International Journal of Research in Advent Technology, Vol.7, No.4S, April 2019 E-ISSN: 2321-9637 Available online at www.ijrat.org 40 Analytical Method Development And Validation For Simultaneous Estimation Of Metformin And Linagliptin Aejaz Ahmed* 1 , Khan G.J 2 , Bagwan Mustaqueem 3 , Ansari Yaasir 4 , Z.E Inamdar 5 1,2,3 Department of Quality Assurance, Ali-Allana College of pharmacy, Akkalkuwa-425415, North Maharashtra University, Jalgaon. 4,5 Lecturer at Jamia College of Pharmacy, Akkalkuwa, dist Nandurbar-425415. Email: aejazboraji@gmail.com Abstract- The aim of this paper was to develop a simple and validated RP- HPLC method for simultaneous estimation of Metformin HCL (MET) and Linagliptin (LINA) in tablet dosage form. Chromatographic separation was achieved on a BDS hypersil C18, 250mm × 4.6mm, 5μ (particle size), and thermo scientific. The mobile phase comprised of Methanol: Water: OPA (50:50:0.05 v/v/v) (Phosphate buffer pH 3.0 was adjusted with H3PO4)at flow rate of 0.9 ml/min and all eluents were detected at 234 nm. The retention times were 2.8000 ± 0.10 and 7.6147 ± 0.10 min for Metformin and Linagliptin respectively. The method was validated according to ICH guidelines. It was found to be accurate and reproducible, linear, and precise. Calibration curves at seven levels for Metformin and Linagliptin were linear in the range of 50-250 μg/mL and 50-250 μg/mL, with r2= 0.999, respectively. There was no interference from excipient in the analysis of Metformin and Linagliptin. Hence, the proposed method can be used for analysis of routine quality control samples of Metformin and Linagliptin tablets. Index Terms: HPLC; Metformin; Linagliptin; Development; Validation. 1. INTRODUCTION: Metformin, chemically N, N-Dimethylimido dicarbonimidic diamide is an oral antidiabetic drug in the biguanide class [Fig.-1]. It is the first-line drug of choice for the treatment of type-II diabetes. MET suppresses glucose production by the liver. It helps in reducing LDL cholesterol and triglyceride levels. Linagliptin,chemically,8-[(3R)-3-aminopiperidin-1- yl]-7-(but-2-yn-1-yl)-3-methyl-1-[(4- methylquinazolin-2-yl)methyl]-3,7-dihydro-1H purine-2,6-dione is an DPP-4 inhibitor developed by Boehringer Ingelheim for treatment of type-II diabetes[Fig.-1]. Linagliptin is an inhibitor of DPP-4. It stimulates the release of insulin in a glucose- dependent manner and decreases the levels of glucagon in the circulation. Fig.1 Structure of MET Fig.2 Structure of TENE The detailed survey of literature revealed that several Spectrophotometric methods, HPLC methods, Stability indicating methods and Plasma extraction methods were reported for the determination these drugs individually or in combination with other drugs in pharmaceutical dosage forms. A few HPLC methods are available with the combination of above- cited drugs, with lower linearity range and or having longer retention times. The author made an attempt to develop and validate a cost-effective RP-HPLC assay method for estimation of MET and LINA from formulated dosage form. The developed method is validated as per ICH and all relevant guidelines for broad linearity range than other available methods and with better retention times. 2. MATERIALS AND METHODS: Chemicals: Pure Standard of MET and LINA were obtained from McCoy Pharma Pvt. Ltd. (Tarapur, India.). ONDERO MET® tablets were purchased from the local medical store. HPLC grade Methanol, OPA and Potassium dihydrogen ortho phosphate were