Yogesh P. Agrawal et al /International Journal of Pharmaceutical Sciences Letters 2013 Vol. 3 (2)| 190-194 Spectrophotometric Estimation of Candesartan Cilexetil by Using Different Hydrotropic Agents             1 Drug Design and Development Laboratory, Government College of Pharmacy, Ratnagiri-415612, India, 2 Central India Institute of Pharmacy, Indore, India Key words: Candesartan, Hydrotropic agents, Spectro- photometric method Received 21 Feb2012; accepted 8 Mar 2013; *Corresponding Author: Yogesh P. Agrawal Drug Design and Development Laboratory, Govern- ment College of Pharmacy, Ratnagiri-415612 Email: yogeshpagrawal@yahoo.co.in ABSTRACT Background: Present study deals with Spectrophotometric methods for quantitation of Candesartan Cilexetil by using five different hydrotropic agents. Methods: These include Potassium acetate (6.0M), Potassium citrate (1.5M), Sodium acetate (4.0M), Sodium cit- rate (1.25M) and Urea (10.0M). All these agents do not show absorbance above 245 nm and hence do not interfere with absorbance of Candesartan (λ max 280 nm). Linearity of Candesartan was found in the concentration range 10 to 50 g/ml by using all hydrotropic agents. Correlation coefficients were found in the range of 0.995 to 0.989 for estimation of Candesartan in all the hydrotropic agents. Results: The mean percentage recovery found for Candesartan with all hydrotropic agents range from 97.19 to 100.93 %. The developed methods were found to be precise for estimation of Candesartan by using all hydrotropic agents. Conclusion: The results of analysis obtained by the method compared very well with those of USP standard limit. Method was found more sensitive, selective, accurate and economic than conventional Spectrophotometric method for estimation of Candesartan. Introduction Candesartan is an Angiotensin-Receptor Blocker (ARB) chemically known as 2-ethoxy-1-({4-[2-(2H-1, 2, 3, 4-tetrazol-5-yl) phenyl] phenyl} methyl)-1H-1, 3- benzodiazole-7-carboxylic acid that was used alone or with other agents to treat hypertension. It selectively blocks the binding of Angiotensin-II to AT1 in many tissues including vascular smooth muscle and the adre- nal glands [1]. This inhibits the AT1-mediated vaso- constrictive and aldosterone-secreting effects of Angio- tensin-II and results in an overall decrease in blood pressure [2]. Candesartan is greater than 10,000 times more selective for AT1 than AT2. Inhibition of aldos- terone secretion may increase sodium and water excre- tion while decreasing potassium excretion. It is admin- istered orally as the prodrug, Candesartan Cilexetil, which is rapidly converted to its active metabolite, Candesartan, during absorption in the gastrointestinal tract. Candesartan may be used to treat hypertension, isolated systolic hypertension, left ventricular hypertro- phy and diabetic nephropathy [3-7]. It may also be used as an alternative agent for the treatment of heart failure, systolic dysfunction, myocardial infarction and coro- nary artery disease [8-9]. The literature survey reveals that Candesartan is practi- cally insoluble in water and sparingly soluble in methanol [10] only few methods are available for the determination of Candesartan in dosage forms based on HPLC [11-13], UV spectrophotometry [14], HPTLC [15] and other ana- lytical techniques [16-18]. Chemical Structure of Candesartan Cilexetil MATERIALS AND METHODS Materials Pharmaceutical grade Candesartan Cilexetil was kindly gifted by Ranbaxy laboratories, Dewas, India. Tablet for- mulation of Candesartan (Candesar) was purchased from local market. All hydrotropic agents, potassium acetate, potassium citrate, sodium acetate, sodium citrate and urea of analytical grade were used. Instrumentation Shimadzu UV‐1800 double beam spectrophotometer with 1 cm path length operated with Shimadzu UV-Probe soft- ware, version 2.21 was used for all Spectrophotometric estimations. 1 cm matched quartz cells were used for Spectrophotometric analysis. Shimadzu balance was used for weighting and solutions were prepared using Ultra- sonicator. Preparation of Standard solution Accurately weighed 25 mg Candesartan was transferred to 25 ml volumetric flask and dissolved in 5 ml (20% v/v) Journal homepage: http://www.ijpsl.com Copyright ©2011 Published by IJPSL. All rights re- ISSN:2277-4564 Research Article N N O O O O O O NH N N N