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.