Polyelectrolyte Complexes of Cihtosan for Production of Sustained Release Tablets of Bupropion Hcl

Abstract

Chitosan (C) has the ability to form hydrogel by polyelectrolyte complexation. Electrostatic attraction among amine group of chitosan and anion groups of other polyelectrolytes leads to formation of polyelectrolyte complex. The objective of this study was preparation of Bupropion sustained release tablets by chitosan polyelectrolyte complexes with natural and synthetic polymers such as Eudragite L100 (E), xanthan (X) and carbopol 934 (CP). The formation of polyelectrolyte complex between chitosan and aforementioned polymers was confirmed by FT-IR. Then 100 mg bupropion sustained release tablets were prepared by direct compression method at different ratios of each chitosan/polyelectrolyte complex. The ratio of ((C) under bar) to (X) in polyelectrolyte complex was (1) under bar :1, (1) under bar :2, (1) under bar :4, (3) under bar :4. The ratio of ((C) under bar) to (CP) 934 was (1) under bar :1, (1) under bar :2 and the ratio of ((C) under bar) to (E) was (3) under bar :4, (1) under bar :2, (1) under bar :4. Physical properties of tablets like: content uniformity, weight variation, hardness, friability, and dissolution test in 3 mediums (water, HCl 0.1 N and saline buffer phosphate solution pH 7.4) were evaluated. Drug release from physical mixture with the same ratio of polymers in the complexes was compared with the polyelectrolyte complexes. Mean dissolution time (MDT) of P C1X1 was significantly greater than other formulations of C:X series. Among C:CP and their pure polymers, P C1CP1 showed the greatest MDT in water and acidic medium and among the complexes of C:E, and these pure polymers, P C1E4 in acidic medium showed slower drug release compared with other formulations in this series. These formulations released bupropion by a Higuchi kinetic model and showed greater MDT compared to their pure polymers or their physical mixtures in the same ratios.