Preparation and In Vitro Controlled Release Characteristics of Salbutamol Microcapsules by Coacervation Phase Separation Technique

Salbutamol microcapsules were prepared by coacervation – phase separation method using ethylcellulose as polymer. Three formulations of microcapsules were prepared in the drug to polymer ratio of 1:5, 1:4 and 1:3 and were evaluated for its drug content, Particle size determination and in vitro release behavior using potassium chloride buffer of pH 2 up to 8hrs and 30min. All the formulation (F₁, F₂ and F₃) showed uniformity in drug content, sieve analysis results indicated that major portion of microcapsules were in the range of 350–700μm. The in vitro studies revealed that F₂ showed better controlled release compared to other formulations up to 8hrs and 30min. The drug release from the matrix and that of marketed product was found to be diffusion controlled by means of the swelling of drug loaded microcapsules. It was concluded that Salbutamol can be effectively microencapsulated using ethylcellulose by coacervation – phase separation technique.