Studies on pharmacokinetics of Yu-mei dissoluble tablets and bioequivalence of its two formulations

A sensitive HPLC method was developed to determine dextrophan and guaifenesin simultaneously in the human plasma. The enzyme hydrolized plasma concentrations of dextrophan and guaifenesin in 18 healthy volunteers after oral doses of dissoluble tablets and syrup (containing 60 mg of dextromethorphan hydrobromide and 400 mg of guaifenesin) were determined and concentration time curves were drawn. Pharmacokinetic parameters of the two formulations were obtained as follows: dextrophan: T max were(189±053)and(181±025)h, C max were(8926±3150)and(8550± 2076)ng/mL ,AUC 0- t were(41532±11519)and(40018± 753 5)ng·mL -1 ·h ; guaifenesin: T max were(065±027)and(0 50± 021)h , C max were(15451±4936)and(19424± 4376)ng/mL ,AUC 0- t were(26898±728 2)and(33828± 8565)ng·mL -1 ·h ,respectively.The statistical analysis results showed that there was no significant difference for dextrophan and guaifenesin between the test and reference formulation.The two formulations were bioequivalent.