Controlled Release Ion Sensitive Floating Oral in situ Gel of a Prokinetic Drug using Gellan Gum.

There are various approaches commonly used for gastric retention, one of which is raft forming system. Floating oral in situ gel is a type of raft forming system. The present work concerns with the formulation, evaluation and optimization of floating oral in situ gel of Itopride Hydrochloride for controlled release. Gellan gum has been used as a gel forming polymer and calcium carbonate as cross linking agent and Ca2+ ion source, and HPMC K100M as release retardant. The floating oral in situ gel undergoes gelation by ion sensitive mechanism. In this formulation 32 factorial designs was performed and the effect of variation in concentration of gellan gum and HPMC K100M on drug release at 1 h, 6 h, and viscosity was evaluated. The gel was evaluated for other parameters like floating lag time, floating duration, gel strength, density, pH, in vitro drug release, drug content, and in vitro gelling capacity. The results of 32 full factorial design revealed that the concentration of gellan gum and of HPMC K100M significantly affected the dependent variables i.e. drug release at 1 h, at 6 h, and viscosity. A controlled release profile was observed for these formulations. The drug release mechanism was found to follow Korsmeyer-Peppas model. In vivo studies revealed higher Tmax of gel compared to plain drug which is suggestive of slower absorption. However the AUC0-12 h was found to be nearly 90% higher than plain drug.