Prajapati BV et al Journal of Drug Delivery & Therapeutics. 2022; 12(3):108-115 ISSN: 2250-1177 [108] CODEN (USA): JDDTAO Available online on 15.05.2022 at http://jddtonline.info Journal of Drug Delivery and Therapeutics Open Access to Pharmaceutical and Medical Research Copyright © 2011-2022 The Author(s): This is an open-access article distributed under the terms of the CC BY-NC 4.0 which permits unrestricted use, distribution, and reproduction in any medium for non-commercial use provided the original author and source are credited Open Access Full Text Article Research Article Development and Validation of New Smartphone Based Colorimetric Method for Metoprolol succinate in Bulk and Tablet Dosage Form Dhruvin M Prajapati* , Rajashree Mashru The Maharaja Sayajirao University of Baroda, G.H. Patel Pharmacy Building, Donor’s Plaza, Fatehgunj, Vadodara 390001, Gujarat, India Article Info: ______________________________________________ Article History: Received 24 March 2022 Reviewed 30 April 2022 Accepted 09 May 2022 Published 15 May 2022 ______________________________________________ Cite this article as: Prajapati DM, Mashru R, Development and Validation of New Smartphone Based Colorimetric Method for Metoprolol succinate in Bulk and Tablet Dosage Form, Journal of Drug Delivery and Therapeutics. 2022; 12(3):108-115 DOI: http://dx.doi.org/10.22270/jddt.v12i3.5469 ______________________________________________ *Address for Correspondence: Dhruvin M Prajapati, The Maharaja Sayajirao University of Baroda, G.H. Patel Pharmacy Building, Donor’s Plaza, Fatehgunj, Vadodara 390001, Gujarat, India Abstract ____________________________________________________________________________________________________________ A method for determining the concentration of coloured compounds in a solution is colorimetry. The intensity of the colour is related to the chemical concentration being measured. Because of its low cost and ability to collect, store, and interpret data all in one device, smartphone-based colorimetry has increased in appeal as an analytical tool. The camera on the phone is used as a detector in smartphone colorimetry. Both the smartphone colorimetric method and the UV method relied on the detection of colour intensity as concentration rose. The ammonium metavanadate reagent is orange red in colour, but when it reacts with Metoprolol succinate, it changes to a green colour complex. The developed method has good linearity in the 20-40µg/ml range. The colour intensity increases as the concentration of API increases. All of the photos were captured on a smartphone and analyzed with photometrix PRO software. The photometrix PRO application turns an image to an RGB histogram, and it also includes regression models. LOD and LOQ value for UV visible spectrophotometry technique is 1.05µg/ml and 3.189µg/ml, respectively. Photometrix PRO LOD and LOQ are 0.0338µg/ml and 0.102µg/ml, respectively. The percent RSD of Metoprolol succinate was <2% utilizing Photometrix PRO and UV method. The results of a statistical tool called a two-paired test on both procedures show that they are both equally significant. Keywords: UV spectrophotometry, Metoprolol succinate, Smartphone based colorimetry, Photometrix PRO, RGB Histogram INTRODUCTION: Metoprolol is a propanol amine that is 1-(propan-2-ylamino) propan-2-ol substituted by a 4-(2-methoxyethyl) phenoxy group at position 1. Iupac name of metoprolol succinate is butanedioic acid; 1-[4-(2-methoxyethyl) phenoxy]-3-(propan- 2-ylamino) propan-2-ol. It has a role as a beta-adrenergic antagonist, an antihypertensive agent, a xenobiotic, an environmental contaminant, and a geroprotector. It is a propanol amine, aromatic ether, secondary alcohol, and a secondary amino compound. Metoprolol is a selective beta-1 blocker commonly employed as the succinate and tartrate derivatives depending if the formulation is designed to be of immediate-release or extended-release. The possibility of the generation of these formulations comes from the lower systemic bioavailability of the succinate derivative. To this date, it is one of the preferred beta-blockers in general clinical guidelines and it is widely prescribed in the Netherlands, New Zealand, and the US. Metoprolol was developed in 1969 by US Pharmaceutical Holdings I and FDA approved in 1978. Metoprolol is a cardioselective beta-blocker that is widely used in the treatment of hypertension and angina pectoris. Metoprolol has been linked to rare cases of drug-induced liver injury. Metoprolol is indicated for the treatment of angina, heart failure, myocardial infarction, atrial fibrillation, atrial flutter, and hypertension. Some off-label uses of metoprolol include supraventricular tachycardia and thyroid storm. All the indications of metoprolol are part of cardiovascular diseases. These conditions correspond to a number of diseases that involve the function of the heart and blood vessels. The underlying causes of these conditions are variable and can be due to genetic disposition, lifestyle decisions such as smoking, obesity, diet, and lack of exercise, and comorbidity with other conditions such as diabetes. Cardiovascular diseases are the leading cause of death on a global scale 1 . Figure 1: Metoprolol succinate (2) Various analytical methods are developed for Metoprolol succinate. Different HPLC methods 3–7 , UV spectroscopic