Life Science Journal 2013; 10(3) http://www.lifesciencesite.com 2510 Modification of the Release Properties of Lornoxicam Gastroretentive Floating Tablets with the Naturally Occurring Okra Mucilage Ahmed Khames 1, 2 Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Beni-suef University 1 , Beni-Suef, Egypt, Taif University 2 , Taif, KSA dr_akhames@yahoo.com Abstract: The aim of the present investigation is to study the effect of Okra mucilage on the buoyancy and release properties of lornoxicam floating gastroretentive tablets. Lornoxicam floating tablet formulae were prepared using HPMC K100M and/or Alginate as floating, release controlling polymers at different drug polymer ratios. Okra mucilage was added to the proposed tablet formulae both as dry powder and as granulating aqueous solution. The prepared tablets were evaluated for weight uniformity, hardness, friability, drug content, swelling index, in-vitro buoyancy, and in-vitro drug release. Results showed that incorporation of Okra mucilage into a floating tablet matrix positively affected the swelling and buoyancy where the swelling index increased to reach 221, 193, and 224 % in comparison to 211, 182, and 208 % respectively, the floating lag-time was shortened to be 0.23 minutes while the total floating duration was extended to exceed 12 hours. The drug release was retarded to be 85.3, and 75.7 % in comparison to 97.7, and 93.4 % respectively after 12 hours without any effect on the drug release kinetics, where the release still follows zero order kinetics. The floating tablet matrix properties and drug release were affected with Okra mucilage ratio and also the incorporation method. Depending on these results, it can be concluded that the naturally occurring Okra mucilage is a promising additive to improve the floating and release properties of gastroretentive floating matrices. [Ahmed Khames. Modification of the Release Properties of Lornoxicam Gastroretentive Floating Tablets with the Naturally Occurring Okra Mucilage. Life Sci J 2013;10(3):2510-2519]. (ISSN: 1097-8135). http://www.lifesciencesite.com . 364 Keywords: Lornoxicam, floating tablets, Okra mucilage, sustained release, swelling index, HPMC K100M. 1. Introduction Oral route has been the most convenient and commonly employed route of drug delivery due to ease of administration, high patient compliance, least sterility requirements and more flexibility in dosage form design so sustained- release oral drug delivery systems have recently received higher research attention. (1) The advantages of sustained-release systems include simpler dosage regimens, better drug utilization and effectiveness, minimum drug accumulation with decreased side effects, minimum fluctuated plasma drug concentration with smoother therapeutic effect, and improved patient compliance through reducing the frequency of the dosing. (2) Several techniques are currently used to control the drug release into the gastrointestinal tract (GIT) and retain an effective plasma drug concentration for prolonged time. Gastroretentive drug delivery systems are those designed to be retained in the stomach for an extended time period to slowly release their drug content in a controlled manner to the upper part of the GIT (3, 4) with minimum variability in bioavailability as compared with some currently available immediate and modified release systems. (5) Drugs that have a narrow absorption window in the small intestinal region, to be dissolved in gastric pH, of low stability in intestinal pH, and/or act locally on GIT are of choice in gastric retention formulations. (6) During the last few decades, the technology of designing new devices to be retained in the upper part of the GIT has showed a large advance result in developing a large variety of systems, including: sinking systems to be retained in the bottom of the stomach (7), floating systems that causes buoyancy in gastric fluid (8-10), mucoadhesive systems (11), expanding, or swelling systems which hinder emptying of the dosage forms through the pyloric sphincter of stomach (12), superporous hydrogel systems (13), magnetic systems. (14) Various approaches have been applied to induce the floatation of the dosage form over the GIT fluid. (15) Gas-generating effervescent buoyant delivery systems depend on the reactions between alkali carbonate/bicarbonate and citric/tartaric acid incorporated within the formula composition to liberate CO 2 , which gets entrapped within the gelled hydrocolloid layer of the delivery system thus reducing its density to remain buoyant over the chyme for an extended time period and release the drug slowly at a specified rate. (16–18) Mucilages and gums are carbohydrate polymers obtained from woody and non-woody plant parts. (19) In modern pharmaceutics, more attention has been