EXHIBIT 4.3

                          SECURITIES PURCHASE AGREEMENT

                  SECURITIES PURCHASE AGREEMENT (this "Agreement"), dated as of
January 19, 1999, among Columbia Laboratories, Inc., a Delaware corporation with
principal executive offices located at 2875 Northeast 191 Street, Suite 400,
Aventura, Florida 33180 (the "Company"), David M. Knott ("Knott") and Knott
Partners, L.P. ("Knott LP") (Knott and Knott LP are herein referred to
individually as a "Purchaser" and collectively as the "Purchasers").

                              W I T N E S S E T H:

                  WHEREAS, the Purchasers desire to purchase from Company, and
the Company desires to issue and sell to the Purchasers, upon the terms and
subject to the conditions of this Agreement, (i) shares of Series C Convertible
Preferred Stock, $.01 par value (the "Series C Preferred Stock"), having the
rights, preferences and privileges set forth in the Certificate of Designations,
Preferences and Rights hereto as EXHIBIT A (the "Certificate of Designations")
and (ii) Warrants to purchase up to an aggregate of 45,500 shares of Common
Stock (as defined below), having the terms and conditions and being in the form
attached hereto as EXHIBIT B (the "Warrants"); and

                  WHEREAS, upon the terms and subject to the conditions set
forth in the Certificate of Designations, the Series C Preferred Stock is
convertible into shares of the Company's common stock, $.01 par value ("Common
Stock").

                  WHEREAS, contemporaneously with the execution and delivery of
this Agreement, the parties hereto are executing and delivering a Registration
Rights Agreement substantially in the form attached hereto as EXHIBIT C (the
"Registration Rights Agreement") pursuant to which the Company has agreed to
provide certain registration rights under the Securities Act of 1933 and the
rules and regulations promulgated thereunder, and applicable state securities
laws.

                  NOW THEREFORE, in consideration of the premises and the mutual
covenants contained herein, the parties hereto, intending to be legally bound,
hereby agree as follows:


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                                   ARTICLE I.

                  PURCHASE AND SALE OF SERIES C PREFERRED STOCK

                  I.1. TRANSACTION. The Purchasers hereby agree to purchase from
the Company, and the Company has offered and hereby agrees to issue and sell to
the Purchasers, the number of shares of Series C Preferred Stock and the number
of Warrants set forth opposite the names of each Purchaser on the signature
pages hereto.

                  I.2. PURCHASE PRICE; FORM OF PAYMENT. The aggregate purchase
price for the Series C Preferred Stock and Warrants to be purchased by the
Purchasers hereunder shall be U.S. $1,300,000. At the Closing referred to in
Section 1.3 below, each Purchaser shall pay in cash the purchase price set forth
next to the name of such Purchaser on the signature pages hereto (the "Purchase
Price"). The Purchase Price shall be paid by wire transfer of immediately
available funds to the Company in accordance with the Company's wire
instructions set forth below. Simultaneously against receipt by the Company of
the Purchase Price by the Purchasers, the Company shall deliver to each
Purchaser (i) the stock certificates evidencing the number of shares of Series C
Preferred Stock purchased by each Purchaser as set forth next to the name of
such Purchaser on the signature pages hereto, and (ii) the number of Warrants
purchased by each Purchaser as set forth next to the name of such Purchaser on
the signature pages hereto, in each case duly executed on behalf of the Company
and registered in the name of each Purchaser.

                  I.3. CLOSING. The closing (the "Closing") of the issuance and
sale of the Series C Preferred Stock shall be January 27, 1999 or such other
date as shall be mutually agreed upon in writing (the "Closing Date") and shall
occur at the offices of Weil, Gotshal & Manges LLP, or at such other place
mutually agreeable to the parties hereto.

                  I.4. METHOD OF PAYMENT. Payment of the Purchase Price shall be
made by wire transfer of immediately available funds to:

                  First Union National Bank
                  18545 Biscayne Blvd.
                  Aventura, FL 33180

                  Bank ABA Number: 063000021
                  Account Number:  2090001613844

                  Account Holder:  Columbia Laboratories, Inc.



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                  I.5. DELIVERY INSTRUCTIONS. The Series C Preferred Stock and
the Warrants shall be delivered by the Company to the Purchasers pursuant to
Section 1.2. hereof on a "delivery-against-payment basis" at the Closing.

                                   ARTICLE II.

                 PURCHASERS' REPRESENTATIONS, WARRANTIES; ACCESS
                   TO INFORMATION; INDEPENDENT INVESTIGATION.

                  Each Purchaser represents and warrants to and covenants and
agrees with the Company as follows:

                  II.1. Each Purchaser is purchasing the Series C Preferred
Stock, the Warrants, the Common Stock issuable upon exercise of the Warrants
(the "Warrant Shares") and the Shares of Common Stock issuable upon conversion
of the Series C Preferred Stock (the "Conversion Shares" and, collectively with
the Series C Preferred Stock, the Warrants and the Warrant Shares, the
"Securities") for its own account, for investment purposes only and not with a
view towards or in connection with the public sale or distribution thereof in
violation of the provisions of the Securities Act of 1933, as amended (the
"Securities Act").

                  II.2. Each Purchaser is (i) an "accredited investor" within
the meaning of Rule 501 of Regulation D under the Securities Act, (ii)
experienced in making investments of the kind contemplated by this Agreement,
(iii) capable, by reason of its business and financial experience, of evaluating
the relative merits and risks of an investment in the Securities, and (iv) able
to afford the loss of its investment in the Securities.

                  II.3. Each Purchaser understands that the Securities are being
offered and sold by the Company in reliance on an exemption from the
registration requirements of the Securities Act and equivalent state securities
and "blue sky" laws, and that the Company is relying upon the accuracy of, and
each Purchasers' compliance with, the Purchasers' representations, warranties
and covenants set forth in this Agreement to determine the availability of such
exemption and the eligibility of each Purchaser to purchase the Securities. Each
Purchaser further understands that the Series C Preferred Stock and Conversion
Shares may not be transferred or resold without (a) registration under the
Securities Act and any applicable state securities laws, or (b) an exemption
from the requirements of the Securities Act and applicable state securities
laws.

                  II.4. Each Purchaser understands that an 


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exemption from such registration is not presently available pursuant to Rule 144
promulgated under the Securities Act by the Commission and that in any event no
Purchaser may sell any securities pursuant to Rule 144 prior to the expiration
of a one-year period after such Purchaser has acquired the securities. Each
Purchaser understands that any sales pursuant to Rule 144 may only be made in
full compliance with the provisions of Rule 144.

                  II.5. Each Purchaser has been furnished with or provided
access to all materials relating to the business, financial position and results
of operations of the Company, including the risk factors relating to the Company
and its business set forth in EXHIBIT D hereto (the "Risk Factors") and all
other materials requested by the Purchasers to enable them to make an informed
investment decision with respect to the Securities.

                  II.6. Each Purchaser acknowledges that the Company's Annual
Report on Form 10-KSB for the fiscal year ended December 31, 1997 and all other
reports and documents heretofore filed by the Company with the Securities and
Exchange Commission (the "Commission") pursuant to the Securities Act and the
Securities Exchange Act of 1934, as amended (the "Exchange Act") since December
31, 1997 (collectively the "Commission Filings") have been made available to
such Purchaser for such Purchaser's review.

                  II.7. Each Purchaser acknowledges that in making its decision
to purchase the Securities it has relied on its own investigation of the Company
and been given an opportunity to ask questions of and to receive answers from
the Company's executive officers, directors and management personnel concerning
the terms and conditions of the private placement of the Securities by the
Company.

                  II.8. Each Purchaser understands that the Securities have not
been approved or disapproved by the Commission or any state securities
commission and that the foregoing authorities have not reviewed any documents or
instruments in connection with the offer and sale to it of the Securities and
have not confirmed or determined the adequacy or accuracy of any such documents
or instruments.

                  II.9. Each Purchaser has the requisite power and authority to
execute and deliver this Agreement and to consummate the transactions
contemplated hereby. This Agreement has been duly and validly authorized,
executed and delivered by each Purchaser and is a valid and binding agreement of
each Purchaser enforceable against it in accordance with its terms, subject to
applicable bankruptcy, insolvency, fraudulent conveyance, reorganization,


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moratorium and similar laws affecting creditors' rights and remedies generally.

                  II.10. Neither the Purchasers nor any of their affiliates nor
any person acting on its or their behalf has the intention of entering, or will
enter into, any put option, short position or other similar instrument or
position with respect to the Common Stock and neither the Purchasers nor any of
their affiliates nor any person acting on its or their behalf will use at any
time shares of Common Stock acquired pursuant to this Agreement or the
Certificate of Designations to settle any put option, short position or other
similar instrument or position that may have been entered into prior to the
execution of this Agreement.

                                  ARTICLE III.

                            COMPANY'S REPRESENTATIONS

                  The Company represents and warrants to the Purchasers that:

                  III.1. CAPITALIZATION. As of the date hereof, the authorized
capital stock of the Company is as set forth on SCHEDULE 3.1. All of the issued
and outstanding shares of capital stock set forth on SCHEDULE 3.1 have been
validly issued and are fully paid and non-assessable. The Series C Preferred
Stock has been duly and validly authorized for issuance by the Company pursuant
to this Agreement, and when issued by the Company pursuant hereto, will be duly
and validly issued, fully paid and non-assessable and will be free of any
preemptive or similar rights. The Conversion Shares and Warrant Shares have been
duly and validly authorized and reserved for issuance by the Company and, when
issued by the Company upon conversion of, or in lieu of accrued dividends on,
the Series C Preferred Stock, or on exercise of the Warrants, will be duly and
validly issued, fully paid and non-assessable. Except as set forth on SCHEDULE
3.1 or in the Commission Filings there are no options, warrants, subscription,
"call" or other similar rights to acquire the Common Stock that have been issued
or granted to any person.

                  III.2. ORGANIZATION. Each of the Company and its subsidiaries
is a corporation duly organized, validly existing and in good standing under the
laws of the jurisdiction of its incorporation or organization and each is duly
qualified as a foreign corporation in all jurisdictions in which the failure to
so qualify would have a material adverse effect on the business, properties,
condition (financial or otherwise) or results of operations 


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of the Company and its subsidiaries taken as a whole or on the consummation of
any of the transactions contemplated by this Agreement (a "Material Adverse
Effect").

                  III.3. AUTHORIZED SHARES. The Company has duly and validly
authorized and reserved for issuance shares of Common Stock sufficient in number
for the conversion, of the shares of Series C Preferred Stock issued to the
Purchasers hereunder (assuming for purposes of this Section 3.3 a Conversion
Price (as defined in the Certificate of Designations) of $2.80) and the exercise
of 45,500 Warrants. The Company understands and acknowledges the potentially
dilutive effect to the Common Stock of the issuance of the Conversion Shares and
Warrant Shares upon conversion of the Series C Preferred Stock and exercise of
the Warrants. The Company further acknowledges that its obligation to issue
Conversion Stock upon conversion of the Series C Preferred Stock and Warrant
Shares upon exercise of the Warrants in accordance with this Agreement, the
Certificate of Designations and the Warrants is absolute and unconditional
regardless of the dilutive effect that such issuance may have on the ownership
interests of other stockholders of the Company.

                  III.4. AUTHORITY; VALIDITY AND ENFORCEABILITY. The Company has
the requisite corporate power and authority to execute and deliver this
Agreement and to consummate the transactions contemplated hereby. The execution,
delivery and performance by the Company of this Agreement and the consummation
by the Company of the transactions contemplated hereby (including without
limitation the filing of the Certificate of Designations, the issuance of the
Series C Preferred Stock, the Warrants and the issuance and reservation for
issuance of the Conversion Shares and Warrant Shares), has been duly authorized
by all requisite corporate action on the part of the Company. This Agreement has
been duly executed and delivered by the Company and (assuming the due
authorization, execution and delivery by the other parties hereto) constitutes a
valid and binding obligation of the Company enforceable against it in accordance
with its terms, subject to applicable bankruptcy, insolvency, fraudulent
conveyance, reorganization, moratorium and similar laws affecting creditors'
rights and remedies generally, and subject, as to enforceability, to general
principles of equity, including principles of commercial reasonableness, good
faith and fair dealing (regardless of whether enforcement is sought in a
proceeding at law or in equity).

                  III.5. NON-CONTRAVENTION. The execution and delivery by the
Company of this Agreement and the consummation by the Company of the
transactions contemplated 


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<PAGE>

hereby do not and will not conflict with or result in a breach by the Company of
any of the terms or provisions of, or constitute a default (or an event which,
with notice, lapse of time or both, would constitute a default), and there is
not currently outstanding any uncured breach or default under (i) the
certificate of incorporation or by-laws of the Company, or (ii) any indenture,
mortgage, deed of trust or other material agreement or instrument to which the
Company is a party or by which its properties or assets are bound, or any law,
rule, regulation, decree, judgment or order of any court or public or
governmental authority having jurisdiction over the Company or any of the
Company's properties or assets, except as to (ii) above such conflict, breach or
default which would not have a Material Adverse Effect.

                  III.6. ABSENCE OF CERTAIN CHANGES. Since December 31, 1997,
except as disclosed in the Commission Filings there has not occurred any change,
event or development in the business, financial condition, prospects or results
of operations of the Company, and there has not existed any condition having or
reasonably likely to have, a Material Adverse Effect.

                  III.7. ABSENCE OF LITIGATION. Except as disclosed in the
Commission Filings, there is no action, suit, claim, proceeding, inquiry or
investigation pending or, to the Company's knowledge, threatened, by or before
any court or public or governmental authority, nor does the Company have
knowledge of any facts or circumstances which would reasonably be likely to give
rise to any such action, suit, claim, inquiry, proceeding or investigation,
which, if determined adversely to the Company or any of its subsidiaries, would
have a Material Adverse Effect.

                  III.8. FINANCIAL STATEMENTS; NO UNDISCLOSED LIABILITIES. Each
of the financial statements included in the Commission Filings complied in all
material respects with the rules and regulations of the Commission with respect
thereto as in effect at the time of filing, have been prepared in accordance
with United States General Accepted Accounting Principles ("GAAP") (subject, in
the case of the interim financial statements, to normal year end adjustments and
the absence of footnotes) and in conformity with the practices consistently
applied by the Company without modification of the accounting principles used in
the preparation thereof, and fairly presents in all material respects the
financial position, results of operations and cash flows of the Company as at
the dates and for the periods indicated.

                  III.9. SECURITIES LAW MATTERS. Assuming the 


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accuracy of the representations and warranties of the Purchasers set forth in
Article II hereof, the offer and sale by the Company of the Securities is exempt
from the registration and prospectus delivery requirements of the Securities Act
and the rules and regulations of the Commission thereunder. No form of general
solicitation or advertising has been used or authorized by the Company or any of
its officers, directors or Affiliates in connection with the offer or sale of
the Series C Preferred Stock (and the Conversion Shares) as contemplated by this
Agreement or any other agreement to which the Company is a party.

                  III.10. INTERNAL CONTROLS AND PROCEDURES. The Company
maintains accurate books and records and internal accounting controls which
provide reasonable assurance that (i) all transactions to which the Company is a
party or by which its properties are bound are executed with management's
authorization; (ii) the reported accountability of the Company's assets is
compared with existing assets at regular intervals; (iii) access to the
Company's assets is permitted only in accordance with management's
authorization; and (iv) all transactions to which the Company is a party or by
which its properties are bound are recorded as necessary to permit preparation
of the financial statements of the Company in accordance with U.S. generally
accepted accounting principles.

                  III.11. COMMISSION FILINGS. None of the Commission Filings
contained at the time they were filed any untrue statement of a material fact or
omitted to state any material fact required to be stated therein or necessary to
make the statements made therein, in light of the circumstances under which they
were made, not misleading.

                  III.12. ABSENCE OF CERTAIN CHANGES. Except as disclosed in the
Commission Filings, since December 31, 1997 there has not occurred any change,
event or development in the business, financial condition, prospects or results
of operations of the Company or its subsidiaries, and there has not existed any
condition having or reasonably likely to have, a Material Adverse Effect.

                  III.13. FILINGS, CONSENTS AND APPROVALS. The Company is not
required to obtain any consent, authorization, or make any filing with, Federal,
state, local or other governmental authority in connection with the issuance and
sale of the Series C Preferred Stock and the Warrants, other than (i) the filing
of the Certificate of Designations with the Secretary of State of Delaware, (ii)
the filings required pursuant to Section 4.2, (iii) the filing of the
Registration Statement with the Securities and Exchange Commission meeting the
requirements set forth in 


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the Registration Rights Agreement, (iv) the application(s) to the American Stock
Exchange for the listing of the Conversion Shares and Warrant Shares for trading
on the American Stock Exchange (and with any other national securities exchange
or market on which the Common Stock is then listed), and (v) in all other cases
where the failure to obtain such consent, waiver, authorization or order, or to
give such notice or make such filing or registration could not have or result
in, individually or in the aggregate, a Material Adverse Effect.

                  III.14. COMPLIANCE WITH LAWS; PERMITS. The Company is in
compliance with all laws, rules, regulations, codes, ordinances and statutes
applicable to them or to the conduct of their respective businesses, except for
such non-compliance which would not have a Material Adverse Effect. The Company
possesses all permits, approvals, authorizations, licenses, certificates and
consents from all public and governmental authorities which are necessary to
conduct its business, except for those the absence of which would not have a
Material Adverse Effect.

                  III.15. PATENTS AND TRADEMARKS. The Company has, or has the
rights to use, all patents, patent applications, trademarks, trademark
applications, licenses and rights which are necessary or material for use in
connection with its business, except where the failure to have any such rights
would not have a Material Adverse Effect.

                                   ARTICLE IV.

                     CERTAIN COVENANTS AND ACKNOWLEDGMENTS.

                  IV.1. RESTRICTIVE LEGEND. The Purchasers acknowledge and agree
that, upon issuance pursuant to this Agreement, the Securities (and any shares
of Common Stock issued in conversion of the Series C Preferred Stock, in lieu of
dividends on the Series C Preferred Stock and on exercise of the Warrants) shall
have endorsed thereon a legend in substantially the following form (and a
stop-transfer order may be placed against transfer of the Series C Preferred
Stock and the Conversion Shares):

         "THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF
         1933, AS AMENDED (THE "SECURITIES ACT"), OR THE SECURITIES LAWS OF ANY
         STATE, AND ARE BEING OFFERED, SOLD OR OTHERWISE TRANSFERRED PURSUANT TO
         AN EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT
         AND SUCH LAWS. THESE SECURITIES MAY NOT BE SOLD OR TRANSFERRED EXCEPT
         PURSUANT TO AN EFFECTIVE 


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         REGISTRATION STATEMENT UNDER THE SECURITIES ACT OR PURSUANT TO AN
         AVAILABLE EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF THE
         SECURITIES ACT OR SUCH OTHER LAWS IN RESPECT OF WHICH THE COMPANY HAS
         RECEIVED AN OPINION OF COUNSEL SATISFACTORY TO THE COMPANY TO SUCH
         EFFECT."

                  IV.2. FILINGS. The Company shall make all necessary SEC and
"blue sky" filings required to be made by the Company in connection with the
sale and issuance of the Securities to the Purchasers and, upon request, shall
promptly provide a copy thereof to the Purchasers after such filing.

                  IV.3. USE OF PROCEEDS. The Company shall use the proceeds from
the sale of the Securities (excluding amounts paid by the Company for legal fees
in connection with such sale) for general corporate and working capital
purposes.

                  IV.4. LISTING. The Company shall use its best efforts to
maintain its listing of the Common Stock on the American Stock Exchange or such
other principal national securities exchange on which the Common Stock may be
then listed.

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                  IV.5. RESERVED CONVERSION SHARES. The Company at all times
from and after the date hereof shall have a sufficient number of shares of
Common Stock duly and validly authorized and reserved for issuance to satisfy
the conversion (pursuant to the Certificate of Designations), in full, of 1,300
Shares of Series C Preferred Stock issued to the Purchasers hereunder (assuming
for purposes of this Section 4.5, a Conversion Price (as defined in the
Certificate of Designations) of $2.80) and the exercise in full of all of the
Warrants issued to the Purchasers hereunder.

                  IV.6. RIGHT OF FIRST REFUSAL. If, during the period ending 120
days after the Closing Date (the "Right of First Refusal Period"), the Company
should propose (the "Proposal") to issue Common Stock or securities convertible
into Common Stock (the "Right of First Refusal Securities") at a price less than
the Current Market Price (as defined in the Certificate of Designations), the
Company shall be obligated to offer the Purchasers an opportunity to purchase
all, but not less than all, of the shares of Common Stock included in the
Proposal on the terms set forth in the Proposal (the "Offer"), and the
Purchasers shall have the right, but not the obligation, to accept such Offer on
such terms. The Purchasers shall have ten (10) business days to accept or reject
any such Offer following written notice to the Purchasers that the Company
proposes to issue any Right of First Refusal Securities on the terms set forth
in the Proposal, which shall accompany the notice. If the Purchaser shall fail
to notify the Company in writing of its intention to exercise its Right of First
Refusal within such time period, the Company may effect the sale of securities
on substantially the terms set forth in the Proposal. Notwithstanding the
foregoing, the Purchasers shall have no rights under this paragraph 4.6. in
respect of Common Stock or any other securities of the Company issuable (i) upon
the exercise or conversion of options, warrants or other rights to purchase
securities of the Company outstanding as of the date hereof, (ii) to officers,
directors or employees of the Company or any of its subsidiaries under any stock
option or similar plan heretofore or hereafter adopted by the Company and
approved by its stockholders.

                  IV.7. NO ISSUANCE OF SERIES C PREFERRED STOCK. As long as any
shares of Series C Preferred Stock are outstanding the Company shall not issue
any shares of Series C Preferred Stock to any person or entity other than (i)
the Purchasers, (ii) the purchasers party to a Securities Purchase Agreement
dated as of January 7, 1999 with the Company with respect to the issuance of the
Series C Preferred Stock or (iii) Windsor Partners, L.P., without the 


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prior written consent of the Purchasers, which consent shall not be unreasonably
withheld.

                                   ARTICLE V.

                          TRANSFER AGENT INSTRUCTIONS.

                  V.1. The Company agrees that it will provide its transfer
agent with customary stop transfer instructions to enable it to issue
certificates, registered in the name of each of the Purchasers or its respective
nominee(s), for the Conversion Shares or the Warrant Shares in such amounts as
may be specified from time to time by such Purchaser to the Company upon
conversion of the Series C Preferred Stock and the exercise of the Warrants, in
all cases in accordance with the terms of the Certificate of Designations or the
Warrants, as the case may be. Nothing contained in this Section 5.1. shall
affect in any way any of the Purchasers' obligations to comply with all
applicable securities laws upon resale of such Common Stock. If, at any time,
any of the Purchasers provides the Company with an opinion of counsel reasonably
satisfactory to the Company that registration of the resale by such Purchaser of
such Common Stock is not required under the Securities Act and that the removal
of restrictive legends is permitted under applicable law, the Company shall
permit the transfer of such Common Stock and, promptly instruct the Company's
transfer agent to issue one or more certificates for Common Stock without any
restrictive legends endorsed thereon.

                  V.2. Each of the Purchasers is permitted to (i) exercise its
right to convert the Series C Preferred Stock in accordance with the terms of
conversion set forth in the Certificate of Designations and (ii) exercise its
right to purchase shares of Common Stock pursuant to exercise of the Warrants in
accordance with the applicable terms of the Warrants.

                                   ARTICLE VI.

                                   CONDITIONS

                  VI.1. CONDITIONS TO THE COMPANY'S OBLIGATION TO SELL. The
obligation of the Company hereunder to issue and sell the Series C Preferred
Stock and the Warrants to each Purchaser at the Closing is subject to the
satisfaction, at or before the Closing Date, of each of the following
conditions, provided that these conditions are for the Company's sole benefit
and may be waived by the Company at any time in its sole discretion by providing
each Purchaser 


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with prior written notice thereof:

                  (i) Each Purchaser shall have executed each of this Agreement
and the Registration Rights Agreement and delivered the same to the Company.

                  (ii) The Certificate of Designations shall have been filed
with the Secretary of State of the State of Delaware.

                  (iii) Each Purchaser shall have delivered to the Company the
Purchase Price for the shares of Series C Preferred Stock being purchased by
such Purchaser at the Closing by wire transfer of immediately available funds
pursuant to the wire instructions provided by the Company.

                  (iv) No statute, rule, regulation, executive order, decree,
ruling or injunction shall have been enacted, entered, promulgated or endorsed
by any court or governmental authority of competent jurisdiction which prohibits
the consummation of any of the transactions contemplated by this Agreement or
the Registration Rights Agreement.

                  (v) The accuracy in all material respects on the Closing Date
of the representations and warranties of the Purchasers contained in this
Agreement as if made on the Closing Date (except for representations and
warranties which, by their express terms, speak as of and relate to a specified
date, in which case such accuracy shall be measured as of such specified date).

              VI.2. CONDITIONS TO THE PURCHASERS' OBLIGATION TO PURCHASE. The
obligations of each Purchaser to purchase the Series C Preferred Stock and the
Warrants at the Closing is subject to the satisfaction, at or before the Closing
Date, of each of the following conditions, provided that these conditions are
for the Purchasers' sole benefit and may be waived by the Purchasers at any time
in its sole discretion by providing the Company with prior written notice
thereof:

                  (i) The Company shall have executed each of this Agreement and
the Registration Rights Agreement, and delivered the same to each Purchaser.

                  (ii) The Certificate of Designations shall have been filed
with the Secretary of State of the State of Delaware, and a copy of the
Certificate of Designations that has been certified by such Secretary of State
shall have been delivered to each of the Purchasers.

                  (iii) No statute, rule, regulation, executive 


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<PAGE>

order, decree, ruling or injunction shall have been enacted, entered,
promulgated or endorsed by any court or governmental authority of competent
jurisdiction which prohibits the consummation of any of the transactions
contemplated by this Agreement or the Registration Rights Agreement.

                  (iv) The Purchasers shall have received the opinion of Weil,
Gotshal & Manges LLP dated as of the Closing Date in substantially the form of
EXHIBIT E attached hereto (the "Company Opinion").

                  (v) The Company shall have executed and delivered to the
Purchasers the Warrants and the stock certificates for the Series C Preferred
Stock being purchased by each of the Purchasers at the Closing.

                  (vi) The accuracy in all material respects on the Closing Date
of the representations and warranties of the Company contained in this Agreement
as if made on the Closing Date (except for representations and warranties which,
by their express terms, speak as of and relate to a specified date, in which
case such accuracy shall be measured as of such specified date).

                                  ARTICLE VII.

                           SURVIVAL; INDEMNIFICATION.

                  VII.1. The representations, warranties and covenants made by
each of the Company and the Purchasers in this Agreement shall survive for two
(2) years following the Closing. In the event of a breach or violation of any of
such representations, warranties or covenants, the party to whom such
representations, warranties or covenants have been made shall have all rights
and remedies for such breach or violation available to it under the provisions
of this Agreement or otherwise, whether at law or in equity, irrespective of any
investigation made by or on behalf of such party on or prior to the Closing
Date.

                  VII.2. The Company hereby agrees to indemnify and hold
harmless the Purchasers, their Affiliates and their respective officers,
directors, partners and members (collectively, the "Purchaser Indemnitees"),
from and against any and all losses, claims, damages, judgments, penalties,
liabilities and deficiencies (collectively, "Losses"), and agrees to reimburse
the Purchaser Indemnitees for all out-of-pocket expenses (including the
reasonable and documented fees and expenses of legal counsel), in each case
promptly as incurred by the Purchaser Indemnitees and to the extent arising out
of or in connection with:

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<PAGE>

                  (a) any misrepresentation, omission of fact or breach of any
         of the Company's representations or warranties contained in this
         Agreement, the annexes, schedules or exhibits hereto or any instrument,
         agreement or certificate entered into or delivered by the Company
         pursuant to or in connection with this Agreement; or

                  (b) any failure by the Company to perform in any material
         respect any of its covenants, agreements, undertakings or obligations
         set forth in this Agreement, or any instrument, agreement or
         certificate entered into or delivered by the Company pursuant to or in
         connection with this Agreement.

                  The Company shall be liable to a Purchaser Indemnitee under
this Section 7.2 only to the extent of, in the aggregate, the lesser of (i) the
amount of any such loss, claim, damage or liability or (ii) the portion of the
Purchase Price received by the Company from such Purchaser in connection with
the purchase of the Series C Preferred Stock hereunder.

                  VII.3. Each Purchaser hereby agrees to indemnify and hold
harmless the Company, its Affiliates and their respective officers, directors,
partners and members (collectively, the "Company Indemnitees"), from and against
any and all Losses, and agrees to reimburse the Company Indemnitees for all
out-of-pocket expenses (including the fees and expenses of legal counsel), in
each case promptly as incurred by the Company Indemnitees, to the extent arising
out of or in connection with:

                  (a) any misrepresentation, omission of fact, or breach of any
         of such Purchaser's representations or warranties contained in this
         Agreement, the annexes, schedules or exhibits hereto or any instrument,
         agreement or certificate entered into or delivered by such Purchaser
         pursuant to this Agreement; or

                  (b) any failure by such Purchaser to perform in any material
         respect any of its covenants, agreements, undertakings or obligations
         set forth in this Agreement or any instrument, certificate or agreement
         entered into or delivered by such Purchaser pursuant to this Agreement.

                  A Purchaser shall be liable to the Company Indemnitees under
this Section 7.3 only to the extent of, in the aggregate, the lesser of (i) the
amount of any such loss, claim, damage or liability or (ii) the portion of the


                                       15
<PAGE>

Purchase Price received by the Company from such Purchaser in connection with
the purchase of the Series C Preferred Stock hereunder.

                  VII.4. Promptly after receipt by either party hereto seeking
indemnification pursuant to this Article VII (an "Indemnified Party") of written
notice of any investigation, claim, proceeding or other action in respect of
which indemnification is being sought (each, a "Claim"), the Indemnified Party
promptly shall notify the party against whom indemnification pursuant to this
Article VI is being sought (the "Indemnifying Party") of the commencement
thereof; but the omission to so notify the Indemnifying Party shall not relieve
it from any liability that it otherwise may have to the Indemnified Party,
except to the extent that the Indemnifying Party is materially prejudiced and
forfeits substantive rights and defenses by reason of such failure. In
connection with any Claim as to which both the Indemnifying Party and the
Indemnified Party are parties, the Indemnifying Party shall be entitled to
assume the defense thereof. Notwithstanding the assumption of the defense of any
Claim by the Indemnifying Party, the Indemnified Party shall have the right to
employ one separate legal counsel and to participate in the defense of such
Claim, and the Indemnifying Party shall bear the reasonable fees, out-of-pocket
costs and expenses of one such separate legal counsel to the Indemnified Party
if (and only if): (x) the Indemnifying Party shall have agreed to pay such fees,
out-of-pocket costs and expenses, (y) representation of the Indemnified Party
and the Indemnifying Party by the same legal counsel would not be appropriate
due to actual or, as reasonably determined by legal counsel to the Indemnified
Party, potentially differing interests between such parties in the conduct of
the defense of such Claim, or if there may be legal defenses available to the
Indemnified Party that are in addition to or disparate from those available to
the Indemnifying Party, or (z) the Indemnifying Party shall have failed to
employ legal counsel reasonably satisfactory to the Indemnified Party within a
reasonable period of time after notice of the commencement of such Claim. If the
Indemnified Party employs separate legal counsel in circumstances other than as
described in clauses (x), (y) or (z) above, the fees, costs and expenses of such
legal counsel shall be borne exclusively by the Indemnified Party. In no event
shall the Indemnifying Party be liable for the fees and expenses of more than
one firm of legal counsel for the Indemnified Party. The Indemnifying Party
shall not, without the prior written consent of the Indemnified Party (which
consent shall not unreasonably be withheld), settle or compromise any Claim or
consent to the entry of any judgment that does not include an unconditional
release of the Indemnified 


                                       16
<PAGE>

Party from all liabilities with respect to such Claim or judgment.

                                       17
<PAGE>

                  VII.5. In the event one party hereunder should have a claim
for indemnification that does not involve a claim or demand being asserted by a
third party, the Indemnified Party promptly shall deliver notice of such claim
to the Indemnifying Party. If the Indemnified Party disputes the claim, such
dispute shall be resolved by mutual agreement of the Indemnified Party and the
Indemnifying Party or by binding arbitration conducted in accordance with the
procedures and rules of the American Arbitration Association. Judgment upon any
award rendered by any arbitrators may be entered in any court having competent
jurisdiction thereof.

                                  ARTICLE VIII.

                          GOVERNING LAW: MISCELLANEOUS.

                  This Agreement shall be governed by and interpreted in
accordance with the laws of the State of New York, without regard to the
conflicts of law principles of such state. Each of the parties consents to the
jurisdiction of the federal courts whose districts encompass any part of the
City of New York or the state courts of the State of New York sitting in the
City of New York in connection with any dispute arising under this Agreement and
hereby waives, to the maximum extent permitted by law, any objection, including
any objection based on FORUM NON CONVENIENS, to the bringing of any such
proceeding in such jurisdictions. A facsimile transmission to the Company of a
Purchaser's signature on this Agreement, upon execution hereof by the Company
and delivery to such Purchaser by facsimile transmission or otherwise, shall be
legal and binding on the Company and such Purchaser. This Agreement may be
signed in one or more counterparts, each of which shall be deemed an original.
The headings of this Agreement are for convenience of reference and shall not
form part of, or affect the interpretation of, this Agreement. If any provision
of this Agreement shall be invalid or unenforceable in any jurisdiction, such
invalidity or unenforceability shall not affect the validity or enforceability
of the remainder of this Agreement or the validity or enforceability of this
Agreement in any other jurisdiction. This Agreement may be amended only by an
instrument in writing signed by the party to be charged with enforcement. Any
provision of this Agreement may be waived only by an instrument in writing
signed by the party against whom enforcement of the waiver is sought. This
Agreement supersedes all prior agreements and understandings among the parties
hereto with respect to the subject matter hereof.

                                       18
<PAGE>

                                   ARTICLE IX.

                                    NOTICES.

                  Except as may be otherwise provided herein, any notice or
other communication or delivery required or permitted hereunder shall be in
writing and shall be delivered personally or sent by certified mail, postage
prepaid, or by a nationally recognized overnight courier service, and shall be
deemed given when so delivered personally or by overnight courier service, or,
if mailed, three (3) days after the date of deposit in the United States mails,
as follows:

                  (1)      if to the Company, to:

                           COLUMBIA LABORATORIES, INC.
                           2875 Northeast 191 Street, Suite 400
                           Aventura, Florida 33180
                           Attention:  David L. Weinberg

                           With a copy to:

                           WEIL, GOTSHAL & MANGES LLP

                           767 Fifth Avenue
                           New York, New York 10153
                           Attention:  Stephen M. Besen, Esq. or
                                       Michael Nissan, Esq.

                  (2)      if to any Purchaser, at the most current address as
                           provided by such Purchaser to the Company in
                           accordance with the provisions of this Article IX,
                           which address shall initially be the address set
                           forth next to such Purchaser's name on the signature
                           pages hereto.

The Company or any Purchaser may change its address for notice by providing
notice pursuant to this Article IX.

                                       19
<PAGE>

                                   ARTICLE X.

                                CONFIDENTIALITY.

                  The Company and each of the Purchasers agree to keep
confidential and not to disclose to or use for the benefit of any third party
the terms of this Agreement or any other information which at any time is
communicated by the other party as being confidential without the prior written
approval of the other party; provided, however, that this provision shall not
apply to information which, at the time of disclosure, is already part of the
public domain (except by breach of this Agreement) and information which is
required to be disclosed by law (including, without limitation, pursuant to Item
10 of Rule 601 of Regulation S-K under the Securities Act and the Exchange Act)
or by subpoena or order of any court or governmental agency.

                                   ARTICLE XI.

                                   ASSIGNMENT.

                  This Agreement shall not be assignable by either of the
parties hereto prior to the Closing without the prior written consent of the
other party, and any attempted assignment contrary to the provisions hereby
shall be null and void.

                                       20
<PAGE>

                  IN WITNESS WHEREOF, the parties hereto have duly executed and
delivered this Agreement as of the date first above written.

                           COLUMBIA LABORATORIES, INC.

                            By:
                               --------------------------------------
                               Name:
                               Title:

                                       21
<PAGE>

                            KNOTT PARTNERS, L.P.

                            By:
                               --------------------------------------
                               Name:
                               Title:

                            Number of Shares of
                            Series C Preferred Stock
                            to be purchased by you -
                            1,188; Number of Warrants -
                            41,580; Aggregate Purchase
                            Price - $1,188,000.

                            Knott Partners, L.P.
                            485 Underhill Blvd.
                            Suite 205
                            Syosset, NY 11791

                            (516) 364-0303

                                       22
<PAGE>

                               
                            -----------------------------------------
                            David M. Knott

                            Number of Shares of
                            Series C Preferred Stock
                            to be purchased by you -
                            112; Number of Warrants -
                            3,920; Aggregate Purchase
                            Price - $112,000.

                            c/o Dorset Management Corporation
                            485 Underhill Blvd.
                            Suite 205
                            Syosset, NY 11791

                            (516) 364-0303

                                       23