Abstract

Nitrofurantoin bearing microspheres of wax were prepared by wax emulsification and congealing techniques. The effects of emulsifier concentration and stirring rate on drug release and other physical parameters of microspheres were studied. Based on in vitro release and urinary excretion data nitrofurantoin wax microspheres appeared to have sustained drug release profile. Bees wax and hard paraffin have been used in the preparation of matrix embedded sustained release formulations of drugs. In the present investigation NFT (nitrofurantoin) was embedded in spherical monoliths of wax prepared by emulsification of wax its subsequent congealing. The variables studied were : stirring rate, emulsifier concentration and drug loading. The effects of these variables on particle size, shape and degree of drug embedding were also studied. The formulation with desirable release rate was selected. The in vivo performance of NFT-wax microspheres was evaluated using urinary excretion profile obtained on dogs.