Exhibit 10.46EXECUTION COPYSIXTH AMENDMENT     SIXTH AMENDMENT (this “Amendment”), dated as of March 11th, 2008 to theAMENDED AND RESTATED CREDIT AGREEMENT, dated as of June 14, 2005 (as amended, supplemented orotherwise modified from time to time, the “Credit Agreement”), among PHARMANET DEVELOPMENTGROUP, INC. (f/k/a SFBC INTERNATIONAL, INC.)(the “Borrower”), the Subsidiary Guarantorsparty thereto (the “Subsidiary Guarantors”), the Lenders and other agents from time to timeparty thereto and UBS AG, STAMFORD BRANCH, as Administrative Agent and Collateral Agent.WITNESSETH:     WHEREAS, the Borrower, the Subsidiary Guarantors, the Lenders and the Administrative Agent areparties to the Credit Agreement, pursuant to which the Lenders have made extensions of credit tothe Borrower; and     WHEREAS, the Borrower has requested that the Lenders agree to make certain amendments to theCredit Agreement, and the Lenders are agreeable to such request but only upon the terms and subjectto the conditions set forth herein;     NOW THEREFORE, in consideration of the premises and for other good and valuable consideration,the receipt of which is hereby acknowledged, the parties hereto hereby agree as follows:     Section 1. Definitions. Terms defined in the Credit Agreement are used hereinwith the respective meanings given to them therein.     Section 2. Amendment to Section 1.01(a) of the Credit Agreement. Section 1.01(a)of the Credit Agreement is hereby amended by:     (a) deleting clause (ix) of the definition of “**Permitted Acquisitions**” in its entiretyand inserting therein a new clause (ix) to read in its entirety as follows:“(ix) immediately after giving effect to such transaction, the aggregate amountof the unused amount of the Revolving Commitments shall be at least $20million.”     (b) inserting a new clause right before the period in the first sentence of thedefinition of “Subsidiary” to read in its entirety as follows:“ *provided*that the Joint Venture shall not be a Subsidiary”     (c) adding the following new defined terms in appropriate alphabetical order: (i) “ ‘**Joint Venture**’ shall mean the joint ventureestablished as a Delaware limited liability company pursuant to, and inaccordance with, an operating agreement between PharmaNet Development
 

 
   Group Inc. and the other parties identified therein, substantially inthe form of the draft operating agreement provided to the Lendersprior to the effective date of the Sixth Amendment.” (ii) “ ‘**Sixth Amendment’**shall mean the SixthAmendment, dated as of March 11th, 2008, to this Agreement.”     Section 3. Amendment to Section 2.09(e) of the Credit Agreement. Section 2.09(e)of the Credit Agreement is hereby amended by deleting the text of such Section in its entiretyand replacing it with the following:"[reserved].”     Section 4. Amendment to Section 6.04 of the Credit Agreement. Section 6.04 ofthe Credit Agreement is hereby amended by:     (a) deleting the word “and” at the end of clause (j);     (b) replacing the period at the end of clause (k) with a semicolon, and adding theword “and” at the end of clause (k);     (c) inserting a new clause (l) to read in its entirety as follows:"(l) Investments in the Joint Venture in an aggregate amount not to exceed $20million.”     Section 5. Amendment to Section 6.09 of the Credit Agreement. Section 6.09(b) ofthe Credit Agreement is hereby amended by deleting the text of such Section in its entiretyand replacing it with the following:     “Investments permitted by Sections 6.04(d), (e) and (l);”     Section 6. Conditions to Effectiveness. This Amendment shall become effective onand as of the date hereof upon the satisfaction of the following conditions precedent (suchdate the “Amendment Effective Date”):     (a) The Administrative Agent shall have received a counterpart of this Amendment dulyexecuted and delivered by the Borrower and the Required Lenders.     (b) The Administrative Agent shall have received an Acknowledgment and Consent,substantially in the form of Exhibit A hereto, duly executed and delivered by eachGuarantor.     (c) The Administrative Agent shall have received all fees required to be paid and allexpenses for which invoices have been presented supported by customary documentation(including reasonable fees, disbursements and other charges of counsel to the AdministrativeAgent), on or before the Amendment Effective Date.
 

 
     Section 7. Representations and Warranties.     The Borrower hereby represents and warrants to the Administrative Agent and each Lender that(before and after giving effect to this Amendment):     (a) No Default or Event of Default has occurred and is continuing.     (b) Each of the representations and warranties made by the Loan Parties in or pursuantto the Loan Documents is true and correct in all material respects on and as of the datehereof as if made on and as of the date hereof, except for any representation and warrantywhich is expressly made as of an earlier date, which representation and warranty shall havebeen true and correct in all material respects as of such earlier date.     Section 8. Limited Amendment. This Amendment shall not constitute an amendmentor waiver of or consent to any provision of the Credit Agreement or any other Loan Documentnot expressly referred to herein and shall not be construed as an amendment, waiver or consentto any action on the part of the Borrower or the Guarantors that would require an amendment,waiver or consent of the Administrative Agent or the Lenders except as expressly statedherein. Except as expressly amended hereby, the provisions of the Credit Agreement and theLoan Documents are and shall remain in full force and effect in accordance with their terms.     Section 9. Payment of Fees and Expenses. The Borrower agrees to pay or reimbursethe Administrative Agent for all of its reasonable out-of-pocket costs and expenses incurredin connection with this Amendment, any other documents prepared in connection herewith and thetransactions contemplated hereby, including, without limitation, the reasonable fees anddisbursements of counsel to the Administrative Agent.     Section 10. Miscellaneous.     (a) Counterparts. This Amendment may be executed by one or more of theparties to this Amendment on any number of separate counterparts, and all of saidcounterparts taken together shall be deemed to constitute one and the same instrument. Aset of the copies of this Amendment signed by all the parties shall be lodged with theBorrower and the Administrative Agent. Delivery of an executed signature page of thisAmendment or of a Lender Consent Letter by facsimile transmission shall be effective asdelivery of a manually executed counterpart thereof.     (b) Binding Effect. The execution and delivery of the Lender Consent Letter byany Lender shall be binding upon each of its successors and assigns (including assignees ofits Loans in whole or in part prior to effectiveness hereof).     (c) **GOVERNING LAW****. THIS AMENDMENT SHALL BE GOVERNED BY, AND CONSTRUED ANDINTERPRETED IN ACCORDANCE WITH, THE LAW OF THE STATE OF NEW YORK.**
 

 
     IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be duly executed anddelivered by their proper and duly authorized officers as of the day and year first above written.      PHARMANET DEVELOPMENT GROUP, INC.