In-vitro diffusion kinetics of salbutamol sulphate from microcapsules coated with Eudragit RS 100.

Diffusion plays an important role in controlled release drug delivery system. Salbutamol sulphate, which is a bronchodilatory drug for asthma, was microencapsulated with a polyacrylic resin: Eudragit RS 100. Drug release data have been analyzed according to various release kinetics like Zero order, First order and Higuchi kinetics. Suice Higuchi mechanism seemed to predominate, the diffusivity rate constant (KBL) and the diffusion coefficient (Da) were estimated according to Baker-Lonsdale method at pH 1.2.

Standardization of process parameters for salbutamol sulphate microcapsules coated with cellulose acetate phthalate and computation of in-vitro release kinetics.

Salbutamol sulphate, a bronchodilatatory drug for asthma, is encapsulated by Emulsion-Solvent-Evaporation technique using cellulose acetatephthalate as coating polymeric material. Different process parameters like Stirring Speed, Drug-Polymer Ratio, Solvent-Polymer Ratio, Internal Phase-External Phase Ratio, Effects of Temperature, and of Surfactants have been studied to standardise the process. At optimal condition of process parameters maximum encapsulation efficiency is obtained and microcapsules produced are free flowing and spherical. The dissolution of the microcapsules is carried out and the data obtained from in-vitro dissolution profile are computed in the light of different kinetic models. Diffusion coefficient (Da) and diffusivity rate constant (KBL) are evaluated with the help of Baker-Lonsdale model.