Abstract

The aim of this article was to fabricate novel ambroxol hydrochloride carboxymethyl chitosan microspheres without burst release. Firstly the blank carboxymethyl chitosan microspheres were fabricated by the emulsion chemical cross-linking method and the blank microspheres showed a controllable biodegradation in vitro in lysozyme solution. Then the ambroxol hydrochloride microspheres were prepared by the column method. The type of bonding between ambroxol hydrochloride and carboxymethyl chitosan microspheres was investigated by X-ray diffraction; the results showed that the drug chemically bonds to the ion exchangeable structure of the microspheres. The evaluation of the microspheres was investigated by dynamic light scattering, scanning electron microscopy (SEM) and UV spectrophotometer. The microspheres were spherical and consistent, and had an average diameter of 7.4 μm, the drug content of the microspheres was 15.3±0.7% (w/w). Finally the in vitro drug release was tested in different ionic concentration dissolution mediums. The results showed that the microspheres had a sustained-release profile for 8 h in vitro without obvious burst release.

Key words: Ambroxol hydrochloride, carboxymethyl chitosan, lung-targeting; microsphere, in vitro.