Original Article STABILITY INDICATING RP-HPLC METHOD DEVELOPMENT AND VALIDATION FOR THE SIMULTANEOUS DETERMINATION OF VILDAGLIPTIN AND METFORMIN IN PHARMACEUTICAL DOSAGE FORM RAMESH JAYAPRAKASH * , SENTHIL KUMAR NATESAN Department of Pharmaceutical Analysis, JKK Munirajah Medical Research Foundation’s-Annai JKK Sampoorani Ammal College of Pharmacy, Komarapalayam, Namakkal-DT, Tamilnadu, India Email: rameshj1974@gmail.com Received: 19 Nov 2016 Revised and Accepted: 17 Jan 2017 ABSTRACT Objective: The present study was aimed to develop a rapid, accurate, linear, sensitive and validate stability-indicating high performance liquid chromatographic [RP-HPLC] method for determination of vildagliptin and metformin in pharmaceutical dosage form. Methods: The chromatographic separation was performed on kromasil-C18 column [4.5 x 250 mm; 5 µm] using a mobile phase consisting of 0.05 mmol potassium dihydrogen phosphate buffer: acetonitrile [80:20 v/v], [pH adjusted to 3.5 using orthophosphoric acid]. The flow rate is 0.9 ml/min and the detection was carried out at 263 nm. Results: The chromatographic condition, the peak retention time of metformin and vildagliptin were found to be 2.215 min and 2.600 min respectively. Stress testing was performed in accordance with an international conference on harmonization [ICH] Q1A R2 guidelines. The method was validated as per ICH Q2 R1 guidelines. The calibration curve was found to be linear in the concentration range of 5-17.5 µg/ml and 50-175 µg/ml for vildagliptin and metformin. The limit of detection and quantification was found to be 0.0182 µg/ml and 0.0553 µg/ml for vildagliptin and 0.4451 µg/ml and 1.3490 µg/ml for metformin respectively. Conclusion: A new sensitive, simple and stability indicating reverse-phase high-performance liquid chromatography [RP-HPLC] method has been developed and validated for the determination of vildagliptin and metformin. The proposed method can be used for routine determination of vildagliptin and metformin. Keywords: Metformin, Method validation, RP-HPLC, Stability indicating method, Vildagliptin © 2016 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/) DOI: http://dx.doi.org/10.22159/ijpps.2017v9i3.16233 INTRODUCTION Vildagliptin [fig. 1] is chemically [S]-1-[N-[3-hydroxy-1-adamantyl] glycyl] pyrrolidine-2-carbonitrile, is a potent di-peptidyl peptidase IV [dip-IV] inhibitor, a drug for the treatment of diabetes. DPP-IV inhibitor represents a new class of oral antihyperglycemic agents to treat patients with type 2 diabetes [1-4]. Metformin HCl [fig. 2] chemically 3-[diaminomethylidene]-1,1- dimethylguanidine HCl is an orally administered biguanide widely used in the treatment of type 2 [non-insulin dependent] diabetes mellitus [5-6]. Literature survey revealed that RP-HPLC [7-16] have been reported for the estimation of vildagliptin and metformin. To the best of our knowledge, no stability indicating reverse- phase high-performance liquid chromatography [RP-HPLC] method has been reported for vildagliptin and metformin. The present work involves stress degradation as per ICH Q1A [R2] and Q1B [17-18] for the developing new, simple, sensitive stability indicating RP-HPLC method; the method was validated as per the ICH guidelines Q2 R1 [19]. The reported methods were not cost effective due to use costly solvents and in some methods the retention time vildagliptin was found to be more [7-16]. So in the present work a simple, precise, sensitive and stability indicating method was developed by using low-cost solvent acetonitrile with buffer in the ratio of 80:20, detected by using a photodiode array detector which was highly sensitive to detect at a lower concentration. The developed method was used for estimation of vildagliptin and metformin in pharmaceutical dosage form. Fig. 1: Chemical structure of vildagliptin Fig. 2: Chemical structure of metformin Hcl MATERIALS AND METHODS Chemicals and reagents Vildagliptin was provided as a gift sample by Aurobindo pharmaceuticals limited [Hyderabad, India]. Metformin HCl was provided as a gift sample by Ranbaxy laboratories limited [Gurgaon, India]. Acetonitrile [HPLC grade] purchased from E-Merck specialities private. Limited [Mumbai, India], and Potassium International Journal of Pharmacy and Pharmaceutical Sciences ISSN- 0975-1491 Vol 9, Issue 3, 2017