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                           OFFER TO PURCHASE FOR CASH
                     ALL OUTSTANDING SHARES OF COMMON STOCK

                                       OF

                            CLINTRIALS RESEARCH INC.

                                       AT

                              $6.00 NET PER SHARE

                                       BY

                            INDIGO ACQUISITION CORP.
                          A WHOLLY OWNED SUBSIDIARY OF

                        INVERESK RESEARCH (CANADA) INC.
                          A WHOLLY OWNED SUBSIDIARY OF

                        INVERESK RESEARCH GROUP LIMITED

  THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT 12:00 MIDNIGHT, NEW YORK CITY
         TIME, ON MONDAY, APRIL 2, 2001, UNLESS THE OFFER IS EXTENDED.

                                                                   March 5, 2001

To Brokers, Dealers, Commercial Banks,
  Trust Companies and other Nominees:

     We have been engaged by Indigo Acquisition Corp., a Delaware corporation
("Purchaser"), which is a wholly owned subsidiary of Inveresk Research (Canada)
Inc., a corporation organized under the laws of Canada ("Inveresk Canada"),
which in turn is a wholly owned subsidiary of Inveresk Research Group Limited, a
company organized under the laws of Scotland ("Parent"), to act as Dealer
Manager in connection with Purchaser's offer to purchase all outstanding shares
of common stock, par value $0.01 per share (the "Shares"), of ClinTrials
Research Inc., a Delaware corporation (the "Company"), at $6.00 per Share, net
to the seller in cash, upon the terms and subject to the conditions set forth in
the Offer to Purchase dated March 5, 2001 (the "Offer to Purchase"), and in the
related Letter of Transmittal (which, together with any amendments or
supplements thereto, collectively constitute the "Offer") enclosed herewith.
Please furnish copies of the enclosed materials to those of your clients for
whom you hold Shares registered in your name or in the name of your nominee.

     The Offer is being made in accordance with an Agreement and Plan of Merger
(the "Merger Agreement"), dated as of February 22, 2001, by and among Parent,
Purchaser and the Company. The Merger Agreement provides for, among other
things, the making of the Offer by Purchaser, and further provides that
Purchaser will merge with and into the Company (the "Merger") as soon as
practicable following the satisfaction or waiver of each of the conditions to
the Merger set forth in the Merger Agreement. Following the Merger, the Company
will continue as the surviving corporation, wholly owned by Inveresk Canada, and
the separate corporate existence of Purchaser will cease.

     THE BOARD OF DIRECTORS OF THE COMPANY, AT A MEETING HELD ON FEBRUARY 22,
2001, BY UNANIMOUS VOTE DETERMINED THAT THE TERMS OF THE OFFER AND THE MERGER
ARE FAIR TO AND IN THE BEST INTERESTS OF THE COMPANY AND THE COMPANY'S
STOCKHOLDERS, APPROVED THE MERGER AND THE OTHER TRANSACTIONS CONTEMPLATED BY THE
MERGER AGREEMENT AND APPROVED THE MERGER AGREEMENT. THE BOARD OF DIRECTORS
UNANIMOUSLY RECOMMENDS THAT THE COMPANY'S STOCKHOLDERS ACCEPT THE OFFER, TENDER
THEIR SHARES IN RESPONSE TO THE OFFER AND, IF
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REQUIRED UNDER DELAWARE LAW OR THE COMPANY'S CERTIFICATE OF INCORPORATION OR
BYLAWS, VOTE TO ADOPT THE MERGER AGREEMENT.

     THE OFFER IS CONDITIONED UPON, AMONG OTHER THINGS, (A) A NUMBER OF SHARES
BEING VALIDLY TENDERED AND NOT WITHDRAWN ON THE APPLICABLE EXPIRATION DATE (AS
DEFINED IN THE OFFER TO PURCHASE) OF THE OFFER THAT, TOGETHER WITH ANY SHARES
OWNED BY PARENT OR ANY OF ITS AFFILIATES (INCLUDING PURCHASER), REPRESENTS AT
LEAST A MAJORITY OF THE TOTAL NUMBER OF ALL OUTSTANDING SHARES PLUS ALL SHARES
ISSUABLE UPON EXERCISE OF OPTIONS AND OTHER SIMILAR RIGHTS TO PURCHASE SHARES
AND (B) THE RECEIPT OF APPROVALS REQUIRED BY OR THE EXPIRATION OR TERMINATION OF
THE APPLICABLE WAITING PERIOD UNDER UNITED STATES AND EUROPEAN ANTITRUST AND
COMPETITION LAWS. THE OFFER IS ALSO SUBJECT TO THE SATISFACTION OR WAIVER OF
CERTAIN OTHER CONDITIONS. SEE SECTIONS 1 AND 13 OF THE OFFER TO PURCHASE.

     For your information and for forwarding to your clients for whom you hold
Shares registered in your name or in the name of your nominee, we are enclosing
the following documents:

          1. Offer to Purchase dated March 5, 2001;

          2. Letter of Transmittal to be used by stockholders of the Company in
     accepting the Offer (facsimile copies of the Letter of Transmittal may be
     used to tender Shares);

          3. Notice of Guaranteed Delivery to be used to accept the Offer if
     certificates for the Shares and all other required documents cannot be
     delivered to SunTrust Bank (the "Depositary"), or if the procedures for
     book-entry transfer cannot be completed, by the Expiration Date or the
     expiration of any Subsequent Offering Period (each as defined in the Offer
     to Purchase);

          4. A printed form of letter which may be sent to your clients for
     whose accounts you hold Shares registered in your name or in the name of
     your nominee, with space provided for obtaining such clients' instructions
     with regard to the Offer;

          5. A letter to stockholders of the Company from Paul Ottaviano,
     President and Chief Executive Officer of the Company, together with a
     Solicitation/Recommendation Statement on Schedule 14D-9 dated March 5,
     2001, which has been filed by the Company with the Securities and Exchange
     Commission which includes the recommendation of the Board of Directors of
     the Company that stockholders accept the Offer and tender their Shares to
     Purchaser pursuant to the Offer;

          6. Guidelines of the Internal Revenue Service for Certification of
     Taxpayer Identification Number on Substitute Form W-9; and

          7. A return envelope addressed to the Depositary.

     Upon the terms and subject to the conditions of the Offer (including, if
the Offer is extended or amended, the terms and conditions of any such extension
or amendment), Purchaser will accept for payment and pay for any Shares validly
tendered (and not properly withdrawn) prior to the Expiration Date, or any
Subsequent Offering Period, when permitted, when, as and if Purchaser gives oral
or written notice to the Depositary of Purchaser's acceptance of such Shares for
payment pursuant to the Offer. If on the Expiration Date the number of Shares
that have been properly tendered and not subsequently withdrawn represents more
than 50% but less than 90% of the outstanding Shares (calculated on a fully
diluted basis), Purchaser intends to elect to provide a Subsequent Offering
Period pursuant to Rule 14d-11 of the Securities Exchange Act of 1934, as
amended. In all cases payment for any Shares purchased pursuant to the Offer
will be made only after timely receipt by the Depositary of (i) certificates for
those Shares, or a timely confirmation of a book-entry transfer of such Shares
into the Depositary's account at The Depository Trust Company, pursuant to the
procedures described in Section 3 of the Offer to Purchase, (ii) the Letter of
Transmittal or a manually signed facsimile of the Letter of Transmittal properly
completed and duly executed with any required signature guarantees, or, in the
case of a book-entry transfer, an Agent's Message (as defined in the Offer to
Purchase) and (iii) all other documents required by the Letter of Transmittal.
Accordingly, tendering stockholders may be paid at different times depending
upon when certificates for Shares or Book-Entry Confirmations (as defined in the
Offer to Purchase) with respect to Shares are actually received by the
Depositary. UNDER NO CIRCUMSTANCES WILL PURCHASER PAY INTEREST ON THE PURCHASE
PRICE OF THE SHARES
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TO BE PAID BY THE PURCHASER, REGARDLESS OF ANY EXTENSION OF THE OFFER OR ANY
DELAY IN PAYING FOR SHARES.

     Purchaser will not pay any fees or commissions to any broker or dealer or
other person (other than the Depositary, the Information Agent and the Dealer
Manager as described in the Offer to Purchase) for soliciting tenders of the
Shares pursuant to the Offer. Purchaser will, however, upon request, reimburse
brokers, dealers, commercial banks and trust companies for customary mailing and
handling costs incurred by them in forwarding the enclosed materials to their
customers.

     Purchaser will pay or cause to be paid all stock transfer taxes applicable
to its purchase of the Shares pursuant to the Offer, except as otherwise
provided in Instruction 6 of the Letter of Transmittal.

     WE URGE YOU TO CONTACT YOUR CLIENTS AS PROMPTLY AS POSSIBLE. PLEASE NOTE
THAT THE OFFER AND WITHDRAWAL RIGHTS EXPIRE AT 12:00 MIDNIGHT, NEW YORK CITY
TIME, ON MONDAY, APRIL 2, 2001, UNLESS THE OFFER IS EXTENDED.

     In order to take advantage of the Offer, (i) a duly executed and properly
completed Letter of Transmittal (or a manually signed facsimile thereof), with
any required signature guarantees, or an Agent's Message (as defined in the
Offer to Purchase) in connection with a book-entry transfer of the Shares, and
any other required documents, should be sent to the Depositary and (ii)
certificates representing the tendered Shares should be delivered or tendered by
book-entry transfer, all in accordance with the Instructions set forth in the
Letter of Transmittal and in the Offer to Purchase.

     If holders of the Shares wish to tender, but it is impracticable for them
to forward their certificates or other required documents or to complete the
procedures for delivery by book-entry transfer prior to the Expiration Date, a
tender may be effected by following the guaranteed delivery procedures specified
in Section 3 of the Offer to Purchase.

     Any inquiries you may have with respect to the Offer should be addressed
to, and additional copies of the enclosed materials may be obtained from, the
Information Agent or the undersigned at the addresses and telephone numbers set
forth on the back cover of the Offer to Purchase.

                                          Very truly yours,

                                          Bear, Stearns & Co. Inc.

     NOTHING CONTAINED HEREIN OR IN THE ENCLOSED DOCUMENTS SHALL CONSTITUTE YOU
AS AN AGENT OF PURCHASER, PARENT, INVERESK CANADA, THE COMPANY, THE DEALER
MANAGER, THE INFORMATION AGENT, THE DEPOSITARY, OR ANY AFFILIATE OF ANY OF THE
FOREGOING, OR AUTHORIZE YOU OR ANY OTHER PERSON TO USE ANY DOCUMENT OR MAKE ANY
STATEMENT ON BEHALF OF ANY OF THEM IN CONNECTION WITH THE OFFER OTHER THAN THE
DOCUMENTS ENCLOSED HEREWITH AND THE STATEMENTS CONTAINED THEREIN.

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