Acute toxicity studies of metformin microspheres prepared by two different methods

Previously microspheres containing metformin hydrochloride were prepared by using two different methods viz. ionotropic gelation and solvent evaporation method. In this study, acute toxicity studies were investigated in male albino rats following oral administration of the microspheres. The rats were carefully observed for any clinical signs for seven days, and gross observations of the organs were performed at 14 days. The blood glucose level was sustained to normal values till 12 h with microspheres using carbopol 934P polymer (C3, prepared by using ionotropic gelation method) and the chitosan microspheres (CH3, prepared by using non-aqueous solvent evaporation method). No toxic symptoms or mortality were observed for all the formulations up to dose 2 g/kg body weight. Treatment with all formulations for fourteen days significantly attenuated (p<0.01) the elevated total cholesterol and triglyceride levels in comparison with the vehicle treated diabetic rats.