BRIEFING

 Guaifenesin and Dextromethorphan Hydrobromide Extended-Release 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 and Dissolution test are based on analyses performed with the Inertsil C8-3 brand of column with L7 packing. The typical retention times for guaifenesin and dextromethorphan are about 4 and 7 min, respectively.

2. The liquid chromatographic procedure in the Organic Impurities, Procedure 1: Guaifenesin Related Substances test is based on analyses performed with the Hypersil BDS C18 brand of column with L1 packing. The typical retention time for guaifenesin is about 7 min.

3. The liquid chromatographic procedure in the Organic Impurities, Procedure 2: Dextromethorphan Hydrobromide Related Substances test is based on analyses performed with the Symmetry C18 brand of column with L1 packing. The typical retention time for dextromethorphan is about 18–23 min.

 (SM2: J. Thomas)

 Correspondence Number—C204312