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

The aim of the present study is the preparation of 2-aminobenzothiazole-loaded microspheres based on cellulose derivatives for controlled and prolonged release. Micro-encapsulation by simple emulsion (O/W) solvent evaporation method was carried out to prepare these formulations using two cellulose derivatives as matrices: ethylcellulose (EC) and cellulose acetate butyrate (CAB). The optimization of the experimental parameters such as the polymer/solvent ratio, the matrix type, stirring speed and the number of blades was studied to get high encapsulation efficiency of drug. The effect of the selected parameters on microsphere characteristics, as well as the release rate was investigated. SEM images show that obtained microparticles are spherical in shape. The effective entrapment of 2-amino-benzothiazole (2-ABZT) in the microspheres was confirmed by FTIR spectroscopy and XRD diffraction. The encapsulation efficiency was improved when the polymer concentration increased reaching 89 %. We have obtained microspheres in the range of 61‑278 µm with EC by varying process conditions and closed to 113µm with CAB. The in vitrorelease kinetics of the cation of 2-ABZT were established at 37°C in simulated gastric medium pH 1.2 and the obtained data were analysed according to Fick’s law. The results showed that the surface morphology and the encapsulation efficiency of the microspheres depended strongly on the polymer/solvent ratio and the release rate can be controlled by adjusting the process conditions.