Study on the bioavailability and pharmacokinetics of guaiphenesin sustained release tablets in Beagle dogs

OBJECTIVE To establish an RP-HPLC method for determination of guaiphenesin and to study the bioavailability and pharmacokinetics of guaiphenesin sustained release tablets in beagle dogs. METHODS Six Beagle dogs were divided into two groups at random and were given test and reference formulation, then the serum was taken at different times and was deter mined by RP-HPLC. The parameters of pharmacokinetic and relative bioavailability and bioequivalent evaluation of two formulations were calculated. RESULTS The parameters of the test and reference formulation: l_(max) was(1.8±0.3)h and(0.92±0.13) h,C_(max) was(4.7±0.6)mg·L~(-1) and(7.4±0.7)mg·L~(-1),AUC_(0-t) was(18.4±2.0)mg·h~(-1)·L~(-1) and(17.3±2.5)mg·h~(-1)·L~(-1), AUC_(0-∞) was(19.8±2.4)mg·h~(-1)·L~(-1) and(18.4±2.8)mg·h~(-1)·L~(-1) respectively. The ln AUC_(0-T) and ln AUC_(0-∞), of the two formulations were bioequivalent with analysis of variance and double single test, the relative bioavailability of guaiphenesin sustained release tablets was(107.1±8.0)%. CONCLUSION Guaiphenesin sustained release tablets had an effect of sustained release in Beagle dogs, and was bioequivalent to reference formulation.