<DOCUMENT>
<TYPE>EX-99.1
<SEQUENCE>4
<FILENAME>l00733aexv99w1.txt
<DESCRIPTION>EXHIBIT 99.1
<TEXT>
<PAGE>

EXHIBIT 99.1


                   CERTIFICATION PURSUANT TO 18 U.S.C. (S)1350

        ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002
                                ("SECTION 906")

In connection with the periodic report of Sheffield Pharmaceuticals, Inc. (the
"Company") on Form 10-Q for the period ended March 31, 2003 dated May 12, 2003,
filed with the Securities and Exchange Commission (the "Report"), I, Thomas M.
Fitzgerald, President, Chief Executive Officer and Acting Chief Financial
Officer of the Company, hereby certify as of the date hereof, solely for
purposes of Title 18, Chapter 63, Section 1350 of the United States Code, that
to the best of my knowledge:

         (1)      the Report fully complies with the requirements of Section
                  13(a) or 15(d), as applicable, of the Securities Exchange Act
                  of 1934, and

         (2)      the information contained in the Report fairly presents, in
                  all material respects, the financial condition and results of
                  operations of the Company at the dates and for the periods
                  indicated.

Date: May 12, 2003

                                      /s/ Thomas M. Fitzgerald
                                      -----------------------------------------
                                      President and Chief Executive Officer and
                                      Acting Chief Financial Officer


A signed original of this written statement required by Section 906 has been
provided to Sheffield Pharmaceuticals, Inc. and will be retained by Sheffield
Pharmaceuticals, Inc. and furnished to the Securities and Exchange Commission or
its staff upon request.


</TEXT>
</DOCUMENT>
