Preparation of ambroxol hydrochloride carboxymethyl chitosan micropheres without burst release

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 m, 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.