Preparation and evaluation of a novel buccal adhesive system

The aim of the present study was to prepare and evaluate a novel buccal adhesive system (NBAS) containing propranolol hydrochloride (PH). A special punch was fabricated and used while preparing an NBAS. Solubility of PH in phosphate buffer solution (pH 6.6), partition coefficient between phosphate buffer (pH 6.6) and 1-octanol, and permeability coefficient through the porcine buccal mucosa were performed and found to be 74.66 mg/mL, 5.17, and 5.6, respectively. Stability of NBAS was determined in natural human saliva, and it was found that both PH and device are stable in human saliva. NBAS was evaluated by weight uniformity, thickness, hardness, friability, swelling, mucoadhesive strength, in vitro drug release, and in vivo human acceptability studies. Swelling index was higher (4.4) for formulations containing hydroxyl propyl methyl cellulose (HPMC) K4M alone, and it decreases with its decreasing concentration in the NBAS. Mucoadhesive strength (MS) was measured by using a modified apparatus. All NBASs showed higher MS with porcine buccal mucosa when compared with that of rabbit buccal mucosa. NBASs containing carbopol (CP) 934P and HPMC K4M at the ratio of 1:1 showed higher MS (44.76 g) with porcine buccal mucosa when compared with 1:2 (39.76 g), 0:1 (23.29 g), and 1:0 (22.22 g) ratios, respectively. The mechanism of PH release was found to be by non-Fickian diffusion (value of "n" between 0.5 and 1.0) and followed first order kinetics. In vivo human acceptability study showed that the newly prepared NBAS was comfortable in the human buccal cavity. It can be concluded that NBAS is a superior, novel system that overcomes the drawback associated with the conventional buccal adhesive tablet.