Formulation and evaluation of gastro-retentive floating tablets of terbinafine

Gastro-retentive dosage forms enable prolonged and continuous input of the drug to the upper parts of the gastrointestinal tract and improve the bioavailability of medications those are characterized by a narrow absorption window. The purpose of this research was to develop a novel gastro retentive drug delivery system based on direct compression method for sustained delivery of active agent to improve the bioavailability, reduce the number of doses and to increase patient compliance. Gastro retentive floating tablets of terbinafine were prepared by direct compression method using altered concentrations of HPMC K4, HPMC K15 and PVP K30 as polymers. The prepared tablets of terbinafine were evaluated tablet hardness, uniformity of weight, friability, uniformity of content, in vitro buoyancy test, swelling index, in vitro dissolution study and stability study. All the compositions were resulted in adequate Pharmacopoeial limits. Compatibility studies was execution during FTIR shown that there was absence of probable chemical interaction between pure drug and excipients. The varying concentration of gas generating agent and polymers was found to affect on in-vitro drug release and floating lag time. In vitro drug release of floating gastro retentive tablet of terbinafine shown that the formulation F5 was found to be the best formulation as it releases 96.22% terbinafine in a controlled manner for an extended period of time (up to 480 min). The release data was fitted to various mathematical models such as Higuchi, Korsmeyer-Peppas, First order and Zero order to evaluate the kinetics and mechanism of the drug release. Prepared floating tablets of terbinafine may prove to be a potential candidate for safe and effective controlled drug delivery over an extended period of time for gastro retentive drug delivery system.