Studies Of Ambroxol Hydrochloride Sustained Release Tablet

Ambroxol HCl(AM) is an expectorant drug, promoting bronchial secretion and having mucolytic properties. Ambroxol HCI is a metabolite of bromhexine. Compared with the first and second generation expectorant drugs, it has much more powerful expectorant function and lower toxicity, and is one of most clinically-used expectorant drugs. To reduce the side effects and maintain relatively constant plasma concentration, a sustained release tablet of once daily administration was designed and prepared by using Compritol 888 ATO as basic matrix material.According to the literature, UV spectrophotometer was developed for in vitro assay during the studies of physicochemical properties, content and release. HPLC was applied in the determination of AM in plasma concentration of dogs. The extraction recovery of Ambroxol HCI was 77.5%.In the preformulation researches, the physicochemical properties of Ambroxol HCI were investigated, which benefit pharmaceutical design. Based on the studies of pharmaceutical preformulation, single-factor tests were carried out to screen the influence of formulation and manufacture process on the release of Ambroxol HCI, and three optimal formulations was obtained by Central Composite Design. Ambroxol HCI was released mainly through diffusion during the erosion of matrix tablet. Stability studies of preparation demonstrated that light, temperature, humidity and air had little effect on Ambroxol HCI sustained release tablet (SRT).The studies of pharmacokinetics of ambroxol HCI SRT in dogs verified that the desired purpose of sustained release of ambroxol HCI was achieved, which proved this formulation successful. The plasma concentration maintained for about 24h.Its relative bioavailability was between 80.0% and 125.0%, The result of statistic analysis showes that Ambroxol HCI SRT is bioequivalent with reference preparation. The release of SRT in vitro iscorrelative with the absorption fraction in vivo.