Assessing the viability of microsponges as gastro retentive drug delivery system of curcumin: Optimization and pharmacokinetics

The work was aimed to validate the gastroretentive potential of microsponges via optimization of targeted floating curcumin microsponges for improved site specific absorption for gastric cancer Modified quasi emulsion solvent diffusion method was used to formulate microsponges using 32 full factorial design. The effect of different levels of ethyl cellulose and polyvinyl alcohol concentration, selected as independent variables was determined on the % entrapment efficiency, % buoyancy and % cumulative drug release. Modified rosette rise apparatus was used for in vitro release and the release data best fitted Higuchi's model and mechanism of drug release was diffusion (n). The optimized formulation (MS5) demonstrated favourable % entrapment efficiency (90.7 +/- 1.7), % buoyancy (82.0 +/- 2.0) and % cumulative drug release (85.2 +/- 1.07) with maximum desirability factor of 0.816. SEM revealed spherical and porous microsponges. DSC confirmed molecular dispersion of the drug in the microsponges polymeric matrix. DRIFT revealed no chemical interaction between the drug and polymer used. The in vitro permeation of curcumin through gastric mucin gel layer affirmed the capability of microsponges to deliver drug across mucin r and reach the target site to treat gastric cancer. Anticancer oral dose of microsponges was calculated as 50 mg by cytotoxicity assay in human cancer cell line KB. The pharmacokinetic evaluation of MS5 in rabbits revealed 10-fold increase in bioavailability as compared to native curcumin, demonstrated the superiority of microsponges over native curcumin as gastro retentive drug delivery system. This study presents a new approach based on floating ability of microsponges for treatment of gastric cancer. (C) 2013 Elsevier B.V. All rights reserved.