Optimized Formulation of Colon Targeted Microsheres for Prednisolone Sodium Phosphate: Application of Taguchi Experimental Design

Abstract

Microspheres of ethyl cellulose containing prednisolone sodium phosphate were prepared by double emulsion solvent diffusion method. A statistical design was used to study and optimize the variables that affect the preparation of microspheres. The experimental results showed that the drug: polymer ratio, stirring speed, concentration of surfactant, and volume of processing media played an important role in the formulation of microspheres. The prepared microspheres were characterized on the basis of particle size, scanning electron microscopy, entrapment efficiency and <italic>in vitro</italic> release. Taguchi experimental design helped to reduce the number of experiments. Optimized formulation exhibited Higuchi square root kinetics displaying diffusion from the microspheres as the main mechanism for drug release.