<PAGE>

                                  EXHIBIT 10.31

                                 LOAN AGREEMENT

Wachovia Bank, National Association
Summit, New Jersey  07901
(Hereinafter referred to as the "Bank")

eResearchTechnology, Inc.
30 South 17Th Street
8th Floor
Philadelphia, Pennsylvania  19103

eRT Investment Corporation
3411 Silverside Road
103 Springer Building
Wilmington, Delaware  19810

eRT Tech Corporation
3411 Silverside Road
103 Springer Building
Wilmington, Delaware  19810
(Individually and collectively, "Borrower")

This Loan Agreement ("Agreement") is entered into September 29, 2006, by and
between Bank and Borrower.

This Agreement amends and restates in its entirety that certain Loan Agreement
dated April 29, 2004 and applies to the loan or loans (individually and
collectively, the "Loan") evidenced by one or more promissory notes dated
September 29, 2006 or other notes subject hereto, as modified from time to time
(whether one or more, the "Note"), the standby letters of credit issued
hereunder (each, a "Letter of Credit" and collectively, the "Letters of Credit")
and all Loan Documents. The terms "Loan Documents" and "Obligations," as used in
this Agreement, are defined in the Note.

Relying upon the covenants, agreements, representations and warranties contained
in this Agreement, Bank is willing to extend credit to Borrower upon the terms
and subject to the conditions set forth herein, and Bank and Borrower agree as
follows:

LETTERS OF CREDIT. Upon the request of Borrower, Bank shall issue standby
Letters of Credit, provided, the aggregate amount available to be drawn under
all standby Letters of Credit plus the aggregate amount of unreimbursed drawings
under all standby Letters of Credit at any one time does not exceed
$3,000,000.00, and further provided, no standby Letter of Credit shall expire
more than 365 days after the date it is issued. Notwithstanding anything to the
contrary contained herein, the aggregate outstanding principal balance of
Advances (as defined in the line of credit Promissory Note in the amount of
$3,000,000.00, dated September 29, 2006) plus the aggregate amount available to
be drawn under all Letters of Credit plus the aggregate amount of unreimbursed
drawings under all Letters of Credit at any one time shall not exceed
$3,000,000.00. The Letters of Credit are to be used by Borrower solely to
support working capital. Bank's obligation to issue Letters of Credit shall
terminate if Borrower is in default (however denominated) under the Note or the
other Loan Documents.

LETTER OF CREDIT FEES. Borrower shall pay to Bank, at such times as Bank shall
require, Bank's standard fees in connection with Letters of Credit, as in effect
from time to time, and with respect to

<PAGE>

standby Letters of Credit, an additional fee equal to 1.00% per annum on the
face amount of each standby Letter of Credit, payable annually, in advance, for
so long as such Letter of Credit is outstanding.

REPRESENTATIONS. Borrower represents that from the date of this Agreement and
until final payment in full of the Obligations: ACCURATE INFORMATION. All
information now and hereafter furnished to Bank is and will be true, correct and
complete in all material respects. Any such information relating to Borrower's
financial condition will accurately reflect Borrower's financial condition as of
the date(s) thereof, (including all contingent liabilities of every type), and
Borrower further represents that its financial condition has not changed
materially or adversely since the date(s) of such documents. AUTHORIZATION;
NON-CONTRAVENTION. The execution, delivery and performance by Borrower and any
guarantor, as applicable, of this Agreement and other Loan Documents to which it
is a party are within its power, have been duly authorized as may be required
and, if necessary, by making appropriate filings with any governmental agency or
unit and are the legal, binding, valid and enforceable obligations of Borrower
and any guarantors; and do not (i) contravene, or constitute (with or without
the giving of notice or lapse of time or both) a violation of any provision of
applicable law, a violation of the organizational documents of Borrower or any
guarantor, or a default under any agreement, judgment, injunction, order, decree
or other instrument binding upon or affecting Borrower or any guarantor, (ii)
result in the creation or imposition of any lien (other than the lien(s) created
by the Loan Documents) on any of Borrower's or any guarantor's assets, or (iii)
give cause for the acceleration of any obligations of Borrower or any guarantor
to any other creditor. ASSET OWNERSHIP. Borrower has good and marketable title
to all of the properties and assets reflected on the balance sheets and
financial statements supplied Bank by Borrower, and all such properties and
assets are free and clear of mortgages, security deeds, pledges, liens, charges,
and all other encumbrances, except as otherwise disclosed to Bank by Borrower in
writing and approved by Bank ("Permitted Liens"). To Borrower's knowledge, no
default has occurred under any Permitted Liens and no claims or interests
adverse to Borrower's present rights in its properties and assets have arisen.
DISCHARGE OF LIENS AND TAXES. Borrower has duly filed, paid and/or discharged
all taxes or other claims that may become a lien on any of its property or
assets, except to the extent that such items are being appropriately contested
in good faith and an adequate reserve for the payment thereof is being
maintained. SUFFICIENCY OF CAPITAL. Borrower is not, and after consummation of
this Agreement and after giving effect to all indebtedness incurred and liens
created by Borrower in connection with the Note and any other Loan Documents,
will not be, insolvent within the meaning of 11 U.S.C. Section 101, as in effect
from time to time. COMPLIANCE WITH LAWS. Borrower and any subsidiary and
affiliate of Borrower and any guarantor are in compliance in all material
respects with all federal, state and local laws, rules and regulations
applicable to its properties, operations, business, and finances, including,
without limitation, any federal or state laws relating to liquor (including 18
U.S.C. Section 3617, et seq.) or narcotics (including 21 U.S.C. Section 801, et
seq.) and/or any commercial crimes; all applicable federal, state and local laws
and regulations intended to protect the environment; and the Employee Retirement
Income Security Act of 1974, as amended ("ERISA"), if applicable. None of
Borrower, or any subsidiary or affiliate of Borrower or any guarantor is a
Sanctioned Person or has any of its assets in a Sanctioned Country or does
business in or with, or derives any of its operating income from investments in
or transactions with, Sanctioned Persons or Sanctioned Countries in violation of
economic sanctions administered by OFAC. The proceeds from the Loan will not be
used to fund any operations in, finance any investments or activities in, or
make any payments to, a Sanctioned Person or a Sanctioned Country. "OFAC" means
the U.S. Department of the Treasury's Office of Foreign Assets Control.
"Sanctioned Country" means a country subject to a sanctions program identified
on the list maintained by OFAC and available at
http://www.treas.gov/offices/enforcement/ofac/sanctions/, or as otherwise
published from time to time. "Sanctioned Person" means (i) a person named on the
list of Specially Designated Nationals or Blocked Persons maintained by OFAC
available at http://www.treas.gov/offices/enforcement/ofac/sdn/, or as otherwise
published from time to time, or (ii) (A) an agency of the government of a
Sanctioned Country, (B) an organization controlled by a Sanctioned Country, or
(C) a person resident in a Sanctioned Country to the extent subject to a
sanctions program administered by OFAC. ORGANIZATION AND AUTHORITY. Each
corporation, partnership or limited liability company Borrower and/or guarantor,
as applicable, is duly created, validly existing and in good standing under the
laws of the state of its organization, and has all powers, governmental
licenses, authorizations, consents and approvals required to operate its
business as now conducted. Each corporation, partnership or limited liability
company Borrower and/or guarantor, as applicable, is duly qualified, licensed
and in good standing in each jurisdiction where qualification or


                                     Page 2

<PAGE>

licensing is required by the nature of its business or the character and
location of its property, business or customers, and in which the failure to so
qualify or be licensed, as the case may be, in the aggregate, could have a
material adverse effect on the business, financial position, results of
operations, properties or prospects of Borrower or any such guarantor. NO
LITIGATION. There are no pending or threatened suits, claims or demands against
Borrower or any guarantor that have not been disclosed to Bank by Borrower in
writing, and approved by Bank. INDEMNITY. Borrower will indemnify Bank and its
affiliates from and against any losses, liabilities, claims, damages, penalties
or fines imposed upon, asserted or assessed against or incurred by Bank arising
out of the inaccuracy or breach of any of the representations contained in this
Agreement or any other Loan Documents.

AFFIRMATIVE COVENANTS. Borrower agrees that from the date hereof and until final
payment in full of the Obligations, unless Bank shall otherwise consent in
writing, Borrower will: ACCESS TO BOOKS AND RECORDS. Allow Bank, or its agents,
during normal business hours, access to the books, records and such other
documents of Borrower as Bank shall reasonably require, and allow Bank, at
Borrower's expense, to inspect, audit and examine the same and to make extracts
therefrom and to make copies thereof. BUSINESS CONTINUITY. Conduct its business
in substantially the same manner and locations as such business is now and has
previously been conducted. CERTIFICATE OF FULL COMPLIANCE FROM ACCOUNTANT.
Deliver to Bank, with the financial statements required herein, a certification
by Borrower's independent certified public accountant that Borrower is in full
compliance with the Loan Documents. COMPLIANCE WITH OTHER AGREEMENTS. Comply
with all terms and conditions contained in this Agreement, and any other Loan
Documents, and swap agreements, if applicable, as defined in the 11 U.S.C.
Section 101, as in effect from time to time. ESTOPPEL CERTIFICATE. Furnish,
within 15 days after request by Bank, a written statement duly acknowledged of
the amount due under the Loan and identifying each outstanding Letter of Credit,
if any, and whether offsets or defenses exist against the Obligations.
INSURANCE. Maintain adequate insurance coverage with respect to its properties
and business against loss or damage of the kinds and in the amounts customarily
insured against by companies of established reputation engaged in the same or
similar businesses including, without limitation, commercial general liability
insurance, workers compensation insurance, and business interruption insurance;
all acquired in such amounts and from such companies as Bank may reasonably
require. MAINTAIN PROPERTIES. Maintain, preserve and keep its property in good
repair, working order and condition, making all replacements, additions and
improvements thereto necessary for the proper conduct of its business, unless
prohibited by the Loan Documents. NOTICE OF DEFAULT AND OTHER NOTICES. (a)
NOTICE OF DEFAULT. Furnish to Bank immediately upon becoming aware of the
existence of any condition or event which constitutes a Default (as defined in
the Loan Documents) or any event which, upon the giving of notice or lapse of
time or both, may become a Default, written notice specifying the nature and
period of existence thereof and the action which Borrower is taking or proposes
to take with respect thereto. (b) OTHER NOTICES. Promptly notify Bank in writing
of (i) any material adverse change in its financial condition or its business;
(ii) any default under any material agreement, contract or other instrument to
which it is a party or by which any of its properties are bound, or any
acceleration of the maturity of any indebtedness owing by Borrower; (iii) any
material adverse claim against or affecting Borrower or any part of its
properties; (iv) the commencement of, and any material determination in, any
litigation with any third party or any proceeding before any governmental agency
or unit affecting Borrower; and (v) at least 30 days prior thereto, any change
in Borrower's name or address as shown above, and/or any change in Borrower's
structure. OTHER FINANCIAL INFORMATION. Deliver promptly such other information
regarding the operation, business affairs, and financial condition of Borrower
which Bank may reasonably request. PAYMENT OF DEBTS. Pay and discharge when due,
and before subject to penalty or further charge, and otherwise satisfy before
maturity or delinquency, all obligations, debts, taxes, and liabilities of
whatever nature or amount, except those which Borrower in good faith disputes.
REPORTS AND PROXIES. Deliver to Bank, promptly, a copy of all financial
statements, reports, notices, and proxy statements, sent by Borrower to
stockholders, and all regular or periodic reports required to be filed by
Borrower with any governmental agency or authority.

NEGATIVE COVENANTS. Borrower agrees that from the date hereof and until final
payment in full of the Obligations, unless Bank shall otherwise consent in
writing, Borrower will not: DEFAULT ON OTHER CONTRACTS OR OBLIGATIONS. Default
on any material contract with or obligation when due to a third party or default
in the performance of any obligation to a third party incurred for money
borrowed.


                                     Page 3

<PAGE>

GOVERNMENT INTERVENTION. Permit the assertion or making of any seizure, vesting
or intervention by or under authority of any governmental entity, as a result of
which the management of Borrower or any guarantor is displaced of its authority
in the conduct of its respective business or such business is curtailed or
materially impaired. JUDGMENT ENTERED. Permit the entry of any monetary judgment
or the assessment against, the filing of any tax lien against, or the issuance
of any writ of garnishment or attachment against any property of or debts due.
RETIRE OR REPURCHASE CAPITAL STOCK. Retire or otherwise acquire any of its
capital stock.

ANNUAL FINANCIAL STATEMENTS. Borrower shall deliver to Bank, within 90 days
after the close of each fiscal year, audited financial statements reflecting its
operations during such fiscal year, including, without limitation, a balance
sheet, profit and loss statement and statement of cash flows, with supporting
schedules and in reasonable detail, prepared in conformity with generally
accepted accounting principles, applied on a basis consistent with that of the
preceding year. If audited statements are required, all such statements shall be
examined by an independent certified public accountant acceptable to Bank. The
opinion of such independent certified public accountant shall not be acceptable
to Bank if qualified due to any limitations in scope imposed by Borrower or any
other person or entity. Any other qualification of the opinion by the accountant
shall render the acceptability of the financial statements subject to Bank's
approval. If audited statements are required, Borrower's accountant shall
provide Bank with a written acknowledgment of the Bank's reliance upon the
statements in accordance with N.J.S. 2A: 53A-25.

PERIODIC FINANCIAL STATEMENTS. Borrower shall deliver to Bank, within 45 days
after the end of each interim fiscal half-year, unaudited management-prepared
semi-annual financial statements including, without limitation, a balance sheet,
profit and loss statement and statement of cash flows, with supporting
schedules; all in reasonable detail and prepared in conformity with generally
accepted accounting principles, applied on a basis consistent with that of the
preceding year. Such statements shall be certified as to their correctness by a
principal financial officer of Borrower and in each case, if audited statements
are required, subject to audit and year-end adjustments.

FINANCIAL COVENANTS. Borrower agrees to the following provisions from the date
hereof until final payment in full of the Obligations, unless Bank shall
otherwise consent in writing, using the financial information for Borrower, its
subsidiaries, affiliates and its holding or parent company, as applicable: TOTAL
LIABILITIES TO TANGIBLE NET WORTH RATIO. Borrower shall, at all times, maintain
a ratio of Total Liabilities to Tangible Net Worth of not more than 0.50 to
1.00, measure semi-annually. "Total Liabilities" shall mean all liabilities of
Borrower, including capitalized leases and all reserves for deferred taxes, debt
fully subordinated to Bank on terms and conditions acceptable to Bank, and other
deferred sums appearing on the liabilities side of a balance sheet and all
obligations as lessee under off-balance sheet synthetic leases of Borrower, all
in accordance with generally accepted accounting principles applied on a
consistent basis. "Tangible Net Worth" shall mean total assets minus Total
Liabilities. For purposes of this computation, the aggregate amount of any
intangible assets of Borrower including, without limitation, goodwill,
franchises, licenses, patents, trademarks, trade names, copyrights, service
marks, and brand names, shall be subtracted from total assets. CURRENT RATIO.
Borrower shall, at all times, maintain a Current Ratio of not less than 2.00 to
1.00, measured semi-annually. "Current Ratio" shall mean the ratio of Current
Assets to Current Liabilities. "Current Assets" shall mean all assets which are
so classified in accordance with generally accepted accounting principles.
"Current Liabilities" shall mean all liabilities which are so classified in
accordance with generally accepted accounting principles.

CONDITIONS PRECEDENT. The obligations of Bank to make the loan and any advances
and to issue any Letters of Credit pursuant to this Agreement are subject to the
following conditions precedent: LETTER OF CREDIT DOCUMENTS. Receipt by Bank of
all documents required by Bank in connection with Letters of Credit, including
without limitation, applications therefor, all in form satisfactory to Bank.
ADDITIONAL DOCUMENTS. Receipt by Bank of such additional supporting documents as
Bank or its counsel may reasonably request.


                                     Page 4

<PAGE>

IN WITNESS WHEREOF, Borrower and Bank, on the day and year first written above,
have caused this Agreement to be executed under seal.

                           eResearchTechnology, Inc.


                           By: /s/ Richard Baron                          (SEAL)
                               -------------------------------------------
                               Richard Baron, Executive Vice President/CFO

                           eRT Investment Corporation


                           By: /s/ Richard Baron                          (SEAL)
                               -------------------------------------------
                               Richard Baron, President

                           eRT Tech Corporation


                           By: /s/ Richard Baron                          (SEAL)
                               -------------------------------------------
                               Richard Baron, President

                           Wachovia Bank, National Association


                           By: /s/ Dante J. Bucci                         (SEAL)
                               -------------------------------------------
                               Dante J. Bucci, Senior Vice President


Tracking #:  102908ph/6996322254/18
CAT - Deal # 687045  Facility ID 503770