<PAGE>

                                                                  EXHIBIT 10.193

10/14/02

                    SECOND LEASE AMENDMENT TO LEASE AGREEMENT

     THIS SECOND AMENDMENT TO LEASE AGREEMENT (this "Amendment") is made as of
the 1st day of October 2002, by and between DUKE REALTY LIMITED PARTNERSHIP, an
Indiana limited partnership doing business in North Carolina as Duke Realty of
Indiana Limited Partnership, successor by merger to Weeks Realty, L.P.,
(hereinafter referred to as "Landlord") and PPD DEVELOPMENT, LP , a Texas
limited partnership and successor in interest to PPD Development, Inc.
(hereinafter referred to as "Tenant").

                                   WITNESSETH:

     WHEREAS, pursuant to a Lease Agreement dated December 16, 1998 by and
between landlord and Tenant, and as amended by that certain First Amendment To
Lease Agreement dated February 28, 2000 (herein collectively referred to as the
"Lease"), Landlord leased to Tenant certain premises in a building located on
certain land (the "Land") at 3500 Paramount Parkway, Raleigh, Wake County, North
Carolina, all as more particularly described in the Lease; and

     WHEREAS, the parties hereto desire to amend the Lease, to delete Paragraph
2 (f) of the Lease.

     NOW, THEREFORE, for and in consideration of Ten Dollars ($10.00) paid by
Landlord and Tenant to one another, and for other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged by
Landlord and Tenant, Landlord and Tenant amend the Agreement as follows:

     1.   Article 2. Base Rent, Operating Expenses and Security Deposit.
Paragraph 2(f) of the Lease is deleted in its entirety and is of no further
force or effect. Landlord covenants to cooperate with Tenant in canceling the
Letter of Credit with the issuing bank.

     2.   Guaranty. In consideration of this Amendment, Tenant shall provide
Landlord with a Guaranty of Lease executed by Pharmaceutical Product
Development, Inc. in the form attached hereto as Exhibit A.

     3.   Effective Date. The provisions of this Amendment shall be and become
effective as of the date and year first above written.

     4.   Severability. In the event any term, covenant or condition of this
Amendment, the Lease, or any amendments thereto shall to any extent be invalid
or unenforceable, the remainder shall not be affected thereby and each term,
covenant or condition shall be valid and enforceable to the full extent
permitted by law.

     5.  Successors and Assigns. This Amendment shall apply to, inure to the
benefit of, and be binding upon the parties hereto and upon their respective
heirs, legal representatives, successors and permitted assigns, except as
otherwise provided herein.

     6.   Authority of Tenant. Tenant certifies to Landlord that it is
authorized to enter into this Amendment, and that those persons signing below on
its behalf are authorized to do so, and shall promptly upon the request of
Landlord provide a resolution to this effect.

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     7.   Interpretation. Although the printed provisions of this Amendment were
drafted by Landlord, such fact shall not cause this Amendment to be construed
either for or against Landlord or Tenant. All capitalized terms, not otherwise
defined, shall be defined as provided in the Lease.

     8.   Full Force and Effect. Except as modified hereby, the Lease remains
unmodified and in full force and effect.

     9.   Governing Law. This Amendment shall be governed by and construed in
accordance with the laws of the State of North Carolina.

     10.  Mutual Acknowledgment of Non-Existence of Claims. Landlord and Tenant
acknowledge and agree that as of the day hereof there are no known claims by
either party against the other party hereto arising from the relationship as
Landlord and Tenant, respectively, pursuant to the Lease, as amended.

     11.  Confidentiality. The terms and provisions of the Lease, and this
Amendment are strictly confidential, are to be shared by Tenant only with its
accountant, employees, and attorneys, and each of those parties shall be advised
of the confidential nature of the lease, and this Amendment.

     IN WITNESS WHEREOF, the undersigned have caused this Amendment to be
executed under seal and delivered as of the day and year first above written.

                                  LANDLORD:
                                  DUKE REALTY LIMITED PARTNERSHIP,
                                  an Indiana limited partnership doing business
                                  in North Carolina as Duke Realty of Indiana
                                  Limited Partnership

                                     By: Duke Realty Corporation,
                                         an Indiana corporation, its
                                         General Partner

                                     By: /s/ H. Andrew Kelton
                                        ---------------------------------------
                                     Name: H. Andrew Kelton
                                          -------------------------------------
                                     Title: Senior V. P.
                                           ------------------------------------


ATTEST:                           TENANT:

   By: /s/ B. Judd Hartman        PPD DEVELOPMENT, LP,  a Texas limited
      ----------------------
   Name: B. Judd Hartman          partnership
        --------------------
   Title: Secretary
         -------------------         By: PPD GP, LLC, a Delaware limited
                                         liability company, its General Partner

                                     By: /s/ Fred B. Davenport, Jr.
                                        ---------------------------------------
                                     Name: Fred B. Davenport, Jr.
                                          -------------------------------------
                                     Title: Vice President
                                           ------------------------------------


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                                    EXHIBIT A
                                GUARANTY OF LEASE

STATE OF NORTH CAROLINA                     :
COUNTY OF WAKE                              :        GUARANTY OF LEASE

     THIS GUARANTY OF LEASE (the "Guaranty"), is made and entered into as of the
1st day of October, 2002, by and between PHARMACEUTICAL PRODUCT DEVELOPMENT,
INC., a North Carolina corporation (hereinafter the "Guarantor") to DUKE REALTY
LIMITED PARTNERSHIP, an Indiana limited partnership doing business in North
Carolina as Duke Realty of Indiana Limited Partnership (the "Landlord");

                              W I T N E S S E T H:

     WHEREAS, pursuant to a Lease Agreement dated December 16, 1998 by and
between landlord and Tenant, and as amended by that certain First Amendment To
Lease Agreement dated February 28, 2000 (herein collectively referred to as the
"Lease"), Landlord leased to Tenant certain premises in a building located on
certain land (the "Land") at 3500 Paramount Parkway, Raleigh, Wake County, North
Carolina, all as more particularly described in the lease; and

     WHEREAS, the Lease is incorporated herein by this reference; and

     WHEREAS, Guarantor has a monetary interest in Tenant and in the Lease and
shall benefit from the execution of the Lease, and is willing to enter into this
Guaranty;

     NOW, THEREFORE, for and in consideration of the Lease, and as an inducement
to Landlord to enter into the same, the Guarantor for itself and its heirs,
successors and assigns, guarantees the full and punctual payment of all base
rent, additional rent, and any and all other sums payable to Tenant to Landlord
under the Lease, when and as the same shall be due and payable under the terms
of the Lease, and guarantees to Landlord the due and punctual performance by
Tenant of each and every term, covenant and condition contained in the Lease to
be observed or performed by the Tenant thereunder; and in the event Tenant shall
default in the payment or performance of the Lease, Guarantor hereby agrees
immediately upon Landlord's request to pay the sums due Landlord or to perform
the defaulted or breached term, covenant or condition of the Lease and to pay
all expenses and costs (including, but not limited to, legal costs and
reasonable attorneys' fees) paid or incurred by Landlord in enforcing the
obligations of the Guarantor under this Guaranty.

     Guarantor hereby consents and agrees that Landlord at any time, and from
time to time, without notice to or further consent from Guarantor, and without
releasing, discharging, modifying or otherwise affecting the obligations and
liabilities of Guarantor in any manner, either with or without consideration,
may upon notice to Guarantor, grant releases, compromises, waivers of compliance
and other indulgences with respect to the Lease and this Guaranty to any persons
or entities now or hereafter liable thereunder or hereunder, release any
Guarantor or any other obligor under the Lease or this Guaranty, all without
affecting the obligations and liabilities of Guarantor hereunder.

     The obligations of Guarantor under this Guaranty shall be direct and
immediate and not conditional or contingent upon the pursuit of any rights or
remedies against Tenant or any other person, not against securities or lien
rights available to Landlord. Guarantor waives any right to require that an
action be brought against Tenant or any other person or entity or to require
that resort be had to any security prior to demand on Guarantor hereunder being
made or prior to enforcement of the Guaranty. In the event of default under the
Lease, Landlord shall have the right to enforce its rights, powers and remedies
thereunder or hereunder in any other, or not at all, and all powers and remedies
available to Landlord in such event shall be nonexclusive and cumulative of all
other rights, powers and remedies provided under the Lease or hereunder or by
law, in equity, or contract.

     Guarantor waives any and all rights to require that Landlord pursue any
other remedy or any other right prior to its pursuit under this Guaranty, and
Guarantor hereby waives the provisions of Chapter 26 of the North Carolina
General Statutes, including, but not limited to, the provisions of N.C. Gen.
Stat. Sec. 26-7, as amended.

     This Guaranty shall be governed by, and be construed in accordance with,
the laws of the State of North Carolina.

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     This Guaranty may not be changed orally or by implication, and no
obligation of the Guarantor or anyone or more of them can be released or waived
by Landlord or any officer, agent, or employee of Landlord, except by writing
signed by a duly authorized partner or agent of Landlord. This Guaranty shall be
irrevocable by Guarantor until all amounts guaranteed hereby have been
completely paid and all terms, covenants and conditions of the Lease guaranteed
hereby have been performed and all obligations and undertakings of Guarantor
hereunder have been completely performed.

     Any notice or demand which by any provision of this Guaranty is required or
allowed to be given to any Guarantor shall be deemed to have been sufficiently
given for all purposes when made in writing and either delivered personally or
delivered to an overnight courier service or deposited in the United States mail
as certified or registered mail, postage prepaid, and either addressed to the
Guarantor concerned at the address appearing beside its signature below or to
such other address as any Guarantor shall furnish to Landlord in writing, the
receipt of which shall be acknowledged in writing by Landlord.

     The provisions of this Guaranty shall be binding upon Guarantor and its
heirs, successors, legal representatives, and assigns. This Guaranty shall in no
event be impaired by any change which may arise by reason of the bankruptcy or
dissolution of Tenant.

     IN WITNESS WHEREOF, the undersigned have executed this Guaranty under seal
as of the day and year first set forth above.

WITNESS:                          GUARANTOR:

                                  PHARMACEUTICAL PRODUCT
                                  DEVELOPMENT, INC., a North Carolina
                                  corporation

 /s/ B. Judd Hartman              By: /s/ Fred B. Davenport, Jr.
--------------------------------     -------------------------------------------
Print Name: B. Judd Hartman       Print Name: Fred B. Davenport, Jr., President
           ---------------------             -----------------------------------
                                  Address:    3151 South 17/th/ Street
                                              ----------------------------------
                                              Wilmington, NC 28412
                                  ----------------------------------------------
                                  FEIN: 56 1640186
                                       --------------------------------------