Formulation and evaluation of Carisoprodol microsphere for sustained drug delivery

Abstract

Sustained release microspheres of Carisoprodol were prepared by emulsification-solvent evaporation method using ethyl cellulose as release retarding agent. The influence of process parameters such as solvent mixture, composition, concentration of the emulsifying agent and speed of stirring has been examined. Microspheres were characterized for the particle size distribution, wall thickness by scanning electron microscopy (SEM), percent drug content, entrapment efficiency and in-vitro dissolution studies. Fourier transform infrared (FT-IR) and differential scanning calorimetric (DSC) studies showed that there was no significant interaction between the drug and polymer. The maximum yield of the microspheres was found to be 72.5 % and the encapsulation efficiency was found to be 90.28%. The prepared microspheres were white, free flowing and spherical in shape. The in-vitro release studies were carried out in phosphate buffer at pH 6.8. Invitro release studies showed that Carisoprodol microspheres of 1:1 ratios showed better sustained effect over a period of 7h.