Formulation and statistical optimization of multiple-unit ibuprofen-loaded buoyant system using 23-factorial design

This present investigation deals with the development and optimization of buoyant beads containing ibuprofen by emulsion-gelation method for gastroretentive delivery. The effect of three independent process variables like amount of sodium alginate, magnesium stearate, and liquid paraffin on drug entrapment, density, and drug release of buoyant beads containing ibuprofen was optimized using 23 factorial design. The observed responses were coincided well with the predicted values, given by the optimization technique. The optimized beads showed drug entrapment efficiency of 83.07 +/- 3.25%, density of 0.89 +/- 0.11 g/cm(3), cumulative drug release of 35.02 +/- 1.24% after 8 h, and floated well over 8h in simulated gastric fluid (pH 1.2) with 4.50 min buoyant lag-time. The average size of all buoyant beads ranged from 1.43 +/- 0.05 to 1.82 +/- 0.14 mm. The buoyant beads were characterized by SEM and FTIR spectroscopy for surface morphology and excipients-drug interaction analysis, respectively. All these beads showed prolonged sustained release of ibuprofen over 8h in simulated gastric fluid (pH 1.2). The ibuprofen release profile from these buoyant beads followed Korsmeyer-Peppas model over a period of 8h with anomalous (non-Fickian) diffusion mechanism for drug release. (C) 2012 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.