DEVELOPMENT OF HPLC STABILITY DEMONSTRATING METHODOLOGY FOR QUANTIFYING AZELNIDIPINE AND TELMISARTAN IN TABLETS AND BULK TYPES: VALIDATION FOLLOWING ICH DIRECTIVES Original Article KRISHNAPHANISRI PONNEKANTI 1* , K. SUNITHA 1 1 Department of Pharmacy, GITAM Institute of Pharmacy, GITAM Deemed to be University, Visakhapatnam, India 530045 Email: krishnaphanisri@gmail.com Received: 18 May 2021, Revised and Accepted: 26 Jun 2021 ABSTRACT Objective: Azelnidipine (AZEL) and Telmisartan (TELM) combination is referred to the sufferers of hypertension. No analytical process has yet been mentioned for the TELM and AZEL combination analysis. We, therefore, have designed for its first time stability demonstrating methodology based on HPLC for analysing TELM and AZEL in the tablets and bulk. Methods: The assay of TELM and AZEL was get done on a 250 mm length C18 column (Supelco, 4.6 mm inner diameter, 5.0 μm particle size), and utilized 0.1M Na2SO4 (pH 3.6) and acetonitrile (55% volume: 45% volume) as the mobile solvents phase, at a stream rate 1.0 ml/min. HPLC recognition of TELM and AZEL was taken by a photodiode array sensor set at 258 nm. For validation of the stability demonstrating methodology proposed in terms of sensitivity, precision, specificity, linearity, device adequacy, robustness and accuracy, ICH directives were followed. Results: Calibration curves of TELM and AZEL were generated in the array of 20-60 µg/ml and 4-12 µg/ml with recovery percentage ranges of 99.62%-101.05% and 97.76%-100.17%, and detection limits of 0.020 µg/ml and 0.009 µg/ml, respectively. TELM and AZEL stability was inspected in the existence of acid, base, light, heat, and oxidation and it was realised to be more stable under oxidation degradation testing conditions employed when compared to acid, alkaline, photo, and heat degradation testing conditions applied. Conclusion: The observations demonstrated that the described HPLC stability demonstrating methodology was suitable for quantitating TELM and AZEL combination in tablets and bulk. Keywords: Azelnidipine, Telmisartan, Hypertension, Stability demonstrating, Analysis © 2021 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open access article under the CC BY license (https://creativecommons.org/licenses/by/4.0/) DOI: https://dx.doi.org/10.22159/ijap.2021v13i5.42099. Journal homepage: https://innovareacademics.in/journals/index.php/ijap INTRODUCTION Hypertension is the extremely avoidable contributing factor for cardiovascular impairments namely coronary cardiac disease, heart attack, heart stroke, atrial fibrillation, pulmonary artery disease and myocardial infarction, progressive renal disease and cognitive decline [1]. Hypertension is the foremost single contributor to the world’s leading basis of demise and disability. In 2010 it is valued that 1.39 billion (31.1%) of adults globally be ill with hypertension. In middle and small revenue nations (1.04 billion people and 31.5%), the occurrence of hypertension among adults was elevated than in the high revenue nations (349 million individuals and 28.5%) [2]. Azelnidipine (AZEL), structure in fig. 1, is a modern dihydropyridine calcium passage antagonist that is particular for the L-kind calcium passages and has received FDA authorization for therapy of the hypertension clients [3]. Antihypertensive outcomes of AZEL are equivalent to that of amlodipine [4]. AZEL is indeed increasingly lipid-soluble and has greater selectivity for the vascular surface than older generational calcium passage antagonists, and in animal experiments treated with AZEL, blood flowing to the brain was markedly enhanced [5]. Telmisartan (TELM), structure in fig. 1, is an angiotensin (II) receptor blockade being used to alleviate minimal to severe hypertension [6-8]. TELM is extremely selective for the type 1 angiotensin (II) receptors. TELM is an extra lipophilic angiotensin (II) receptor blocker than utmost other angiotensin (II) receptor inhibitors, which aids its oral uptake and tissue as well as cell permeation [9]. TELM too has an impact on the peroxisome proliferator triggered receptors, which are nuclear hormone receptor superfamily ligand triggered transcription elements. TELM, a drug that treats both diabetes and hypertension, may well be an alternative therapy choice [10, 11]. The combination of TELM and AZEL is recommended for hypertension sufferers. In hypertension sufferers, TELM and AZEL combination drops blood pressure, enables blood to flow more effectively to numerous tissues, allows the heart to operate more effectively, and increases oxygen flow across the body, and thereby reducing heart-associated chest pain [12]. Fig. 1: Azelnidipine (AZEL) and Telmisartan (TELM) structures Stress tests must be implemented on a medication compound to ascertain its basic stability properties, bestowing to the “ICH Q1A (R2)” parent drug permanency evaluation recommendations [13]. Understanding how a drug substance's consistency varies with times and the nature of deterioration products generated under different International Journal of Applied Pharmaceutics ISSN- 0975-7058 Vol 13, Issue 5, 2021