To Formulate and Check Stability Evaluation of a Gastric Floating Tablet

Abstract

This research details the formulation development, in vitro characterization, and accelerated stability evaluation of a gastric floating drug delivery system containing the acid-labile proton pump inhibitor, pantoprazole sodium. To overcome the limitations of the drug's short biological half-life (1.0 - 1.9 hours) and optimize its localized therapeutic action within the gastric mucosa, floating matrix tablets were developed using the direct compression technique. Hydrophilic matrix-forming polymers, including hydroxypropyl methylcellulose (HPMC K4M, HPMC K15M), hydroxyethyl cellulose (HEC), and natural gums (xanthan gum and Limonia acidissima gum), were evaluated in varying proportions. An effervescent couple consisting of sodium bicarbonate and anhydrous citric acid was incorporated to initiate rapid in situ carbondioxide (CO2) generation upon contact with acidic gastric fluids. The precompression powder blends exhibited excellent micromeritic properties,with angles of repose ranging from 25.17o ± 0.2o to 28.70o ± 0.6o and Carr's compressibility index values between 3.61% and 19.83%. The optimized formulation (F3/F4) demonstrated a floating lag time of less than 60seconds, sustained buoyancy exceeding 12 - 18 hours in simulated gastric fluid (0.1 N HCl, pH 1.2), and controlled release kinetics (R2 = 0.992) governed by an anomalous (non-Fickian) diffusion mechanism. Accelerated stability testing conducted in compliance with ICH guidelines (40oC ± 2 oC and 75% ± 5% relative humidity) for up to two months demonstrated that the physical integrity, buoyancy profiles, and drug content (98.12% - 99.08%) of the floating tablets remained stable. These findings confirm that the inclusion of an alkaline gas-generating agent effectively buffers the tablet's microenvironment, protecting the acid-labile pantoprazole sodium from rapid acid-catalyzed hydrolytic degradation. This gastro-retentive formulation represents a robust alternative to conventional enteric-coated dosage forms for the localized treatment of gastric ulcers and the eradication of Helicobacter pylori.