<PAGE>

               AMENDMENT TO AMENDED AND RESTATED RIGHTS AGREEMENT

         This Amendment, dated as of August 5, 2003 (this "Amendment"), to the
Amended and Restated Rights Agreement, dated as of June 26, 2001 (the "Rights
Agreement"), is between CIMA LABS INC., a Delaware corporation (the "Company"),
and WELLS FARGO BANK MINNESOTA, N.A., a national banking association (the
"Rights Agent").

                                    RECITALS

         1. The Company and the Rights Agent have heretofore executed and
entered into the Rights Agreement.

         2. Pursuant to Section 27 of the Rights Agreement, the Company and the
Rights Agent may from time to time supplement or amend the Rights Agreement in
accordance with the provisions of Section 27 thereof.

         3. The Company proposes to enter into a merger transaction (the
"Merger") whereby Crimson MergerCo, Inc., a Delaware corporation and a direct,
wholly-owned subsidiary of Scarlet Holding Corporation, a Delaware corporation
("Holding Company"), would merge with and into the Company with the Company
continuing after the Merger as a wholly-owned subsidiary of Holding Company.

         4. In anticipation of the Merger, the Company desires to amend the
Rights Agreement to provide that the Merger will not result in the occurrence of
a Distribution Date, a Shares Acquisition Date, a party thereto becoming an
Acquiring Person or otherwise result in a trigger of the Rights (as such terms
are defined in the Rights Agreement).

         5. All acts and things necessary to make this Amendment a valid
agreement according to its terms have been done and performed, and the execution
of delivery of this Amendment by the Company and the Rights Agent have been in
all respects authorized by the Company and the Rights Agent.

                                    AGREEMENT

         In consideration of the foregoing premises and mutual agreements set
forth in the Rights Agreement and this Amendment, the parties hereto agree as
follows:

         1. Section 1(a) of the Rights Agreement is hereby modified by adding as
the final sentence thereto the following:

         Notwithstanding the foregoing, aaiPharma Inc., a Delaware corporation
         ("aaiPharma"), or any Affiliate or Associate thereof, including Scarlet
         Holding Corporation, a Delaware corporation and wholly-owned subsidiary
         of aaiPharma ("Holding Company"), and Crimson MergerCo, Inc., a
         Delaware corporation and wholly-owned subsidiary of Holding Company
         (collectively with Holding Company, aaiPharma and any Affiliate or
         Associate of aaiPharma,


<PAGE>

         "Parent"), shall not become an "Acquiring Person" as a result of the
         approval, execution or delivery of, or consummation of the transactions
         contemplated by, that certain Agreement and Plan of Merger dated as of
         August 5, 2003 (the "Merger Agreement"), by and among the Company,
         aaiPharma, Holding Company, C MergerCo, Inc. and Scarlet MergerCo,
         Inc., a Delaware corporation and wholly-owned subsidiary of Holding
         Company, including the approval, execution and delivery of the Cima
         Voting Agreements (as such term is defined in the Merger Agreement);
         provided, however, that Parent will become an "Acquiring Person" in the
         event that Parent becomes the Beneficial Owner of an aggregate of 15%
         or more of the Common Shares of the Company then outstanding other than
         pursuant to the terms of the Merger Agreement or the Cima Voting
         Agreements.

         2. Section 1(m) of the Rights Agreement is hereby modified and amended
to read in its entirety as follows:

         (m) "SHARES ACQUISITION DATE" shall mean the first date of public
         announcement by the Company or an Acquiring Person that an Acquiring
         Person has become such; PROVIDED, HOWEVER that, if such Person is
         determined not to have become an Acquiring Person pursuant to clause
         (y) of the penultimate sentence of Section 1(a) hereof, then no Shares
         Acquisition Date shall be deemed to have occurred. Notwithstanding
         anything in this Agreement to the contrary, no Shares Acquisition Date
         shall be deemed to have occurred solely as a result of (i) the
         approval, execution or delivery of the Merger Agreement or the Cima
         Voting Agreements, (ii) adoption of the Merger Agreement by the
         Company's stockholders, (iii) the exchange of the Company's Common
         Shares pursuant to the Merger Agreement, (iv) the consummation of the
         Cima Merger (as defined in the Merger Agreement) or (v) the
         consummation of all of the events described in clauses (i) through
         (iv), or of any and all other transactions contemplated by the Merger
         Agreement or the Cima Voting Agreements.

         3. Section 3(a) of the Rights Agreement is hereby amended by adding as
the final sentence thereto the following:

         Notwithstanding anything in this Agreement to the contrary, no
         Distribution Date shall be deemed to have occurred solely as a result
         of (i) the approval, execution or delivery of the Merger Agreement or
         the Cima Voting Agreements, (ii) adoption of the Merger Agreement by
         the Company's stockholders, (iii) the exchange of the Company's Common
         Shares pursuant to the Merger Agreement, (iv) the consummation of the
         Cima Merger (as



                                       2
<PAGE>

         defined in the Merger Agreement) or (v) consummation of all of the
         events described in clauses (i) through (iv), or of any and all other
         transactions contemplated by the Merger Agreement or the Cima Voting
         Agreements.

         4. Clause (i) of Section 7(a) of the Rights Agreement is hereby amended
and restated in its entirety to read as follows:

         (i) the earlier of (A) the Close of Business on June 26, 2011 or (B)
         the time that is immediately prior to the Effective Time, as defined in
         the Merger Agreement (the date on which the earlier of (A) or (B)
         occurs, the "Final Expiration Date")

         5. Section 13(a) of the Rights Agreement is hereby amended by adding as
the final sentence thereto the following:

         Notwithstanding anything in this Agreement to the contrary, none of the
         events described in clauses (x) through (z) of the first sentence of
         Section 13(a) shall be deemed to have occurred solely as a result of
         (i) the approval, execution or delivery of the Merger Agreement or the
         Cima Voting Agreements, (ii) adoption of the Merger Agreement by the
         Company's stockholders, (iii) the exchange of the Company's Common
         Shares pursuant to the Merger Agreement, (iv) the consummation of the
         Cima Merger (as defined in the Merger Agreement) or (v) the
         consummation of all of the events described in clauses (i) through
         (iv), or of any and all other transactions contemplated by the Merger
         Agreement or the Cima Voting Agreements.

         6. A new Section 35 shall be added and shall read as follows:

         Immediately prior to the Effective Time (as defined in the Merger
         Agreement), this Agreement shall be terminated and all outstanding
         Rights shall expire.

         7. This Amendment shall be governed by and construed in accordance with
the laws of the State of Delaware.

         8. This Amendment may be executed in any number of counterparts and
each of such counterparts shall for all purposes be deemed an original, and all
such counterparts shall together constitute but one and the same instrument.

         9. Except as expressly set forth herein, this Amendment to the Rights
Agreement shall not by implication or otherwise alter, modify, amend or in any
way affect any of the terms, conditions, obligations, covenants or agreements
contained in the Rights Agreement, all of which are ratified and affirmed in all
respects and shall continue in full force effect.



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<PAGE>

         10. Capitalized terms used herein but not defined (either directly
herein or by reference to the Merger Agreement) shall have the meanings given to
them in the Rights Agreement.

         11. The term "Agreement" as used in the Rights Agreement shall be
deemed to refer for all purposes to the Rights Agreement as amended by this
Amendment.

                            [signature page follows]



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<PAGE>

                  IN WITNESS WHEREOF, the parties hereto have caused this
Amendment to be duly executed as of the day and year first above written.


                                             CIMA LABS INC.


                                             By: /s/ Steven B. Ratoff
                                                 -------------------------------
                                                 Name: Steven B. Ratoff
                                                 Title: Interim Chief Executive
                                                        Officer


                                             WELLS FARGO BANK MINNESOTA, N.A.,
                                             as Rights Agent


                                             By: /s/ John D. Baker
                                                 -------------------------------
                                                 Name: John D. Baker
                                                 Title: Assistant Vice President



                 SIGNATURE PAGE TO AMENDMENT TO RIGHTS AGREEMENT