In vitro release study of 2-aminobenzothiazole from microspheres as drug carriers

Abstract

The aim of the present study was the preparation of 2-aminobenzothiazole- loaded microspheres based on cellulose derivatives for controlled and prolonged release. Micro-encapsulation by the simple emulsion (O/W) solvent evaporation method was performed to prepare these formulations using two cellulose derivatives as matrices: ethyl cellulose (EC) and cellulose acetate butyrate (CAB). Optimization of the experimental parameters, such as the polymer/ solvent ratio, the matrix type, stirring speed and the number of blades, was performed to obtain a high encapsulation efficiency of the drug. The effect of the selected parameters on microsphere characteristics, as well as the release rate was investigated. SEM images show that the obtained microparticles were spherical in shape. The effective entrapment of 2-amino-benzothiazole (2-ABZT) in the microspheres was confirmed by FTIR spectroscopy and XRD diffraction analysis. The encapsulation efficiency was improved when the polymer concentration increased reaching 89 %. Microspheres in the size range of 61?278 ?m with EC and close to 113 ?m with CAB were obtained by varying the process conditions. The in vitro release kinetics of the cation of 2-ABZT were established at 37 ?C in simulated gastric medium pH 1.2 and the obtained data were analyzed according to the Fick law. The results showed that the surface morphology and encapsulation efficiency of the microspheres depended strongly on the polymer/solvent ratio and the release rate could be controlled by adjusting the process conditions.