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                                                                   Exhibit 10.21

                   AMENDMENT TO EXECUTIVE EMPLOYMENT AGREEMENT

            THIS AMENDMENT (this "Amendment") dated as of January 9, 2004 by and
between QUINTILES TRANSNATIONAL CORP., a North Carolina corporation (the
"Company") and Michael Mortimer ("Executive").

            WHEREAS, the Company and Executive have entered into that certain
Executive Employment Agreement, dated as of June 1, 2003 (the "Agreement"); and

            WHEREAS, the Company and Executive desire to amend the Agreement to
reflect the acquisition of the Company on September 25, 2003 by Pharma Services
Holding, Inc., a Delaware Corporation ("Pharma") pursuant to that certain
Agreement and Plan of Merger, dated as of April 10, 2003 by and among the
Company, Pharma and Pharma Services Acquisition Corp., a North Carolina
corporation and wholly-owned subsidiary of Pharma.

            NOW, THEREFORE, in consideration of the mutual covenants and
agreements and the representations and warranties herein contained, and for
other good and valuable consideration, the receipt and sufficiency of which are
hereby acknowledged, the parties hereto hereby agree that the Agreement shall be
amended as follows, effective as of September 25, 2003:

1.    Section 2 of the Agreement shall be amended by deleting the phrase
"reporting directly to the Chairman," in the first sentence thereof and by
adding the following sentence to the end of the first paragraph thereof:

      Executive shall also serve, without additional compensation, in such other
officer and director positions of Affiliates to which he may be appointed.

2.    Section 3.1 of the Agreement shall be amended to replace "$350,000" with
"$400,000".

3.    Section 3.2 of the Agreement shall be amended to read as follows:

            3.2 ANNUAL CASH BONUS PLAN. Executive may participate on a basis
      commensurate with his position as a senior executive officer, as
      determined by the Company, in the Company's annual cash bonus plan which
      may be made available from time to time to Company executives; provided,
      however, that Executive's participation is subject to the applicable
      terms, conditions and eligibility requirements of the plan documents, some
      of which are within the plan administrator's discretion, as they may exist
      from time to time.

4.    Section 5.2 shall be amended to read as follows:

            5.2 If the Company terminates Executive's employment pursuant to
Section 4.1 (notice of non-renewal) or 4.2 (without cause), or if Executive
terminates

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Executive's employment pursuant to Section 4.4 (breach of Agreement), then the
Company's sole obligation to Executive, in lieu of any other damages or other
relief to which he otherwise may be entitled, shall be to pay: (i) amounts due
on the effective date of the termination; (ii) any amounts subsequently due
pursuant to the plan described in Section 3.2; and (iii) subject to Executive's
compliance with Sections 6, 7, 8 and 9 and subject to Sections 3.7 and 5.6
(release), 24 monthly payments, where each payment equals Executive's monthly
rate of base salary in effect at the time of such termination multiplied by
1.55.

5.    The first sentence of Section 5.3 of the Agreement shall be amended by
adding "(but in no event after the date the Executive becomes eligible for
comparable coverage)" immediately after the reference to Section 5.2.

6.    Section 5.5 of the Agreement shall be deleted in its entirety and labeled
"[Reserved]".

12.   Section 14 of the Agreement shall be amended to read as follows:

            14. ENTIRE AGREEMENT. This Agreement, along with two letters from
Pharma to Executive, each dated January 9, 2003 relating to the acquisition of
stock under the Pharma Stock Incentive Plan (collectively, the "Pharma
letters"), (i) supersede all other understandings, offers and agreements, oral
or written, between or among Executive, Pharma, the Company or any of their
affiliates; and (ii) constitute the sole agreement between or among Executive,
Pharma and the Company with respect to employment, compensation (including
equity compensation) and benefits. Executive acknowledges that: (i) no
representations, inducements, promises or agreements, oral or written, have been
made by any party or by anyone acting on behalf of any party, which are not
embodied in this Agreement or the Pharma letters; and (ii) no agreement,
statement or promise not contained in this Agreement or the Pharma letters shall
be valid. No change or modification of this Agreement shall be valid or binding
upon the parties unless such change or modification is in writing and is signed
by the parties.

13.   A new Section 19 shall be added to the Agreement to read as follows:

            18. TAX WITHHOLDING. The Company shall have the right to deduct and
withhold such amounts from any payment made hereunder as may be necessary to
enable the Company to satisfy any applicable withholding obligation imposed by
law.

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            IN WITNESS WHEREOF, this Amendment has been duly executed and
delivered by Executive and by a duly authorized officer of the Company as of the
date and year first above written.

                                      QUINTILES TRANSNATIONAL CORP.

                                      By: /s/  KELLEY MOYE
                                          -----------------------------------
                                      Name:    VP + Assoc. Gen. Counsel
                                      Title:   QTRN

                                      /s/ Michael Mortimer
                                      ---------------------
                                          Michael Mortimer

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