Mucoadhesive Patches of Salbutamol Sulphate for Unidirectional Buccal Drug Delivery: Development and Evaluation

Mucoadhesive buccal patches of Salbutamol Sulphate were prepared using five different polymers (polyvinyl pyrrolidone [PVP]), polyvinyl alcohol [PVA], water soluble chitosan [CHWS], acid soluble chitosan [CHAS], hydroxypropyl methyl cellulose [HPMC]) in various proportions and combinations (CHWS/PVP/HPMC, CHWS/PVA/HPMC, CHAS/PVP/HPMC, and CHAS/PVA/HPMC). A 32 full factorial design was used to design the experiments. A total of 72 patches were prepared. Thickness of the patches ranged between 0.3 +/- 0.003 and 0.6 +/- 0.009 mm. Mass of the patches were in the range of 68.12 +/- 4.6 to 95.52 +/- 5.0 mg. Patches showed increased mass whenever PEG -400 was used as plasticizer. The surface pH of patches were acidic to neutral (pH 4-pH 7). Patches showed satisfactory drug loading efficiency (85% to 97%). Eight formulations (C9, C18, C27, C36, D9, D18, D27 and D36)-which showed high folding endurance-were selected for further characterization. Patches with PEG -400 showed higher swelling index when compared to PG. The residence time of the patches ranged between 115 min and 120 min. Formulation C18 showed the maximum in vitro drug release of 101.4 % over a period of 120 min. Formulations D36 and C36 were best fitted to Higuchi model. The remaining formulations were best fitted to the Korsmeyer-Peppas model. Drug permeation was fast and showed the similar profile as that of the in vitro drug release. Patches were stable, during and at the end of the accelerated stability study.