<PAGE>

                                                                   EXHIBIT 10.2

                                            *** CERTAIN CONFIDENTIAL INFORMATION
                                            CONTAINED IN THIS DOCUMENT
                                            (INDICATED BY ASTERISKS) HAS BEEN
                                            OMITTED AND FILED SEPARATELY WITH
                                            THE SECURITIES AND EXCHANGE
                                            COMMISSION PURSUANT TO A REQUEST FOR
                                            CONFIDENTIAL TREATMENT UNDER 17
                                            C.F.R. SECTIONS 200.80(B)(4), 200.83
                                            AND 230.406.

                           EXCLUSIVE LICENSE AGREEMENT
                                     BETWEEN
                  THE UNIVERSITY OF MISSOURI AND SANTARUS, INC.

        This Exclusive License Agreement ("Agreement") is effective as of the
26th day of January 2001 (the "Effective Date"), by and between THE CURATORS OF
THE UNIVERSITY OF MISSOURI, a public corporation organized under the laws of
Missouri, having a principal place of business at 615 Locust Street Building,
Third Floor, Columbia, Missouri 65211-1400 ("the University"), and SANTARUS,
INC. ("Santarus"), a California corporation, having a principal place of
business at 12230 El Camino Real, Suite 300, San Diego, California 92130.

                                    RECITALS

        Whereas, certain discoveries useful for the administration of proton
pump inhibitors using pharmaceutically acceptable carriers were made in the
course of research under the direction of Dr. Jeffrey O. Phillips ("Dr.
Phillips") at the University (the "Research") and are claimed in the patents and
patent applications included in the Patent Rights (defined below);

        Whereas, Santarus has requested a license of certain rights from the
University to commercialize Licensed Products (defined below) based on such
discoveries;

        Whereas, the University is willing to grant such license rights to
Santarus; and

        Whereas, the University hereby responds to the request of Santarus by
granting the following rights to Santarus so that the products and other
benefits derived from the Patent Rights can be enjoyed by the general public.

                                    AGREEMENT

        Now, therefore, in consideration of the representations and covenants
set forth herein, the payments made hereunder, and for other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
parties agree as follows:

        1. DEFINITIONS

        Capitalized terms used but not elsewhere defined in this Agreement shall
have the meanings set forth below:

                1.1 "AFFILIATE(s)" of either party to this Agreement means any
entity which, directly or indirectly, controls the party, is controlled by the
party, or is under common control with the party ("control" for these purposes
being defined as the actual, present capacity to elect a majority of the
directors or curators, as the case may be, of such entity, or if not, the power
to direct at least     ***     of the voting rights entitled to elect
directors or curators); provided, however, that in any country where the local
law will not permit foreign equity participation of a majority, then an
"Affiliate" of Santarus will include any company in which Santarus owns or
controls, directly or indirectly, the maximum percentage of such outstanding



                                       1

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<PAGE>

stock or voting rights permitted by local law. Each reference to Santarus herein
will be deemed to include its Affiliates.

                1.2 "ANDA" means an Abbreviated New Drug Application filed with
the FDA.

                1.3 "COMBINATION PRODUCT" means any product which is a Licensed
Product and which also contains other product(s) or component(s) ("Other
Product"), which Other Product (i) is not a Licensed Product; (ii) the sale, use
or import of which, by itself, does not contribute to the infringement of the
Patent Rights; (iii) could be sold separately by Santarus; and (iv) enhances the
market price of the final Licensed Product(s) sold, used or imported by
Santarus.                                   ***

                                            ***
                                            ***
                      ***

                1.4 "FDA" means the United States Food and Drug Administration.

                1.5 "FIELD OF USE" means all uses within the Patent Rights.

                1.6 "FIRST COMMERCIAL SALE" means the first sale of a Licensed
Product in the country in the Territory, such Licensed Product intended for
administration to a patient for a therapeutic use approved by the FDA or other
similar regulatory agency in a foreign country; provided, however, if approval
by a similar regulatory agency is not required in a particular foreign country,
then such approval shall not be an element of the definition of "First
Commercial Sale."

                1.7 "FUNDED RESEARCH" has the meaning set forth in Section 4.16
("Funded Research").

                1.8 "IND" means an Investigational New Drug application filed
with the FDA.

                1.9 "JOINT VENTURE" means any separate entity established
pursuant to an agreement between a third party and Santarus to constitute a
vehicle for a joint business enterprise, in which the separate entity
manufactures, uses, or sells Licensed Products, or purchases or acquires
Licensed Products from Santarus.

                1.10 "LICENSED PRODUCT" shall mean any product that cannot be
manufactured, used or sold without (i) infringing one or more claims under the
Patent Rights (including the claims in pending applications) or (ii) using any
part of the Technical Information not otherwise includable within the Patent
Rights.

                1.11 "NDA" means a New Drug Application filed with the FDA.



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                                       2
<PAGE>

                1.12 "NET SALES" means the amount invoiced as a result of the
sale of Licensed Products by Santarus, Joint Ventures, and sublicensees to
independent third parties for cash or other forms of consideration in accordance
with generally accepted accounting principles ("GAAP") limited to the following
deductions (if not already deducted from the gross invoice price and at rates
customary within the industry): ***

                                    ***
                                    ***
                                    ***

                1.13 " *** LICENSED PRODUCT" means any Licensed Product other
than an *** Licensed Product.

                1.14 "NOTICE OF DEFAULT" and "NOTICE OF TERMINATION" have the
meanings set forth in Article 8 ("Term and Termination; Resolution of
Disputes").

                1.15 " *** LICENSED PRODUCT" means any Licensed Product that
contains *** .

                1.16 "ORAL LIQUID" means a composition intended for oral
administration to a patient comprising any of (i) a liquid solution, (ii) a
solid-in-liquid suspension, and (iii) a powder or other solid formulation
intended to be reconstituted into a liquid solution or a solid-in-liquid
suspension.

                1.17 "PATENT METHOD" means any process or method covered by the
claims of a patent application or patent within Patent Rights or the use or
practice of which would constitute in a particular country, but for the license
granted to Santarus pursuant to this Agreement, an infringement of an unexpired
claim of a patent or pending claim of a patent application were it issued as a
claim in a patent within Patent Rights in that country in which the Patent
Method is used or practiced.

                1.18 "PATENT RIGHTS" means all United States patents and patent
applications and foreign patents and patent applications, including any
reissues, re-examinations, extensions, substitutions, continuations,
divisionals, and continuation-in-part applications (only to the extent, however,
that claims in the continuation-in-part applications are enabled and
specifically described in the specification of the parent patent application),
based on and including any subject matter claimed in or covered by the United
States patent applications (a) set forth on Exhibit A hereto, and (b) which may
be filed based on the Results of Funded Research.

                1.19 "DR. PHILLIPS" means Dr. Jeffrey 0. Phillips.

                1.20 "PPI" means a proton pump inhibitor.

                1.21 "PRIMARY COUNTRIES" shall mean the following: *** *** .

                1.22 "PROPRIETARY INFORMATION" has the meaning set forth in
Section 14.1.



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                                       3
<PAGE>

                1.23 "RESEARCH" has the meaning set out in the first paragraph
under "RECITALS."

                1.24 "TECHNICAL INFORMATION" means: the information which is
described in the Patent Rights; know-how, trade secrets, unpublished patent
applications, software, unpatented technology, technical information,
statistical information and analysis, biological materials, chemical reagents,
preclinical and clinical information (collectively, "Results"), which has been
conceived and reduced to practice in the conduct of the Research; and Results
(including any patents which may issue thereon) of the Funded Research.

                1.25 "TERRITORY" means the world.

        2. GRANT

                2.1 LICENSE. Subject to the limitations set forth in this
Agreement the University hereby grants to Santarus an exclusive, world-wide
license under the Patent Rights, in the Field of Use, to make, have made, use,
sell, have sold, offer for sale, and import Licensed Products and to practice
the Patent Method. The license is exclusive for the life of the Patent Rights.

                2.2 SUBLICENSE RIGHTS. The University also grants to Santarus
the right to issue sublicenses to third parties of the rights licensed to
Santarus pursuant to this Agreement, provided Santarus retains current exclusive
rights thereto under this Agreement. Such sublicenses will incorporate Santarus'
obligations to the University, consistent with the terms and conditions of this
Agreement, shall obligate Santarus to pay to the University royalties with
respect to sales of Licensed Products by Santarus' sublicensees in accordance
with Article 4 ("Consideration") hereof, and shall provide for the assignment to
the University of the sublicenses in the event of the termination of this
Agreement.

                2.3 SUBLICENSE OBLIGATIONS. Santarus will notify the University
of each sublicense granted hereunder and provide the University with a copy of
each sublicense upon request. Santarus will collect and pay all amounts due the
University from the sublicensees. Santarus will require the sublicensees to
provide Santarus with royalty reports in accordance with the provisions herein.

                2.4 EFFECT OF TERMINATION ON SUBLICENSES. Upon termination of
this Agreement for any reason, any sublicenses will remain in full force and
effect and will be assigned to the University.

                2.5 DISCLOSURE OF TECHNICAL INFORMATION. Upon execution of this
Agreement, the University shall make available to Santarus the Technical
Information, to the extent the University has not already done so. Santarus may
use the Technical Information as necessary to exploit the license granted to it
hereunder.

                2.6 RESERVATION OF RIGHTS. The University shall have the right
throughout the term of this Agreement to make and to use and to grant
nonexclusive licenses to make and to use, for internal research and educational
purposes only, and not for commercial purposes, the



                                       4
<PAGE>

Patent Method, Patent Rights and Technical Information.          ***
                                    ***
                                    ***
                                    ***

        3. PUBLICATION AND USE OF TECHNICAL DATA

        Nothing in this Agreement will be deemed to limit the right of the
University to publish any and all technical data resulting from any research
performed by the University relating to the Licensed Products and to make and
use the Licensed Products, Patent Method(s), and associated technology solely
for educational and research purposes. The foregoing notwithstanding, any
publication and/or use of the technical data must be delivered to Santarus at
least forty-five (45) days in advance of its submission for publication.

        4. CONSIDERATION

                4.1 INITIAL PAYMENT. On or before January 31, 2001, as a
one-time, up-front license fee, Santarus shall pay to the University the sum of
one million dollars ($1,000,000) as consideration for entering into this
Agreement and the licenses granted hereunder.

                4.2 MILESTONE PAYMENTS. Santarus shall make the following
one-time milestone payments to the University:

                      (a)                   ***
                                            ***
                                            ***

                      (b)                   ***
                                            ***

                      (c)                   ***
                                            ***

                4.3 ADDITIONAL MILESTONE PAYMENTS. Santarus shall make the
following one-time payments to the University for the first time each of the
following Net Sales milestones for *** Licensed Products is achieved in a
calendar year:

                      (a)                   ***
                                            ***

                      (b)                   ***
                                            ***
                                            ***

                      (c)                   ***
                                            ***



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                                       5
<PAGE>

                      (d)                   ***
                                            ***
                                            ***

                      (e)                   ***
                                            ***

For the avoidance of doubt, in no event shall Santarus be required to make more
than one payment pursuant to each of a, b, c, d and e of this Section 4.3.

                4.4 SANTARUS STOCK. Santarus agrees to issue to the University
an aggregate of five hundred seventy-five thousand (575,000) shares of Santarus
common stock upon the terms and conditions set forth in an agreement
substantially in the form of Exhibit B hereto.

                4.5 EARNED ROYALTIES. As consideration for the rights and
licenses granted to Santarus, Santarus will pay to the University earned
royalties on Net Sales of (1) *** Licensed Products by Santarus or its
sublicensees and (2) *** Licensed Products by Santarus, at the following rates:

                4.5.1 The following royalty rates shall apply on total worldwide
        Net Sales of Licensed Products sold in countries where there is at least
        one pending patent application and/or existing patent within the Patent
        Rights:

                        (a)     ***
                                ***
                                ***

                        (b)     ***
                                ***
                                ***
                                ***

                        (c)     ***
                                ***
                                ***

        The foregoing notwithstanding, in countries where it is generally known
that patent rights are not reasonably enforceable, if (i) a competitor sells a
product that otherwise infringes one or more of the issued or pending claims of
the Patent Rights; and (ii) the Net Sales of the Licensed Products are adversely
affected by such competition, then the royalty rate on all Net Sales of Licensed
Products in such country or countries shall be    ***     . Notwithstanding the
foregoing, if such competitor's product no longer meets condition (ii) above,
then the royalty rates shall be restored to the higher rates set forth above in
this Section 4.5.1. For the avoidance of doubt, all such Net Sales in such
countries shall be included in the total and incremental Net Sales figures of
Sections 4.3 and 4.5.1 (a-c); provided, however, that Santarus is only obligated
to pay the lower royalty rate of    *** for Net Sales arising from such
countries.



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                                       6
<PAGE>

                                    ***
                                    ***
                                    ***

                4.5.2 In countries where (i) there are no pending patent
        applications (either PCT or nationalized) or existing patents within the
        Patent Rights, or (ii) there is at least one pending patent application
        and/or existing patent within the Patent Rights, but the Patent Rights
        are sub-licensed to others pursuant to compulsory or mandatory
        sub-licensing at controlled royalty rates, thereby resulting in sales of
        competitive products (which would infringe issued or pending claims
        under the Patent Rights but for such compulsory or mandatory
        sub-license) in such country, the royalty rates for Net Sales of
        Licensed Products sold in such countries shall be ***. For the avoidance
        of doubt, Net Sales arising from countries meeting condition (i) in this
        Section 4.5.2 shall not be included in the total and incremental Net
        Sales figures of Sections 4.3 and 4.5.l(a-c), but Net Sales arising from
        countries meeting condition (ii) in this Section 4.5.2 shall be included
        in the total and incremental Net Sales figures of Sections 4.3 and
        4.5.1(a-c). Notwithstanding the foregoing, Santarus is only obligated to
        pay the lower royalty rate of *** for Net Sales arising from countries
        meeting condition (ii). ***

                                    ***
                                    ***
                                    ***

                4.6 ACCRUAL OF EARNED ROYALTIES. Earned royalties will accrue in
each country commencing with the First Commercial Sale of Licensed Products.
Earned royalties will be payable to the University when invoiced by Santarus
and/or its sublicensees. By way of example and not limitation, earned royalties
will not accrue on the delivery of sales samples or units used for clinical
trials.

                4.7 SUBLICENSE CONSIDERATION. If Santarus sublicenses some or
all of its rights under this Agreement with respect to *** Licensed Products,
within *** days of Santarus' receipt of any consideration with respect to such
*** Licensed Product under any such sublicense, Santarus shall pay to the
University:

                        (a)     ***
                                ***
                                *** and

                        (b)     ***
                                ***
                                ***

                4.8 RIGHT OF OFFSET. In the event that Santarus and the
University reasonably determine that in any country any Licensed Product
infringes upon the patent rights of a third party, and Santarus obtains a
license under such third party rights, then, in lieu of any other right or
remedy, Santarus shall have the right to deduct from the royalties otherwise due
and payable under Section 4.5 ("Earned Royalties") arising from the sale of
Licensed Products in such country, the amount, up to a maximum of *** of the
royalties otherwise



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                                       7
<PAGE>

payable, that Santarus is obliged to pay under the third party license in order
to obtain rights from such third party in such country.

                4.9 COMBINATION PRODUCTS. In the event that a Licensed Product
is also a Combination Product, then the Net Sales on which earned royalties are
payable by the Licensee shall be calculated as hereinafter set forth. ***
                                                                      ***
                                                                      ***

                4.10 TIMING OF PAYMENTS. Subject to the other terms and
conditions of this Agreement, including without limitation Sections 4.8 ("Right
of Offset") and 4.9 ("Combination Products"), payments owed by Santarus to the
University pursuant to Sections 4.2 ("Milestone Payments"), 4.3 ("Additional
Milestone Payments") and 4.5 ("Earned Royalties") which become payable with
respect to, or as a result of events occurring in, a particular calendar quarter
will be paid to the University no later than the due date of Santarus' royalty
***

                4.11 MULTIPLE PATENTS. For the avoidance of doubt, the parties
hereby agree that, notwithstanding how many patents or patent applications under
the Patent Rights being licensed under this Agreement are utilized for a single
Licensed Product, only one royalty will be earned on the sale of that Licensed
Product.

                4.12 CURRENCY. All monies due to the University will be payable
in United States dollars. When Licensed Products are sold for monies other than
United States dollars, the earned royalties ***
                                            ***
                                            ***
If the transfer of or conversion into US dollars of all currency is not lawful
or possible, the payment of such part of royalties that is necessary shall be
made by the deposit thereof, in the currency of the country where the sale was
made on which the royalty was based, to the credit and account of the University
in any commercial bank or trust company of Santarus' choice located in that
country. Prompt notice of any such deposit will be given by Santarus to the
University.

                4.13 TAXES. Earned royalties and royalty milestone payments on
Net Sales of Licensed Products occurring in any country outside the United
States may be reduced by any taxes, fees, or other charges imposed by the
government of such country and actually paid by Santarus after deduction of all
credits, deductions and offsets to which Santarus is lawfully entitled.



                                       8

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                4.14 INVALIDITY OF PATENTS. In the event that any patent or any
claim thereof included within the Patent Rights is held invalid ***
                                                                ***
                                                                ***

                4.15 REDUCTION IN ROYALTY RATE. In the event that no patent with
respect to any Patent Rights issues within ***  of the filing date of any
application(s) therefor, then the royalty payable on the sale of Licensed
Products shall be reduced to the amounts determined in accordance with Section
4.5.2 herein. This reduction shall apply prospectively only, and shall continue
only until such time, if ever, a patent covering such Patent Right is issued.

                4.16 FUNDED RESEARCH. Pursuant to the terms of a research
agreement to be mutually agreed upon between Santarus and the University,
Santarus shall pay to the University *** period beginning with the first
calendar quarter commencing after the Effective Date, to support research to be
conducted by or under the supervision of Dr. Phillips with respect to the
further development of Licensed Products (such research, the "Funded Research").

                4.17 LATE PAYMENTS. In the event royalty payments, fees or
patent prosecution costs are not received by the University when due, Santarus
will pay to the University interest charges at a rate of *** per month. Such
interest will be calculated from the date payment was due until actually
received by the University. Acceptance by the University of any late payment
interest from Santarus under this Section 4.17 will in no way affect the
provisions of Section 16.2 herein.

        5. DUE DILIGENCE

                5.1 COMMERCIALLY REASONABLE EFFORTS. Santarus, upon execution of
this Agreement, will use commercially reasonable efforts to develop,
manufacture, market and sell Licensed Products in commercially reasonable
quantities sufficient to meet the market demands therefor in accordance with the
Schedule of Events attached as Exhibit C to this Agreement. Santarus shall
promptly notify the University of any material deviation from the Schedule of
Events; provided, however, any such notification shall not relieve Santarus of
its due diligence obligations under this Article 5.

                5.2 BUSINESS JUDGMENT. Santarus will be entitled to exercise
prudent and reasonable business judgment in the manner in which it meets its due
diligence obligations hereunder. In no case, however, will Santarus be relieved
of its obligations to meet the due diligence provisions of this Article 5.



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                                       9
<PAGE>

                5.3 GOVERNMENT APPROVALS. Santarus will obtain all necessary
governmental approvals in each country it chooses to manufacture, use, or sell
Licensed Products.

                5.4 DILIGENCE. If Santarus is unable to fill the market demand
for Licensed Products in any of the Primary Countries during the period starting
*** after commencement of marketing of Licensed Products therein, then with
respect to any such Primary Country, the University will have the right and
option to terminate this Agreement or reduce the exclusive licenses granted to
Santarus to non-exclusive licenses in accordance with Section 5.5 ("Exercise of
Rights") hereof. The exercise of this right and option by the University
supersedes the rights granted in Article 2 ("Grant").

                5.5 EXERCISE OF RIGHTS. To exercise either the right to
terminate this Agreement or reduce the exclusive licenses granted to Santarus to
non-exclusive licenses for lack of diligence required in this Article 5 ("Due
Diligence"), the University will give Santarus written notice of the deficiency.
Santarus thereafter will have *** to cure the deficiency and provide the
University with written notice of such cure. If Santarus has not cured the
deficiency within the *** period and has not provided written tangible evidence
to the University thereof, then the University may, at its option, terminate
this Agreement or reduce the exclusive licenses granted to Santarus to
non-exclusive licenses by giving written notice to Santarus. These notices will
be subject to Article 13 ("Notices").

        6. PROGRESS AND ROYALTY REPORTS

                6.1 ROYALTY REPORTS. Santarus will provide the University with
quarterly royalty reports on or before the earlier of *** days following the end
of each calendar quarter and (ii) *** days after Santarus' receipt of all
applicable information concerning Net Sales of Licensed Products. Such quarterly
reports will contain sufficient detail to allow the University to verify the
accuracy of the proper and accurate calculation of payments due, and at a
minimum will show:

                        (a)     the date of First Commercial Sale of Licensed
                                Products, on a product-by-product in a
                                country-by-country basis, by Santarus, its
                                sublicensees and Joint Ventures;

                        (b)     the gross sales and Net Sales of Licensed
                                Products sold on a product-by-product in a
                                country-by-country basis, by Santarus, its
                                sublicensees and Joint Ventures during the most
                                recently completed calendar quarter;

                        (c)     the number of Licensed Products sold or
                                distributed on a product-by-product in a
                                country-by-country basis, by Santarus, its
                                sublicensees and Joint Ventures;

                        (d)     the royalties, in U.S. dollars, payable
                                hereunder with respect to Net Sales; and



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                                       10
<PAGE>

                        (e)     the exchange rates used, if any.

                6.2 NO SALES. If no sales of Licensed Products have been made
during any reporting period after the First Commercial Sale of a Licensed
Product, then a statement to this effect is required in the quarterly report
required in Section 6.1.

                6.3 PROGRESS REPORTS. Concurrently with the royalty report due
for the calendar quarter ending December 31, Santarus shall deliver to the
University a report on the progress of the Licensed Products, which report shall
include but not be limited to reports of progress on research and development,
regulatory approvals, manufacturing, sublicensing, marketing and sales during
the preceding year as well as plans for the succeeding calendar year. Such
progress report shall also include any material deviations from the Schedule of
Events attached as Exhibit C.

        7. BOOKS AND RECORDS

                7.1 SANTARUS' OBLIGATION. Santarus will keep books and records
accurately showing all Licensed Products manufactured, used, and/or sold under
the terms of this Agreement. Such books and records will be preserved for at
least *** after the date of the royalty payment to which they pertain and will
be open to inspection by representatives or agents of the University at
reasonable times not to exceed *** to determine the accuracy of the books and
records and to determine compliance by Santarus with the terms of this Agreement
in accordance with generally accepted accounting principles.

                7.2 AUDIT EXPENSES. The fees and expenses of representatives of
the University performing such an examination will be borne by the University.
However, if an underpayment to the University in an amount in excess of *** for
a particular year is discovered, then the reasonable fees and expenses of such
representatives will be borne by Santarus.

        8. TERM AND TERMINATION; RESOLUTION OF DISPUTES

                8.1 TERM. Unless otherwise terminated by operation of law or by
acts of the parties in accordance with the terms of this Agreement, this
Agreement will be in force from the Effective Date and shall expire on a
country-by-country basis, on the date upon which the last to expire of the
patents covering the Patent Rights shall expire, or until the last patent
application licensed under this Agreement is abandoned. The foregoing
notwithstanding, Santarus' obligations under Section 4.5.2 shall terminate on a
country-by-country basis on the fifteenth anniversary of the First Commercial
Sale of Licensed Products in each such country.

                8.2 TERMINATION FOR CAUSE BY SANTARUS. If the University should
violate or fail to perform any material term or covenant of this Agreement, then
Santarus may give *** *** written notice to the University setting forth the
alleged breach ("Notice of Default"). If the University should fail to cure such
alleged breach within such *** period, then Santarus shall have the right to
terminate this Agreement by giving a second written notice



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                                       11
<PAGE>

to the University of such termination ("Notice of Termination") and this
Agreement shall terminate upon receipt of the Notice of Termination.

                8.3 TERMINATION FOR CAUSE BY THE UNIVERSITY. If Santarus should
violate or fail to perform any material term or covenant of this Agreement, then
the University may give *** written notice to Santarus setting forth the alleged
breach ("Notice of Default"). If Santarus should fail to cure such alleged
breach within such *** period, then the University shall have the right to
terminate this Agreement by giving a second written notice to Santarus of such
termination ("Notice of Termination") and this Agreement shall terminate upon
receipt of the Notice of Termination.

                8.4 DISCRETIONARY TERMINATION BY SANTARUS. Santarus will have
the right at any time to terminate this Agreement in whole or as to any portion
of the Patent Rights by giving notice in writing to the University. Such notice
of termination will be subject to Article 13 ("Notices") and termination will be
effective *** days after the effective date thereof.

                8.5 INSOLVENCY. Should Santarus become bankrupt or insolvent, or
should the business of Santarus be placed in the hands of a receiver, this
Agreement shall terminate at the option of the University. At least ***
days prior to filing a petition in bankruptcy, Santarus must inform the
University of its intention to file the petition or of another's intention to
file an involuntary petition in bankruptcy. Further, failure to conform to this
requirement shall be deemed a material, pre-petition incurable breach.

                8.6 RIGHTS IN DATA FOLLOWING TERMINATION. Following termination
of this Agreement by the University under Sections 8.3 or 8.5 hereof, or
termination of this Agreement by Santarus under Section 8.4 hereof, ***
                                                                    ***
                                                                    ***.

                8.7 SURVIVAL. Any termination of this Agreement will not affect
the rights and obligations set forth in the following Articles:

                Article 7           Books and Records

                Article 8           Term and Termination; Resolution of Disputes

                Article 9           Use of Names

                Article 10          Limited Warranty

                Article 12          Indemnification



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                                       12
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                Article 14          Confidentiality

                Article 16          Miscellaneous

                8.8 EFFECT OF TERMINATION. Any termination of this Agreement
shall not relieve Santarus of its obligation to pay any monies due or owing at
the time of such termination and shall not relieve any obligations, of either
party to the other party, established prior to termination.

                8.9 RESOLUTION OF DISPUTES. If Santarus and the University are
unable to reach agreement by negotiating in good faith concerning any matter
under this Agreement, or if any other dispute arises under this Agreement, the
parties agree to resolve the dispute themselves, and failing to do so, they
agree that any dispute remaining under the operation of this Agreement shall
first be subjected to a mediation process under the commercial rules of the
American Arbitration Association which shall be completed within *** days after
determination that an unresolved dispute has arisen. A dispute shall be deemed
to have arisen under this Agreement when either Santarus or the University gives
notice to the other party as provided in Article 13 ("Notices"). Such notice
shall set forth the nature of the unresolved dispute and request mediation
pursuant to this Section 8.9. The parties shall refrain from court proceedings
during the ninety-day period, or such longer period as the parties may agree in
writing.

                8.10 RIGHT TO INSTITUTE LEGAL ACTIONS. Notwithstanding the
termination provisions of this Article 8 ("Term and Termination; Resolution of
Disputes"), the parties may, subject to Section 8.9 herein, institute any other
legal action or pursue any other remedy against the other party permitted by
applicable law if the other party does not substantially cure any breach or
default of any material obligation as provided herein.

                8.11 DISPOSITION OF LICENSED PRODUCTS ON HAND UPON TERMINATION.
Upon termination of this Agreement, Santarus and its Joint Ventures and
sublicensees will have the right to sell all previously made or partially made
Licensed Products within a period of *** following the effective date of
termination, provided, however, that the sale of such Licensed Products will be
subject to the terms of this Agreement including, but not limited to the payment
of royalties based on the Net Sales of Licensed Products at the rates and at the
times provided herein and the rendering of reports in connection therewith.

        9. USE OF NAMES

                9.1 NO RIGHT TO USE NAME. Nothing contained in this Agreement
will be construed as conferring any right to use in advertising, publicity, or
other promotional activities any name, trade name, trademark, or other
designation of either party hereto by the other (including contraction,
abbreviation or simulation of any of the foregoing). Notwithstanding the
foregoing, subject to prior reasonable notice, either party may disclose and
report that it has entered into this Agreement with the other party. In
addition, for the avoidance of doubt, the parties agree that this Section does
not prohibit Santarus from referencing the University in scientific publications
and business plans, and in the ordinary course of business in



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                                       13
<PAGE>

communications with bankers, investors or others in order to obtain financing,
or with other third parties in negotiating future scientific or business
collaborations. In addition, for further avoidance of doubt, the parties agree
that this Section does not prohibit the University from referencing Santarus in
scientific publications and presentations and when required by law to disclose
such information.

        10. LIMITED WARRANTY

                10.1 LIMITED WARRANTY. The University hereby represents and
warrants that:

                        (a)     it has full right and power to enter into this
                                Agreement;

                        (b)     the University is the sole owner of all rights
                                in the Patent Rights, and the University has
                                authority to license those rights under the
                                terms and conditions stated in this Agreement,
                                as evidenced by the signature of the
                                University's duly authorized representative on
                                this Agreement;

                        (c)     the University is not aware that the Patent
                                Rights are subject to any liens or encumbrances;

                        (d)     the University has not granted licenses to the
                                Patent Rights that would restrict the license
                                granted to Santarus under the Patent Rights; and

                        (e)     there are no claims, judgments or settlements
                                known to the University to be paid by the
                                University with respect to the Patent Rights,
                                nor are there any pending claims or litigation
                                relating to the Patent Rights known to the
                                University.

                10.2 NO OTHER WARRANTIES. THE UNIVERSITY MAKES NO OTHER
WARRANTIES CONCERNING THE PATENT RIGHTS OR TECHNICAL INFORMATION COVERED BY THIS
AGREEMENT, INCLUDING WITHOUT LIMITATION, ANY EXPRESS OR IMPLIED WARRANTY OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE AS TO PATENT RIGHTS,
TECHNICAL INFORMATION OR ANY LICENSED PRODUCT. THE UNIVERSITY MAKES NO WARRANTY
OR REPRESENTATION AS TO THE VALIDITY OR SCOPE OF THE PATENT RIGHTS, OR THAT ANY
LICENSED PRODUCT WILL BE FREE FROM AN INFRINGEMENT ON PATENTS OR OTHER
INTELLECTUAL PROPERTY RIGHTS OF THIRD PARTIES, OR THAT NO THIRD PARTIES ARE IN
ANY WAY INFRINGING THE PATENT RIGHTS OR TECHNICAL INFORMATION COVERED BY THIS
AGREEMENT.

                10.3 NO CONSEQUENTIAL DAMAGES. IN NO EVENT SHALL EITHER PARTY'S
LIABILITY OF ANY KIND INCLUDE ANY SPECIAL, INDIRECT, INCIDENTAL, OR
CONSEQUENTIAL LOSSES OR DAMAGES, EVEN IF SUCH PARTY HAS BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.



                                       14
<PAGE>

        11. PATENT MATTERS

                11.1 PROSECUTION. The University will diligently prosecute and
maintain the United States and foreign patents comprising Patent Rights using
***. Both parties hereto will keep this documentation in confidence in
accordance with the provisions of Article 14 ("Confidentiality") herein. Counsel
for the University will take instructions only from the University.
Notwithstanding the foregoing, the University shall give due consideration to
the requests of Santarus concerning submissions of documents to government
patent offices.

                11.2 AMENDMENTS REQUESTED BY SANTARUS. The University will use
all reasonable efforts to amend any patent application to include claims
requested by Santarus and required to protect the Licensed Products contemplated
to be sold or Patent Method to be practiced under this Agreement. The foregoing
shall not require the University to narrow such claims if Santarus requests the
University to do so.

                11.3 EXTENSIONS. The University and Santarus will cooperate in
applying for an extension of the term of any patent included within Patent
Rights, if appropriate, under the Drug Price Competition and Patent Term
Restoration Act of 1984. Santarus will prepare all such documents, and the
University will execute such documents and will take such additional action as
Santarus may reasonably request in connection therewith.

                11.4 FOREIGN FILINGS. The University will, at the request of
Santarus, file, prosecute, and maintain patent applications and patents covered
by Patent Rights in foreign countries if available. Santarus must notify the
University within *** of the filing of the corresponding United States
application of its decision to request the University to file foreign
counterpart patent applications. This notice concerning foreign filing must be
in writing and must identify the countries desired. The absence of such a notice
from Santarus to the University within the *** period will be considered an
election by Santarus not to request the University to secure foreign patent
rights on behalf of Santarus. The University will have the right to file patent
applications at its own expense in any country Santarus has not included in its
list of desired countries, and such applications and resultant patents, if any,
will not be included in the licenses granted under this Agreement.

                11.5 PROSECUTION EXPENSES. All reasonable costs of preparing,
filing, prosecuting and maintaining all United States and foreign patent
applications and all reasonable costs and fees relating to the preparation and
filing of patents covered by Patent Rights will be



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                                       15
<PAGE>
***
***
***. Santarus will reimburse the University for all such costs and charges, as a
separate payment apart from any royalties or other revenues owed by Santarus to
the University, within *** days following receipt of an itemized invoice from
the University for same. ***. Notwithstanding anything to the contrary in this
Section 11.5, Santarus shall have no obligation to reimburse any such costs to
the extent that any third party has reimbursed the University for such costs.

                11.6 TERM OF OBLIGATION. The obligation of Santarus to
underwrite and to pay patent preparation, filing, prosecution, maintenance, and
related costs will continue for costs incurred until *** days after receipt by
either party of a notice of termination ("Notice of Termination") of this
Agreement or license with respect to a particular patent or patent application
within the Patent Rights. Santarus will reimburse the University for all patent
costs incurred during the term of this Agreement and for *** days thereafter
whether or not invoices for such costs are received during the *** day period
after receipt of a Notice of Termination. Santarus may with respect to any
particular patent application or patent terminate its obligations in any or all
designated countries upon *** days written notice to the University. The
University may continue prosecution and/or maintenance of such application(s) or
patent(s) at its sole discretion and expense, provided, however, that Santarus
will have no further licenses with respect to such application(s) or patent(s)
hereunder.

                11.7 SMALL ENTITY STATUS. Santarus will notify the University of
any change of its status as a small entity (as defined by the United States
Patent and Trademark Office) and of the first sublicense granted to an entity
that does not qualify as a small entity as defined therein.

                11.8 PATENT MARKING. Santarus will mark all Licensed Products
made, used, or sold under the terms of this Agreement, or their containers, in
accordance with the applicable patent marking laws.

                11.9 EXPORT CONTROLS. The Patent Rights made available to
Santarus hereunder may be subject to export control under the Export
Administration Regulations of the United States Department of Commerce, or
export control regulations of other United States Government agencies including
the Department of State and Department of Treasury. Santarus agrees that it will
not export the Patent Rights, or the direct product thereof, directly or
indirectly, to any countries to which such export is now or hereafter becomes
illegal under any such regulations. The University neither represents that a
license shall not be required nor that, if required, it shall be issued.

                11.10 INSTRUCTIONS TO COUNSEL. The University will give
instructions to the University's patent counsel to forward all relevant patent
prosecution documentation covered in the Patent Rights to Santarus
simultaneously when forwarding such documentation to the



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                                       16
<PAGE>

University so long as this Agreement is active. Santarus may request that the
University supply estimates of patent expenses associated with the filing and
prosecution of foreign and United States patents in the Patent Rights, and the
University shall make reasonable efforts to supply such information to Santarus
on a timely basis. Santarus may also request estimates of such expenses from the
University's patent counsel if Santarus desires to do so.

                11.11 PATENT INFRINGEMENT. In the event that either party learns
of the substantial infringement of any patent licensed under this Agreement,
such party will call the attention of the other party thereto in writing and
will provide the other party with reasonable evidence of such infringement. Both
parties to this Agreement acknowledge that during the period and in a
jurisdiction where Santarus has exclusive rights under this Agreement, neither
will notify a third party of the infringement of any of Patent Rights without
first obtaining consent of the other party, which consent will not be
unreasonably withheld. Both parties will use their best efforts in cooperation
with each other to terminate such infringement without litigation.

                11.12 SANTARUS ENFORCEMENT. Santarus shall have the right to
prosecute in its own name and at its own expense any infringement, offers to
sell and importation of Patent Rights, ***. In the event Santarus elects to
bring suit in accordance with this Section, the University may thereafter join
such suit at its own expense.

                11.13 INFRINGEMENT EXPENSES. All recoveries will be allocated in
the following order: ***
                     ***
                     ***

                  11.14 SETTLEMENT. ***
                                    ***
                                    ***

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                                       17
<PAGE>

                11.15 UNIVERSITY ENFORCEMENT. In the event that Santarus elects
not to exercise its right to prosecute an infringement of the Patent Rights
pursuant to Section 11.12 above, the University may do so at its own expense,
***.

                11.16 COOPERATION. Each party will cooperate with the other in
litigation proceedings instituted hereunder ***.

        12. INDEMNIFICATION

                12.1 OBLIGATION. Santarus shall (and require its sublicensees
and Joint Ventures to) at all times during the term of this Agreement and
thereafter, indemnify, hold harmless, and defend the University, and its then
current and former Curators, officers, employees, and agents; *** against any
and all claims, suits, losses, damage, costs, fees, and expenses, including
legal expenses and reasonable attorneys' fees, resulting from or arising out of
the death of or injury to any person or persons or out of any damage to property
and against any other claim, proceeding, demand, expense and liability of any
kind whatsoever resulting from the production, sale or use of the Patent Rights
and Technical Information or of any Patent Method or Licensed Products, or
Santarus' operation under this Agreement or arising from any obligation of
Santarus hereunder.

                12.2 INSURANCE. Santarus shall during the term of this
Agreement, carry occurrence-based liability insurance with policy limits of at
least *** dollars ($ ***) per occurrence and *** dollars ($ *** ) annual
aggregate. Upon request, Santarus will provide the University with evidence of
such insurance. *** It is agreed that the insurance required to required in the
public interest, and that the University does not assume any liability for acts
of Santarus, its officers, agents, and employees, in connection with the
granting of this Agreement.

        13. NOTICES

        Any notice or payment required to be given to either party will be
deemed to have been properly given and to be effective:

                13.1 on the date of delivery if delivered in person;

                13.2 on the date of mailing if mailed by first-class certified
mail, postage paid; or



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                                       18
<PAGE>

                13.3 on the date of mailing if mailed by any global express
carrier service that requires the recipient to sign the documents demonstrating
the delivery of such notice or payment;

to the respective addresses given below, or to another address as designated in
writing by the party changing its prior address.

In the case of Santarus:         Santarus, Inc.
                                 12230 El Camino Real, Suite 300
                                 San Diego, CA 92130
                                 Telephone:  858-350-7940
                                 Facsimile:  858-350-7941
                                 Attention:  Gerald T. Proehl, President & COO

In the case of the University:   Office of Technology & Special Projects
                                 The University of Missouri-Columbia
                                 615 Locust Street Building, Third Floor
                                 Columbia, Missouri 65211-1400
                                 Telephone:  573-882-2821
                                 Facsimile:  573-882-1160
                                 Attention:  Thomas R. Sharpe, Ph.D.,
                                             Executive Director

        14. CONFIDENTIALITY

                14.1 Santarus and the University respectively will treat and
maintain the proprietary business, patent prosecution, software, engineering
drawings, process and technical information, and other proprietary information
("Proprietary Information") of the other party in confidence using at least the
same degree of care as that party uses to protect its own proprietary
information of a like nature for a period from the date of disclosure until ***
years after the date of termination of this Agreement.

                14.2 All Proprietary Information will be labeled or marked
confidential or as otherwise similarly appropriate by the disclosing party, or
if the Proprietary Information is orally or visually disclosed, it will be
reduced to writing or some other physically tangible form, marked and labeled as
set forth above by the disclosing party, and delivered to the receiving party
within 30 days after the oral or visual disclosure as a record of the disclosure
and the confidential nature thereof. Notwithstanding the foregoing, Santarus and
the University may use and disclose Proprietary Information to its employees,
agents, consultants, contractors, and, in the case of Santarus, its Joint
Ventures and sublicensees, provided that any such parties are bound by a like
duty of confidentiality.

                14.3 Nothing contained herein will in any way restrict or impair
the right of Santarus or the University to use, disclose, or otherwise deal with
any Proprietary Information:



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                                       19
<PAGE>

                        (a)     that recipient can demonstrate by written
                                records was previously known to it;

                        (b)     that is now, or becomes in the future, public
                                knowledge other than through acts or omissions
                                of recipient;

                        (c)     that is lawfully obtained without restrictions
                                by recipient from sources independent of the
                                disclosing party;

                        (d)     that is required to be disclosed to a
                                governmental entity or agency in connection with
                                seeking any governmental or regulatory approval,
                                or pursuant to the lawful requirement or request
                                of a governmental entity or agency; or

                        (e)     is required by law to be disclosed.

                14.4 Upon termination of this Agreement, Santarus and the
University will destroy or return to the disclosing party, at the disclosing
party's option, proprietary information received from the other in its
possession within fifteen (15) days following the effective date of termination.
Santarus and the University will provide each other, within thirty (30) days
following termination, with a written notice that Proprietary Information has
been returned or destroyed. Each party may, however, retain one copy of
Proprietary Information for archival purposes in non-working files.

        15. PROJECT TEAM

                15.1 ESTABLISHMENT. The parties shall establish a project team
consisting of persons designated by Santarus and the University (the "Project
Team"). The Project Team shall meet ***  in person or by telephone or other
mutually agreed upon method. The Project Team may also develop "sub-teams"
comprising a smaller number of Project Team members to discuss selected topics
in more detail.

                15.2 FUNCTIONS. The primary function of the Project Team is to
guide the preclinical and clinical development and the commercialization of the
Licensed Products. After each Project Team meeting, a Santarus member of the
Project Team will prepare a project report summarizing the meeting and
distribute the report to the Project Team members. The University members of the
Project Team will serve in an advisory capacity only.

        16. MISCELLANEOUS

                16.1 ASSIGNMENT. Neither party may assign any of its obligations
or rights under this Agreement without the other party's prior, express, written
consent, which consent shall not be unreasonably withheld; provided, however,
that either party is free to assign any or all of its obligations under this
Agreement to its Affiliates; provided, further, Santarus may assign its rights
and obligations hereunder to any entity which succeeds to the business and
assets of Santarus *** of the outstanding voting securities of Santarus. Any
other attempted assignment is void. This Agreement shall be binding upon and
shall inure to the benefit of any permitted assigns. For the avoidance of doubt,
Santarus shall not


                                       20

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<PAGE>

be precluded from contracting with third parties for the manufacture of or
distribution of Licensed Products.

                16.2 WAIVER. It is agreed that no waiver by either party hereto
of any breach or default of any of the covenants or agreements herein set forth
will be deemed a waiver as to any subsequent and/or similar breach or default.

                16.3 FORCE MAJEURE. The parties to this Agreement will be
excused from any performance required hereunder if such performance is rendered
impossible or unfeasible due to any acts of God, catastrophes, or other major
events beyond their reasonable control, including, without limitation, war,
riot, and insurrection; laws, proclamations, edicts, ordinances, or regulations;
strikes, lock-outs, or other serious labor disputes; and floods, fires,
explosions, or other natural disasters. However, any party to this Agreement
will have the right to terminate this Agreement upon *** prior written notice if
either party is unable to fulfill its obligations under this Agreement due to
any of the causes mentioned above and such inability continues for a period of
***. Notices will be subject to Article 13 ("Notices").

                16.4 HEADINGS. The headings of the several sections are inserted
for convenience of reference only and are not intended to be a part of or to
affect the meaning or interpretation of this Agreement.

                16.5 EFFECTIVENESS OF AGREEMENT. This Agreement will not be
binding upon the parties until it has been signed below on behalf of each party,
in which event, it will be effective as of the Effective Date.

                16.6 AMENDMENT. No amendment or modification hereof will be
valid or binding upon the parties unless made in writing and signed on behalf of
each party.

                16.7 ENTIRE AGREEMENT. This Agreement embodies the entire
understanding of the parties and will supersede all previous communications,
representations or understandings, either oral or written, between the parties
relating to the subject matter hereof.

                16.8 SEVERABILITY. In case any of the provisions contained in
this Agreement are held to be invalid, illegal, or unenforceable in any respect,
such invalidity, illegality, or unenforceability will not affect any other
provisions hereof, but this Agreement will be construed as if such invalid or
illegal or unenforceable provisions had never been contained herein.

                16.9 JOINT PREPARATION. This Agreement has been negotiated and
prepared jointly by both parties and shall not be construed for or against any
party but shall be given a fair and reasonable construction in accordance with
the intention of the parties.

                16.10 INDEPENDENT CONTRACTORS. The relationship between the
parties is that of independent contractors. The parties are not joint venturers,
partners, principal and agent, master and servant, employer and employee, and
have no other relationship other than independent contracting parties. Neither
party shall have power to bind or obligate each other in any manner, other than
as is expressly set forth in this Agreement.



                                       21

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<PAGE>

                16.11 EMPLOYMENT OF INVENTOR. Santarus ***

                16.12 COMPLIANCE WITH LAWS. Each party shall comply with all
applicable federal, state and local laws and regulations in connection with its
activities pursuant to this Agreement.

                16.13 GOVERNING LAW. This Agreement will be interpreted and
construed in accordance with the laws of the State of ***, excluding any choice
of law rules that would direct the application of the laws of another
jurisdiction, but the scope and validity of any patent or patent application
will be governed by the applicable laws of the country of such patent or patent
application.

        IN WITNESS WHEREOF, both the University and Santarus have executed this
Agreement, in duplicate originals, by their respective officers hereunto duly
authorized, on the date and year hereinafter written.


THE CURATORS OF THE UNIVERSITY OF MISSOURI    SANTARUS, INC.


By: /s/ Thomas R. Sharpe                  By: /s/ Gerald T. Proehl
   -------------------------------------     -------------------------------
        Thomas R. Sharpe, Ph.D.              Gerald T. Proehl
        Executive Director, Office of        President & Chief Operating Officer
        Technology & Special Projects

Date: January 26, 2001                    Date: January 26, 2001
     -----------------------------------       ---------------------------------



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<PAGE>

                                    EXHIBIT A

                    PATENTS AND PATENT APPLICATIONS LICENSED

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------
   Patent or
Application No.       Type        Filing Date           Title          Inventor       Status
-------------------------------------------------------------------------------------------------
<S>                   <C>         <C>                   <C>            <C>            <C>
*                                            ***
                                             ***
                                             ***
</TABLE>



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                                       23
<PAGE>

                                    EXHIBIT B

                            STOCK PURCHASE AGREEMENT

THIS STOCK PURCHASE AGREEMENT (the "Agreement") is made as of January 26, 2001
(the "Effective Date") by and between Santarus, Inc., a California corporation
(the "Corporation"), and The Curators of the University of Missouri, a public
corporation organized under the laws of Missouri ("University").

                                   WITNESSETH:

WHEREAS, the Corporation and University have entered into an Exclusive License
Agreement dated January 26, 2001 (the "License Agreement") pursuant to which
Corporation agreed to issue certain shares of Common Stock of the Corporation to
University; and

WHEREAS, the Corporation and University now wish to set forth the terms and
conditions of the issuance of such Common Stock.

NOW, THEREFORE, IT IS AGREED between the parties as follows:

1. Issuance of Stock. University is hereby acquiring from the Corporation and
the Corporation is hereby issuing to University, at a price $0.05 per share (the
"Original Issue Price"), Five Hundred Seventy-Five Thousand (575,000) shares of
the Corporation's Common Stock (the "Stock"). University's payment of the
purchase price for the Stock is hereby acknowledged by the Corporation as a
result of University's execution of the License Agreement and the grant to the
Corporation of certain license rights thereunder.

2. Stock Restriction and Registration Rights Agreement. Concurrently with their
execution of this Agreement, the University and the Corporation are entering
into a Stock Restriction and Registration Rights Agreement of even date in the
form attached hereto as Exhibit I ("Restriction Agreement") and the University
shall hold the Stock subject to the terms thereof.

3. Representations and Warranties of the Corporation. The Corporation hereby
represents and warrants to the University as follows:

        (a) Organization and Standing; Articles and By-Laws. The Corporation is
a corporation duly organized, validly existing and in good standing under the
laws of the State of California and has all requisite corporate power and
authority to carry on its businesses as now conducted and as proposed to be
conducted. The Corporation is qualified or licensed to do business as a foreign
corporation in all jurisdictions where such qualification or licensing is
required, except where the failure to so qualify would not have a material
adverse effect upon the Corporation.

        (b) Corporate Power. The Corporation has now all requisite corporate
power to enter into this Agreement and the Restriction Agreement and to sell and
issue the Stock. This Agreement and the Restriction Agreement are valid and
binding obligations of the Corporation enforceable in accordance with their
terms, except as the same may be limited by bankruptcy,



                                       24
<PAGE>

insolvency, moratorium, and other laws of general application affecting the
enforcement of creditors' rights.

        (c) Subsidiaries. The Corporation does not control, directly or
indirectly, any other corporation, association or business entity.

        (d) Capitalization. The authorized capital stock of the Corporation is
15,000,000 shares of Common Stock, of which 4,313,249 shares are outstanding,
and 10,000,000 shares of Preferred Stock. 620,000 shares of Preferred Stock have
been designated Series A Preferred Stock, all of which are issued and
outstanding, and 5,326,000 shares of Preferred Stock have been designated Series
B Preferred Stock, 5,276,000 of which are issued and outstanding. All such
issued and outstanding shares have been duly authorized and validly issued, are
fully paid and nonassessable, and were issued in compliance with all applicable
state and federal laws concerning the issuance of securities.

        (e) Authorization.

                (i) Corporate Action. All corporate action on the part of the
Corporation, its officers, directors and shareholders necessary for the sale and
issuance of the Stock and the performance of the Corporation's obligations
hereunder and under the Restriction Agreement has been taken.

                (ii) Valid Issuance. The Stock, when issued in compliance with
the provisions of this Agreement, will be duly authorized, validly issued, fully
paid and nonassessable and will be free of any liens or encumbrances caused or
created by the Corporation; provided, however, the Stock is subject to
restrictions on transfer as set forth herein and in the Restriction Agreement,
and as may be required by future changes in such laws.

        (f) No Preemptive Rights. Except as provided in the Restriction
Agreement, no person has any right of first refusal or any preemptive rights in
connection with the issuance of the Stock other than the preemptive rights of
the holders of the Corporation's Series B Preferred Stock which have been
expressly waived in connection with the issuance of the Stock.

        (g) Offering. Subject in part to the truth and accuracy of the
University's representations set forth in Section 4 of this Agreement, the
offer, sale and issuance of the Stock as contemplated by this Agreement are
exempt from the registration requirements of any applicable state and federal
securities laws, and neither the Corporation nor any authorized agent acting on
its behalf will take any action hereafter that would cause the loss of such
exemption.

        (h) Compliance with Other Instruments. The execution, delivery and
performance of this Agreement and the consummation of the transactions
contemplated hereby will not result in any violation of the Corporation's
Articles of Incorporation or Bylaws, or in any material respect of any
instrument, judgment, order, writ, decree or contract to which the Corporation
is a party or by which it is bound, or of any provision of any federal or state
statute, rule or regulation applicable to the Corporation or be in conflict with
or constitute, with or without the passage of time and giving of notice, either
a default under any such provision, instrument, judgment, order, writ, decree or
contract or an event that results in the creation of any lien, charge or
encumbrance upon any assets of the Corporation or the suspension, revocation,
impairment, forfeiture or




                                       25
<PAGE>

nonrenewal of any material permit, license, authorization or approval applicable
to the Corporation, its business or operations or any of its assets or
properties.

4. Representations, Warranties and Covenants of the University. University
hereby agrees, represents, warrants and covenants follows:

        (a) University is acquiring the Stock solely for its own account for
investment and not with a view to, or for resale in connection with, any
distribution thereof within the meaning of the Securities Act of 1933 as amended
(the "Act"). Except as contemplated in Section 4(f)(ii) hereof, University
further represents that it does not have any present intention of selling,
offering to sell or otherwise disposing of or distributing the Stock or any
portion thereof; and that the entire legal and beneficial interest of the Stock
it is purchasing is being purchased for, and will be held for the account of,
University only and neither in whole nor in part for any other person.

        (b) University is aware of the Corporation's business affairs and
financial condition and has acquired sufficient information about the
Corporation to reach an informed and knowledgeable decision to acquire the
Stock. University further represents and warrants that it has discussed the
Corporation and its plans, operations and financial condition with its officers,
has received all such information as it deems necessary and appropriate to
enable it to evaluate the financial risk inherent in making an investment in the
Stock and has received satisfactory information concerning the business and
financial condition of the Corporation in response to all inquiries in respect
thereof.

        (c) University realizes that its acquisition of the Stock will be a
highly speculative investment, and it is able, without impairing its financial
condition, to hold the Stock for an indefinite period of time.

        (d) The Corporation has disclosed to University that:

                (i) The issuance of the Stock has not been registered under the
Act, and the Stock must be held indefinitely unless a transfer of it is
subsequently registered under the Act or an exemption from such registration is
available, and that the Corporation is under no obligation to register the
Stock;

                (ii) The Corporation will make a notation in its records of the
aforementioned restrictions on transfer and legends.

        (e) University is aware of the provisions of Rule 144, promulgated under
the Act, which, in substance, permits limited public resale of "restricted
securities" acquired, directly or indirectly, from the issuer thereof (or an
affiliate of such issuer), in a non-public offering subject to the satisfaction
of certain conditions, including among other things: the resale occurring not
less than one year from the date University has purchased and paid for the
Stock; the availability of certain public information concerning the
Corporation; the sale being through a broker in an unsolicited "broker's
transaction" or in a transaction directly with a market maker (as said term is
defined under the Securities Exchange Act of 1934); and that any sale of the
Stock may be made by it only in limited amounts during any three-month period
not exceeding specified limitations. University further represents that it
understands that at the time it wishes to sell the



                                       26
<PAGE>

Stock there may be no public market upon which to make such a sale, and that,
even if such a public market then exists, the Corporation may not be satisfying
the current public information requirements of Rule 144, and that, in such
event, it would be precluded from selling the Stock under Rule 144 even if the
one-year minimum holding period had been satisfied. University represents that
it understands that in the event all of the requirements of Rule 144 are not
satisfied, registration under the Act or compliance with an exemption from
registration will be required; and that, notwithstanding the fact that Rule 144
is not exclusive, the staff of the SEC has expressed its opinion that persons
proposing to sell private placement securities other than in a registered
offering and otherwise than pursuant to Rule 144 will have a substantial burden
of proof in establishing that an exemption from registration is available for
such offers or sales, and that such persons and their respective brokers who
participate in such transactions do so at their own risk.

        (f) Without in any way limiting University's representations and
warranties set forth above, University further agrees that it shall in no event
make any disposition of all or any portion of the Stock which it is purchasing
unless and until:

                (i) There is then in effect a registration statement under the
Act covering such proposed disposition and such disposition is made in
accordance with said Registration Statement; or

                (ii) University transfers all or any portion of the Stock
subject to the Restriction Agreement to an affiliate or employee of the
University, which is expressly permitted hereunder; or

                (iii) University shall have (1) notified the Corporation of the
proposed disposition and furnished the Corporation with a detailed statement of
the circumstances surrounding the proposed disposition, and (2) furnished the
Corporation with an opinion of its own counsel to the effect that such
disposition will not require registration of such shares under the Act, and such
opinion of its counsel shall have been concurred in by counsel for the
Corporation and the Corporation shall have advised University of such
concurrence.

5. Counterparts. This Agreement may be executed in any number of counterparts,
each of which shall be an original, but all of which together shall constitute
one instrument.



                                       27
<PAGE>

        IN WITNESS WHEREOF, the parties hereto have executed this Agreement as
of the day and year first above written.

"UNIVERSITY"                            "CORPORATION"

THE CURATORS OF THE UNIVERSITY          SANTARUS, INC.
OF MISSOURI

By:                                     By:
   --------------------------------        -------------------------------------
   Thomas R. Sharpe,                        Gerald T. Proehl, President & COO
   Executive Director                   Address:  12230 El Camino Real
   Office of Technology                           Suite 300
   & Special Projects                             San Diego, CA 92130
Address: 615 Locust Street Building
         Third Floor
         Columbia, MO 65211-1400



                                       28
<PAGE>

                                    EXHIBIT I

               STOCK RESTRICTION AND REGISTRATION RIGHTS AGREEMENT


        THIS STOCK RESTRICTION AND REGISTRATION RIGHTS AGREEMENT is made as of
January 26, 2001 the ("Effective Date") by and between Santarus, Inc., a
California corporation (the "Corporation"), and The Curators of the University
of Missouri, a public corporation organized under the laws of Missouri (the
"University"). All capitalized terms used herein and not otherwise defined shall
have the same meaning given to such terms in the Stock Purchase Agreement of
even date between the Corporation and the University ("Stock Purchase
Agreement") and the Exclusive License Agreement dated of even date between the
Corporation and the University ("License Agreement").

        WHEREAS, under the terms of the Stock Purchase Agreement and in partial
consideration for the University's execution of the License Agreement, the
Corporation has issued the Stock to the University.

        WHEREAS, the Corporation and the University have agreed that the Stock
will be held subject to the terms of this Stock Restriction and Registration
Rights Agreement.

        NOW, THEREFORE, IT IS AGREED between the parties as follows:

        1. Unvested Share Repurchase Option. In the event of the termination of
the License Agreement by the Corporation pursuant to Section 8.2 thereof, the
Corporation shall have the right to reacquire the shares of the Stock which have
not vested pursuant to the provisions of this Section 1 ("Unvested Shares")
under the terms and subject to the conditions set forth in this Section 1 (the
"Unvested Share Repurchase Option").

                1.1. Vesting of Shares. The term "Initial Vesting Date" shall
mean the Effective Date. The shares of Stock will vest (the "Vested Shares") on
the dates and/or upon the occurrence of the events set forth below:

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------
Date                                            Number of Shares Vested
--------------------------------------------------------------------------------
<S>                                             <C>
On the Initial Vesting Date                       ***    shares of Stock
--------------------------------------------------------------------------------
Upon           ***                                ***    shares of Stock
               ***
        ***
--------------------------------------------------------------------------------
Upon           ***                                ***   shares of Stock
               ***
        ***
--------------------------------------------------------------------------------
</TABLE>



***     Portions of this page have been omitted pursuant to a request for
        Confidential Treatment and filed separately with the Commission.



                                       29
<PAGE>

The foregoing notwithstanding, all shares of the Stock shall become fully vested
effective upon termination of the License Agreement by the University pursuant
to Section 8.3 thereof or by the Corporation pursuant to Section 8.4 thereof.

                1.2. Exercise of Unvested Share Repurchase Option. The
Corporation may exercise the Unvested Share Repurchase Option by written notice
to University within ninety (90) days after the Corporation's termination of the
License Agreement pursuant to Section 8.2 thereof.

                1.3. Payment for Shares and Return of Shares. Payment by the
Corporation to University shall be made in cash within sixty (60) days after the
date of the mailing of the written notice of exercise of the Unvested Share
Repurchase Option. The purchase price per share being purchased by the
Corporation shall be an amount equal to the Original Issue Price, as adjusted
for stock splits, stock dividends, recapitalizations and the like after the date
hereof. Within thirty (30) days after payment by the Corporation, University
shall deliver to the Corporation a certificate for the shares which the
Corporation has purchased.

                1.4. Legends. The Corporation may at any time place a legend or
legends referencing the Unvested Share Repurchase Option on any certificates for
shares subject to the Unvested Share Repurchase Option. Upon request of the
University at any time that any Unvested Shares have vested, the Corporation
will remove such legend from the applicable certificates.

        2. Stock Dividends. etc. If, from time to time, there is any stock
dividend, stock split or other change in the character or amount of any of the
outstanding stock of the Corporation, then in such event any and all new
substituted or additional securities to which University is entitled by reason
of University's ownership of Unvested Shares acquired pursuant to this Agreement
shall be considered Stock and shall be an adjustment to the number of shares set
forth in Section 1.1 above to which such shares relate, shall be subject to
vesting in accordance with Section 1.1 and shall be immediately subject to the
Unvested Share Repurchase Option with the same force and effect as the shares
subject to the Unvested Share Repurchase Option immediately before such event in
accordance with the provisions set forth in Section 1.1 above.

        3. Right of First Refusal. University cannot transfer, assign or
otherwise dispose of, voluntarily or involuntarily, any Unvested Shares or any
interest in those shares. Before any Vested Shares registered in the name of
University may be sold or transferred (including transfer by operation of law)
other than a transfer to an affiliate or employee of the University (a
"Permitted Transferee") which transfer shall be expressly subject to this
Agreement, such shares shall first be offered to the Corporation, which will
have the right to purchase all, but not less than all, of the Vested Shares
proposed to be transferred ("Right of First Refusal"), in the following manner:

                3.1. University shall first give written notice (the "Transfer
Notice") of any proposed transfer other than to a Permitted Transferee to the
Corporation. The Transfer Notice shall name the proposed transferee, state the
number of shares of Stock to be transferred, and if the transfer is voluntary,
the price per share and all other terms of the offer. The Transfer Notice




                                       30
<PAGE>

shall be signed by University and the prospective transferee and must constitute
a binding agreement for the transfer of the Stock subject only to the Right of
First Refusal.

                3.2. Within thirty (30) days of delivery of University's notice
of a proposed voluntary transfer, the Corporation shall determine the bona fide
nature of the proposed voluntary transfer and give University written notice of
its determination. If the proposed transfer is deemed to be bona fide, the
remaining subsections of this section shall apply to the sale. If the proposed
transfer is deemed not to be bona fide, University will be responsible for
providing additional information to the Corporation to show the bona fide nature
of the proposed transfer and no Stock will be transferred on the books of the
Corporation until the Corporation has approved the proposed transfer as bona
fide.

                3.3. If the Corporation fails to exercise in full the Right of
First Refusal within thirty (30) days from the later of the date the Transfer
Notice is delivered to the Corporation or thirty (30) days after the date the
transfer is determined to be bona fide (if University is required to provide
additional information as provided in Section 3.2 above), University may, not
later than one hundred twenty (120) days following delivery to the Corporation
of the Transfer Notice, conclude a transfer of the shares of Stock subject to
the Transfer Notice on the terms and conditions described in the Transfer
Notice. Any proposed transfer on terms and conditions different from those
described in the Transfer Notice, as well as any subsequent proposed transfer by
University, shall again be subject to the Right of First Refusal and shall
require compliance by University with the procedure described in this Section 3.
If the Corporation exercises the Right of First Refusal, the parties shall
consummate the sale of shares of Stock on the terms set forth in the Transfer
Notice by the later of sixty (60) days after the delivery of the Transfer Notice
to the Corporation or thirty (30) days after the date the transfer is determined
to be bona fide (if University is required to provide additional information as
provided in Section 3.2 above); provided, however, in the event the Transfer
Notice provides for the payment for the shares of Stock other than in cash, the
Corporation shall have the option of paying for the shares of Stock by the
discounted cash equivalent of the consideration described in the Transfer Notice
as reasonably determined by University and the Corporation.

                3.4. The foregoing notwithstanding, University may sell or
otherwise assign, with or without consideration, any shares of Stock to any
Permitted Transferee who shall thereafter be bound by the provisions of this
Agreement.

                3.5. All transferees of shares of Stock or any interest therein
including any Permitted Transferee other than the Corporation shall be required
as a condition of such transfer to agree in writing (in a form satisfactory to
the Corporation) that they will receive and hold such shares of Stock or
interests subject to the provisions of this Agreement, including the Right of
First Refusal and upon thereby becoming a party to this Agreement shall have all
of the rights of the University under this Agreement with respect to such
shares.

                3.6. The Right of First Refusal shall terminate at such time as
a public market exists for the Corporation's Common Stock (or any other stock
issued by the Corporation, or any successor, in exchange for the Stock). For the
purpose of this Agreement, a "public market" shall be deemed to exist if (a)
such stock is listed on a national securities exchange (as that term is used in
the Securities Exchange Act of 1934) or (b) such stock is traded on the
over-the-counter



                                       31
<PAGE>

market and prices therefore are published daily on business days in a recognized
financial journal.

        4. Legends. All certificates representing any shares of Stock subject to
the provisions of this Agreement shall have endorsed thereon the following
legends:

                4.1. "THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO
A RIGHT OF FIRST REFUSAL AS SET FORTH IN AN AGREEMENT EXECUTED BY THE REGISTERED
HOLDER, OR HIS OR ITS PREDECESSOR IN INTEREST, A COPY OF WHICH IS ON FILE AT THE
PRINCIPAL OFFICE OF THIS CORPORATION."

                4.2. "THE SECURITIES EVIDENCED BY THIS CERTIFICATE HAVE. NOT
BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, AND MAY NOT BE
SOLD, TRANSFERRED, ASSIGNED OR HYPOTHECATED UNLESS THERE IS AN EFFECTIVE
REGISTRATION STATEMENT UNDER SUCH ACT COVERING SUCH SECURITIES, THE SALE IS MADE
IN ACCORDANCE WITH RULE 144 UNDER THE ACT, OR THE COMPANY RECEIVES AN OPINION OF
COUNSEL FOR THE HOLDER OF THESE SECURITIES REASONABLY SATISFACTORY TO THE
COMPANY, STATING THAT SUCH SALE, TRANSFER, ASSIGNMENT OR HYPOTHECATION IS EXEMPT
FROM THE REGISTRATION AND PROSPECTUS DELIVERY REQUIREMENTS OF SUCH ACT."

                4.3. For Unvested Shares only subject to Section 1.4 above, the
certificates shall have the following additional legend:

"THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO A REPURCHASE OPTION
AS SET FORTH IN AN AGREEMENT EXECUTED BY THE REGISTERED HOLDER, OR HIS OR ITS
PREDECESSOR IN INTEREST, A COPY OF WHICH IS ON FILE AT THE PRINCIPAL OFFICE OF
THIS CORPORATION."

        5. Registration.

                5.1. Definitions. As used in this Section 5:

                        (a) The terms "register", "registered" and
"registration" refer to a registration effected by preparing and filing a
registration statement in compliance with the Securities Act and the declaration
or ordering of the effectiveness of such registration statement;

                        (b) The term "Registrable Securities" means: (i) the
Stock, and (ii) any other shares of the Corporation's stock issued as a dividend
or other distribution with respect to, or in exchange for or in replacement of,
the Stock;

                        (c) The term "Holder" means any holder of outstanding
Registrable Securities who acquired such Registrable Securities in a transaction
or series of transactions not involving any registered public offering;



                                       32
<PAGE>

                5.2. Corporation Registration.

                        (a) Notice of Registration. If at any time or from time
to time, the Corporation shall determine to register any of its securities,
either for its own account or the account of a security holder or holders (other
than a registration relating solely to employee stock option or purchase plans
or relating solely to an SEC Rule 145 transaction or to debt securities), the
Corporation will:

                                (i) promptly give to each Holder written notice
thereof; and

                                (ii) include in such registration (and any
related qualification under state securities laws or other compliance), and in
any underwriting involved therein, all the Registrable Securities specified in a
written request or requests, received within twenty (20) days after such written
notice from the Corporation, by any Holder or Holders, except as set forth in
Section 5.2(b) below.

                        (b) Underwriting. If the registration of which the
Corporation gives notice is for a registered public offering involving an
underwriting, the Corporation shall so advise the Holders as a part of the
written notice given pursuant to Section 5.2(a)(i). In such event the right of
any Holder to registration pursuant to this Section 5.2 shall be conditioned
upon the inclusion of such Holder's Registrable Securities in the underwriting.
All Holders proposing to distribute their securities shall (together with the
Corporation and other holders distributing their securities through such
underwriting) enter into an underwriting agreement in customary form with the
underwriter or underwriters selected for such underwriting by the Corporation.
Notwithstanding any other provision of this Section 5.2, if the underwriter
determines that marketing factors require a limitation of the number of
securities to be included in the registration, the underwriter may cause to be
excluded some or all of the Registrable Securities on a pro rata basis based on
the total number of the Registrable Securities held by the Holders and shall
have no obligation to limit or reduce the inclusion of other securities (other
than Registrable Securities) entitled to registration held by other persons or
organizations selling securities pursuant to registration rights granted them by
the Corporation. The Corporation shall advise all Holders of Registrable
Securities which would otherwise be registered and underwritten pursuant hereto
of any such limitations, and the number of shares of Registrable Securities that
may be included in the registration. If any Holder disapproves of the terms of
any such underwriting, it may elect to withdraw therefrom by written notice to
the Corporation and the underwriter. Any securities excluded or withdrawn from
such underwriting shall not be transferred prior to 90 days after the effective
date of the registration statement for such underwriting, or such shorter period
as the underwriter may require.

                5.3. Expenses of Registration. All expenses incurred in
connection with any registration, qualification or compliance pursuant to this
Section 5, including all registration, filing and qualification fees, printing
expenses, fees and disbursements of counsel for the Corporation, and expenses of
any special audits incidental to such registration, shall be borne by the
Corporation; provided, however, the Corporation shall not be required to pay
underwriters' discounts, commissions, or stock transfer taxes relating to
Registrable Securities or the fees of any counsel retained by the Holders.



                                       33
<PAGE>

                5.4. Registration Procedures. In the case of each registration,
qualification or compliance effected by the Corporation pursuant to Section 5,
the Corporation will keep each Holder participating therein advised in writing
as to the initiation of each registration, qualification and compliance and as
to the completion thereof. At its expense the Corporation will:

                        (a) keep such registration, qualification or compliance
pursuant to Section 5.2, effective for a period of three months or until the
Holder or Holders have completed the distribution described in the registration
statement relating thereto, whichever first occurs; and

                        (b) furnish such number of prospectuses and other
documents incident thereto as a Holder from time to time may reasonably request.

                5.5. Indemnification.

                        (a) The Corporation will indemnify each Holder of
Registrable Securities, each of its officers, directors and partners, and each
person controlling such Holder, with respect to which registration,
qualification or compliance has been effected pursuant to this Section 5,
against all claims, losses, damages, costs, expenses and liabilities whatsoever
(or actions in respect thereof) arising out of or based on any untrue statement
(or alleged untrue statement) of a material fact contained in any registration
statement, prospectus, offering circular or other documents (including any
related registration, statement, notification or the like) incident to any such
registration, qualification or compliance, or based on any omission (or alleged
omission) to state therein a material fact required to be stated therein or
necessary to make the statements therein not misleading, or any violation by the
Corporation of the Securities Act or any state securities law or of any rule or
regulation promulgated under the Securities Act or any state securities law
applicable to the Corporation and relating to action or inaction required of the
Corporation in connection with any such registration, qualification or
compliance, and will reimburse each such Holder, each of its officers and
directors, and each person controlling such Holder, for any legal and any other
expenses reasonably incurred in connection with investigating or defending any
such claim, loss, damage, cost, expense, liability or action, provided that the
Corporation will not be liable in any such case to the extent that any such
claim, loss, damage, cost, expense, or liability arises out of or is based on
any untrue statement or omission based upon written information furnished to the
Corporation by an instrument duly executed by any such Holder and stated to be
specifically for use therein.

                        (b) Each Holder will, if Registrable Securities held by
or issuable to such Holder are included in the securities as to which such
registration, qualification or compliance is being effected, indemnify the
Corporation, each of its directors and officers who sign such registration
statement, each underwriter, if any, of the Corporation's securities covered by
such a registration statement, each person who controls the Corporation within
the meaning of the Securities Act, and each other Holder, each of such other
Holder's officers and directors and each person controlling such other Holder,
against all claims, losses, damages, costs, expenses and liabilities whatsoever
(or actions in respect thereof) arising out of or based on any untrue statement
(or alleged untrue statement) of a material fact contained in any such
registration statement, prospectus, offering circular or other documents
(including any related registration



                                       34
<PAGE>

statement, notification or the like) incident to any such registration,
qualification or compliance, or based on any omission (or alleged omission) to
state therein a material fact required to be stated therein or necessary to make
the statements therein not misleading, and will reimburse the Corporation, such
other Holders, such directors, officers, persons or underwriters for any legal
or any other expenses reasonably incurred in connection with investigating or
defending any such claim, loss, damage, cost, expense, liability or action, in
each case to the extent, but only to the extent, that such untrue statement (or
alleged untrue statement) or omission (or alleged omission) is made in such
registration statement, prospectus, offering circular or other document in
reliance upon and in conformity with written information furnished to the
Corporation by an instrument duly executed by such Holder and stated to be
specifically for use therein; provided, however, that the foregoing indemnity
agreement is subject to the condition that, insofar as it relates to any such
untrue statement (or alleged untrue statement) or omission (or alleged omission)
made in the preliminary prospectus but eliminated or remedied in the amended
prospectus on file with the SEC at the time the registration statement becomes
effective or the amended prospectus filed with the SEC pursuant to Rule 424(b)
(the "Final Prospectus"), such indemnity agreement shall not inure to the
benefit of any underwriter or any Holder, if there is no underwriter, if a copy
of the Final Prospectus was furnished to the person or entity asserting the
loss, liability, claim or damage at or prior to the time such action is required
by the Securities Act; and provided further, the total amount for which any
Holder shall be liable under this Section 5.5 shall not in any event exceed the
aggregate proceeds received by such Holder from the sale of Registrable
Securities held by such Holder in such registration.

                        (c) Each party entitled to indemnification under this
Section 5.5 (the "Indemnified Party") shall give notice to the party required to
provide indemnification (the "Indemnifying Party") promptly after such
Indemnified Party has actual knowledge of any claim as to which indemnity may be
sought, and shall permit the Indemnifying Party to assume the defense of any
such claim or any litigation resulting therefrom, provided that counsel for the
Indemnifying Party, who shall conduct the defense of such claim or litigation,
shall be approved by the Indemnified Party (whose approval shall not
unreasonably be withheld), and the Indemnified Party may participate in such
defense at such party's expense, and provided further that the failure of any
Indemnified Party to give notice as provided herein shall not relieve the
Indemnifying Party of its obligations under this Section 5. No Indemnifying
Party, in the defense of any such claim or litigation, shall, except with the
consent of each Indemnified Party, consent to entry of any judgment or enter
into any settlement which does not include as an unconditional term thereof the
giving by the claimant or plaintiff to such Indemnified Party of a release from
all liability in respect to such claim or litigation. If any such Indemnified
Party shall have been advised by counsel chosen by it that there may be one or
more legal defenses available to such Indemnified Party which are different from
or additional to those available to the Indemnifying Party, the Indemnifying
Party shall not have the right to assume the defense of such action on behalf of
such Indemnified Party and will reimburse such Indemnified Party and any person
controlling such Indemnified Party for the reasonable fees and expenses of any
counsel retained by the Indemnified Party, it being understood that the
Indemnifying Party shall not, in connection with any one action or separate but
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 for such Indemnified Party
or controlling person, which firm shall be designated in writing by the
Indemnified Party to the Indemnifying Party.



                                       35
<PAGE>

                5.6. Information by Holder. The Holder or Holders of Registrable
Securities included in any registration shall furnish to the Corporation such
information regarding such Holder or Holders and the distribution proposed by
such Holder or Holders as the Corporation may request in writing and as shall be
required in connection with any registration, qualification or compliance
referred to in this Section 5.

                5.7. Sale Without Registration. If at the time of any transfer
(other than a transfer not involving a change in beneficial ownership or other
than to a Permitted Transferee) of any Registrable Securities, such Registrable
Securities shall not be registered under the Securities Act, the Corporation may
require, as a condition of allowing such transfer, that the Holder or transferee
furnish to the Corporation (a) such information as is necessary in order to
establish that such transfer may be made without registration under the
Securities Act; and (b) at the expense of the Holder or transferee, an opinion
by legal counsel designated by such Holder or transferee and satisfactory to the
Corporation, satisfactory in form and substance to the Corporation, to the
effect that such transfer may be made without registration under such Act;
provided that nothing contained in this Section 5 shall relieve the Corporation
from complying with any request for registration, qualification or compliance
made pursuant to the other provisions of this Section 5.

                5.8. Rule 144 Reporting. With a view to making available to the
Holders the benefits of certain rules and regulations of the U.S. Securities and
Exchange Commission ("SEC") which may permit the sale of the Registrable
Securities to the public without registration, the Corporation agrees to:

                        (a) make and keep public information available, as those
terms are understood and defined in SEC Rule 144, at all times after ninety days
after the effective date of the first registration filed by the Corporation
which involves a sale of securities of the Corporation to the general public;

                        (b) file with the SEC in a timely manner all reports and
other documents required of the Corporation under the Securities Act and the
Securities Exchange Act of 1934, as amended (the "Securities Exchange Act");

                        (c) furnish to Holders so long as Holders own any
Registrable Securities forthwith upon request a written statement by the
Corporation that it has complied with the reporting requirements of said Rule
144 (at any time after ninety days after the effective date of said first
registration statement filed by the Corporation) and of the Securities Act and
the Securities Exchange Act (at any time after it has become subject to such
reporting requirements), a copy of the most recent annual or quarterly report of
the Corporation, and such other reports and documents so filed by the
Corporation as may be reasonably requested in availing Holders of any rule or
regulation of the SEC permitting the selling of any such securities without
registration.

                5.9. Transfer of Registration Rights. The fights to cause the
Corporation to register securities granted by the Corporation under Section 5.2,
may be assigned by any Holder to a transferee or assignee, provided that such
transfer must otherwise be effected in accordance with applicable securities
laws and provided further that the Corporation is given written notice



                                       36
<PAGE>

by such Holder at the time of or within a reasonable time after said transfer,
stating the name and address of said transferee or assignee and identifying the
securities with respect to which such registration rights are being assigned.

                5.10. "Market Stand-Off' Agreement. Each Holder hereby agrees
that, during the period of duration specified by the Corporation and an
underwriter of common stock or other securities of the Corporation (such period
shall not exceed one hundred eighty days), following the effective date of a
registration statement of the Corporation filed under the Securities Act, it
shall not, to the extent requested by the Corporation and such underwriter,
directly or indirectly sell, offer to sell, contract to sell (including, without
limitation, any short sale), grant any option to purchase or otherwise transfer
or dispose of (other than to donees who agree to be similarly bound) any
securities of the Corporation held by it at any time during such period except
common stock included in such registration; provided, however, that such
agreement shall not be required unless all officers and directors of the
Corporation and all other persons with registration rights (whether or not
pursuant to this Agreement) or purchasing common stock of the Corporation enter
into similar agreements.

        In order to enforce the foregoing covenant, the Corporation may impose
stop-transfer instructions with respect to the Registrable Securities of each
Holder (and the shares of securities of every other person subject to the
foregoing restriction) until the end of such period.

                5.11. Expiration of Rights. All registration rights shall expire
and not apply to any Holder upon the earlier of seven years from the
Corporation's initial public offering or the date such Holder is eligible to
sell in a three-month period pursuant to SEC Rule 144 all Registrable Securities
held by such Holder.

        6. Miscellaneous.

                6.1. Waivers and Amendments. With the written consent of the
record holders of at least a majority of the Registrable Securities, the
obligations of the Corporation and the rights of the Holders under this
Agreement may be waived or amended (either generally or in a particular
instance); provided, however, that no such waiver or amendment shall reduce the
aforesaid proportion of Registrable Securities, the holders of which are
required to consent to any waiver or supplemental agreement, without the consent
of the record holders of all of the Registrable Securities. Upon the
effectuation of each such waiver or amendment, the Corporation shall promptly
give written notice thereof to the record holders of the Registrable Securities
who have not previously consented thereto in writing. Except to the extent
provided in this subsection 6.1, this Agreement or any provision hereof may be
amended, waived, discharged or terminated only by a statement in writing signed
by the party against which enforcement of the amendment, waiver, discharge or
termination is sought.

                6.2. Governing Law. This Agreement shall be governed in all
respects by the laws of the State of California as such laws are applied to
agreements between California residents entered into and to be performed
entirely within California.



                                       37
<PAGE>

                6.3. Successors and Assigns. Except as otherwise expressly
provided herein, the provisions hereof shall inure to the benefit of, and be
binding upon, the successors, assigns, heirs, executors and administrators of
the parties hereto.

                6.4. Entire Agreement. This Agreement and the Stock Purchase
Agreement constitute the full and entire understanding and agreement between the
parties with regard to the subjects hereof and thereof and they supersede, merge
and render void every other prior written and/or oral understanding or agreement
among or between the parties hereto.

                6.5. Notices. etc. All notices and other communications required
or permitted hereunder shall be in writing and shall be delivered personally,
mailed by first class mail, postage prepaid, or delivered by courier or
overnight delivery, addressed (a) if to the University, at its address set forth
in the Stock Purchase Agreement, or at such other address as the University
shall have furnished to the Corporation in writing or (b) if to the Corporation,
at its address set forth in the Stock Purchase Agreement, or at such other
address as the Corporation shall have furnished to the University in writing.
Notices that are mailed shall be deemed received five (5) days after deposit in
the United States mail. Notices sent by courier or overnight delivery shall be
deemed received two (days) after they have been so sent.

                6.6. Severability. In case any provision of this Agreement shall
be found by a court of law to be invalid, illegal or unenforceable, the
validity, legality and enforceability of the remaining provisions of this
Agreement shall not in any way be affected or impaired thereby.

                6.7. Titles and Subtitles. The titles of the sections and
subsections of this Agreement are for convenience of reference only and are not
to be considered in construing this Agreement.

                6.8. Counterparts. This Agreement may be executed in any number
of counterparts, each of which shall be an original, but all of which together
shall constitute one instrument.

                6.9. Delays or Omissions. No delay or omission to exercise any
right, power or remedy accruing to the Corporation or to any holder of any
securities issued or to be issued hereunder shall impair any such right, power
or remedy of the Corporation or such holder, nor shall it be construed to be a
waiver of any breach or default under this Agreement, or an acquiescence
therein, or of or in any similar breach or default thereafter occurring; nor
shall any delay or omission to exercise any right, power or remedy or any waiver
of any single breach or default be deemed a waiver of any other right, power or
remedy or breach or default theretofore or thereafter occurring. All remedies,
either under this Agreement, or by law otherwise afforded to the Corporation or
any holder, shall be cumulative and not alternative.



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<PAGE>

        IN WITNESS WHEREOF, the parties hereto have executed this Agreement as
of the date first written above.


SANTARUS, INC.                          THE CURATORS OF THE
                                        UNIVERSITY OF MISSOURI


By:                                     By:
   -------------------------------         -------------------------------------
   Gerald T. Proehl, President & COO       Thomas R. Sharpe, Executive Director
                                           Office of Technology
                                           & Special Projects



                                       39
<PAGE>

                                    EXHIBIT C

                               Schedule of Events

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***     Portions of this page have been omitted pursuant to a request for
        Confidential Treatment and filed separately with the Commission.




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