HPMC-based gastroretentive dual working matrices coated with Ca+2 ion crosslinked alginate-fenugreek gum gel membrane

Novel alginate-fenugreek gum (FG) gel membrane coated hydroxypropylmethylcellulose (HPMC) based matrix tablets were developed for intragastric quetiapine fumarate (QF) delivery by combining floating and swelling mechanisms. The effects of polymer blend ratios [HPMC K4M:HPMC E15] and citric acid contents on time taken for 50% drug release (t(50%), min) and drug release at 8 h (Q(8) h. %) were studied to optimize the core tablets by 3(2) factorial design. The optimized tablets (F-O) exhibited t(50%) of 247.67 +/- 3.51 min and Q(8) h of 71.11 +/- 032% with minimum errors in prediction. The optimized tablets were coated with Ca+2 ions crosslinked alginate-FG gel membrane by diffusion-controlled interfacial complexation technique. The biopolymeric-coated optimized matrices exhibited superior buoyancy, preferred swelling characteristics and slower drug release rate. The drug release profiles of the QF-loaded uncoated and coated optimized matrices were best fitted in Korsmeyer-Peppas model with anomalous diffusion driven mechanism. The uncoated and coated tablets containing QF were also characterized for drug-excipients compatibility, thermal behaviour and surface morphology by FTIR, DSC and SEM analyses, respectively. Thus, the newly developed alginate-FG gel membrane coated HPMC matrices are appropriate for intragastric delivery of QF over a prolonged period of time with greater therapeutic benefits. (C) 2016 Elsevier B.V. All rights reserved.