BRIEFING

 Ambrisentan Tablets. 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 used in the Assay and Dissolution test is based on analyses performed using the X Bridge C18 brand of column with L1 packing. The typical retention time for ambrisentan is about 4.5 min.

2. The liquid chromatographic procedure used in the test for Organic Impurities is based on analyses performed using the Sunfire C18 brand of column with L1 packing. The typical retention time for ambrisentan is about 12 min.

3. The liquid chromatographic procedure used in the test for Limit of Ambrisentan Related Compound E is based on analyses performed using the LiChrospher 60 RP select B brand of column with L7 packing. The typical retention time for ambrisentan is about 31.5 min.

 (SM5: S. Ramakrishna)

 Case ID—SUB-1152; SUB-1161; SUB-1162