<PAGE>

                                                                     EXHIBIT 4.3

     NEITHER THIS WARRANT NOR THE SHARES ISSUABLE UPON EXERCISE OF THIS WARRANT
HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR THE
SECURITIES LAWS OF ANY STATE AND MAY NOT BE SOLD, TRANSFERRED OR OTHERWISE
DISPOSED OF EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT OR EXEMPTION
FROM REGISTRATION UNDER THE FOREGOING LAWS.

     VOID AFTER 5:00 P.M. EASTERN TIME ON DECEMBER 29, 2005 ("EXPIRATION DATE").


                        SHEFFIELD PHARMACEUTICALS, INC.

                     WARRANT TO PURCHASE 112,500 SHARES OF
           COMMON STOCK, PAR VALUE $0.01 PER SHARE ("Common Stock")

     For VALUE RECEIVED, The Tail Wind Fund Ltd. ("Warrantholder"), is entitled
to purchase, subject to the provisions of this Warrant, from Sheffield
Pharmaceuticals, Inc., a Delaware corporation ("Company"), at any time not later
than 5:00 P.M., Eastern time, on the Expiration Date, at an exercise price per
share equal to $4.983 (the exercise price in effect being herein called the
"Warrant Price"), 112,500 shares ("Warrant Shares") of Common Stock. The number
of Warrant Shares purchasable upon exercise of this Warrant and the Warrant
Price shall be subject to adjustment from time to time as described herein.

     Section 1.  Registration. The Company shall maintain books for the transfer
                 ------------
and registration of the Warrant. Upon the initial issuance of the Warrant, the
Company shall issue and register the Warrant in the name of the Warrantholder.

     Section 2.  Transfers.  As provided herein, this Warrant may be transferred
                 ---------
only pursuant to a registration statement filed under the Securities Act of
1933, as amended ("Securities Act") or an exemption from such registration;
provided, however, this Warrant may only be transferred to an affiliate of the
Warrantholder. Subject to such restrictions, the Company shall transfer this
Warrant from time to time upon the books to be maintained by the Company for
that purpose, upon surrender thereof for transfer properly endorsed or
accompanied by appropriate instructions for transfer and such other documents as
may be reasonably required by the Company to establish that such transfer is
being made in accordance with the terms hereof, and a new Warrant shall be
issued to the transferee and the surrendered Warrant shall be canceled by the
Company.

     Section 3.  Exercise of Warrant.  Subject to the provisions hereof, the
                 -------------------
Warrantholder may exercise this Warrant in whole or in part at any time upon
surrender of the Warrant, together with delivery of the duly executed Warrant
exercise form attached hereto (the "Exercise Agreement") and payment by cash,
certified check or wire transfer of funds for the Warrant Price for that number
of Warrant Shares then being purchased, to the Company during normal business
hours on any business day at the Company's principal executive offices (or such
other office or agency of the Company as it may designate by
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notice to the holder hereof). The Warrant Shares so purchased shall be deemed to
be issued to the holder hereof or such holder's designee, as the record owner of
such shares, as of the close of business on the date on which this Warrant shall
have been surrendered (or evidence of loss, theft or destruction thereof and
security or indemnity satisfactory to the Company), the Warrant Price shall have
been paid and the completed Exercise Agreement shall have been delivered.
Certificates for the Warrant Shares so purchased, representing the aggregate
number of shares specified in the Exercise Agreement, shall be delivered to the
holder hereof within a reasonable time, not exceeding seven (7) business days,
after this Warrant shall have been so exercised. The certificates so delivered
shall be in such denominations as may be requested by the holder hereof and
shall be registered in the name of such holder or such other name as shall be
designated by such holder. If this Warrant shall have been exercised only in
part, then, unless this Warrant has expired, the Company shall, at its expense,
at the time of delivery of such certificates, deliver to the holder a new
Warrant representing the number of shares with respect to which this Warrant
shall not then have been exercised.

          Each exercise hereof shall constitute the representation and warranty
of the Warrantholder to the Company that the representations and warranties
contained in Article 5 of the Purchase Agreement (as defined below) are true and
correct in all material respects with respect to the Warrantholder as of the
time of such exercise.

     Section 4.  Compliance with the Securities Act of 1933. Neither this
                 ------------------------------------------
Warrant nor the Common Stock issued upon exercise hereof nor any other security
issued or issuable upon exercise of this Warrant may be offered, sold or
transferred except as provided in this agreement and in conformity with the
Securities Act, and then only against receipt of an agreement of such person to
whom such offer of sale is made to comply with the provisions of this Section 4
with respect to any resale or other disposition of such security. The Company
may cause the legend set forth on the first page of this Warrant to be set forth
on each Warrant or similar legend on any security issued or issuable upon
exercise of this Warrant, unless counsel for the Company is of the opinion as to
any such security that such legend is unnecessary.

     Section 5.  Payment of Taxes. The Company will pay any documentary stamp
                 ----------------
taxes attributable to the initial issuance of Warrant Shares issuable upon the
exercise of the Warrant; provided, however, that the Company shall not be
required to pay any tax or taxes which may be payable in respect of any transfer
involved in the issuance or delivery of any certificates for Warrant Shares in a
name other than that of the registered holder of this Warrant in respect of
which such shares are issued, and in such case, the Company shall not be
required to issue or deliver any certificate for Warrant Shares or any Warrant
until the person requesting the same has paid to the Company the amount of such
tax or has established to the Company's satisfaction that such tax has been
paid. The holder shall be responsible for income taxes due under federal, state
or other law, if any such tax is due.

     Section 6.  Mutilated or Missing Warrants. In case this Warrant shall be
                 -----------------------------
mutilated, lost, stolen, or destroyed, the Company shall issue in exchange and
substitution of and upon cancellation of the mutilated Warrant, or in lieu of
and substitution for the Warrant

                                       2
<PAGE>

lost, stolen or destroyed, a new Warrant of like tenor and for the purchase of a
like number of Warrant Shares, but only upon receipt of evidence reasonably
satisfactory to the Company of such loss, theft or destruction of the Warrant,
and with respect to a lost, stolen or destroyed Warrant, reasonable indemnity or
bond with respect thereto, if requested by the Company.

     Section 7.  Reservation of Common Stock. The Company hereby represents and
                 ---------------------------
warrants that there have been reserved, and the Company shall at all applicable
times keep reserved until issued (if necessary) as contemplated by this Section
7, out of the authorized and unissued Common Stock, sufficient shares to provide
for the exercise of the rights of purchase represented by the Warrant. The
Company agrees that all Warrant Shares issued upon exercise of the Warrant shall
be, at the time of delivery of the certificates for suchWarrant Shares, duly
authorized, validly issued, fully paid and non-assessable shares of Common Stock
of the Company.

     Section 8.  Adjustments. Subject and pursuant to the provisions of this
                 -----------
Section 8, the Warrant Price and number of Warrant Shares subject to this
Warrant shall be subject to adjustment from time to time as set forth
hereinafter.

          (a)  If the Company shall at any time or from time to time while the
Warrant is outstanding, pay a dividend or make a distribution on its Common
Stock in shares of Common Stock, subdivide its outstanding shares of Common
Stock into a greater number of shares or combine its outstanding shares into a
smaller number of shares or issue by reclassification of its outstanding shares
of Common Stock any shares of its capital stock (including any such
reclassification in connection with a consolidation or merger in which the
Company is the continuing corporation), then the number of Warrant Shares
purchasable upon exercise of the Warrant and the Warrant Price in effect
immediately prior to the date upon which such change shall become effective,
shall be adjusted by the Company so that the Warrantholder thereafter exercising
the Warrant shall be entitled to receive the number of shares of Common Stock or
other capital stock which the Warrantholder would have received if the Warrant
had been exercised immediately prior to such event upon payment of a Warrant
Price that has been adjusted to reflect a fair allocation of the economics of
such event to the Warrantholder. Such adjustments shall be made successively
whenever any event listed above shall occur.

          (b)  If any capital reorganization, reclassification of the capital
stock of the Company, consolidation or merger of the Company with another
corporation in which the Company is not the survivor, or sale, transfer or other
disposition of all or substantially all of the Company's assets to another
corporation shall be effected, then, as a condition of such reorganization,
reclassification, consolidation, merger, sale, transfer or other disposition,
lawful and adequate provision shall be made whereby each Warrantholder shall
thereafter have the right to purchase and receive upon the basis and upon the
terms and conditions herein specified and in lieu of the Warrant Shares
immediately theretofore issuable upon exercise of the Warrant, such shares of
stock, securities or assets as would have been issuable or payable with respect
to or in exchange for a number of Warrant Shares equal to the number of Warrant
Shares immediately theretofore issuable upon exercise of the

                                       3
<PAGE>

Warrant, had such reorganization, reclassification, consolidation, merger, sale,
transfer or other disposition not taken place, and in any such case appropriate
provision shall be made with respect to the rights and interests of each
Warrantholder to the end that the provisions hereof (including, without
limitations, provision for adjustment of the Warrant Price) shall thereafter be
applicable, as nearly equivalent as may be practicable in relation to any shares
of stock, securities or properties thereafter deliverable upon the exercise
thereof. The Company shall not effect any such consolidation, merger, sale,
transfer or other disposition unless prior to or simultaneously with the
consummation thereof the successor corporation (if other than the Company)
resulting from such consolidation or merger, or the corporation purchasing or
otherwise acquiring such assets or other appropriate corporation or entity shall
assume the obligation to deliver to the holder of the Warrant such shares of
stock, securities or assets as, in accordance with the foregoing provisions,
such holder may be entitled to purchase and the other obligations under this
Warrant. The provisions of this paragraph (b) shall similarly apply to
successive reorganizations, reclassifications, consolidations, mergers, sales,
transfers or other dispositions.

          (c)  In case the Company shall fix a payment date for the making of a
distribution to all holders of Common Stock (including any such distribution
made in connection with a consolidation or merger in which the Company is the
continuing corporation) of evidences of indebtedness or assets (other than cash
dividends or cash distributions payable out of consolidated earnings or earned
surplus or dividends or distributions referred to in Section 8(a)), or
subscription rights or warrants, the Warrant Price to be in effect after such
payment date shall be determined by multiplying the Warrant Price in effect
immediately prior to such payment date by a fraction, the numerator of which
shall be the total number of shares of Common Stock outstanding multiplied by
the Market Price per share of Common Stock (as defined below), less the fair
market value (as determined by the Company's Board of Directors in good faith)
of said assets or evidences of indebtedness so distributed, or of such
subscription rights or warrants, and the denominator of which shall be the total
number of shares of Common Stock outstanding multiplied by such Market Price per
share of Common Stock. "Market Price" shall mean the average of the closing bid
prices of the Common Stock over the twenty (20) consecutive trading days
preceding the date in question. Such adjustment shall be made successively
whenever such a payment date is fixed.

          (d)  During the term of this Warrant, the Warrant Price shall be
subject to adjustment on a basis consistent with the provisions of Section
7.1(a) of the Purchase Agreement by and between the Company and the Investors
named therein dated December 29, 2000 (the "Purchase Agreement"), except that
the Warrant Price shall be adjusted to a price equal to 125% of the adjusted
Purchase Price, if such adjustment to the Warrant Price would result in a lower
Warrant Price and that the adjustment shall be made regardless of whether the
Holder of this Warrant then holds any other shares of Common Stock subject to
adjustment under the terms of Section 7.1(a) of the Purchase Agreement. Such
adjustments shall be made successively whenever required regardless of the
Holder's then Common Stock ownership.

                                       4
<PAGE>

          (e)  An adjustment shall become effective immediately after the
payment date in the case of each dividend or distribution and immediately after
the effective date of each other event which requires an adjustment.

          (f)  In the event that, as a result of an adjustment made pursuant to
Section 8(a), the holder of this Warrant shall become entitled to receive any
shares of capital stock of the Company other than shares of Common Stock, the
number of such other shares so receivable upon exercise of this Warrant shall be
subject thereafter to adjustment from time to time in a manner and on terms as
nearly equivalent as practicable to the provisions with respect to the Warrant
Shares contained in this Warrant.

     Section 9.  Fractional Interest. The Company shall not be required to issue
                 -------------------
fractions of Warrant Shares upon the exercise of the Warrant. If any fraction of
a Warrant Share would, except for the provisions of this Section, be issuable
upon the exercise of the Warrant (or specified portions thereof), the fractional
share shall be disregarded and the number of shares to be issued upon exercise
shall be the number of whole shares only.

     Section 10. Benefits. Nothing in this Warrant shall be construed to give
                 --------
any person, firm or corporation (other than the Company and the Warrantholder)
any legal or equitable right, remedy or claim, it being agreed that this Warrant
shall be for the sole and exclusive benefit of the Company and the
Warrantholder.

     Section 11. Notices to Warrantholder. Upon the happening of any event
                 ------------------------
requiring an adjustment of the Warrant Price, the Company shall promptly give
written notice thereof to the Warrantholder at the address appearing in the
records of the Company, stating the adjusted Warrant Price and the adjusted
number of Warrant Shares resulting from such event and setting forth in
reasonable detail the method of calculation and the facts upon which such
calculation is based. In the event of a dispute with respect to any such
calculation, the certificate of the Company's independent certified public
accountants shall be conclusive evidence of the correctness of any computation
made, absent manifest error. Failure to give such notice to the Warrantholder or
any defect therein shall not affect the legality or validity of the subject
adjustment.

     Section 12. Identity of Transfer Agent. The Transfer Agent for the Common
                 --------------------------
Stock is Computershare Investor Services. Upon the appointment of any subsequent
transfer agent for the Common Stock or other shares of the Company's capital
stock issuable upon the exercise of the rights of purchase represented by the
Warrant, the Company will mail to the Warrantholder a statement setting forth
the name and address of such transfer agent.

                                       5
<PAGE>

     Section 13. Notices. Any notice pursuant hereto to be given or made by the
                 -------
Warrantholder to or on the Company shall be sufficiently given or made if sent
by certified mail, return receipt requested, postage prepaid, addressed as
follows:

          Sheffield Pharmaceuticals, Inc.
          425 South Woodsmill Road
          Suite 270
          St. Louis, MO 63017-3441
          Attn: President
          Fax:  314-579-9799

or such other address as the Company may specify in writing by notice to the
Warrantholder complying as to delivery with the terms of this Section 13.

     Any notice pursuant hereto to be given or made by the Company to or on the
Warrantholder shall be sufficiently given or made if personally delivered or if
sent by an internationally recognized courier services by overnight or two-day
service, to the address set forth on the books of the Company or, as to each of
the Company and the Warrantholder, at such other address as shall be designated
by such party by written notice to the other party complying as to delivery with
the terms of this Section 13. All such notices, requests, demands, directions
and other communications shall, when sent by courier be effective two (2) days
after delivery to such courier as provided and addressed as aforesaid.

     Section 14. Registration Rights. The initial holder of this Warrant is
                 -------------------
entitled to the benefit of certain registration rights in respect of the Warrant
Shares as provided in the Registration Rights Agreement dated as of as of
December 29, 2000.

     Section 15. Successors. All the covenants and provisions hereof by or for
                 -----------
the benefit of the Warrantholder shall bind and inure to the benefit of its
respective successors and assigns hereunder.

     Section 16. Governing Law. This Warrant shall be deemed to be a contract
                 -------------
made under the laws of the State of New York, without giving effect to its
conflict of law principles, and for all purposes shall be construed in
accordance with the laws of said State.

     IN WITNESS WHEREOF, the parties hereto have caused this Warrant to be duly
executed, as of the day and year first above written.

                                   SHEFFIELD PHARMACEUTICALS, INC.

                                   By:  /s/ Loren G. Peterson
                                        -------------------------------------
                                        President and Chief Executive Officer

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<PAGE>

                        Sheffield Pharmaceuticals, Inc.
                             WARRANT EXERCISE FORM

To: Sheffield Pharmaceuticals, Inc.

     This undersigned hereby irrevocably elects to exercise the right of
purchase represented by the within Warrant ("Warrant") for, and to purchase
thereunder by the payment of the Warrant Price and surrender of the Warrant,
_______________ shares of Common Stock ("Warrant Shares") provided for therein,
and requests that certificates for the Warrant Shares be issued as follows:

                     ____________________________________
                     Name
                     ____________________________________
                     Address
                     ____________________________________
                     ____________________________________
                     Federal Tax ID or Social Security No.

     and delivered by   certified mail to the above address, or
                        electronically (provide DWAC Instructions:_________), or
                        other (specify: ______________________________________).

and, if the number of Warrant Shares shall not be all the Warrant Shares
purchasable upon exercise of the Warrant, that a new Warrant for the balance of
the Warrant Shares purchasable upon exercise of this Warrant be registered in
the name of the undersigned Warrantholder or the undersigned's Assignee as below
indicated and delivered to the address stated below.

     By exercising the rights represented by this Warrant, the undersigned
hereby certifies that, as of the date of exercise of this Warrant, the
representations and warranties contained in Section 5 of the Purchase Agreement
are true and correct in all material respects with respect to the undersigned.

Dated:___________________, ____

Note: The signature must correspond with       Signature:_______________________
the name of the registered holder as written
on the first page of the Warrant in every      ______________________________
particular, without alteration or enlargement  Name (please print)
or any change whatever, unless the Warrant
has been assigned.                             ______________________________
                                               ______________________________
                                               Address
                                               ______________________________
                                               Federal Identification or
                                               Social Security No.

                                               Assignee:
                                               ______________________________
                                               ______________________________
                                               ______________________________
                                               ______________________________

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