Preparation of Ambroxol Hydrochloride Push-pull Osmotic Pump Controlled-release Tablets and Its Pharmacokinetics in Dogs

The push-pull osmotic pump-based controlled-release tablets loaded with ambroxol hydrochloride were prepared,with polyethylene oxide of different molecular weight as suspending agent and extender.Using similar factor(?2) as evaluation index,different suspending agent in drug layer and different extender in push layer were investigated by in vitro release.Following orthogonal design,in vitro release and release mechanism of the preparation were investigated.The pharmacokinetics of the preparation in Beagle dogs was also studied.The results showed that the preparation possessed character of zero-order release(r=0.992 1) and drug release completely(90%).The pH of media and rotation speed had no significant effect on the in vitro release,while hardness and size of tablets hardly influenced.The correlation coefficient between the fraction of absorption in vivo and the release rate in vitro was 0.984 9.