Conjugation of Polycarbophil: Preparation and Evaluation of Bilayered Buccoadhesive Tablet form Polycarbophil Conjugate

The purpose of the present research envisaged was synthesize, characterize polycarbophil conjugate, to study the effect of conjugation on bioadhesion and drug release from the buccoadhesive tablet. The polycarbophil conjugate was synthesised by covalent attachment of thiol group of L-cysteine with the carboxylic acid group of polycarbophil. The synthesised conjugate was characterised by charring point determination, fourier transmission infra-red spectroscopic, differential scanning calorimetric analysis and measurement of gel strength. The bilayered buccoadhesive tablets provide the unidirectional diffusion. The drug core layer was prepared by various proportions of polycarbophil and polycarbophil conjugate with diltiazem hydrochloride. The backing layer was prepared by hydrophobic polymer Ethylcellulose. The buccoadhesive drug core was subjected to following evaluation tests such as weight uniformity, hardness, thickness, drug content, swelling index, moisture uptake, ex vivo bioadhesion strength, ex vivo bioadhesion time; in vitro drug release and in vitro drug permeation; ex vivo drug permeation was carried out in modified Franz diffusion cell. The study concluded that as the proportion of polycarbophil conjugate increased, increased drug release and drug permeation with enhanced ex vivo bioadhesive properties.