Formulation and Evaluation of Diltiazem Hydrochloride Microspheres for Oral Controlled Release Drug Delivery using Poly (ε-Caprolactone)

The work entitled “Formulation and Evaluation of Diltiazem hydrochloride Microspheres for Oral Controlled Release Drug Delivery using Poly (ε-caprolactone)” was formulated and evaluated. The study can be concluded that from the investigations a proper selection of formulation parameters are important to achieve the desired particle size, drug loading efficiency and to sustain the release of drug from PCL microspheres. It was observed that particle size increased as the polymer concentration increased. A secondary emulsification process is required where the particle size can be further reduced which was not carried in our present work. Increase in stirring speed also decreases the particle size. In case of drug loading efficiency, when the concentration of polymer and emulsifier was increased, the drug loading efficiency decreased. Increase in stirring speed also caused a decrease in drug loading efficiency. The release of drug from the microspheres was sustained when the concentration of polymer is increased. When the stirring speed was increased from 500-1500 rpm, the drug release was high. The invitro release profiles of drug from all formulations could be best expressed by Higuchi’s equation