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                                                                     Exhibit 4.7


THE WARRANTS REPRESENTED BY THIS CERTIFICATE AND THE COMMON STOCK ISSUABLE UPON
EXERCISE OF SUCH WARRANTS HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF
1933, AS AMENDED, OR UNDER ANY STATE SECURITIES LAWS, AND ARE TRANSFERABLE ONLY
                         IN COMPLIANCE WITH SUCH LAWS

                             WARRANT CERTIFICATE

                   20,000 Warrants to Purchase Common Stock

                        Sheffield Pharmaceuticals, Inc.

            (Incorporated under the laws of the State of Delaware)

          This is to certify that, for value received, The P. L. Thomas Group,
Inc., or registered assigns, is the owner of 20,000 Warrants, each of which
entitles the registered owner to purchase from Sheffield Pharmaceuticals, Inc.,
a Delaware corporation (the "Corporation"), at any time after the date
specified below, one share of fully paid and non-assessable common stock
(the "Common Stock") of the Corporation, at a purchase price per share of $3.00
(the "Applicable Exercise Price"), subject to adjustment as set forth herein.
This Warrant Certificate covers an aggregate of 20,000 shares of Common Stock,
subject to adjustment as set forth herein. The shares of Common Stock issuable
upon the exercise of the Warrants are sometimes called the "Warrant Share."

          Subject to the provisions hereof, the Warrants represented by this
Warrant Certificate may be exercised by the registered holder in whole or in
part by surrender of this Warrant Certificate at the principal executive offices
of the Corporation with the form of election to exercise attached hereto duly
executed and with payment in full to the Corporation of the Applicable Exercise
Price for each of the Warrant Shares so purchased. Payment of such Applicable
Exercise Price shall be made in cash or by certified official bank check.
Thereupon, the Warrants shall be deemed to have been exercised and the person
exercising the same to have become a holder of record of the Warrant Shares so
purchased (or of the other securities or property to which such person is
entitled upon such exercise) for all purposes; and certificates for Warrant
Shares so purchased shall be delivered to the purchaser within a reasonable time
(not exceeding 10 days) after the Warrants shall have been exercised as set
forth above.

          The right of the registered holder to exercise the Warrants
represented by this Warrant Certificate shall be exercisable in full on or after
October 15, 1997, and until 5:00 p.m., Eastern Standard Time, October 15, 2002
(the "Expiration Time"). Any Warrants not exercised on or before the Expiration
Time shall expire and be of no further force or effect. If only a portion of the
Warrants shall be exercised, the holder of this Warrant Certificate shall be
entitled to

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receive a similar warrant certificate of like tenor and date covering the number
of Warrants which shall not have been exercised.

          This Warrant Certificate is exchangeable upon surrender by its
registered holder at the principal executive offices of the Corporation, for new
warrant certificates of like tenor and date representing in the aggregate the
right to purchase the number of Warrant Shares which may be purchased hereunder.

          This Warrant Certificate and the rights evidenced hereby may not be
sold, conveyed, pledged or otherwise transferred by the holder hereof without
the prior written consent of the Corporation.

          The Corporation covenants and agrees that all shares of Common Stock
which may be issued upon the exercise of the rights represented by this Warrant
Certificate will, upon issuance, be validly issued, fully paid and non-
assessable and free from all taxes, liens and charges with respect to the issue
thereof (other than taxes in respect of any transfer occurring contemporaneously
with such issue). The Corporation further covenants and agrees that it will at
all times have authorized and reserved a sufficient number of shares of Common
Stock to provide for the exercise of the rights represented by this Warrant
Certificate.

                                   ARTICLE I

          Section 1.1  Adjustment of Applicable Exercise Price.
                       ---------------------------------------

          (a)  The Applicable Exercise Price shall be subject to adjustment from
time to time as follows:

          (i)  If the number of shares of Common Stock outstanding at any time
     after the date hereof is increased by a stock dividend payable in shares of
     Common Stock or by a subdivision or split-up of shares of Common Stock,
     then, following the record date fixed for the determination of holders of
     Common Stock entitled to receive such stock dividend, subdivision or split-
     up, the number of Warrants and the Applicable Exercise Price shall be
     appropriately adjusted so that the number of shares of Common Stock
     issuable on exercise of each Warrant shall be increased and the Applicable
     Exercise Price decreased in proportion to such increase of outstanding
     shares.

          (ii) If the number of shares of Common Stock outstanding at any time
     after the date hereof is decreased

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     by a combination of the outstanding shares of Common Stock, then, following
     the record date for such combination, the number of Warrant Shares issuable
     upon exercise of Warrants and the Applicable Exercise Price shall be
     appropriately adjusted so that the number of shares of Common Stock
     issuable on exercise of each Warrant shall be decreased and the Applicable
     Exercise Price shall be increased in proportion to such decrease in
     outstanding shares.

          (iii) If any consolidation or merger of the Corporation with or into
     another entity, or the sale of all or substantially all its assets to
     another entity shall be effected, or in case of any capital reorganization
     or reclassification of the capital stock of the Corporation, then lawful
     and adequate provision shall be made whereby each holder of Warrants shall
     thereafter have the right to receive upon the basis and upon the terms and
     conditions specified herein and in lieu of the shares of Common Stock of
     the Corporation immediately theretofore receivable upon the conversion of
     such Warrants, such shares of stock, securities, interests or assets as may
     be issued or payable with respect to or in exchange for a number of
     outstanding shares of Common Stock equal to the number of shares of Common
     Stock immediately theretofore so receivable by such holder had such
     consolidation, merger, sale, reorganization or reclassification not taken
     place, and in any such case appropriate provision shall be made with
     respect to the rights and interests of the holder to the end that the
     provisions hereof (including without limitation provisions for adjustment
     of the Applicable Exercise Price) shall thereafter be applicable, as nearly
     as may be in relation to any shares of stock, securities or assets
     thereafter deliverable upon the exercise of such conversion rights.

          (iv)  All calculations under this paragraph (a) shall be made to the
     nearest cent or to the nearest one hundredth (1/100) of a share, or one
     cent ($.01), as the case may be.

          (b)    In any case in which the provisions of this Article I shall
require that an adjustment shall become effective immediately after a record
date for an event, the Corporation may defer until the occurrence of such event
(x) issuing to the holder of any Warrant exercised after such record date and
before the occurrence of such event, the additional shares of Common Stock
issuable upon such exercise by reason of the adjustment required by such event
over and above the shares of Common Stock issuable upon such exercise before
giving effect to such adjustment and (y) paying to such holder any amount in
cash in lieu of a fractional share of Common Stock pursuant to

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Section 1.2; provided, however, that the Corporation shall deliver to such
             --------  -------
holder a due bill or other appropriate instrument evidencing such holder's right
to receive such additional shares, and such cash, upon the occurrence of the
event requiring such adjustment.

          (c)  Except in the case of shares registered pursuant to Section 2.1,
any and all Warrant Shares issued pursuant to the exercise of the Warrants shall
bear a legend reflecting that such Warrant Shares have not been registered under
the Securities Act of 1933, as amended, or under any state securities law, and
cannot be transferred by sale, pledge or otherwise, except in compliance with
such securities laws and all regulations thereunder. As a condition to the
issuance of Warrant Shares, the holder hereof requesting to so exercise the
Warrants shall execute appropriate investment letters and shall deliver such
other documents (including legal opinions) as may be reasonably required by the
Corporation and its counsel to assure that Warrant Shares are issued only in
compliance with applicable securities law.

          (d)  In the event the Corporation proposes to take any action of the
types described in this Section 1.1, the Corporation shall give notice to each
holder of Warrants, at the address of such holder shown on the books of the
Corporation, which notice shall specify the record date, if any, with respect to
any such action and the date on which such action is to take place. The notice
shall also set forth the facts with respect thereto reasonably necessary to
indicate the effect of the action (to the extent the effect may be known at the
date of such notice) on the Applicable Exercise Price and the number, kind or
class of shares or other securities or property which shall be deliverable or
purchasable upon the occurrence of such action or deliverable upon exercise of
the Warrants. In the case of any action which would require the fixing of a
record date, notice shall be given at least 10 days prior to the date so fixed,
and in case of all other action, such notice shall be given at least 15 days
prior to taking of such proposed action. Failure to give such notice, or any
defect therein, shall not affect the legality or validity of any such action,
and the holder of these Warrants shall have no right to prevent or delay any
such action by injunction or otherwise.

          (e)  In the event that at any time as a result of an adjustment made
pursuant to this Section 1.1, the holder of any Warrants thereafter surrendered
or exercised shall become entitled to receive any shares of the Corporation or
another corporation other than shares of Common Stock, the provisions of

                                      -4-

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this Section 1.1 and Section 1.2 with respect to the Common Stock shall apply on
like terms to any such other shares.

          Section 1.2.  No certificates for fractional shares of Common Stock
shall be issued upon the exercise of Warrants, but in lieu thereof the
Corporation shall pay, upon exercise in full of the Warrants represented by this
Warrant Certificate, out of funds legally available therefor, a cash adjustment
in respect of such fractional shares based upon the then effective Applicable
Exercise Price.

                                  ARTICLE II

          Section 2.1.  If the Corporation at any time after the date hereof,
proposes to register any of its shares of Common Stock under the Securities Act
pursuant to a registration statement (other than pursuant to a registration
statement on Form S-4 or S-8 or any successor or similar forms), it will
promptly give written notice to the registered holder hereof of its intention to
do so and, upon the written request of the holder given within 20 days after
receipt of any such notice (which request shall state the intended method of
disposition of such Warrant Shares by such holder), the Corporation will use its
best efforts to cause any or all of the Warrant Shares held by such holder, or
which may be acquired by such holder upon exercise of the Warrants, to be
registered under the Securities Act, all to the extent requisite to permit the
sale or other disposition (in accordance with the intended methods thereof, as
aforesaid) by such holder of such Warrant Shares; provided, however, that the
Corporation may at any time withdraw or cease proceeding with any such
registration if it shall at the same time withdraw or cease proceeding with the
registration of such other Common Stock originally proposed to be registered;
provided, further, that if the Corporation's underwriters recommend a reduction
in the number of shares to be registered, the number of Warrant Shares which the
Corporation is required to register hereunder on behalf of the holder shall be
reduced in the same ratio that recommended reduction bears to the total number
of shares (other than shares of Common Stock issuable by the Company) originally
proposed to be registered. The Corporation need not reduce the number of any
shares which it proposes to sell, in which case any reduction shall be allocated
proportionately among the balance of the shares to be registered (other than
shares of Common Stock issuable by the Company), including the Warrant Shares.
In addition, if at any time after the date hereof the Corporation proposes to
register shares of its date hereof the Corporation proposes to register shares
of its Common Stock for offering otherwise than in connection with an
underwritten public offering (including pursuant to

                                      -5-

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Rule 415(a)(iii) or (viii) of the Securities Act), the Corporation will use its
best efforts to cause any Warrant Shares not theretofore issued to be registered
for issuance upon exercise thereof.

     Section 2.2.   All expenses incurred by the Corporation in complying with
this Article II, including, without limitation, all registration and filing fees
(including all expenses incident to filing with the National Association of
Securities Dealers, Inc.), printing expenses, fees and disbursements of counsel
for the Corporation, the expense of any special audits incident to or required
by any such registration, and the expense (including counsel fees) of complying
with securities or Blue Sky laws shall be paid by the Corporation; provided in
no event shall the Corporation be liable for any fees payable to counsel or
accountants retained by any holder hereof or for underwriting fees, discounts or
selling commissions attributable to such Warrant Shares.

     Section 2.3.   In the event of any registration of Warrant Shares under the
Securities Act pursuant to this Article 2, the Corporation will indemnify and
hold harmless the holder against any losses, claims, damages or liabilities to
which such holder may become subject under the Securities Act or otherwise,
insofar as such losses, claims, damages or liabilities (or actions in respect
thereof) arise out of or are based upon any untrue statement or alleged untrue
statement of any material fact contained (on the effective date thereof) in any
registration statement under which such Warrant Shares were registered under the
Securities Act, any preliminary prospectus, prospectus subject to completion or
final prospectus contained therein, or any amendment or supplement thereto, or
arise out of or are based upon the omission or alleged omission to state therein
a material fact required to be stated therein or necessary to make the
statements therein not misleading; and will reimburse such holder for reasonable
legal or any other expenses reasonably incurred by such holder in connection
with investigating or defending any such loss, claim, damage, liability or
action; provided, however, that the Corporation will not be liable in any such
case to the extent that any such loss, claim, damage or liability arises out of
or is based upon an untrue statement or omission or alleged omission made in
said registration statement, said preliminary prospectus, prospectus subject to
completion or final prospectus, or said amendment or supplement in reliance upon
and in conformity with written information furnished to the Corporation through
an instrument duly executed by such holder specifically for use in the
preparation thereof.

                                      -6-
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     Section 2.4.   In the event of any registration of any Warrant Shares
pursuant to this Article II, the holder will indemnify and hold harmless the
Corporation, its attorneys, accountants, underwriters and each other person, if
any, who controls the Corporation within the meaning of the Securities Act,
against any losses, claims, damages or liabilities, joint or several, to which
the Corporation or such other person may become subject under the Securities Act
or otherwise, insofar as such losses, claims, damages or liabilities (or actions
in respect thereof) arise out of or are based upon any untrue statement or
alleged untrue statement of any material fact contained (on the effective date
thereof) in any registration statement under which such Warrant Shares were
registered under the Securities Act, any preliminary prospectus, prospectus
subject to completion or final prospectus contained therein, or any amendment or
supplement thereto, or arise out of or are based upon the omission or alleged
omission to state therein a material fact required to be stated therein or
necessary to make the statements therein not misleading, in each case to the
extent and only to the extent that any such loss, claim, damage or liability
arises out of or is based upon an untrue statement or alleged untrue statement
or omission or alleged omission made in said registration statement, said
preliminary prospectus, prospectus subject to completion or said amendment or
supplement in reliance upon and in conformity with written information furnished
to the Corporation through an instrument duly executed by such holder
specifically for use in the preparation thereof, and such holder will reimburse
the Corporation and each such other person for any legal or any other expenses
reasonably incurred by the Corporation or such other person in connection with
investigating or defending any such loss, claim, damage, liability or action.

     Section 2.5.   In the event of any claim for which indemnity is sought
under Section 2.3 or 2.4, above, the party seeking indemnification shall give
prompt notice of its claim to the other party and shall permit the other party
to engage counsel and to defend against the same.

     Section 2.6.   The holder's right to request registration of Warrant Shares
under this Article II shall cease and terminate as to any particular Warrant
Shares when such Warrant Shares shall have been effectively registered under the
Securities Act or when such Warrant Shares shall have become eligible for sale
pursuant to Rule 415 of the Securities Act. The holder's right to request
registration of Warrant Shares under this Article II shall be transferable in
connection with any disposition of such shares to a permitted transferee of at
least 5,000 of such Warrant Shares upon the agreement of such transferee to be
bound by the terms hereof; provided, however, if

                                      -7-
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at any time The P. L. Thomas Group, Inc., shall hold less than 5,000 Warrant
Shares as a result of having transferred Warrant Shares together with
registration rights hereunder, its registration rights with respect to the
Warrant Shares it still holds shall terminate. For purposes of this Warrant
Certificate, shares of Common Stock shall cease to be Warrant Shares when such
shares have been sold pursuant to an effective registration statement under the
Securities Act or pursuant to an effective registration statement under the
Securities Act or pursuant to an exemption from registration thereunder or when
such Warrant Shares shall have become eligible for sale pursuant to Rule 415 of
the Securities Act.

                                  ARTICLE III

     Section 3.1. The issue of any stock or other certificate upon the exercise
of the Warrants shall be made without charge to the registered holder hereof for
any transfer or issuance tax in respect of the issue thereof. The Corporation
shall not, however, be required to pay any tax which may be payable in respect
of any transfer involved in the issue and delivery of any certificate in a name
other than that of the registered holder of this Warrant Certificate, and the
Corporation shall not required to issue or deliver any such certificate unless
and until the person or persons requesting the issue thereof shall have paid to
the Corporation the amount of such tax or shall have established to the
satisfaction of the Corporation that such tax has been paid.

     Section 3.2. If this Warrant Certificate shall be lost, stolen, mutilated
or destroyed, the Corporation shall, on such terms as to indemnify or otherwise
protect the Corporation as the Corporation may in its discretion impose, issue a
new warrant certificate of like denomination, tenor and date as the Warrant
Certificate so lost, stolen, mutilated or destroyed. Any such new warrant
certificate shall constitute an original contractual obligation of the
Corporation, whether or not the allegedly lost, stolen, mutilated or destroyed
Warrant Certificate shall be at any time enforceable by anyone.

     Section 3.3.   The Corporation may deem and treat the registered holder of
this Warrant Certificate as the absolute owner of this Warrant Certificate for
all purposes and shall not be affected by any notice to the contrary. This
Warrant Certificate and all rights hereunder are transferable on the books of
the Corporation, upon surrender of this Warrant Certificate, with the form of
assignment attached hereto duly executed by the registered holder hereof or by
his attorney duly authorized in writing, to the Corporation at its principal

                                      -8-
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executive offices and thereupon there shall be issued in the name of the
transferee or transferees, in exchange for this Warrant Certificate, a new
warrant certificate or warrant certificates of like tenor and date, representing
in the aggregate the right to subscribe for and purchase the number of shares
which may be subscribed for and purchased hereunder; provided that the
Corporation shall not be obligated to record or give effect to any transfer of
Warrants, unless the holder shall furnish evidence reasonably satisfactory to
the Corporation that the proposed transfer does not violate any applicable
securities law or regulation. References in this Certificate to a "holder" shall
include any transferee or transferees to whom the Warrants may be transferred
pursuant to the foregoing. Notwithstanding the foregoing, this Warrant
Certificate and the rights represented hereby may not be sold, conveyed, pledged
or otherwise transferred without the prior written consent of the Corporation.

          Section 3.4.  Except as otherwise provided herein, this Warrant
Certificate shall not entitle the holder to any rights of a stockholder of the
Corporation either at law or in equity, including, without limitation, the right
to vote, to receive dividends and other distributions, to exercise any
preemptive rights or to receive any notice of meetings of stockholders or of any
other proceedings of the Corporation.

          Section 3.5.  Upon the exercise or permitted transfer of any Warrants
hereunder, if the holder has Warrants with different Applicable Exercise Prices,
he shall designate the Applicable Exercise Price with respect to the Warrants
exercised or transferred. Such designation shall be recorded by the Corporation
in its books and records and shall be specifically identified with such
Warrants.

          Section 3.6.  This Warrant Certificate shall, in all events, remain
outstanding and fully exercisable until it is exercised in its entirety or
terminates in accordance with the terms hereof.

          Section 3.7. In the event that one or more of the provisions of this
Warrant Certificates shall for any reason be held to be invalid, illegal or
unenforceable in any respect, such invalidity, illegality or unenforceability
shall not affect any other provison of this Warrant Certificate, but this
Warrant Certificate shall be construed as if such invalid, illegal or
unenforceable provision had never been contained herein.

          Section 3.8.  This Warrant Certificate shall be governed by and
construed in accordance with the laws of the

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State of New York applicable to agreements made and to be entirely performed
within such State.

          Dated: As of 4/30, 1997.
                       ----

                                            Sheffield Pharmaceuticals, Inc.


                                            By /s/ Loren G. Peterson
                                               ----------------------------
                                               Chief Financial Officer

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                               FORM OF EXERCISE
                               ----------------
               (to be executed by the registered holder hereof)

          The undersigned hereby exercises the right to purchase ___________
shares of common stock ("Common Stock") of Sheffield Pharmaceuticals, Inc.,
evidenced by the within Warrant Certificate for an Applicable Exercise Price of
$___________ per share and herewith makes payment of the purchase price in full
of $____________.  Kindly issue certificates for shares of Common Stock (and for
the unexercised balance of the Warrants evidenced by the within Warrant
Certificate, if any) in accordance with the instructions given below.

Dated: ________________, 19_____.

                                                 _______________________________

Instructions for registration of stock

______________________________________
         Name (Please Print)

Social Security or other identifying Number: _____________________

Address: _______________________________________
                City/State and Zip Code

          Instructions for registration of certificate representing
                 the unexercised balance of Warrants (if any)

______________________________________
         Name (Please Print)

Social Security or other identifying Number: _____________________

Address: _______________________________________
                City, State and Zip Code

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                        TRANSFER OF WARRANT CERTIFICATE
                        -------------------------------

          For value received ___________________________________________________
hereby sells, assigns and transfers unto _______________________________________
the rights to purchase ____________________ shares of common stock of Sheffield
Pharmaceuticals, Inc. (the "Corporation"), at an Applicable Exercise Price of
$_________ per share, which rights are represented by the within Warrant
Certificate, and does hereby irrevocably constitute and appoint ________________
attorney to transfer said rights on the books of the within named Corporation,
with full power of substitution in the premises.  The undersigned acknowledges
that such sale, assignment and transfer is subject to the written approval of
the Corporation in accordance with the terms of the Warrant Certificate.


                                             ___________________________________

DATED:

In the Presence of ____________________________


Social Security and other Identifying
Number of Assignee: _________________


Address of Assignee:


_____________________________________
     City, State and Zip Code