ABSTRACT
Polysaccharides of natural, synthetic or semi-synthetic origin have been used from time immemorial in the development of drug delivery systems designed to achieve tailored and site-specific drug release. Starch-based polysaccharides derived from plants have been extensively studied in this regard. Natural polymeric excipients are preferred over their synthetic counterparts owing to their low cost, availability, biocompatibility, biodegradability and non-toxicity. The present review attempts to provide a new direction and a comprehensive insight on the physical properties, rheological behavior, toxicity profile, pharmaceutical applications, swelling behavior and drug diffusion kinetics from dosage forms based on non-starch polysaccharides of plant origin such as, psyllium, pectin, arabinoxylan, xyloglucan, guar gum galactomannan and konjac glucomannan. It has been observed from the current review that non-starch polysaccharides are safe for human consumption and can be successfully employed to deliver drugs specifically to stomach and colon in a sustained fashion. They have thus widened the scope of natural polymeric excipients and demand better industrial utilization on a commercial scale to minimize cost of production and to satisfy therapeutic needs in safe and effective manner.
ABSTRACT
Drug release kinetics from matrix dosage form is governed by polymer swelling and erosion, drug dissolution/diffusion and polymeric combination. For the preparation of controlled release dosage form, hydrophilic, swellable polymers in optimum combination are essential. The major objective of the current study is to prepare Amoxicillin trihydrate-loaded bucco-matrix tablets by direct compression technique and to study the effect of ratio of HPMCK100M and HPMCK15M used in the formulation on the basic properties and on drugrelease and permeation kinetics. The tablets offered satisfactory physicochemical results. The buccal strength, detachment force and bond strength of the tablets were good enough to hold the tablets in the buccal region. The drug release data generated during in vitro drug release study of bucco-matrix tablets in phosphate buffer pH 6.8 were evaluated by zero-order, first-order, Higuchi, Korsmeyer – Peppas, and Kopcha models. Release exponent (n) of Korsmeyer- Peppas equation of the formulations exhibited diffusion as the principal mechanism of drug release. It was further confirmed by Kopcha model. Evaluation of diffusion and erosion terms in the Kopcha model showed that diffusion dominated swelling or erosion process through out the study. The permeation kinetics of the drug showed linearity when studied across goat buccal mucosa. Permeation coefficient of drug decreased with increase in % swelling index of the formulations.