Study on pharmacokinetics and bioavailability of sustained-release roxithromycin tablets in beagle dogs

AIM:To investigate the pharmacokinetics of the roxithromycin sustained-release tablets in 8 beagle dogs. METHODS:Microbiological method was used to determine the serum concentration of roxithromycin after normal and sustained-release tablets were orally administrated in 8 healthy beagle dogs. Pharmacokinetic parameters were calculated, and the bioequiverlence was estimated by statistical method. RESULTS:The pharmacokinetic parameters of sustained-release and normal tablets after single oral dose study were as following: the tmax were 4.74 ± 1.21 h and 1.21 ± 0.64 h, the C_ max were 21.08 ± 4.24 μg·ml -1 , and 28.26 ± 5.41 μg·ml -1 , respectively; the AUC were 164.49 ± 28.55 μg·h·ml -1 and 177.95 ± 27.63 μg·h·ml -1 respectively. Compared to normal tablets, the bioavailability of sustained-release tablets was 93.6 %± 10.5 %. There was much difference for t_ max and C_ max parameters between the two tablets. CONCLUSION: The results of the present study indicate that the absorption speed was slower for sustained-release tablets than normal tablets, but the extend of absorption for the two roxithromycin tablets was bioequivalent.