Original Article SIMULTANEOUS ESTIMATION OF IRBESARTAN AND HYDROCHLOROTHIAZIDE BY UV SPECTROSCOPY PIUSHA SHAKYA 1* , PUSHPENDRA KUMAR JAIN, S. P. SHRIVASTAVA 1 , ASMITA GAJBHIYE 2 1 Department of Chemistry, Dr. H. S. Gour Central University, Sagar (MP) 470003 India, 2 Received: 02 Feb 2015 Revised and Accepted: 28 Feb 2015 ABSTRACT Objective: The literature survey revealed that various methods are reported for determination of Irbesartan and Hydrochlorothiazide alone or in combination with other drugs So, the main objective of our study was to develop simple, accurate and reproducible methods for the simultaneous estimation of Irbesartan and Hydrochlorothiazide in a combined dosage form. Methods: The method for the simultaneous determination of Irbesartan and Hydrochlorothiazide by spectroscopy has been developed. The simple, accurate and precise method includes Area Under the Curve (AUC) method. On response to the effect of solvent on spectral behaviors of Irbesartan and Hydrochlorothiazide, methanol was selected as solvent. Irbesartan shows maximum absorbance at 224 nm and Hydrochlorothiazide shows maximum absorbance at 271 nm. For the AUC method, the wavelength ranges between 225-230 nm and 258-265 nm respectively were selected with reference to the absorbance curves plotted between the wavelengths of 200-400 nm. This method allows rapid analysis of two drug combinations. Results: The result of analysis was validated statistically by recovery study following ICH method validation guideline. Tablet containing both drugs was assayed using the method developed, showing a good accuracy and precision. Conclusion: It can therefore be concluded that use of this method can save more time and money and it can be used in small laboratories with accuracy Department of Pharmaceutical Sciences, Dr. H. S. Gour Central University, Sagar (MP) 470003 India Email: piushashakya@gmail.com Keywords: Spectroscopy, Irbesartan, Hydrochlorothiazide, Area Under Curve Method. INTRODUCTION Irbesartan (fig. 1) and Hydrochlorothiazide (fig. 2) are the combination angiotensin II receptor blocker and diuretic. The angiotensin II receptor blocker works by relaxing the blood vessels. The effect of diuretics on lowering the blood pressure is still unknown, but it helps the kidneys to eliminate fluid and sodium from the body. Irbesartan (Irb) is a non-peptide compound, chemically described as a 2- butyl-3-[p-(o-1H-tetrazol-5-ylphenyl) benzyl]-1,3-diazaspiro[4.4] non-1- en-4-one. Its empirical formula is C25H28N6 A hydrochlorthiazide (HCTZ; fig. 2) diuretic often considered as the prototypical member of this class. It reduces the re-absorption of electrolytes from the renal tubules. Thus results in increased excretion of water and electrolytes, including sodium, potassium, chloride, and magnesium. It has been used in the treatment of several disorders including edema, hypertension, diabetes insipidus, and hypoparathyroidism. (14) O, and its structural formula (15) is in fig. Fig. 1: chemical structure of Irbesartan Fig. 2: Chemical structure of Hydrochlorthiazide Many analytical methods like HPLC, capillary electrophoresis and UV spectroscopy (7-10) were reported for determination of Irb and HCTZ (11-13) in combination. However, no area under curve spectro photometric method is reported for simultaneous determination of these drugs. In this communication, we report a new UV spectro photometric method using area under curve spectroscopy. MATERIALS AND METHODS Instruments A UV Probe type UV-VIS double beam spectrophotometer (shimadzu 1800) with 1 cm Quartz cells was used in this experiment. Analysis was performed using direct mode over a wavelength range from 200-400 nm. The instrument settings were zero order and first derivative mode and band width of 2 nm in the range of 200-400 nm. All weights were taken on an electronic balance. Reagents and chemicals Irbesartan, working standard was obtained as a gift sample from Sanofi Aventis (Goa) and Hydrochlorothiazide, as a gift sample from CTX Life Sciences Pvt Ltd. Methanol (Spectrochem Chemicals) and Irbesartan and Hydrochlorothiazide combination tablet (Irovel-H, Sun pharma) were purchased from local market. Preparation of standard stock solutions 10 mg each of standard Irbesartan and Hydrochlorothiazide were weighed and transferred to two separate 100 ml volumetric flasks and International Journal of Pharmacy and Pharmaceutical Sciences ISSN- 0975-1491 Vol 7, Issue 6, 2015 Innovare Academic Sciences