
and permitted assigns. This Agreement and the rights and obligations hereunder
shall not be assignable or transferable by the Company or the Investor without
the prior written consent of the other party hereto, which consent shall not be
unreasonably withheld; provided, however, that the Investor may, upon written
                       --------   -------
notice to the Company, assign all of its rights, interests and obligations
hereunder to an affiliate of the Investor prior to the date that the
Registration Statement becomes effective in the event that such assignment is
not in violation of the Securities Act.

     14.  Counterparts. This Agreement may be executed in two or more
counterparts, each of which shall constitute an original, but all of which, when
taken together, shall constitute but one instrument, and shall become effective
when one or more counterparts have been signed by each party hereto and
delivered to the other parties.

     15.  Confidential Disclosure Agreement. Notwithstanding any provision of
this Agreement to the contrary, any confidential disclosure agreement previously
executed by the Company and the Investor in connection with the transactions
contemplated by this Agreement shall remain in full force and effect in
accordance with its terms following the execution of this Agreement and the
consummation of the transactions contemplated hereby.

                                      -19-
<PAGE>

                                   Exhibit A

                              ADOLOR CORPORATION

                        STOCK CERTIFICATE QUESTIONNAIRE


     Pursuant to Sections 5 and 6 of the Agreement, please provide us with the
following information:


1.  The exact name that your Shares are to be registered
    in (this is the name that will appear on your stock
    certificate(s)). You may use a nominee name if
    appropriate:                                           _____________________

2.  The relationship between the Investor and the
    registered holder listed in response to item 1 above:  _____________________

3.  The mailing address of the registered holder listed
    in response to item 1 above:                           _____________________

4.  The Social Security Number or Tax Identification
    Number of the registered holder listed in the
    response to item 1 above:                              _____________________


                                      A-1
<PAGE>

                                   Exhibit B

                              ADOLOR CORPORATION

                            INVESTOR QUESTIONNAIRE

               (all information will be treated confidentially)

To: Adolor Corporation

     This Investor Questionnaire ("Questionnaire") must be completed by each
potential investor in connection with the offer and sale of the shares of the
common stock, par value $.0001 per share, of Adolor Corporation (the
"Securities"). The Securities are being offered and sold by Adolor Corporation
(the "Corporation") without registration under the Securities Act of 1933, as
amended (the "Act"), and the securities laws of certain states, in reliance on
the exemptions contained in Section 4(2) of the Act and on Regulation D
promulgated thereunder and in reliance on similar exemptions under applicable
state laws. The Corporation must determine that a potential investor meets
certain suitability requirements before offering or selling Securities to such
investor. The purpose of this Questionnaire is to assure the Corporation that
each investor will meet the applicable suitability requirements. The information
supplied by you will be used in determining whether you meet such criteria, and
reliance upon the private offering exemption from registration is based in part
on the information herein supplied.

     This Questionnaire does not constitute an offer to sell or a solicitation
of an offer to buy any security. Your answers will be kept strictly
confidential. However, by signing this Questionnaire you will be authorizing the
Corporation to provide a completed copy of this Questionnaire to such parties as
the Corporation deems appropriate in order to ensure that the offer and sale of
the Securities will not result in a violation of the Act or the securities laws
of any state and that you otherwise satisfy the suitability standards applicable
to purchasers of the Securities. All potential investors must answer all
applicable questions and complete, date and sign this Questionnaire. Please
print or type your responses and attach additional sheets of paper if necessary
to complete your answers to any item.

Background Information

<TABLE>
<S>                                            <C>                                          <C>
Name:______________________________________________________________________________________________________________

Business Address:__________________________________________________________________________________________________
                                                (Number and Street)

___________________________________________________________________________________________________________________
(City)                                          (State)                                     (Zip Code)

Telephone Number:  (         )_____________________________________________________________________________________

Residence Address:_________________________________________________________________________________________________
                                                (Number and Street)

___________________________________________________________________________________________________________________
(City)                                          (State)                                     (Zip Code)

Telephone Number:  (         )_____________________________________________________________________________________

If an individual:

Age:______                 Citizenship:__________             Where registered to vote:____________________________

If a corporation, partnership, limited liability company, trust or other entity:

Type of entity:____________________________________________________________________________________________________
</TABLE>

                                      B-1

<PAGE>

<TABLE>
<S>                                                               <C>
State of formation:______________                                 Date of formation:______________________________

Social Security or Taxpayer Identification No.____________________________________________________________________

Send all correspondence to (check one):  ____ Residence Address                              ____ Business Address
</TABLE>

IN WITNESS WHEREOF, the undersigned has executed this Questionnaire this _____
day of _____________, 2001, and declares under oath that it is truthful and
correct.


                                Print Name

                                By:_____________________________________________
                                Signature

                                Title:__________________________________________
                                       (required for any purchaser that is a
                                       corporation, partnership, trust or other
                                       entity)

                                      B-2
<PAGE>

                                   Exhibit C

                              ADOLOR CORPORATION

                        CERTIFICATE OF SUBSEQUENT SALE

StockTrans, Inc.

     RE:  Sale of Shares of Common Stock of Adolor Corporation (the "Company")
          pursuant to the Company's Prospectus dated _______________, 2001 (the
          "Prospectus")

Dear Sir/Madam:

     The undersigned hereby certifies, in connection with the sale of shares of
Common Stock of the Company included in the table of Selling Shareholders in the
Prospectus, that the undersigned has sold the Shares pursuant to the Prospectus
and in a manner described under the caption "Plan of Distribution" in the
Prospectus and that such sale complies with all applicable securities laws,
including, without limitation, the Prospectus delivery requirements of the
Securities Act of 1933, as amended.

     Selling Shareholder (the beneficial owner):________________________________

     Record Holder (e.g., if held in name of nominee):__________________________

     Restricted Stock Certificate No.(s):_______________________________________

     Number of Shares Sold:_____________________________________________________

     Date of Sale:______________________________________________________________

     In the event that you receive a stock certificate(s) representing more
shares of Common Stock than have been sold by the undersigned, then you should
return to the undersigned a newly issued certificate for such excess shares in
the name of the Record Holder and BEARING A RESTRICTIVE LEGEND. Further, you
should place a stop transfer on your records with regard to such certificate.

                                           Very truly yours,

                                           By: _________________________________

                                           Print Name:__________________________

                                           Title:_______________________________


Dated:_______________________________

cc:    Investor Relations
       Adolor Corporation
       620 Pennsylvania Avenue
       Exton, PA 19341

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