Abstract

GASTRO RETENTIVE DRUG DELIVERY: AN INSIGHT VIEW

M. N. Anjana*, B. S. Venkateswarlu, A. Pasupathi, R. Margret Chandira and K. P. Sampath Kumar

ABSTRACT

Gastro-retentive drug delivery system (GRDDS) has gained immense popularity in the field of oral drug delivery recently. It is a widely employed approach to retain the dosage form in the stomach for an extended period of time and release the drug slowly that can address many challenges associated with conventional oral delivery, including poor bioavailability. Different innovative approaches like magnetic field assisted gastro-retention, plug type swelling system, muco-adhesion technique, floating system with or without effervescence are being applied to fabricate GRDDS. Gastro-retentive drug delivery systems potentially prolong the gastric retention time and controlled/sustained release of a drug, thereby increasing the concentration of the drug at the application site, potentially improving its bioavailability and reducing the necessary dosage. Recommended gastroretentive drug delivery systems for enhancing local drug delivery include floating systems, bioadhesive systems and expandable systems. In spite of the many advantages, high subject variations in gastrointestinal physiological condition, effect of food, and variable rate of gastric emptying time are the challenges that limit the number of available GRDDS in the market. Apart from in vitro characterization, successful GRDDS development demands well designed in vivo study to establish enhanced gastro-retention and prolonged drug release. Gama scintigraphy and MRI are popular techniques to evaluate in vivo gastric residence time. However, checking of their overall in-vivo efficacy still remains a major challenge for this kind of dosage form, especially in small animals like mice or rat. Reported in vivo studies with beagle dogs, rabbits, and human subjects are only a handful in spite of a large number of encouraging in vitro results. The aim of writing this review on gastroretentive drug delivery system was to present the recent literature in a more concise way with special focus on various techniques to achieve gastric retention. In addition, important challenges ahead with gastro-retention, advantages and limitations are also discussed.

Keywords: Gastroretention, Floating, Gastric Residence Time, buoyancy.