Exhibit 10.78 July 1, 1997 Mr. Randy M. Sloan 5203 Lexington Ridge Drive Lexington, MA 02173 Re: Amendment of Employment Agreement Dear Randy, This letter agreement serves to amend the employment agreement dated as of October 1, 1996, by and between...

Exhibit 10.78



                                                                    July 1, 1997





Xx. Xxxxx X. Xxxxx
0000 Xxxxxxxxx Xxxxx Xxxxx
Xxxxxxxxx, XX   00000

                      Re: Amendment of Employment Agreement
Dear Xxxxx,

This  letter  agreement  serves to amend the  employment  agreement  dated as of
October 1,  1996,  by and  between  you and  PolyMedica  Industries,  Inc.  (the
"Company"), (the "Employment Agreement").

         Salary.  The Base Salary, as defined in Section 3.1. of the Employment
         Agreement, is increased to $155,000 effective August 1, 1997.

If the foregoing is acceptable to you, please indicate your agreement by signing
a copy of this letter agreement and returning it to the undersigned.

                                                      Very truly yours,


                                                      /s/ Xxxxxx X. Xxx
                                                      Xxxxxx X. Xxx
                                                      Chairman and Chief 
                                                      Executive Officer

ACCEPTED AND AGREED TO:


/s/ Xxxxx X. Xxxxx
------------------------------
Xxxxx X. Xxxxx