FORMULATION OF CARBAMAZEPINE MUCOADHESIVE BUCCAL PATCHES: IN VITRO AND EX VIVO CHARACTERIZATION
A total of 36 formulations were prepared using different hydrophilic polymers by a 32 full factorial design. The thickness of the patches varied between 0.2 ± 0.017 and 0.4 ± 0.241 mm. The mass differed from 141.6 ± 0.67 to 196.1 ± 0.21 mg. The pH of the prepared patches is almost neutral and there was no mucosal irritation was estimated. The drug loading efficiency of the patches varied between 18.0 ± 0.2 and 19.9 ± 0.5 mg and showed folding endurance of ˃ 180. Out of these 36 formulations, six formulations (FA22, FA25, FB19, FB22, FB28, FB33 and FB36) showed high folding endurance of ˃ 255. These patches were selected for further evaluation such as swelling studies, ex vivo mucoadhesion time, ex vivo mucoadhesive strength, ex vivo permeation, in vitro drug release, accelerated stability studies, FTIR and X-ray diffraction spectral analysis. The percentage of swelling was higher up to 58 ± 2.0 for FB22 after 160 min. The ex vivo mucoadhesion time of selected patches was ranged between 109 ± 0.4 to 140 ± 0.8 min. The highest mucoadhesive force was observed with formulation FB33. In vitro release revealed that formulation FB33 showed maximum release of 98.5% after 90 min and followed by FB36 (100 min), FB22 (120 min), FA22 (120 min), FA25 (130 min), FB28 (130 min) and FB19 (130 min). In vitro drug release and ex vivo permeation studies showed good correlation. The accelerated stability study of tested patches showed almost similar values as it was observed in the beginning of the study