%0 Journal Article %T Pharmacodynamics and Pharmacokinetics Evaluation of Ranitidine Microemulsion on Experimental Animals %A Sajal Kumar Jha %A Roopa Karki %A Venkatesh Dinnekere Puttegowda %A Amitava Ghosh %J Advances in Pharmaceutics %D 2014 %R 10.1155/2014/304392 %X Ranitidine microemulsion was investigated for its pharmacodynamic and pharmacokinetic evaluation to find out the suitability of microemulsion as a potential drug delivery system in the treatment of ulcer. The bioavailability of ranitidine after oral administration is about 50% and is absorbed via the small intestine; this may be due to low intestinal permeability. Hence the aim of present investigation was to maximize the therapeutic efficacy of ranitidine by developing microemulsion to increase the intestinal permeability as well as bioavailability. A ground nut oil based microemulsion formulation with Tween-80 as surfactant and PEG-400 as cosurfactant was developed for oral delivery of ranitidine and characterized for physicochemical parameters. In pharmacodynamic studies, significant () variation in parameters estimated was found between the treated and control groups. Ranitidine microemulsion exhibited higher absorption and Cmax (863.20£¿ng¡¤h/mL) than the standard (442.20£¿ng/mL). It was found that AUC0¨C24£¿hr obtained from the optimized ranitidine test formulation (5426.5£¿ng¡¤h/mL) was significantly higher than the standard ranitidine (3920.4£¿ng¡¤h/mL). The bioavailability of optimized formulation was about 1.4-fold higher than that of standard drug. This enhanced bioavailability of ranitidine microemulsion may be used as an effective and alternative drug delivery system for the antiulcer therapy. 1. Introduction Gastric ulcer is said to occur due to an imbalance between luminal acid synthesis and mucosal defense. Acid and pepsin components constitute the aggressive factors, and the mucous layer of mucin-bicarbonate secretion, prostaglandins, and other healing factors constitute the defensive factors [1]. The mucosal defense against these aggressive factors includes the function of the mucus-bicarbonate barrier, surface active phospholipids, prostaglandin, mucosal blood flow, cell renewal and migration, antioxidative enzymes, and some growth factors. Even though wide range of drugs available for the treatment of ulcer may do not fulfill the requirements and have many side effects such as arrhythmias, impotence and hemopoietic changes are noted. H2 antagonists, unlike anticholinergics, do not delay gastric emptying time which may reflexly stimulate gastric secretion because of food remaining in the stomach for long time. Also it does not cause abdominal colic and diarrhoea caused by proton pump inhibitors. In recent years large advance in chemical and pharmacological studies has contributed to the knowledge about new therapeutically active compounds and %U http://www.hindawi.com/journals/ap/2014/304392/