PREPARATION AND EVALUATION OF HOLLOW MICROSPHERE DRUG DELIVERY SYSTEM OF ZIDOVUDINE

Zidovudine is the first approved compound for the treatment of HIV; however the main limitation to therapeutic effectiveness of Zidovudine is its dose dependent toxicity, short biological half-life and poor bioavailability. Thus, to overcome the problem the gastroretentive floating drug delivery system is developed. Floating drug delivery system is a low density system which have capacity to remain buoyant on gastric fluid in the stomach without affecting gastric emptying rate for prolonged period of time. The objective of present investigation was to developed hollow microsphere drug delivery system of Zidovudine using Eudragit S100 as polymer by novel O/W emulsification solvent diffusion technique. The hollow microspheres was evaluated for in-vitro buoyancy, micromeritic properties, particle size, percentage yield, entrapment efficiency, drug-polymer compatibility, scanning electron microscopy and in-vitro drug release. The prepared hollow microspheres were floated more than 12hrs on 0.1N HCl. The percentage yield and entrapment efficiency were found to be in range of 86.66% to 52.22% and 86.60% to 72.9%, respectively. The hollow microspheres were found to be regular in shape and highly porous. The release rate was determined on 0.1N HCl at 37^oC. The formulation demonstrated favorable in-vitro release characteristics. The data obtained for the designed system thus suggest that the dosing frequency of zidovudine thus can be reduce as well as increase the biological half-life which will subsequently improve the bioavailability.