EFFECT OF FORMULATION VARIABLES ON THE RELEASE BEHAVIOR OF MICROSPHERES

Abstract

The main aim of present study was to study the effect surfactant, antacid and anti adherent on the percentage drug release of antifungal agents as ketoconazole microspheres. Sustained release microspheres of ketoconazole drug were prepared using one of the best method of preparation of microspheres i.e. solvent evaporation method using cellulose derivative such as ethyl cellulose (as film forming polymer) and methyl cellulose ( provides shape and integrity to the microspheres) as release rate controlling polymers. 2² factorial design was selected for optimization of the number of polymers to be used. Maximum percentage release of drug was seen with initial drug load of 25% w/w concentration of Ketoconazole. Approximate 70% of drug was released in acidic environment (0.1 N HCl) at 2 hours and after this it sustained and reached up to 51.22% at the end of 8 hour in Alkaline medium (phosphate buffer pH 7.2). Comparative % drug release of various variables shows significant effects as compared to drug loaded microspheres. A decline in the percentage release rate of the drug observed when mixed with antacid while increased % drug release observed when treated with surfactant. Drug release profile of anti adherent showed no change in % drug release. The release profile of Ketoconazole could be represented by Jander’s equation, exhibiting pH-dependency and therefore the release of ketoconazole was governed by the diffusion within the microspheres and the solubility.