Novel Buccal Adhesive Tablets Using Aloe vera L and Sinapis alba—A Promising Option for Improved Bioavailability of Diltiazem Hydrochloride

Abstract

In the current investigation, white mustard mucilage from whole seeds of Sinapis alba was evaluated for its physical properties and compared with the other mucoadhesive polymers such as hydroxy propyl methylcellulose 5Cps and Carbopol 934P. Further, methanol precipitable solids from whole leaves of Aloe Vera L were used as permeation enhancer. To achieve improved bioavailability of diltiazem, novel buccal adhesive tablets (NBATs) in cup and core fashion designed to achieve unidirectional release towards mucosa were prepared in a three-stage process using specially fabricated punches. The adhesive cups were studied for its shear, tensile, and peel strengths by specially designed apparatus using excised ruminant and porcine buccal mucosa as model substrates. Ex vivo permeation studies in a Franz diffusion cell were conducted through porcine buccal mucosa. Fourier transform infrared spectroscopy studies and differential scanning calorimetry thermographs showed no remarkable interactions. Histopathological studies showed no remarkable damage of buccal mucosa by the NBATs. In vivo studies were conducted on anaesthetized male New Zealand albino rabbits, estimated by reversed-phase high-performance liquid chromatography, and the pharmacokinetics were compared with the oral and intravenous bolus injection. NBATs exhibited a C_max 74.6 ng/mL, T_max 3.5 h, t^1/2 4.36 h. The NBATs prevented salivary scavenging effect and exhibited 82.1% bioavailability.