Factors influencing release of salbutamol sulphate from poly(lactide-co-glycolide) microspheres prepared by water-in-oil-in-water emulsion technique

Abstract

Biodegradable microspheres containing salbutamol sulphate were prepared using water-in-oil-in-water (w/o/w) emulsion technique. Biodegradable polymers of two different molecular weights were used: PLGA 50/50 and PLGA 75/25. In the preparation of the formulations, we used 2 3 factorial design based on three independent variables which are drug loading, amount of gelatin and concentration of PVA. The dependent variables are particle size of the microspheres and entrapment ratio %. The in-vitro release of PLGA microspheres was studied in buffer solution of pH 7.4 at 37°C. A biphasic release behavior of salbutamol sulphate from microspheres was observed. Initially, a burst effect and then slow release was observed. It was found that the biodegradable microspheres of salbutamol sulphate were prepared with PLGA 75/25 by w/o/w emulsion technique obtained extended release obtained for 8 h. PVA concentration was effective on the particle size of microspheres prepared with PLGA 75/25 ( p < 0.05).