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                                                                    Exhibit 10.1


                                7,350,000 SHARES

                                 SANTARUS, INC.

                             SHARES OF COMMON STOCK
                               ($0.0001 PAR VALUE)

                            PLACEMENT AGENT AGREEMENT

                                                                 August 16, 2005


SG COWEN & CO., LLC
RBC CAPITAL MARKETS CORPORATION
c/o SG Cowen & Co., LLC
1221 Avenue of the Americas
New York, New York 10020

Dear Sirs:

         Santarus, Inc., a Delaware corporation (the "COMPANY"), proposes to
sell to the Purchasers, pursuant to the terms of this Placement Agent Agreement
(this "AGREEMENT") and the Subscription Agreements in the form of Exhibit A
attached hereto (the "SUBSCRIPTION AGREEMENTS") entered into with the Purchasers
identified therein (each a "PURCHASER" and, collectively, the "PURCHASERS"), an
aggregate of 7,350,000 shares of Common Stock, $0.0001 par value (the "COMMON
STOCK"), of the Company. The aggregate of 7,350,000 shares of Common Stock so
proposed to be sold is hereinafter referred to as the "STOCK." The Company
hereby confirms its agreement with the placement agents named on Schedule I
attached hereto (the "PLACEMENT AGENTS"), as set forth below. SG Cowen & Co.,
LLC is acting as the representative of the Placement Agents and in such capacity
is hereinafter referred to as the "REPRESENTATIVE." Certain terms used herein
are defined in Section 13 hereof.

1. AGREEMENT TO ACT AS PLACEMENT AGENTS; PLACEMENT OF SECURITIES. On the basis
of the representations, warranties and agreements of the Company herein
contained, and subject to all the terms and conditions of this Agreement:

         (a) The Company hereby authorizes the Placement Agents to act as its
         exclusive agents to solicit offers for the purchase of all or part of
         the Stock from the Company in connection with the proposed offering of
         the Stock (the "OFFERING"). Until the Closing Date (as defined in
         Section 3 hereof), the Company shall not, without the prior consent of
         the Representative, solicit or accept offers to purchase the Stock
         otherwise than through the Placement Agents.
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         (b) The Placement Agents agree, as agents of the Company, to use their
         reasonable best efforts to solicit offers to purchase the Stock from
         the Company on the terms and subject to the conditions set forth in the
         Base Prospectus (as defined below) and the Prospectus Supplement (as
         defined below). The Placement Agents shall make commercially reasonable
         efforts to assist the Company in obtaining performance by each
         Purchaser whose offer to purchase Stock has been solicited by the
         Placement Agents and accepted by the Company, but the Placement Agents
         shall not, except as otherwise provided in this Agreement, be obligated
         to disclose the identity of any potential purchaser or have any
         liability to the Company in the event any such purchase is not
         consummated for any reason. Under no circumstances will the Placement
         Agents be obligated to purchase any Stock for their own account and, in
         soliciting purchases of Stock, the Placement Agents shall act solely as
         the Company's agents and not as principals. Notwithstanding the
         foregoing and except as otherwise provided in Section 1(c), it is
         understood and agreed that the Placement Agents (or their affiliates)
         may, solely at their discretion and without any obligation to do so,
         purchase Stock as principals; provided, however, that any such offers
         to purchase by the Placement Agents (or their affiliates) shall be
         fully disclosed to the Company (including the identity of the
         Purchaser) and accepted by the Company in accordance with Section 1(c)
         below.

         (c) Subject to the provisions of this Section 1, offers for the
         purchase of Stock may be solicited by the Placement Agents as agents
         for the Company at such times and in such amounts as the Placement
         Agents deem advisable. Each Placement Agent shall communicate to the
         Company, orally or in writing, each reasonable offer to purchase Stock
         received by it as agent of the Company. The Company shall have the sole
         right to accept offers to purchase the Stock and may reject any such
         offer, in whole or in part. Each Placement Agent shall have the right,
         in its discretion reasonably exercised, subject to providing reasonable
         prior notice to the Company, to reject any offer to purchase Stock
         received by it, in whole or in part, and any such rejection shall not
         be deemed a breach of its agreement contained herein.

         (d) The purchases of the Stock by the Purchasers shall be evidenced by
         the execution of the Subscription Agreements by each of the parties
         thereto.

         (e) As compensation for services rendered, on the Closing Date the
         Company shall pay to the Placement Agents by wire transfer of
         immediately available funds to an account or accounts designated by the
         Representative, an amount equal to six percent (6.0%) of the gross
         proceeds received by the Company from the sale of the Stock on such
         Closing Date.

         (f) No Stock which the Company has agreed to sell pursuant to this
         Agreement shall be deemed to have been purchased and paid for, or sold
         by the Company, until such Stock shall have been delivered to the
         Purchaser thereof against payment by such Purchaser. If the Company
         shall default in its obligations to deliver Stock to a Purchaser whose
         offer it has accepted and who has delivered the requisite payment for
         the Stock, the Company shall indemnify and hold the Placement Agent
         harmless against any loss, claim or damage arising from or as a result
         of such default by the Company.


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2. REPRESENTATIONS AND WARRANTIES OF THE COMPANY. The Company represents and
warrants to, and agrees with, the several Placement Agents and, as provided in
the Subscription Agreements, the Purchasers that:

         (a) The Company meets the requirements for use of Form S-3 under the
         Securities Act of 1933, as amended (the "SECURITIES ACT"), and has
         filed with the Securities and Exchange Commission (the "COMMISSION") a
         registration statement on such form (Registration File No. 333-124830),
         which became effective as of June 16, 2005, for the registration under
         the Securities Act of the Stock and certain other securities as
         described therein. Such registration statement meets the requirements
         set forth in Rule 415(a)(1)(x) under the Securities Act and complies
         with said Rule. The Company will file with the Commission pursuant to
         Rule 424(b) under the Securities Act, and the rules and regulations
         (the "RULES AND REGULATIONS") of the Commission promulgated thereunder,
         a supplement to the form of prospectus included in such registration
         statement relating to the placement of the Stock and the plan of
         distribution thereof and has advised the Representative of all further
         information (financial and other) with respect to the Company required
         to be set forth therein. Such registration statement, including the
         exhibits thereto, as amended at the date of this Agreement, is
         hereinafter called the "REGISTRATION STATEMENT;" such prospectus in the
         form in which it appears in the Registration Statement is hereinafter
         called the "BASE PROSPECTUS;" and the supplemented form of prospectus,
         in the form in which it will be filed with the Commission pursuant to
         Rule 424(b) (including the Base Prospectus as so supplemented) is
         hereinafter called the "PROSPECTUS SUPPLEMENT." Any reference herein to
         the Registration Statement, the Base Prospectus or the Prospectus
         Supplement shall be deemed to refer to and include the documents
         incorporated by reference therein (the "INCORPORATED DOCUMENTS")
         pursuant to Item 12 of Form S-3 which were filed under the Securities
         Exchange Act of 1934, as amended (the "EXCHANGE ACT"), on or before the
         date of this Agreement, or the issue date of the Base Prospectus or the
         Prospectus Supplement, as the case may be; and any reference herein to
         the terms "amend," "amendment" or "supplement" with respect to the
         Registration Statement, the Base Prospectus or the Prospectus
         Supplement shall be deemed to refer to and include the filing of any
         document under the Exchange Act after the date of this Agreement, or
         the issue date of the Base Prospectus or the Prospectus Supplement, as
         the case may be, deemed to be incorporated therein by reference. All
         references in this Agreement to financial statements and schedules and
         other information which is "contained," "included," "described," "set
         forth" or "stated" in the Registration Statement, the Base Prospectus
         or the Prospectus Supplement (and all other references of like import)
         shall be deemed to mean and include all such financial statements and
         schedules and other information which is or is deemed to be
         incorporated by reference in the Registration Statement, the Base
         Prospectus or the Prospectus Supplement, as the case may be. No stop
         order suspending the effectiveness of the Registration Statement or the
         use of the Base Prospectus or the Prospectus Supplement has been
         issued, and no proceeding for any such purpose is pending or, to the
         best of the Company's knowledge, has been initiated or threatened by
         the Commission.


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         (b) The Registration Statement (and any further documents to be filed
         with the Commission) contains all exhibits and schedules as required by
         the Securities Act. Each of the Registration Statement and any
         post-effective amendment thereto, at the time it became effective,
         complied in all material respects with the Securities Act and the
         Exchange Act and the applicable Rules and Regulations and did not and,
         as amended or supplemented, if applicable, will not, contain any 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 not
         misleading. The Base Prospectus and the Prospectus Supplement, each as
         of its respective date, comply in all material respects with the
         Securities Act and the Exchange Act and the applicable Rules and
         Regulations. Each of the Base Prospectus and the Prospectus Supplement,
         as amended or supplemented, did not and will not contain as of the date
         thereof any untrue statement of a material fact or omit to state a
         material fact necessary in order to make the statements therein, in
         light of the circumstances under which they were made, not misleading.
         The Incorporated Documents, when they were filed with the Commission,
         conformed in all material respects to the requirements of the Exchange
         Act and the applicable Rules and Regulations, and none of such
         documents, when they were filed with the Commission, contained any
         untrue statement of a material fact or omitted to state a material fact
         necessary to make the statements therein not misleading; and any
         further documents so filed and incorporated by reference in the Base
         Prospectus or Prospectus Supplement, when such documents are filed with
         the Commission, will conform in all material respects to the
         requirements of the Exchange Act and the applicable Rules and
         Regulations, as applicable, and will not contain any untrue statement
         of a material fact or omit to state a material fact necessary to make
         the statements therein not misleading. Notwithstanding the foregoing,
         the Company makes no representations or warranties as to information,
         if any, contained in or omitted from the Prospectus Supplement or any
         amendment thereof or supplement thereto in reliance upon and in
         conformity with information furnished in writing to the Company by or
         on behalf of any Placement Agent specifically for use in the
         Registration Statement or the Prospectus Supplement, which information
         the parties hereto agree is limited to the Placement Agents'
         Information as defined in Section 15. No post-effective amendment to
         the Registration Statement reflecting any facts or events arising after
         the date thereof which represent, individually or in the aggregate, a
         fundamental change in the information set forth therein is required to
         be filed with the Commission. There are no documents required to be
         filed with the Commission in connection with the transaction
         contemplated hereby that (x) have not been filed as required pursuant
         to the Securities Act or (y) will not be filed within the requisite
         time period. There are no contracts or other documents required to be
         described in the Base Prospectus or Prospectus Supplement, or to be
         filed as exhibits or schedules to the Registration Statement, which
         have not been described or filed as required.

         (c) The Company has delivered, or will as promptly as practicable
         deliver, to the Representative complete conformed copies of the
         Registration Statement and of each consent and certificate of experts
         filed as a part thereof, and conformed copies of the Registration
         Statement (without exhibits) and the Base Prospectus and the Prospectus
         Supplement, as amended or supplemented, in such quantities and at such
         places as the Representative reasonably requests. Neither the Company
         nor any of its directors and


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         officers has distributed and none of them will distribute, prior to the
         completion of the distribution of Stock, any offering material in
         connection with the offering and sale of the Stock other than the Base
         Prospectus, the Prospectus Supplement, the Registration Statement,
         copies of the documents incorporated by reference therein and any other
         materials permitted by the Securities Act.

         (d) The Company has been duly incorporated and is validly existing as a
         corporation under the laws of the State of Delaware, is duly qualified
         to do business and is in good standing (or the equivalent thereof, if
         any) as a foreign corporation in each jurisdiction in which its
         ownership or lease of property or the conduct of its business requires
         such qualification, and has all power and authority necessary to own or
         hold its properties and to conduct the businesses in which it is
         engaged, except where the failure to be so qualified and in good
         standing or have such power or authority would not have, singularly or
         in the aggregate, a material adverse effect on the condition (financial
         or otherwise), results of operations, business, properties or prospects
         of the Company taken as a whole (a "MATERIAL ADVERSE EFFECT").

         (e) The Stock to be issued and sold by the Company hereunder and under
         the Subscription Agreements has been duly and validly authorized and,
         when issued and delivered against payment therefor as provided herein
         and therein, will be duly and validly issued, fully paid and
         nonassessable and free of any preemptive or similar rights. The Stock
         conforms to the description thereof contained in, or incorporated by
         reference in, the Base Prospectus and the Prospectus Supplement.

         (f) The Company has an authorized capitalization as set forth in, or
         incorporated by reference in, the Base Prospectus and the Prospectus
         Supplement; all of the issued and outstanding shares of capital stock
         of the Company have been duly and validly authorized and issued, are
         fully paid and non-assessable, have been issued in compliance with
         federal and state securities laws, and conform to the description
         thereof contained in, or incorporated by reference in, the Base
         Prospectus and the Prospectus Supplement. None of the outstanding
         shares of Common Stock was issued in violation of any preemptive
         rights, rights of first refusal or other similar rights to subscribe
         for or purchase securities of the Company, other than such rights that
         have been waived. Other than options granted by the Company in the
         ordinary course of business since June 30, 2005, there are no
         authorized or outstanding options, warrants, preemptive rights, rights
         of first refusal or other rights to purchase, or equity or debt
         securities convertible into or exchangeable or exercisable for, any
         capital stock of the Company that have been granted by the Company
         other than those accurately described in, or incorporated by reference
         in, the Base Prospectus and the Prospectus Supplement.

         (g) The Company has the full right, power and authority to enter into
         this Agreement and each of the Subscription Agreements and to perform
         and to discharge its obligations hereunder and thereunder; and each of
         this Agreement and each of the Subscription Agreements has been duly
         authorized, executed and delivered by the Company, and constitutes a
         valid and binding obligation of the Company enforceable in accordance
         with its terms, except as limited by applicable bankruptcy, insolvency,
         reorganization, moratorium or similar laws affecting creditors' and
         contracting parties' rights generally


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         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 Company herein may be legally unenforceable.

         (h) The execution, delivery and performance of this Agreement and the
         Subscription Agreements by the Company and the consummation of the
         transactions contemplated hereby and thereby will not conflict with or
         result in a breach or violation of any of the terms or provisions of,
         or constitute a default under, any indenture, mortgage, deed of trust,
         loan agreement or other agreement or instrument to which the Company is
         a party or by which the Company is bound or to which any of the
         property or assets of the Company is subject, except any such
         conflicts, breaches or violations which would not reasonably be
         expected to have a Material Adverse Effect, nor will such actions
         result in any violation of the provisions of the charter or by-laws of
         the Company or any statute, law, rule or regulation or any judgment,
         order or decree of any court or governmental agency or body having
         jurisdiction over the Company or any of its properties or assets.

         (i) There is no franchise, contract, lease, instrument or other
         document of a character required by the Securities Act or the Rules and
         Regulations to be described in the Base Prospectus and the Prospectus
         Supplement, or to be filed as an exhibit to the Registration Statement,
         which is not described or filed as required, including, but not limited
         to, exhibit filings with the Incorporated Documents; and all statements
         summarizing any such franchises, contracts, leases, instruments or
         other documents or legal matters contained in the Registration
         Statement are accurate and complete in all material respects. Other
         than as described in, or incorporated by reference in, the Base
         Prospectus and the Prospectus Supplement, no such franchise, contract,
         lease, instrument or other document has been suspended or terminated
         for convenience or default by the Company or any of the other parties
         thereto, the Company has not sent or received any communication
         regarding intent not to renew any such franchise, contract, lease,
         instrument or other document, and the Company has not received notice
         or any other knowledge of any such pending or threatened suspension,
         termination or non-renewal, except for such pending or threatened
         suspensions, terminations or non-renewals that would not reasonably be
         expected to, singularly or in the aggregate, have a Material Adverse
         Effect.

         (j) The Company possesses all licenses, certificates, authorizations
         and permits issued by, and has made all declarations and filings with,
         the appropriate state, federal or foreign regulatory agencies or bodies
         which are necessary or desirable for the ownership of its properties or
         the conduct of its business as described in the Base Prospectus and the
         Prospectus Supplement (including those that may be required by the U.S.
         Food and Drug Administration (the "FDA") and any state, federal or
         foreign agencies or bodies engaged in the regulation of
         pharmaceuticals) except where any failures to possess or make the same,
         singularly or in the aggregate, would not have a Material Adverse
         Effect, and the Company has not received notification of any revocation
         or modification of any such license, authorization or permit and has no
         reason to believe that any such license, certificate, authorization or
         permit will not be renewed.


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         (k) The minute books of the Company have been made available to the
         Placement Agents and counsel for the Placement Agents, and such books
         (i) contain a complete summary of all meetings and actions of the board
         of directors (including each board committee) and stockholders of the
         Company since the time of its incorporation through the date of the
         latest meeting and action, subject to formal approval by the board or
         applicable board committee of minutes marked as "drafts," and (ii)
         accurately in all material respects reflect all transactions referred
         to in such minutes.

         (l) No consent, approval, authorization, filing with or order of or
         registration with, any court or governmental agency or body is required
         in connection with the transactions contemplated herein or in the
         Subscription Agreements, except such as (i) have been obtained or made
         under the Securities Act or the Exchange Act, (ii) may be required from
         the National Association of Securities Dealers and the Nasdaq National
         Market in connection with the purchase and sale of the Stock, and (iii)
         may be required under the securities, or blue sky, laws of any
         jurisdiction in connection with the offer and sale of the Stock by the
         Company in the manner contemplated herein and in the Base Prospectus
         and the Prospectus Supplement.

         (m) Except as provided herein, no person has the right to act as an
         underwriter, placement agent or financial advisor to the Company in
         connection with and as a result of the offer and sale of the Shares,
         whether as a result of the filing or effectiveness of the Registration
         Statement or the sale of the Shares as contemplated thereby or
         otherwise; except as described in, or incorporated by reference in, the
         Base Prospectus and the Prospectus Supplement, no person has the right,
         contractual or otherwise, to cause the Company to register under the
         Securities Act any shares of Common Stock or shares of any other
         capital stock or other securities of the Company, or to include any
         such shares or interests in the Registration Statement or the offering
         contemplated thereby, whether as a result of the filing or
         effectiveness of the Registration Statement or the sale of the Stock as
         contemplated hereby or otherwise, except for persons and entities who
         have expressly waived such right or had such right waived on their
         behalf or who have been given timely and proper notice and have failed
         to exercise such right within the time or times required under the
         terms and conditions of such right, and the Company is not required to
         file any registration statement for the registration of any securities
         of any person or register any such securities pursuant to any other
         registration statement filed by the Company under the Securities Act
         for a period of at least 90 days after the date hereof, subject to the
         determination of the Board of Directors of the Company set forth in
         Sections 2.2(c) and 2.4(d) of that certain Amended and Restated
         Investors' Rights Agreement, dated as of April 30, 2003, as amended.

         (n) The financial statements, together with the related notes and
         schedules, of the Company included in the Base Prospectus, the
         Prospectus Supplement or the Registration Statement, or incorporated by
         reference therein, as the case may be, fairly present the financial
         condition and results of operations of the Company as of the dates and
         for the periods indicated, comply in all material respects with the
         Securities Act and the Rules and Regulations thereunder, and have been
         prepared in accordance with generally accepted accounting principles
         applied on a consistent basis throughout the periods involved except as
         may be set forth in the Base Prospectus, the Prospectus Supplement or
         the Registration Statement; provided, however, that statements that are
         unaudited are


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         subject to year-end adjustments and do not contain footnotes required
         under generally accepted accounting principles. No other financial
         statements or supporting schedules or exhibits are required by the
         Securities Act or the Rules and Regulations thereunder to be included
         in the Base Prospectus, the Prospectus Supplement or the Registration
         Statement, or incorporated by reference therein, as the case may be.

         (o) Except as set forth in, or incorporated by reference in, the Base
         Prospectus and the Prospectus Supplement, there is no legal or
         governmental proceeding pending to which the Company is a party or of
         which any property or assets of the Company is the subject which
         singularly or in the aggregate, if determined adversely to the Company,
         might have a Material Adverse Effect or would prevent or adversely
         affect the ability of the Company to perform its obligations under this
         Agreement; and to the best of the Company's knowledge, no such
         proceedings are threatened or contemplated by governmental authorities
         or threatened by others.

         (p) Except as described in, or incorporated by reference in, the Base
         Prospectus and the Prospectus Supplement, the Company has good and
         marketable title in fee simple to, or have valid rights to lease or
         otherwise use, all items of real or personal property which are
         material to its business, in each case free and clear of all liens,
         encumbrances, claims and defects that may result in a Material Adverse
         Effect.

         (q) The Company is not (i) in violation of its charter or bylaws, (ii)
         in default in any respect, and no event has occurred which, with notice
         or lapse of time or both, would constitute such a default, in the due
         performance or observance of any term, covenant, or condition of any
         indenture, contract, lease, mortgage, deed of trust, note agreement,
         loan agreement or other agreement, obligation, condition, covenant or
         instrument to which it is a party or by which it is bound or to which
         any of its property or assets is subject, or (iii) in violation in any
         respect of any law, ordinance, governmental rule, regulation, or court
         decree to which it or its properties or assets may be subject, except
         any violations or defaults which, singularly or in the aggregate, would
         not have a Material Adverse Effect.

         (r) No labor disturbance by the employees of the Company exists or, to
         the best of the Company's knowledge, is imminent, which might be
         expected to have a Material Adverse Effect. The Company is not aware
         that any key employee or significant group of employees of the Company
         plans to terminate employment with the Company, which might be expected
         to have a Material Adverse Effect.

         (s) No "prohibited transaction" (as defined in Section 406 of the
         Employee Retirement Income Security Act of 1974, as amended, including
         the regulations and published interpretations thereunder ("ERISA"), or
         Section 4975 of the Internal Revenue Code of 1986, as amended from time
         to time (the "CODE")) or "accumulated funding deficiency" (as defined
         in Section 302 of ERISA) or any of the events set forth in Section
         4043(b) of ERISA (other than events with respect to which the 30-day
         notice requirement under Section 4043 of ERISA has been waived) has
         occurred with respect to any employee benefit plan which could have a
         Material Adverse Effect; each employee benefit plan is in compliance in
         all material respects with applicable law, including ERISA and the
         Code; the Company has not incurred and does not expect to incur
         liability


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         under Title IV of ERISA with respect to the termination of, or
         withdrawal from, any "pension plan"; and each "pension plan" (as
         defined in ERISA) for which the Company would have any liability that
         is intended to be qualified under Section 401(a) of the Code is so
         qualified in all material respects and nothing has occurred, whether by
         action or by failure to act, which could cause the loss of such
         qualification.

         (t) The Company carries, or is covered by, insurance in such amounts
         and covering such risks as is adequate for the conduct of its business
         and the value of its properties and as is customary for companies
         engaged in similar businesses in similar industries.

         (u) There is no pending or threatened action, suit, claim or proceeding
         which may cause any such Permit to be limited, revoked, cancelled,
         suspended, modified or not renewed and the Company has not received any
         notice of proceedings relating to the limitation, revocation,
         cancellation, suspension, modification or non-renewal of any such
         Permit which, singularly or in the aggregate, if the subject of an
         unfavorable decision, ruling or finding, would have a Material Adverse
         Effect, whether or not arising from transactions in the ordinary course
         of business, except as set forth in or contemplated by the Base
         Prospectus or the Prospectus Supplement.

         (v) Ernst & Young LLP, who have expressed their opinions on certain
         audited financial statements of the Company included in the Base
         Prospectus, the Prospectus Supplement or the Registration Statement, or
         incorporated by reference therein, as the case may be, are independent
         registered public accountants with respect to the Company within the
         meaning of the Securities Act and the Rules and Regulations.

         (v) The Company (i) has filed all necessary federal, state and foreign
         income and franchise tax returns, except where the failure to do so
         would not have a Material Adverse Effect, (ii) has paid all federal,
         state, local and foreign taxes due and payable for which it is liable,
         except to the extent such taxes are being contested in good faith, and
         (iii) does not have any tax deficiency or claims outstanding or
         assessed or, to the best of the Company's knowledge, proposed against
         it which could reasonably be expected to have a Material Adverse
         Effect.

         (w) The principal executive officer and principal financial officer of
         the Company have made all certifications required by the Sarbanes-Oxley
         Act of 2002 and the rules and regulations promulgated in connection
         therewith (the "SARBANES-OXLEY ACT"), and the statements contained in
         any such certification are complete and correct. The Company maintains
         "disclosure controls and procedures" (as defined in Rule 13a-14(c)
         under the Exchange Act), and such controls and procedures are
         reasonably designed to ensure that information required to be disclosed
         by the Company in the reports that it files or submits under the
         Exchange Act is (i) recorded, processed, summarized and reported,
         within the time periods specified in the Commission's rules and forms
         and (ii) accumulated and communicated to the Company's management,
         including its principal executive officer and principal financial
         officer, as appropriate to allow timely decisions regarding required
         disclosure. The Company does not have any material weaknesses in
         internal controls, and there has been no reported fraud, whether or not
         material, that involves management or other employees who have a
         significant role in the Company's


                                       9
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         internal controls. The Company is otherwise in compliance in all
         respects with all applicable effective provisions of the Sarbanes-Oxley
         Act and the rules and regulations promulgated by the Commission (and
         intends to comply with all applicable provisions that are not yet
         effective upon effectiveness).

         (x) The Company maintains a system of internal accounting controls
         sufficient to provide reasonable assurance that (i) transactions are
         executed in accordance with management's general or specific
         authorizations; (ii) transactions are recorded as necessary to permit
         preparation of financial statements in conformity with generally
         accepted accounting principles and to maintain accountability of
         assets; (iii) access to assets is permitted only in accordance with
         management's general or specific authorization; and (iv) the recorded
         accountability for assets is compared with the existing assets at
         reasonable intervals and appropriate action is taken with respect to
         any differences.

         (y) There has been no storage, generation, transportation, handling,
         treatment, disposal, discharge, emission, or other release of any kind
         of toxic or other wastes or other hazardous substances by, due to, or
         caused by the Company (or, to the best of the Company's knowledge, any
         other entity for whose acts or omissions the Company is or may be
         liable) upon any of the property now or previously owned or leased by
         the Company, or upon any other property, in violation of any statute or
         any ordinance, rule, regulation, order, judgment, decree or permit or
         which would, under any statute or any ordinance, rule (including rule
         of common law), regulation, order, judgment, decree or permit, give
         rise to any liability, except for any violation or liability which
         would not have, singularly or in the aggregate with all such violations
         and liabilities, a Material Adverse Effect; there has been no disposal,
         discharge, emission or other release of any kind onto such property or
         into the environment surrounding such property of any toxic or other
         wastes or other hazardous substances with respect to which the Company
         has knowledge, except for any such disposal, discharge, emission or
         other release of any kind which would not have, singularly or in the
         aggregate with all such discharges and other releases, a Material
         Adverse Effect.

         (z) The Company owns or possesses the right to use all patents,
         trademarks, trademark registrations, service marks, service mark
         registrations, trade names, copyrights, licenses, inventions, trade
         secrets and rights described in the Prospectus as being owned by it for
         the conduct of its business as now conducted and as proposed to be
         conducted or otherwise necessary or used in connection with the
         commercialization of the Company's existing marketed product and the
         Company's products specifically described in the Base Prospectus and
         the Prospectus Supplement as being under development (collectively, the
         "COMPANY INTELLECTUAL PROPERTY"), and, except as described in, or
         incorporated by reference in, the Base Prospectus and the Prospectus
         Supplement, the Company is not aware of any claim to the contrary or
         any challenge by any other person to the rights of the Company with
         respect to the foregoing. To the best of the Company's knowledge, none
         of the patents owned or licensed by the Company is unenforceable or
         invalid, and none of the patent applications owned or licensed by the
         Company would be unenforceable or invalid if issued as patents. The
         Company is not obligated to pay a royalty, grant a license or provide
         other consideration to any third


                                       10
<PAGE>
         person in connection with the Company Intellectual Property other than
         as described in, or incorporated by reference in, the Base Prospectus
         and the Prospectus Supplement. To the best of the Company's knowledge,
         the Company's business as now conducted and as proposed to be conducted
         does not and will not infringe or conflict with any valid intellectual
         property or franchise right, including patents, trademarks, service
         marks, trade names, copyrights, trade secrets or licenses of any
         person, except as described in the Prospectus or as would not have a
         Material Adverse Effect. Except as described in the Prospectus and for
         claims relating to trademarks that are not material to the business of
         the Company, no written claim has been made against the Company
         alleging the infringement by the Company of any patent, trademark,
         service mark, trade name, copyright, trade secret, license in or other
         intellectual property right or franchise right of any person.

         (aa) The studies, tests and preclinical and clinical trials conducted
         by or on behalf of the Company that are described or referred to in the
         Base Prospectus or Prospectus Supplement were and, if still pending,
         are being conducted in material compliance with applicable regulatory
         requirements. The descriptions of the results of such studies, tests
         and trials contained or referred to in the Base Prospectus or
         Prospectus Supplement are accurate and complete in all material
         respects. The Company is not aware of any studies, tests or trials the
         results of which the Company believes reasonably call into question in
         any material respect the clinical trial results described or referred
         to in the Base Prospectus or Prospectus Supplement when viewed in the
         context in which such results are described and the clinical state of
         development. The Company has not received any notices or correspondence
         from the FDA or any foreign, state or local governmental body
         exercising comparable authority requiring the termination, suspension
         or material modification of any studies, tests or preclinical or
         clinical trials conducted by or on behalf of the Company. For the
         avoidance of doubt, the Company makes no representation or warranty
         that the results of any studies, tests or preclinical or clinical
         trials conducted by or on behalf of the Company will be sufficient to
         obtain governmental approval from the FDA or any foreign, state or
         local governmental body exercising comparable authority.

         (bb) The Company does not own any "margin securities" as that term is
         defined in Regulation U of the Board of Governors of the Federal
         Reserve System (the "FEDERAL RESERVE BOARD"), and none of the proceeds
         of the sale of the Stock will be used, directly or indirectly, for the
         purpose of purchasing or carrying any margin security, for the purpose
         of reducing or retiring any indebtedness which was originally incurred
         to purchase or carry any margin security or for any other purpose which
         might cause any of the Securities to be considered a "purpose credit"
         within the meanings of Regulation T, U or X of the Federal Reserve
         Board.

         (cc) No relationship, direct or indirect, exists between or among the
         Company on the one hand and the directors, officers, stockholders,
         customers or suppliers of the Company on the other hand which is
         required to be described in, or incorporated by reference in, the Base
         Prospectus and the Prospectus Supplement and which is not so described.


                                       11
<PAGE>
         (dd) The Company is not and, after giving effect to the offering and
         sale of the Stock and the application of the proceeds thereof as
         described in the Base Prospectus and the Prospectus Supplement, will
         not become an "INVESTMENT COMPANY" as defined in the Investment Company
         Act of 1940, as amended.

         (ee) No forward-looking statement (within the meaning of Section 27A of
         the Securities Act and Section 21E of the Exchange Act) contained in
         the Base Prospectus and the Prospectus Supplement has been made or
         reaffirmed without a reasonable basis or has been disclosed other than
         in good faith.

         (ff) Other than as contemplated by this Agreement, the Company is not a
         party to any contract, agreement or understanding with any person that
         would give rise to a valid claim against the Company or the Placement
         Agents for a brokerage commission, finder's fee or like payment in
         connection with the offering and sale of the Stock.

         (gg) The Company has not sustained, since the date of the latest
         audited financial statements included in the Base Prospectus, the
         Prospectus Supplement or the Registration Statement, or incorporated by
         reference therein, as the case may be, any material loss or
         interference with its business from fire, explosion, flood, terrorist
         act or other calamity, whether or not covered by insurance, or from any
         labor dispute or court or governmental action, order or decree,
         otherwise than as set forth in or contemplated by the Base Prospectus
         and the Prospectus Supplement; and, since such date, there has not been
         any change in the capital stock or long-term debt of the Company or any
         material adverse change, or any development involving a prospective
         material adverse change, in or affecting the business, general affairs,
         management, financial position, stockholders' equity or results of
         operations of the Company, otherwise than as set forth or contemplated
         in the Base Prospectus Prospectus and the Prospectus Supplement or the
         issuance of shares of Common Stock upon exercise of stock options and
         warrants disclosed as outstanding in, or incorporated by reference in,
         the Registration Statement, the Base Prospectus and the Prospectus
         Supplement and the grant of options under existing stock option plans
         described in, or incorporated by reference in, the Registration
         Statement, the Base Prospectus and the Prospectus Supplement.

         (hh) Except as set forth in, incorporated by reference in, or as
         otherwise contemplated by, the Registration Statement, the Base
         Prospectus or the Prospectus Supplement, subsequent to the respective
         dates as of which information is given in the Registration Statement,
         the Base Prospectus and the Prospectus Supplement, there has not been
         (i) any material adverse change, or any development that would
         reasonably be expected to result in a material adverse change, in the
         business, properties, management, financial condition or results of
         operations of the Company taken as a whole, (ii) any transaction which
         is material to the Company taken as a whole, (iii) any obligation,
         direct or contingent (including any off-balance sheet obligations),
         incurred by the Company outside the ordinary course of business, which
         is material to the Company taken as a whole, (iv) any change in the
         capital stock (other than the issuance of shares of Common Stock upon
         exercise of stock options and warrants disclosed as outstanding in, or
         incorporated by reference in, the Registration Statement, the Base
         Prospectus and the Prospectus Supplement and the grant of options under
         existing stock option plans described in, or


                                       12
<PAGE>
         incorporated by reference in, the Registration Statement, the Base
         Prospectus and the Prospectus Supplement) or outstanding indebtedness
         of the Company or (v) any dividend or distribution of any kind
         declared, paid or made on the capital stock of the Company.

         (ii) Any statistical and market-related data included in the
         Registration Statement, the Base Prospectus or the Prospectus
         Supplement are based on or derived from sources that the Company
         believes to be reliable and accurate, and the Company has obtained the
         written consent or otherwise has the right to the use of such data from
         such sources to the extent required.

         (jj) The Stock is registered under the Exchange Act and is duly listed
         and admitted and authorized for trading, subject to official notice of
         issuance, on the Nasdaq National Market ("NASDAQ") and the Company has
         taken no action designed to terminate, or likely to have the effect of
         terminating the registration of the Common Stock under the Exchange Act
         or delisting or suspending from trading the Common Stock from Nasdaq,
         nor, except as described in the Registration Statement, Base Prospectus
         and Prospectus Supplement, has the Company received any information
         suggesting that the Commission or the National Association of
         Securities Dealers, Inc. ("NASD") is contemplating terminating or
         suspending such registration or listing.

         (kk) Neither the Company nor any of its officers, directors or
         affiliates has taken or will take, directly or indirectly, any action
         designed or intended to stabilize or manipulate the price of any
         security of the Company, or which caused or resulted in, or which might
         in the future reasonably be expected to cause or result in,
         stabilization or manipulation of the price of any security of the
         Company.

         (ll) To the best of the Company's knowledge, there are no affiliations
         with the NASD among the Company's officers, directors or any five
         percent or greater stockholder of the Company, except as set forth in
         the Base Prospectus, the Prospectus Supplement or the Registration
         Statement or otherwise disclosed in writing to the Representative.

         (mm) There are no outstanding loans, advances (except normal advances
         for business expense in the ordinary course of business) or guarantees
         of indebtedness by the Company to or for the benefit of any of the
         officers or directors of the Company, except as disclosed in the Base
         Prospectus, the Prospectus Supplement or the Registration Statement.

         (nn) There are no transactions, arrangements or other relationships
         between and/or among the Company, any of its affiliates (as such term
         is defined in Rule 405 of the Securities Act) and any unconsolidated
         entity, including, but not limited to, any structured finance, special
         purpose or limited purpose entity that could reasonably be expected to
         materially affect the Company's liquidity or the availability of or
         requirements for its capital resources required to be described in the
         Prospectus which have not been described as required.


                                       13
<PAGE>
         (oo) The Company is and will be in compliance with all applicable
         corporate governance requirements set forth in the Nasdaq National
         Marketplace Rules that are currently in effect and is actively taking
         steps to ensure that it will be in compliance with other applicable
         corporate governance requirements set forth in the Nasdaq National
         Marketplace Rules not currently in effect upon and all times after the
         effectiveness of such requirements.

         (pp) No approval of the stockholders of the Company under the rules and
         regulations of any trading market is required for the Company to issue
         and deliver to the Purchasers the Stock on the terms set forth in the
         Prospectus Supplement, including such as may be required pursuant to
         Rule 4350 of the Nasdaq National Marketplace Rules.

         Any certificate signed by any officer of the Company and delivered to
the Placement Agents or counsel for the Placement Agents in connection with the
offering of the Stock shall be deemed a representation and warranty by the
Company, as to the matters covered thereby, to the Placement Agents and the
Purchasers.

3. THE CLOSING. The time and date of closing and delivery of the documents
required to be delivered to the Placement Agent pursuant to Section 6 hereof
shall be at 10:00 A.M., local time, on August 22, 2005 (the "CLOSING DATE") at
the offices of Latham & Watkins LLP located at 12636 High Bluff Drive, Suite
400, San Diego, CA 92130.

4. Further Agreements of the Company. The Company agrees with the Placement
Agents:

         (a) (i) to make no further amendment or supplement prior to the Closing
         Date to the Registration Statement or any amendment or supplement to
         the Prospectus Supplement, without the prior written consent of the
         Placement Agent, which consent shall not be unreasonably withheld; (ii)
         for so long as the delivery of a prospectus is required in connection
         with the offering or sale of the Stock, to advise the Representative
         promptly after it receives notice thereof, of the time when any
         amendment to the Registration Statement has been filed or becomes
         effective or any supplement to the Prospectus Supplement or any amended
         Prospectus Supplement has been filed and to furnish the Representative
         with copies thereof; (iii) to file all reports and any definitive proxy
         or information statements required to be filed by the Company with the
         Commission and Nasdaq pursuant to Section 13(a), 15 or 15(d) of the
         Exchange Act subsequent to the date of the Prospectus Supplement and
         for so long as the delivery of a prospectus is required in connection
         with the offering or sale of the Stock; (iv) to advise the
         Representative, promptly after it receives notices thereof, (x) of any
         request by the Commission to amend the Registration Statement or to
         amend or supplement the Prospectus Supplement or for additional
         information and (y) of the issuance by the Commission, of any stop
         order suspending the effectiveness of the Registration Statement or any
         post-effective amendment thereto or any order directed at any
         Incorporated Document or any amendment or supplement thereto or any
         order preventing or suspending the use of the Base Prospectus or the
         Prospectus Supplement or any amendment or supplement thereto, of the
         suspension of the qualification of the Stock for offering or sale in
         any jurisdiction, of the institution or threatening of any proceeding
         for any such purpose, or of any request by the Commission for the
         amending or supplementing of the Registration Statement or Prospectus
         Supplement or for additional information; and, (v) in the event of the
         issuance


                                       14
<PAGE>
         of any stop order or of any order preventing or suspending the use of
         the Base Prospectus or Prospectus Supplement or suspending any such
         qualification, promptly to use its reasonable best efforts to obtain
         the withdrawal of such order.

         (b) To comply with the Securities Act and the Exchange Act, and the
         Rules and Regulations thereunder, so as to permit the completion of the
         distribution of the Stock as contemplated in this Agreement and the
         Prospectus Supplement. If during the period in which a prospectus is
         required by law to be delivered by a Placement Agent or a dealer in
         connection with the distribution of Stock contemplated by the
         Prospectus Supplement, any event shall occur as a result of which, in
         the judgment of the Company or in the reasonable opinion of the
         Placement Agents or counsel for the Placement Agents, it becomes
         necessary to amend or supplement the Prospectus Supplement in order to
         make the statements therein, in the light of the circumstances existing
         at the time the Prospectus Supplement is delivered to a purchaser, not
         misleading, or, if it is necessary at any time to amend or supplement
         the Prospectus Supplement to comply with any law, the Company promptly
         will prepare and file with the Commission, and furnish at its own
         expense to the Representative and to dealers, an appropriate amendment
         to the Registration Statement or supplement to the Prospectus
         Supplement so that the Prospectus Supplement as so amended or
         supplemented will not, in the light of the circumstances when it is so
         delivered, be misleading, or so that the Prospectus Supplement will
         comply with such law. Before amending the Registration Statement or
         supplementing the Base Prospectus in connection with the Offering, the
         Company will furnish the Representative with a copy of such proposed
         amendment or supplement and will not file such amendment or supplement
         to which the Representative reasonably objects.

         (c) To furnish promptly to the Representative and to counsel for the
         Placement Agents a copy of the Registration Statement as originally
         filed with the Commission, and each amendment thereto filed with the
         Commission, including all consents and exhibits filed therewith.

         (d) To deliver promptly to the Representative such number of the
         following documents as the Representative shall reasonably request: (i)
         conformed copies of the Registration Statement as originally filed with
         the Commission and each amendment thereto (in each case excluding
         exhibits), (ii) the Base Prospectus, (iii) the Prospectus Supplement
         (not later than 10:00 A.M., New York time, on the Business Day
         following the execution and delivery of this Agreement) and any
         amendment or supplement thereto (not later than 10:00 A.M., New York
         City time, on the Business Day following the date of such amendment or
         supplement); and (iv) any document incorporated by reference in the
         Base Prospectus or Prospectus Supplement. The Company will pay the
         expenses of printing or other production of all documents relating to
         the Offering.

         (e) To make generally available to its stockholders and the
         Representative as soon as practicable, but in any event not later than
         eighteen months after the effective date of the Registration Statement
         (as defined in Rule 158(c) under the Securities Act), an earnings
         statement of the Company (which need not be audited) complying with
         Section 11(a) of the Securities Act and the Rules and Regulations
         (including, at the option of the Company, Rule 158).


                                       15
<PAGE>
         (f) To promptly take from time to time such actions as the
         Representative may reasonably request to qualify the Stock for offering
         and sale under the securities, or blue sky, laws of such jurisdictions
         (including without limitation any post-filing requirements) as the
         Representative may designate and to continue such qualifications in
         effect for so long as required for the distribution of the Stock, and
         the Company will pay the fee of the NASD in connection with its review
         of the Offering, if applicable. The Company shall not be obligated to
         qualify as a foreign corporation in any jurisdiction in which it is not
         so qualified or to file a general consent to service of process in any
         jurisdiction.

         (g) Not to directly or indirectly offer, sell, assign, transfer,
         pledge, contract to sell, or otherwise dispose of any shares of Common
         Stock or securities convertible into or exercisable or exchangeable for
         Common Stock for a period of 90 days from the date of the Prospectus
         Supplement without the prior written consent of the Representative,
         other than the Company's sale of the Stock hereunder and the issuance
         of shares of Common Stock or securities convertible into or exercisable
         or exchangeable for Common Stock pursuant to (i) employee benefit
         plans, qualified stock option plans or other employee compensation
         plans existing on the date hereof or described in, or incorporated by
         reference in, the Base Prospectus or the Prospectus Supplement, (ii)
         currently outstanding options, warrants or rights, (iii) a joint
         venture, collaboration, co-promotion, lending or similar arrangement,
         or in connection with the acquisition or license by the Company of any
         business, products or technologies or (iv) a strategic partnership,
         joint venture, collaboration or similar arrangement for the purposes of
         developing, promoting, marketing or distributing the Company's current
         product candidates (which product candidates are described in the Base
         Prospectus or the Prospectus Supplement); provided, however, that, if
         (1) during the period that begins on the date that is 15 calendar days
         plus 3 business days before the last day of the 90-day restricted
         period and ends on the last day of the 90-day restricted period, the
         Company issues a earnings release or material news or a material event
         relating to the Company occurs or (2) prior to the expiration of the
         90-day restricted period, the Company announces that it will release
         earnings results during the 16-day period beginning on the last day of
         the 90-day period, the restrictions imposed by this section shall
         continue to apply until the expiration of the date that is 15 calendar
         days plus 3 business days after the date on which the issuance of the
         earnings release or the material news or material event occurs. The
         Company will cause each of its executive officers and directors to
         furnish to the Placement Agents, prior to the Closing Date, a letter,
         substantially in the form of Exhibit B attached hereto, pursuant to
         which each such person shall agree not to directly or indirectly offer,
         sell, assign, transfer, pledge, contract to sell, or otherwise dispose
         of any shares of Common Stock or securities convertible into or
         exercisable or exchangeable for Common Stock for a period of 90 days
         from the date of the Prospectus Supplement, without the prior written
         consent of Representative.

         (h) Prior to the Closing Date, not to issue any press release or other
         communication directly or indirectly or hold any press conference with
         respect to the Company, its condition, financial or otherwise, or
         earnings, business affairs or business prospects (except for routine
         oral marketing communications in the ordinary course of business and
         consistent with the past practices of the Company and of which the
         Representative is


                                       16
<PAGE>
         notified), without the prior written consent of the Representative,
         unless in the judgment of the Company and its counsel, and after
         notification to the Representative, such press release or communication
         is required by law.

         (i) To apply the net proceeds from the sale of the Stock as set forth
         in the Prospectus Supplement under the heading "USE OF PROCEEDS."

         (j) To comply in all material respects with all applicable securities
         and other applicable laws, rules and regulations, including, without
         limitation, the Sarbanes-Oxley Act, and use its best efforts to cause
         the Company's directors and officers, in their capacities as such, to
         comply with such laws, rules and regulations, including, without
         limitation, the provisions of the Sarbanes-Oxley Act.

         (k) To engage and maintain, at its expense, a registrar and transfer
         agent for the Stock.

         (l) To not take any action prior to the Closing Date which would
         require the Prospectus Supplement to be amended or supplemented
         pursuant to Section 4(b).

         (m) To supply the Representative with copies of all correspondence to
         and from, and all documents issued to and by, the Commission in
         connection with the registration of the Stock under the Securities Act.

         (n) The Company will use its best efforts to ensure that the Stock is
         quoted on the Nasdaq National Market at the Closing Date.

5. Payment of Expenses. The Company agrees with the Placement Agents to pay (a)
the costs incident to the authorization, issuance, sale, preparation and
delivery of the Stock to the Purchasers and any taxes payable in that
connection; (b) the costs incident to the Registration of the Stock under the
Securities Act; (c) the costs incident to the preparation, printing and
distribution of the Registration Statement, Base Prospectus and Prospectus
Supplement and any amendments and exhibits thereto or any document incorporated
by reference therein, and the costs of printing, reproducing and distributing,
this Agreement by mail, telex or other means of communication; (d) the fees and
expenses (including related fees and expenses of counsel for the Placement
Agents) incurred in connection with filings, if any, made with the NASD, if
applicable, not to exceed $10,000; (e) any applicable Nasdaq National Market
listing or other similar fees; (f) the fees and expenses of qualifying the Stock
under the securities laws of the several jurisdictions as provided in Section
4(f) and of preparing, printing and distributing Blue Sky Memoranda (including
related fees and expenses of counsel to the Placement Agents, not to exceed
$10,000); (g) all fees and expenses of the registrar and transfer agent of the
Stock; and (h) all other costs and expenses incident to the Company's
performance of its obligations under this Agreement (including, without
limitation, the fees and expenses of the Company's counsel and the Company's
independent accountants and the travel and other expenses incurred by Company
personnel in connection with any "roadshow" including, without limitation, any
expenses advanced by the Placement Agents on the Company's behalf (which will be
promptly reimbursed)); provided that, except as otherwise provided in this
Section 5 and in Sections 7 and 9, the Placement Agents shall pay their own
costs and expenses.


                                       17
<PAGE>
6. CONDITIONS TO THE OBLIGATIONS OF THE PLACEMENT AGENTS AND THE PURCHASERS, AND
THE SALE OF THE STOCK. The respective obligations of the Placement Agents and
the Purchasers, and the closing of the sale of the Stock hereunder are subject
to the accuracy, when made and on the Closing Date, of the representations and
warranties on the part of the Company contained herein, to the accuracy of the
statements of the Company made in any certificates pursuant to the provisions
hereof, to the performance by the Company of their obligations hereunder, and to
each of the following additional terms and conditions:

         (a) No stop order suspending the effectiveness of the Registration
         Statement shall have been issued and no proceedings for that purpose
         shall have been initiated or threatened by the Commission, and any
         request for additional information on the part of the Commission (to be
         included in the Registration Statement, the Base Prospectus or the
         Prospectus Supplement or otherwise) shall have been complied with to
         the reasonable satisfaction of the Representative. Any filings required
         to be made by the Company in accordance with Section 4(a) shall have
         been timely filed with the Commission.

         (b) None of the Placement Agents shall have discovered and disclosed to
         the Company on or prior to the Closing Date that the Registration
         Statement, the Base Prospectus or the Prospectus Supplement or any
         amendment or supplement thereto contains an untrue statement of a fact
         which, in the opinion of counsel for the Placement Agents, is material
         or omits to state any fact which, in the opinion of such counsel, is
         material and is required to be stated therein or is necessary to make
         the statements therein not misleading.

         (c) All corporate proceedings and other legal matters incident to the
         authorization, form, execution, delivery and validity of each of this
         Agreement, the Stock, the Registration Statement, the Base Prospectus
         and the Prospectus Supplement and all other legal matters relating to
         this Agreement and the transactions contemplated hereby shall be
         reasonably satisfactory in all material respects to counsel for the
         Placement Agents, and the Company shall have furnished to such counsel
         all documents and information that they may reasonably request to
         enable them to pass upon such matters.

         (d) Latham & Watkins LLP shall have furnished to the Placement Agent
         such counsel's (i) written opinion, as counsel to the Company,
         addressed to the Placement Agents and dated as of the Closing Date, in
         substantially the form attached hereto as Exhibit C-1, and (ii) written
         statement, as counsel to the Company, addressed to the Underwriters and
         as of the Closing Date, in substantially the form attached hereto as
         Exhibit C-2.

         (e) Wilson Sonsini Goodrich & Rosati, a Professional Corporation, shall
         have furnished to the Placement Agents such counsel's written opinion,
         as special patent counsel to the Company, addressed to the Placement
         Agents and dated as of the Closing Date, in substantially the form
         attached hereto as Exhibit C-3.

         (f) The Placement Agents shall have received from Brown Raysman
         Millstein Felder & Steiner LLP, such opinion or opinions, dated the
         Closing Date and addressed to the Placement Agents, with respect to the
         issuance and sale of the Stock, the Registration


                                       18
<PAGE>
         Statement, the Base Prospectus, the Prospectus Supplement (together
         with any supplement thereto) and other related matters as the
         Representative may reasonably require, and the Company shall have
         furnished to such counsel such documents as they request for the
         purpose of enabling them to pass upon such matters.

         (g) The Company shall have furnished to the Placement Agents and the
         Purchasers a certificate, dated as of the Closing Date, executed by its
         Chief Executive Officer and its Chief Financial Officer stating that
         (i) such officers have carefully examined the Registration Statement,
         the Base Prospectus and the Prospectus Supplement and, in their
         opinion, the Registration Statement (including the Base Prospectus) as
         of its effective date and the Prospectus Supplement, as of each such
         effective date, did not include any untrue statement of a material fact
         and did not omit to state a material fact required to be stated therein
         or necessary to make the statements therein not misleading, (ii) since
         the effective date of the Registration Statement no event has occurred
         which should have been set forth in a supplement or amendment to the
         Registration Statement, the Base Prospectus or the Prospectus
         Supplement, (iii) to the best of their knowledge after reasonable
         investigation, as of the Closing Date, the representations and
         warranties of the Company in this Agreement are true and correct and
         the Company has complied with all agreements and covenants contained in
         this Agreement and satisfied all conditions on its part to be performed
         or satisfied hereunder at or prior to the Closing Date, (iv) subsequent
         to the date of the most recent financial statements included or
         incorporated by reference in the Base Prospectus and the Prospectus
         Supplement, there has been no change in the financial position or
         results of operation of the Company that could have a Material Adverse
         Effect, or any material change, or any material development including a
         prospective change, in or affecting the condition (financial or
         otherwise), results of operations, business or prospects of the
         Company, except as set forth in the Base Prospectus and the Prospectus
         Supplement, and (v) the Registration Statement became effective on June
         16, 2005, and to their knowledge, as of the Closing Date (I) no stop
         order suspending the effectiveness of the Registration Statement has
         been issued and no proceedings for that purpose have been commenced or
         are pending before or are contemplated by the Commission and (II) no
         action has been taken by any governmental agency, body or official, and
         no injunction, restraining order or order of any nature by any federal
         or state court has been issued, which would prevent the issuance of the
         Stock.

         (h) At the Execution Time, the Placement Agents shall have received
         from Ernst & Young LLP a letter, addressed to the Placement Agents and
         dated such date, in form and substance reasonably satisfactory to the
         Representative (i) confirming that they are independent registered
         public accountants with respect to the Company within the meaning of
         the Securities Act and the Rules and Regulations and (ii) stating the
         conclusions and findings of such firm with respect to the financial
         statements and certain financial information contained or incorporated
         by reference in the Base Prospectus and the Prospectus Supplement.

         (i) On the Closing Date, the Representative shall have received a
         letter (the "BRING-DOWN LETTER") from Ernst & Young LLP addressed to
         the Placement Agents and dated the Closing Date confirming, as of the
         date of the bring-down letter (or, with respect to matters involving
         changes or developments since the respective dates as of which


                                       19
<PAGE>
         specified financial information is given in the Base Prospectus and the
         Prospectus Supplement as of a date not more than three Business Days
         prior to the date of the bring-down letter), the conclusions and
         findings of such firm with respect to the financial information and
         other matters covered by its letter delivered to the Representative
         concurrently with the execution of this Agreement pursuant to Section
         6(h).

         (j) The Company shall not have sustained since the date of the latest
         audited financial statements included or incorporated by reference in
         the Base Prospectus and the Prospectus Supplement any loss or
         interference with its business from fire, explosion, flood, terrorist
         act or other calamity, whether or not covered by insurance, or from any
         labor dispute or court or governmental action, order or decree,
         otherwise than as set forth in or contemplated by the Base Prospectus
         and the Prospectus Supplement, and (ii) except for the exercise of
         options in the ordinary course of the Company's business, since such
         date there shall not have been any change in the capital stock or
         long-term debt of the Company or any change, or any development
         involving a prospective change, in or affecting the business, general
         affairs, management, financial position, stockholders' equity, results
         of operations or prospects of the Company, otherwise than as set forth
         in or contemplated by the Base Prospectus and the Prospectus
         Supplement, the effect of which, in any such case described in clause
         (i) or (ii), is, in the judgment of the Representative, so material and
         adverse as to make it impracticable or inadvisable to proceed with the
         sale or delivery of the Stock on the terms and in the manner
         contemplated by the Base Prospectus and the Prospectus Supplement.

         (k) The Stock shall be registered under the Exchange Act and, as of the
         Closing Date, the Stock shall be listed and admitted and authorized for
         trading on the Nasdaq National Market, and satisfactory evidence of
         such actions shall have been provided to the Representative. The
         Company shall have taken no action designed to, or likely to have the
         effect of terminating the registration of the Stock under the Exchange
         Act or delisting or suspending from trading the Stock from Nasdaq, nor
         has the Company received any information suggesting that the Commission
         or Nasdaq is contemplating terminating such registration or listing.

         (l) At the Execution Time, the Company shall have furnished to the
         Representative a letter substantially in the form of Exhibit B hereto
         from each executive officer and director of the Company.

         (m) Subsequent to the execution and delivery of this Agreement, there
         shall not have occurred any of the following: (i) trading in securities
         generally on the New York Stock Exchange, the Nasdaq National Market or
         the American Stock Exchange or in the over-the-counter market, or
         trading in any securities of the Company on any exchange or in the
         over-the-counter market, shall have been suspended or minimum or
         maximum prices or maximum ranges for prices shall have been established
         on any such exchange or such market by the Commission, by such exchange
         or by any other regulatory body or governmental authority having
         jurisdiction, (ii) a banking moratorium shall have been declared by
         Federal or state authorities or a material disruption has occurred in
         commercial banking or securities settlement or clearance services in
         the United States, (iii) the United States shall have become engaged in
         new hostilities in which it is not


                                       20
<PAGE>
         currently engaged, or the subject of an act of terrorism, there shall
         have been an escalation in existing hostilities involving the United
         States or there shall have been a declaration of a national emergency
         or war by the United States or (iv) there shall have occurred any other
         calamity or crisis or any adverse change in general economic, political
         or financial conditions in the United States or other country or
         location which would materially affect the financial markets in the
         United States, as to make it, in the sole judgment of the
         Representative, impracticable or inadvisable to proceed with the sale
         or delivery of the Stock on the terms and in the manner contemplated by
         the Base Prospectus and the Prospectus Supplement.

         (n) No action shall have been taken and no statute, rule, regulation or
         order shall have been enacted, adopted or issued by any governmental
         agency or body which would, as of the Closing Date, prevent the
         issuance or sale of the Stock; and no injunction, restraining order or
         order of any other nature by any federal or state court of competent
         jurisdiction shall have been issued as of the Closing Date which would
         prevent the issuance or sale of the Stock.

         (o) The Company shall have prepared and filed with the Commission a
         Current Report on Form 8-K with respect to the Offering, including as
         an exhibit thereto this Agreement and any other documents relating
         thereto which may be required to be filed therewith.

         (p) The Company shall have entered into Subscription Agreements with
         each of the Purchasers and such agreements shall be in full force and
         effect.

         (q) Prior to the Closing Date, the Company shall have furnished to the
         Placement Agents such further information, certificates and documents
         as the Representative may reasonably request.

         All opinions, letters, evidence and certificates mentioned above or
elsewhere in this Agreement shall be deemed to be in compliance with the
provisions hereof only if they are in form and substance consistent with the
forms set forth as exhibits to this Agreement or, if no such form is provided,
in a form and substance reasonably satisfactory to counsel for the Placement
Agent.

7. INDEMNIFICATION AND CONTRIBUTION.

         (a) The Company shall indemnify and hold harmless each Placement Agent,
         its officers, employees, representatives and agents and each person, if
         any, who controls any Placement Agent within the meaning of the
         Securities Act (collectively the "PLACEMENT AGENT INDEMNIFIED PARTIES"
         and each a "PLACEMENT AGENT INDEMNIFIED PARTY") against any loss,
         claim, damage or liability, joint or several, or any action in respect
         thereof, to which that Placement Agent Indemnified Party may become
         subject, under the Securities Act or otherwise, insofar as such loss,
         claim, damage, liability or action arises out of or is based upon (i)
         any untrue statement or alleged untrue statement of a material fact
         contained in the Base Prospectus, the Registration Statement or the
         Prospectus Supplement or in any amendment or supplement thereto, (ii)
         the omission or alleged


                                       21
<PAGE>
         omission to state in the Base Prospectus, the Registration Statement or
         the Prospectus Supplement or in any amendment or supplement thereto a
         material fact required to be stated therein or necessary to make the
         statements therein not misleading, or (iii) any act or failure to act,
         or any alleged act or failure to act, by any Placement Agent in
         connection with, or relating in any manner to, the Stock or the
         offering contemplated hereby, and which is included as part of or
         referred to in any loss, claim, damage, liability or action arising out
         of or based upon matters covered by clause (i) or (ii) above; (provided
         that the Company shall not be liable in the case of any matter covered
         by this clause (iii) to the extent that it is determined in a final
         judgment by a court of competent jurisdiction that such loss, claim,
         damage, liability or action resulted directly from any such act or
         failure to act undertaken or omitted to be taken by such Placement
         Agent through its gross negligence or willful misconduct) and shall
         reimburse each Placement Agent Indemnified Party promptly upon demand
         for any legal or other expenses reasonably incurred by that Placement
         Agent Indemnified Party in connection with investigating or preparing
         to defend or defending against or appearing as a third party witness in
         connection with any such loss, claim, damage, liability or action as
         such expenses are incurred; provided, however, that the Company shall
         not be liable in any such case to the extent that any such loss, claim,
         damage, liability or action arises out of or is based upon an untrue
         statement or alleged untrue statement in or omission or alleged
         omission from the Base Prospectus, the Registration Statement or the
         Prospectus Supplement or any such amendment or supplement in reliance
         upon and in conformity with written information furnished to the
         Company by or on behalf of any Placement Agent through the
         Representative specifically for use therein, which information the
         parties hereto agree is limited to the Placement Agents' Information
         (as defined in Section 15). This indemnity agreement is not exclusive
         and will be in addition to any liability, which the Company might
         otherwise have and shall not limit any rights or remedies which may
         otherwise be available at law or in equity to each Placement Agent
         Indemnified Party.

         (b) Each Placement Agent, severally and not jointly, shall indemnify
         and hold harmless the Company, its officers, employees, representatives
         and agents, each of its directors and each person, if any, who controls
         the Company within the meaning of the Securities Act (collectively the
         "COMPANY INDEMNIFIED PARTIES" and each a "COMPANY INDEMNIFIED PARTY")
         against any loss, claim, damage or liability, joint or several, or any
         action in respect thereof, to which the Company Indemnified Parties may
         become subject, under the Securities Act or otherwise, insofar as such
         loss, claim, damage, liability or action arises out of or is based upon
         (i) any untrue statement or alleged untrue statement of a material fact
         contained in the Base Prospectus, the Registration Statement or the
         Prospectus Supplement or in any amendment or supplement thereto or (ii)
         the omission or alleged omission to state therein a material fact
         required to be stated therein or necessary to make the statements
         therein not misleading, but in each case only to the extent that the
         untrue statement or alleged untrue statement or omission or alleged
         omission was made in reliance upon and in conformity with written
         information furnished to the Company by or on behalf of that Placement
         Agent through the Representative specifically for use therein, and
         shall reimburse the Company Indemnified Parties for any legal or other
         expenses reasonably incurred by such parties in connection


                                       22
<PAGE>
         with investigating or preparing to defend or defending against or
         appearing as third party witness in connection with any such loss,
         claim, damage, liability or action as such expenses are incurred;
         provided that the parties hereto hereby agree that such written
         information provided by the Placement Agents consist solely of the
         Placement Agents' Information. This indemnity agreement is not
         exclusive and will be in addition to any liability, which the Placement
         Agents and the Purchasers might otherwise have and shall not limit any
         rights or remedies which may otherwise be available at law or in equity
         to the Company Indemnified Parties. Notwithstanding the provisions of
         this Section 7(b), in no event shall any indemnity by any Placement
         Agent under this Section 7(b) exceed the total compensation received by
         such Placement Agent in accordance with Section 1(e).

         (c) Promptly after receipt by an indemnified party under this Section 7
         of notice of any claim or the commencement of any action, the
         indemnified party shall, if a claim in respect thereof is to be made
         against the indemnifying party under this Section 7, notify the
         indemnifying party in writing of the claim or the commencement of that
         action; provided, however, that the failure to notify the indemnifying
         party shall not relieve it from any liability which it may have under
         this Section 7 except to the extent it has been materially prejudiced
         by such failure; and, provided, further, that the failure to notify the
         indemnifying party shall not relieve it from any liability which it may
         have to an indemnified party otherwise than under this Section 7. If
         any such claim or action shall be brought against an indemnified party,
         and it shall notify the indemnifying party thereof, the indemnifying
         party shall be entitled to participate therein and, to the extent that
         it wishes, jointly with any other similarly notified indemnifying
         party, to assume the defense thereof with counsel reasonably
         satisfactory to the indemnified party. After notice from the
         indemnifying party to the indemnified party of its election to assume
         the defense of such claim or action, the indemnifying party shall not
         be liable to the indemnified party under this Section 7 for any legal
         or other expenses subsequently incurred by the indemnified party in
         connection with the defense thereof other than reasonable costs of
         investigation; provided, however, that any indemnified party shall have
         the right to employ separate counsel in any such action and to
         participate in the defense thereof but the fees and expenses of such
         counsel shall be at the expense of such indemnified party unless (i)
         the employment thereof has been specifically authorized by the
         indemnifying party in writing, (ii) such indemnified party shall have
         been advised by such counsel that there may be one or more legal
         defenses available to it which are different from or additional to
         those available to the indemnifying party and in the reasonable
         judgment of such counsel it is advisable for such indemnified party to
         employ separate counsel or (iii) the indemnifying party has failed to
         assume the defense of such action in accordance with the terms hereof
         and employ counsel reasonably satisfactory to the indemnified party, in
         which case, if such indemnified party notifies the indemnifying party
         in writing that it elects to employ separate counsel at the expense of
         the indemnifying party, the indemnifying party shall not have the right
         to assume the defense of such action on behalf of such indemnified
         party, it being understood, however, that the indemnifying party shall
         not, in connection with any one such action or separate but
         substantially similar or related actions in the same jurisdiction
         arising out of the same general allegations or circumstances, be liable
         for the reasonable fees and expenses of more than one separate firm of
         attorneys at any time for all such indemnified parties,


                                       23
<PAGE>
         which firm shall be designated in writing by the Representative, if the
         indemnified parties under this Section 7 consist of any Placement Agent
         Indemnified Party, or by the Company if the indemnified parties under
         this Section 7 consist of any Company Indemnified Parties. Each
         indemnified party, as a condition of the indemnity agreements contained
         in Sections 7(a) and 7(b) shall use all reasonable efforts to cooperate
         with the indemnifying party in the defense of any such action or claim.
         Subject to the provisions of Section 7(d) below, no indemnifying party
         shall be liable for any settlement, compromise or consent to the entry
         of judgment in connection with any such action effected without its
         written consent (which consent shall not be unreasonably withheld), but
         if settled with its written consent or if there be a final judgment for
         the plaintiff in any such action (other than a judgment entered with
         the consent of such indemnified party), the indemnifying party agrees
         to indemnify and hold harmless any indemnified party from and against
         any loss or liability by reason of such settlement or judgment.

         (d) If at any time an indemnified party shall have requested that an
         indemnifying party reimburse the indemnified party for fees and
         expenses of counsel, such indemnifying party agrees that it shall be
         liable for any settlement of the nature contemplated by this Section 7
         effected without its written consent if (i) such settlement is entered
         into more than 45 days after receipt by such indemnifying party of the
         request for reimbursement, (ii) such indemnifying party shall have
         received notice of the terms of such settlement at least 30 days prior
         to such settlement being entered into and (iii) such indemnifying party
         shall not have reimbursed such indemnified party in accordance with
         such request prior to the date of such settlement.

         (e) If the indemnification provided for in this Section 7 is
         unavailable or insufficient to hold harmless an indemnified party under
         Section 7(a) or 7(b), then each indemnifying party shall, in lieu of
         indemnifying such indemnified party, contribute to the amount paid or
         payable by such indemnified party as a result of such loss, claim,
         damage or liability, or action in respect thereof, (i) in such
         proportion as shall be appropriate to reflect the relative benefits
         received by the Company on the one hand and the Placement Agents on the
         other from the offering of the Stock or (ii) if the allocation provided
         by clause (i) above is not permitted by applicable law, in such
         proportion as is appropriate to reflect not only the relative benefits
         referred to in clause (i) above but also the relative fault of the
         Company on the one hand and the Placement Agents on the other with
         respect to the statements or omissions which resulted in such loss,
         claim, damage or liability, or action in respect thereof, as well as
         any other relevant equitable considerations. The relative benefits
         received by the Company on the one hand and the Placement Agents on the
         other with respect to such offering shall be deemed to be in the same
         proportion as the total net proceeds from the offering of the Stock
         purchased under this Agreement (before deducting expenses) received by
         the Company bears to the total compensation received by the Placement
         Agents with respect to the Stock purchased under this Agreement. The
         relative fault shall be determined by reference to, among other things,
         whether the untrue or alleged untrue statement of a material fact or
         the omission or alleged omission to state a material fact relates to
         information supplied by the Company on the one hand or the Placement
         Agents on the other, the intent of the parties and their relative
         knowledge, access to information and opportunity to correct or prevent
         such untrue statement or omission; provided that the parties hereto
         agree that the written information furnished to


                                       24
<PAGE>
         the Company by the Representative for use in the Prospectus Supplement
         consists solely of the Placement Agents' Information. The Company and
         the Placement Agents agree that it would not be just and equitable if
         contributions pursuant to this Section 7(e) were to be determined by
         pro rata allocation or by any other method of allocation which does not
         take into account the equitable considerations referred to herein. The
         amount paid or payable by an indemnified party as a result of the loss,
         claim, damage or liability, or action in respect thereof, referred to
         above in this Section 7(e) shall be deemed to include, for purposes of
         this Section 7(e), 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
         Section 7(e), no Placement Agent shall be required to contribute any
         amount in excess of the total compensation received by such Placement
         Agent in accordance with Section 1(e), less the amount of any damages
         which such Placement Agent has otherwise paid or become liable to pay
         by reason of any untrue or alleged untrue statement or omission or
         alleged omission. 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 Placement Agents' obligations to contribute as provided in this
         Section 7(e) are several in proportion to the total compensation
         received by each of the Placement Agents in accordance with Section
         1(e) and not joint.

8. TERMINATION. The obligations of the Placement Agents and the Purchasers
hereunder and under the Subscription Agreements may be terminated by the
Representative, in its absolute discretion by notice given to the Company prior
to delivery (including electronic delivery) of and payment for the Stock if,
prior to that time, any of the events described in Sections 6(i) or 6(l) have
occurred or if the Purchasers shall decline to purchase the Stock for any reason
permitted under this Agreement or the Subscription Agreements.

9. REIMBURSEMENT OF PLACEMENT AGENTS' EXPENSES. If the sale of the Stock
provided for herein is not consummated, because (a) any condition to the
obligations of the Placement Agents and the Purchasers set forth in Section 6
hereof is not satisfied, (b) of any termination pursuant to Section 8 hereof, or
(c) of any refusal, inability or failure on the part of the Company to perform
any agreement herein or comply with any provision hereof, then the Company will
reimburse the Placement Agents upon demand for out-of-pocket expenses (including
the reasonable fees and disbursements of counsel and any reasonable expenses
advanced by the Placement Agents on the Company's behalf) that shall have been
incurred by the Placement Agents in connection with this Agreement and the
proposed purchase and sale of the Stock and, upon demand, the Company shall pay
the amount thereof to the Representative.

10. SUCCESSORS; PERSONS ENTITLED TO BENEFIT OF AGREEMENT. This Agreement shall
inure to the benefit of and be binding upon the Placement Agents, the Company,
and their respective successors. Nothing expressed or mentioned in this
Agreement is intended or shall be construed to give any person other than the
persons mentioned in the preceding sentence any legal or equitable right, remedy
or claim under or in respect of this Agreement, or any provisions herein
contained, this Agreement and all conditions and provisions hereof being
intended to be and being for the sole and exclusive benefit of such persons and
for the benefit of no other person;


                                       25
<PAGE>
except that the representations, warranties, covenants, agreements and
indemnities of the Company contained in this Agreement shall also be for the
benefit of the Placement Agent Indemnified Parties, and the indemnities of the
Placement Agents shall also be for the benefit of the Company Indemnified
Parties. It is understood that the Placement Agents' responsibilities to the
Company are solely contractual in nature and the Placement Agents do not owe the
Company, or any other party, any fiduciary duty as a result of this Agreement.

11. SURVIVAL OF INDEMNITIES, REPRESENTATIONS, WARRANTIES, ETC. The respective
indemnities, covenants, agreements, representations, warranties and other
statements of the Company and the Placement Agents, as set forth in this
Agreement or made by them respectively, pursuant to this Agreement, shall remain
in full force and effect, regardless of any investigation made by or on behalf
of the Placement Agents, the Company, the Purchasers or any person controlling
any of them and shall survive delivery of and payment for the Stock.

12. NOTICES. All statements, requests, notices and agreements hereunder shall be
in writing, and:

         (a) if to the Placement Agents, shall be delivered or sent by mail,
         telex or facsimile transmission to SG Cowen & Co., LLC, 1221 Avenue of
         the Americas, New York, New York 10020, Attention: Veronica Iuliano
         (Fax: 212-278-7995), with a copy to: Brown Raysman Millstein Felder &
         Steiner LLP, 900 Third Avenue, New York, New York 10022, Attention:
         Stuart Bressman, Esq. (Fax: 212-895-2900).

         (b) if to the Company, shall be delivered or sent by mail, telex or
         facsimile transmission to Santarus, Inc., 10590 West Ocean Drive, Suite
         200, San Diego, CA 92130, Attention: Carey J. Fox, Esq., Vice
         President, Legal Affairs (Fax: (848) 314-5702), with a copy to: Latham
         & Watkins LLP, 12636 High Bluff Drive, Suite 300, San Diego, CA 92130,
         Attention: Scott N. Wolfe, Esq. (Fax: (858) 523-5450).

13. DEFINITIONS OF CERTAIN TERMS. The terms which follow, when used in this
Agreement, shall have the meanings indicated.

                  "BUSINESS DAY" shall mean any day other than a Saturday, a
         Sunday, a legal holiday, a day on which banking institutions or trust
         companies are authorized or obligated by law to close in New York City
         or any day on which the Nasdaq National Market is not open for trading.

                  "EFFECTIVE DATE" shall mean each date and time that the
         Registration Statement (and any post-effective amendment or amendments
         thereto) became or becomes effective.

                  "EXECUTION TIME" shall mean the date and time that this
         Agreement is executed and delivered by the parties hereto.

                  "TO THE COMPANY'S KNOWLEDGE" and words of similar import shall
         mean that which the Company knows or should have known using the
         exercise of reasonable due diligence.


                                       26
<PAGE>
14. GOVERNING LAW. This Agreement shall be governed by and construed in
accordance with the laws of the State of New York.

15. PLACEMENT AGENT'S INFORMATION. The parties hereto acknowledge and agree
that, for all purposes of this Agreement, the Placement Agent's Information
consists solely of the statements concerning the Placement Agent contained in
the third paragraph under the heading "Plan of Distribution" in the Prospectus
Supplement.

16. PARTIAL UNENFORCEABILITY. The invalidity or unenforceability of any Section,
paragraph or provision of this Agreement shall not affect the validity or
enforceability of any other Section, paragraph or provision hereof. If any
Section, paragraph or provision of this Agreement is for any reason determined
to be invalid or unenforceable, there shall be deemed to be made such minor
changes (and only such minor changes) as are necessary to make it valid and
enforceable.

17. GENERAL. This Agreement constitutes the entire agreement of the parties to
this Agreement and supersedes all prior written or oral and all contemporaneous
oral agreements, understandings and negotiations with respect to the subject
matter hereof. In this Agreement, the masculine, feminine and neuter genders and
the singular and the plural include one another. The section headings in this
Agreement are for the convenience of the parties only and will not affect the
construction or interpretation of this Agreement. This Agreement may be amended
or modified, and the observance of any term of this Agreement may be waived,
only by a writing signed by the Company and the Placement Agent.

18. COUNTERPARTS. This Agreement may be signed in any number of counterparts,
each of which shall be an original, with the same effect as if the signatures
thereto and hereto were upon the same instrument.

19. CONSENT TO ACT AS REPRESENTATIVE. RBC Capital Markets Corporation ("RBC")
consents and agrees that SG Cowen & Co., LLC ("SG COWEN") will act as
Representative of the Placement Agents under this Agreement and with respect to
the sale of the Stock. Accordingly, RBC authorizes SG Cowen to manage the
Offering and the sale of the Stock and to take such action in connection
therewith as SG Cowen in its sole discretion deems appropriate or desirable,
consistent with the provisions of the Agreement Among Underwriters previously
entered into between SG Cowen and RBC, taking into account that the Offering of
the Stock will be in the form of a best efforts placement and not a firm
commitment underwriting.


                                       27
<PAGE>
         If the foregoing is in accordance with your understanding of the
agreement between the Company and the Placement Agents, kindly indicate your
acceptance in the space provided for that purpose below.

                                          Very truly yours,


                                          SANTARUS, INC.


                                          By:  /s/ Gerald T. Proehl
                                               Name:   Gerald T. Proehl
                                               Title:  President and
                                                       Chief Executive Officer



Accepted as of
the date first above written:

SG COWEN & CO., LLC


By:  /s/ Richard E. Gormley
     Name:   Richard E. Gormley
     Title:  Managing Director

RBC CAPITAL MARKETS CORPORATION


By:  /s/ Michael J. Rosso
     Name:  Michael J. Rosso
     Title: Managing Director


                                       28
<PAGE>
                                   SCHEDULE I

                                Placement Agents

SG COWEN & CO., LLC
RBC CAPITAL MARKETS CORPORATION


                                       29
<PAGE>
                                    EXHIBIT A

                         FORM OF SUBSCRIPTION AGREEMENT


                                       30
<PAGE>
                                    EXHIBIT B

                            FORM OF LOCK-UP AGREEMENT


                                       31
<PAGE>
                                   EXHIBIT C-1

                      LEGAL OPINION OF LATHAM & WATKINS LLP



                                       32
<PAGE>
                                   EXHIBIT C-2

             NEGATIVE ASSURANCES STATEMENT OF COUNSEL TO THE COMPANY


                                       33
<PAGE>
                                   EXHIBIT C-3

                LEGAL OPINION OF WILSON SONSINI GOODRICH & ROSATI


                                       34