<DOCUMENT>
<TYPE>EX-99
<SEQUENCE>2
<FILENAME>exhibit99-1_1149929.txt
<DESCRIPTION>EXHIBIT 99.1
<TEXT>

                                                                    Exhibit 99.1

                             JOINT FILING AGREEMENT

     The  undersigned  hereby agree that  statements on Schedules 13G and/or 13D
and Forms 3, 4 and 5 with  respect  to the shares of common  stock of  Sheffield
Pharmaceuticals,  Inc.  and  any  amendments  thereto  signed  by  each  of  the
undersigned shall be filed on behalf of each of the undersigned  pursuant to and
in  accordance  with the  provisions  of Rule  13d-1(k)  promulgated  under  the
Securities  Exchange Act of 1934, as amended.  The  undersigned  hereby  further
agree that this Joint  Filing  Agreement  may be  included as an exhibit to such
statements  or  amendments.  This Joint Filing  Agreement may be executed in any
number of counterparts, all of which taken together shall constitute one and the
same instrument.


Dated: As of November 29, 2006


                                                             *
                                          --------------------------------------
                                          Wayne Holman, individually


                                          RIDGEBACK CAPITAL INVESTMENTS LTD.

                                      By:                    *
                                          --------------------------------------
                                          Name: Wayne Holman
                                          Title: Director


                                          RIDGEBACK CAPITAL MANAGEMENT LLC

                                      By:                    *
                                          --------------------------------------
                                          Name: Wayne Holman
                                          Title: Managing Member



*By: /s/ Bud Holman
     --------------------------------------------
     Bud Holman, Attorney-in-Fact
     Power of attorney filed as an exhibit hereto
</TEXT>
</DOCUMENT>
