RESEARCH ARTICLE e-ISSN: 2249-622X *Corresponding author: Vinod R | Research Scholar, ShriJagdish Prasad JhabarmalTibrewala University, Rajasthan | E-mail: vinodr_ram@outlook.com Page38 Page38 Formulation and Evaluation of Sustained Release Matrix Tablets Using Natural Gum Limonia acidissimaas Release Modifier Vinod R Research Scholar, ShriJagdish Prasad Jhabarmal Tibrewala University, Rajasthan ABSTRACT The objective of this study was to design oral sustained release matrix tablets of nicorandil using different proportion of Limonia acidissima gum as the release retardant and to study the effect of formulation factor such asin-vitro release of drug. The gum is extracted and evaluated for physico-chemical and phyto-chemical property of the gum. The granules were evaluated for angle of repose, loose bulk density, tapped bulk density and compressibility index, showed satisfactory results. Compressed tablets were evaluated for thickness, friability, hardness, drug content, weight variation and in-vitro dissolution studies. Fourier transform infrared (FTIR) study revealed that there was no chemical interaction between drug and the gum used. All the formulation showed compliance with Pharmacopoeial standards. In-vitro drug release studies were carried out using USP 35/NF30 dissolution apparatus type II at 50 rpm (rate per minute). The release kinetics was analyzed using the zero-order, first-order model, Higuchi’s square-root equation and the Korsmeyer-peppas model. In-vitro release studies revealed that the release rate decreased with increase in gum proportion. The developed sustained release matrix tablets of nicorandil, with good initial release (15% in first hour) and extension of release for more than 12 h, can overcome the disadvantages of conventional tablets of nicorandil. Keywords: Controlled release, Limonia acidissima, Matrix tablets, Nicorandil. 1. INTRODUCTION: The oral route is the route most often used for administration of drugs. Tablets are the most popular oral formulations available in the market and are preferred by patients and physicians alike. In long-term therapy for the treatment of chronic disease conditions, conventional formulations are required to be administered in multiple doses and therefore have several disadvantages 1 . Sustained release tablet formulations are preferred for such therapy because they offer better patient compliance, maintain uniform drug levels, reduce dose and side effects, and increase the safety margin for high- potency drugs 2 . Different types of oral sustained release formulations have been developed to improve the efficacy and patient compliance 3 . The sustained release formulations are fabricated to release a drug at predetermined rate for prolonged time period. The most commonly used method to formulate is by conventional wet granulation method or direct compression. The formulation of sustained release tablets is very simple and cost effective. Matrix technology is used for sustaining effect or rate controlling polymer. The mechanism of drug release is due to hydration of polymer, which results in the formation of a gel layer that controls the drug release rate 5 . Nicorandil, a drug approved for the treatment of ischemic heart disease, is believed to have dual properties. The intrinsic mechanism of the drug (selective activation of K + ATP channels atthe sarcolemmal and mitochondrial level) allows coronary and peripheral vasodilatation with subsequent reduction of preload and afterload. Secondly, because of the role K + ATP channels in ischemic preconditioning, nicorandil have been attributed cardio - Received: 22 th Aug 2013 Received in revised form: 30 th Aug 2013 Accepted: 5 th Sept 2013 Available online: 15 th Sept 2013 Online ISSN 2249–622X http://www.jbiopharm.com