Innovat International Journal Of Medical & Pharmaceutical Sciences Vol 4 Issue 1 2019 Innovat International Journal Of Medical & Pharmaceutical Sciences, 2019; 4(1) A NEW VALIDATED RP-HPLC METHOD FOR SIMULTANEOUS ESTIMATION OF AZILSARTAN MEDOXIMIL AND AMLODIPINE IN BULK AND COMBINED TABLET DOSAGE FORMS www.innovatpublisher.com ISSN No. 2456-8694 Research Article G.KUMARASWAMY*, V.USHA, D.SUDHEER KUMAR Dept.of Pharmaceutical Analysis, Care College of Pharmacy-Warangal,Telangana. Email id:kumaraswamy.gandla@gmail.com Received 2019.01.05-Accepted 2019.01.08 ABSTRACT A accurate and precise RP-HPLC has been developed for the validation of Azilsartan medoxilmil and Amlodipine in bulk and combined tablet dosage forms. Separation was achieved on a Primesil (4.6 × 250mm, 5μm particle size) 5μ column using a mixture of Methanol: Acetonitrile: Water 60:20:20v/v as the mobile phase at a flow rate of 1.0 mL/min, the detection was carried out at 230nm. The retention time of the Azilsartan and Amlodipine was 2.813, 3.886 respectively. The method produce linear responses in the concentration range of 10-50μg/ml of Azilsartan and 66.6-330μg/ml of Amlodipine. The method precision for the determination of assay was below 1%RSD. The method is useful in the quality control of bulk and pharmaceutical formulations. Key word: Azilsartan , Amlodipine; Tablet dosage forms; RP-HPLC, Method development and validation. INTRODUCTION Azilsartan Azilsartan kamedoxomil is chemically (5-methyl-2-oxo-1,3-dioxol-4- yl)methyl 2- ethoxy-1- ([2'-(5-oxo-4,5-dihydro-1,2,4-oxadiazol-3- yl)biphenyl-4-yl]methyl)-1H-benzimidazole-7- carboxylic acid, potassium salt. It is angiotensin II receptor antagonist. It stops vasoconstriction and decrease the blood pressure by blocking the angiotensin receptor via vasopressor hormone. Azilsartan is partially soluble in water and freely soluble in methanol and dimethyl sulfoxide. Chemical structure of Azilsartan Amlodipine Besylate is chemically 3-O-ethyl 5-O-methyl 2-(2- aminoethoxymethyl)-4-(2- chlorophenyl)-6-methyl-1,4-dihydropyridine- 3,5-dicarboxylate. It is a synthetic long acting dihydropyridine calcium channel blocking agent. It has antihypertensive and antianginal properties and used in management of coronary artery disease. It lowers blood pressure by inhibiting the influx of calcium in cell. Amlodipine is used with or without other medications to treat high blood pressure. It is slightly soluble in water and freely soluble in methanol. Chemical structure of Amlodipine MATERIALS AND METHODS Chromatographic conditions A perominence isocratic HPLC system (Shimadzu HPLC and SPD 10AD) column Primesil C18 (4.6 x 250mm, 5μm). A 10μL Rheodyne injection syringe was used for sample injection. HPLC grade Water ,Acetonitrile and Methanol were used for the preparing the mobile phase. A freshly prepared Acetonitrile and Potassium di hydrogen phosphate (70:30 v/v) was used as the mobile phase. The solvents was filtered through a 0.45μ membrane filter and sonicated before use. The flow rate of the mobile phase was maintained at 1mL/min., column temperature was maintained at room temperature and the detection of the drug was carried out at 230nm. Preparation of mobile phase Accurately measured 600 ml (60%) of Acetonitrile 200 ml of Water (20%) and 200ml (20%) of Methanol were mixed and degassed in digital ultrasonicater for 10 minutes and then filtered through 0.45 μ filter under vacuum filtration. Diluent Preparation The Mobile phase was used as the diluent. Preparation of Standard Solution Accurately weigh and transfer 10 mg of Azilsartan and 10mg of Amlodipine working standard into a 10 ml of clean dry volumetric flasks individually and add about 7ml of Diluents to each volumetric flasks and sonicate to dissolve it completely and make up the volume up to the mark with the same solvent. (Stock solution) Further pipette 0.3ml and 1.98ml of the above Azilsartan , Amlodipine stock solutions into a 10ml volumetric flask and dilute up to the mark with diluents. Preparation of Sample Solution Accurately weigh 10mg equivalent weight of the combination powder sample into a 10mL clean dry volumetric flask add about 7mL of Diluents and sonicate to dissolve it completely and make volume up to the mark with the same solvent. (Stock solution) Further pipette 1.98ml of above stock solution into a 10ml volumetric flask and dilute up to the mark with diluent. The standard and sample solutions of 30μg/ml of Azilsartan , 198μg/ml of Amlodipine were injected for five times and the peak areas were recorded. The mean and percentage relative standard deviation were calculated from the peak areas. Method validation Linearity The linearity of the method was demonstrated over the concentration range of 66.6 – 330 ppm of the Amlodipine target concentration. Aliquots of 66.6,132,198,264 and 330 μg/ml were prepared from above stock solution, it includes 10-50ppm of Azilsartan concentrations of the pure drug were injected into the chromatographic system. Calibration curve of Azilsartan