BRIEFING

 Brimonidine Tartrate and Timolol Maleate Ophthalmic Solution. Because there is no existing USP monograph for this drug product, a new monograph based on validated methods of analysis is proposed.

1. The liquid chromatographic procedure in the Assay, Procedure for Brimonidine Tartrate was validated using the PerfectSil 100 ODS-3 brand of column with L1 packing. The typical retention time for brimonidine is about 10 min.

2. The liquid chromatographic procedure in the Assay, Procedure for Timolol Maleate was validated using the PerfectSil 100 ODS-3 brand of column with L1 packing. The typical retention time for timolol is about 24 min.

3. The liquid chromatographic procedure in the Organic Impurities, Brimonidine Tartrate test was validated using the Kromasil 100-5 brand of column with L1 packing. The typical retention time for brimonidine is about 8 min.

4. The liquid chromatographic procedure in the Organic Impurities, Timolol Maleate test was validated using the Kromasil 100-5 brand of column with L1 packing. The typical retention time for timolol is about 20 min.

 (SM6: M. Chang; H. Ramanathan)

 Case ID—SUB-130