In-vitro release kinetics, in-vitro buoyancy studies and in-vivo floating behaviour of gastro-retentive tablets of Ciprofloxacin and Metronidazole

Abstract

An oral sustained release dosage form of a combination of Ciprofloxacin HCl and Metronidazole based on gastric floating matrix tablets was studied. The release of Ciprofloxacin HCl and metronidazole was dependent on the matrix forming polymers HPMC K100M and HPMC E10M and the swelling agent guar gum used in the formulation. The release data of Ciprofloxacin HCl as well as Metronidazole from the matrix tablets were analysed kinetically using zero order, first order, Higuchi model and Krosmeyer Peppas models. The floating lag time, floating duration and drug release data for ciprofloxacin and metronidazole was studied. The overall release mechanism can be explained as a result of rapid hydration of polymer on the surface of the floating tablet and formation of a gel layer surrounding the matrix that controls water penetration into its core matrix. On the basis of in vitro release data, the optimised batch F14 comprising of polymers HPMCK100 and HPMC E10M at a ratio of 2:1 and guar gum at a concentration of 3.3 % was subjected to in-vitro buoyancy studies in 0.1 N hydrochloric acid and in-vivo floating behaviour in dogs. It was concluded that the formulated combination tablet resulted into floating duration of more than 20 hours, which would increase the bioavailability with minimum dosage regimen.