BRIEFING

 Carbidopa, Levodopa, and Entacapone 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 procedures in the Assay, Procedure 1 and Organic Impurities, Procedure 1 were validated using the Symmetry C18 brand of column with L1 packing. The typical retention times for levodopa and carbidopa are about 4 and 12 min, respectively.

2. The liquid chromatographic procedures in the Assay, Procedure 2 and Organic Impurities, Procedure 2 were validated using the XTerra MS C18 brand of analytical and guard columns with L1 packing. The typical retention time for entacapone is about 12 min.

3. The liquid chromatographic procedure in the Dissolution, Test for carbidopa and levodopa was validated using the XTerra MS C18 brand of analytical and guard columns with L1 packing. The typical retention times for levodopa and carbidopa are about 1 and 2 min, respectively.

 (SM4: Y. Yang)

 Case ID—SUB-1265