EXHIBIT 99.1

                              MACROCHEM CORPORATION

                               OPTION CERTIFICATE


     Stock option (the "Option") granted by MacroChem Corporation, a Delaware
corporation with its principal office at 110 Hartwell Avenue, Lexington, MA
02421 (the "Company"), to Robert J. Palmisano (the "Optionee").

1.   GRANT OF OPTION

     This certificate evidences the grant, effective upon the Optionee's
execution of an employment agreement to be dated no later than April 9, 2001 by
and between the Optionee and the Company (the "Employment Agreement"), by the
Company on March 22, 2001, to the Optionee of an Option to purchase, in whole or
in part, on the terms provided herein, a total of 1,000,000 shares of Common
Stock of the Company (the "Shares"), par value $.01 per share (the "Stock"), at
$3.02 per share, the average price on the date of grant, March 22, 2001. This
Option is not intended to qualify as an incentive stock option within the
meaning of Section 422A of the U.S. Internal Revenue Code of 1986, as amended.
The latest date on which this Option may be exercised (the "Final Exercise
Date") is March 22, 2011.

     This Option will vest in the following installments prior to the Final
Exercise Date:

             Date                                     Number of Shares

       April 9, 2001                                        310,000
       April 9, 2002                                        230,000
       April 9, 2003                                        230,000
       April 9, 2004                                        230,000

2.   EXERCISE OF OPTION

     Each election to exercise this Option shall be in writing, signed by the
Optionee, by the person or persons to whom this Option is transferred in
accordance with the provisions of this Option or by the Optionee's executor or
administrator or by the person or persons to whom this Option is transferred by
will or the applicable laws of descent and distribution (the "Legal
Representative"), and received by the Company at its principal office,
accompanied by payment in full and by such additional documentation evidencing
the right to exercise (or, in the case of a Legal Representative, the authority
of such person) as the Company may require. The purchase price may be paid (i)
in cash or by personal check, bank check or money order payable to the order of
the Company, or (ii) by delivery of a promissory note of the Optionee to the
Company, payable on such terms as are specified by the Compensation Committee of
the Board of Directors of the Company (the "Committee"), or (iii) by delivery of
an unconditional and irrevocable undertaking by a broker to deliver promptly to


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the Company sufficient funds to pay the exercise price, or (iv) by delivery of
shares of Stock of the Company which have been outstanding for at least six (6)
months (unless the Committee approves a shorter period) and which have a fair
market value equal to the exercise price, or (v) by any combination of the
permissible forms of payment; provided, that if the Stock delivered upon
exercise of the Option is an original issue of authorized Stock, at least so
much of the exercise price as represents the par value of such Stock must be
paid other than by the Optionee's promissory note.

3.   ACCELERATION UPON A CHANGE OF CONTROL

     In the event that the Optionee's employment is terminated by the Company
other than for Cause or the Optionee terminates his employment for Good Reason,
in each case at any time subsequent to a Change of Control, this Option will
become immediately exercisable with respect to all Shares and remain exercisable
until the Final Exercise Date. "Cause", "Good Reason," and "Change of Control"
shall have the meanings provided in the Employment Agreement.

4.   STATUS CHANGE

     Except as provided in Section 3, upon the cessation of the Optionee's
employment for any reason (a "Status Change"), this Option shall terminate as to
any Shares for which it was not exercisable immediately prior to the Status
Change; provided, that the Committee in its sole discretion may provide (either
prior to or following the Status Change) that any or all of such portion of this
Option not otherwise exercisable prior to the Status Change shall be treated as
having become exercisable immediately prior to the Status Change. As to that
number of Shares for which the Option was exercisable (or deemed exercisable by
action of the Committee) immediately prior to the Status Change, it shall remain
exercisable as follows:

     (i) if the Status Change occurs for any reason other than death, for a
     period of six (6) months following the date of the Status Change, except as
     provided in clause (ii) below (but in no event beyond the Final Exercise
     Date), or

     (ii) if the Status Change results from (x) retirement of the Optionee on or
     after age 65, (y) retirement on or after age 55 after ten (10) years of
     continuous employment by the Company or (z) disability (as determined by
     the Company), until the Final Exercise Date; or

     (iii) following death, for a period of one year ending upon the first
     anniversary of the Optionee's death, not to extend beyond the Final
     Exercise Date.

Notwithstanding the foregoing or Section 3, if the Optionee is terminated for
Cause pursuant to the Employment Agreement, this Option shall immediately
terminate simultaneously with the termination of the Optionee's employment.

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5.   NONTRANSFERABILITY OF OPTION

     This Option may not be transferred other than by will or by the laws of
descent and distribution, and during the Optionee's lifetime may be exercised
only by the Optionee (or in the event of the Optionee's incapacity, the person
or persons legally appointed to act on the Optionee's behalf), except that this
Option may be transferred to (i) Immediate Family Members, (ii) a trust or
trusts for the exclusive benefit of Immediate Family Members, or (iii) a
partnership in which such Immediate Family Members are the only partners,
provided that (x) there may be no consideration for any such transfer and (y)
subsequent transfers of this Option shall be prohibited except those made in
accordance with this Section 5. Following such transfer, this Option shall
continue to be subject to all the terms and conditions hereof. "Immediate Family
Members" shall mean the spouse, children and grandchildren of the Optionee.

6.   RIGHTS AS A STOCKHOLDER

     This Option will not give the Optionee rights of a stockholder; the
Optionee will obtain such rights upon actual receipt of the Shares. However, the
Committee may, on such conditions as it deems appropriate, provide that the
Optionee will receive a benefit in lieu of cash dividends that would have been
payable on any or all Shares subject to the Option had such Shares been
outstanding. Without limitation, the Committee may provide for payment to the
Optionee of amounts representing such dividends, either currently or in the
future, or for the investment of such amounts on behalf of the Optionee.

7.   ADJUSTMENTS

     In the event of a stock dividend, stock split or combination of shares,
recapitalization or other change in the Company's capital structure, the
Committee will make appropriate adjustments to the number of Shares that may be
delivered under this Option, and will also make appropriate adjustments to the
number and kind of Shares subject to the Option then outstanding or subsequently
granted, any exercise price relating to the Option and any other provision of
the Option affected by such change.

     The Committee may also make adjustments of the type described above to take
into account distributions to common stockholders, or any other event, if the
Committee determines that adjustments are appropriate to avoid distortion in the
operation of the Option and to preserve the value of the Option made hereunder.

8.   REORGANIZATION

     In the event of a transaction by the Company in which there is an acquiring
or surviving entity (a "Covered Transaction"), the Committee may provide for the
assumption of the Option, or for the grant of a new option in substitution
therefor, by the acquirer or survivor or an affiliate of such acquirer or
survivor, in each case on such terms and subject to such conditions as the
Committee determines; provided, that in the absence of such an assumption, or if
there is no surviving or acquiring entity, the Option shall become fully
exercisable at least twenty (20) days prior to the Covered Transaction and shall
terminate upon consummation of the Covered Transaction.



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9.   WITHHOLDING TAXES

     The Committee will have the right to require that the Optionee or other
appropriate person remit to the Company an amount sufficient to satisfy the
withholding requirements or make other arrangements satisfactory to the
Committee with regard to such requirements, prior to the delivery of any Shares.
The Committee may, but need not, hold back Shares or permit the Optionee to
tender previously owned shares of Stock of the Company in satisfaction of tax
withholding requirements.

10.  GENERAL PROVISIONS

     1. (a) Amendment of Option. This Option may not be modified or amended
     except by an instrument in writing signed by the parties hereto.

     2. (b) Governing Law. This Option and the respective rights and obligations
     of the parties hereunder shall be governed by, and construed in accordance
     with, the laws of the Commonwealth of Massachusetts (without giving effect
     to the conflict of law principles thereof).

     3. (c) Notices. Notices, demands and all other communications provided for
     in this Option shall be in writing and shall be deemed to have been duly
     given when delivered, if delivered personally, or (unless otherwise
     specified) mailed by United States certified or registered mail, return
     receipt requested, postage prepaid, and when received if delivered
     otherwise, addressed as set forth in the first paragraph of this Option or
     to such other address as any party may have furnished to the other in
     writing in accordance herewith, except that notices of change of address
     shall be effective only upon receipt.


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     IN WITNESS THEREOF, the Company has caused this Option to be executed under
its corporate seal by its duly authorized officer. This Option shall take effect
as a sealed instrument.

                                             MACROCHEM CORPORATION


                                             By: /s/ John Zabriskie
                                                 ------------------
                                             Name:   John Zabriskie
                                             Title:  Chairman of the Board
Accepted and Agreed:


/s/    Robert J. Palmisano
--------------------------
Name:  Robert J. Palmisano

Dated:  5/10/01




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