EXHIBIT 99.1


                            CERTIFICATION PURSUANT TO
                             18 U.S.C. SECTION 1350
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Annual Report of the Mylan Profit Sharing 401(k) Plan
(the "Plan") on Form 11-K for the year ended December 31, 2002 as filed with the
Securities and Exchange Commission on the date hereof (the "Report"), each of
the undersigned, in the capacities and on the dates indicated below, hereby
certifies pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906
of the Sarbanes-Oxley Act of 2002, that to his knowledge:

1.   The Report fully complies with the requirements of Section 13(a) or 15(d)
     of the Securities Exchange Act of 1934; and

2.   The information contained in the Report fairly presents, in all material
     respects, the net assets available for benefits and changes in net assets
     available for benefits of the Plan.

Date:  June 30, 2003

                                        /s/ Robert J. Coury
                                        ------------------------------
                                        Robert J. Coury
                                        Chief Executive Officer


                                        /s/ Edward J. Borkowski
                                        ------------------------------
                                        Edward J. Borkowski
                                        Chief Financial Officer


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

The foregoing certification is being furnished in accordance with Securities and
Exchange Commission Release No. 34-47551 and shall not be considered filed as
part of the Form 11-K.