Pregabalin and Tranexamic Acid Evaluation by Two Simple and Sensitive Spectrophotometric Methods

Abstract

This paper demonstrates colorimetric visible spectrophotometric quantification methods for amino acid, namely, tranexamic acid and pregabalin. Both drugs contain the amino group, and when they are reacted with 2,4-dinitrophenol and 2,4,6-trinitrophenol, they give rise to yellow colored complexes showing absorption maximum at 418 nm and 425 nm, respectively, based on the Lewis acid base reaction. Detailed optimization process and stoichiometric studies were conducted along with investigation of thermodynamic features, that is, association constant and standard free energy changes. The method was linear over the concentration range of 0.02–200 µgmL−1 with correlation coefficient of more than 0.9990 in all of the cases. Limit of detection was in range from 0.0041 to 0.0094 µgmL−1 and limit of quantification was in the range from 0.0137 to 0.0302 µgmL−1. Excellent recovery in Placebo spiked samples indicated that there is no interference from common excipients. The analytical methods under proposal were successfully applied to determine tranexamic acid and pregabalin in commercial products. t-test and F ratio were evaluated without noticeable difference between the proposed and reference methods.

A Portable Reflective Absorbance Spectrophotometric Smartphone Device for the Rapid and Highly Accurate Determination of Amlodipine in Pharmaceutical Formulation and Human Urine Samples

“…Job's continuous variations curve for this reaction was investigated to understand the mole ratio between amlodipine and picric acid, as indicated in Figure. occurring as picrate ion, which increased yellow intensity, [34][35][36][37] as indicated in Figure. S3.…”

Kinetic Approach to Determine 3-Amino Methyl Hexanoic Acid in Pharmaceutical Formulations

“…Pregabalin does not possess prominent chromophore, therefore it is a very low UV absorbing molecule. 17 Thus use of conventional UV spectrophotometric methods was out of question due to its poor sensitivity. For high sensitivity and specificity HPLC is usually used but due to low specific absorption, a high concentration has to be injection onto the column to get viable peak which would cause column deterioration.…”

“…Chem., 2019, 72, 189-194, <https://journals.sabinet.co.za/content/journal/chem/>. out the molar ratio of pregabalin with NIN 17,29 was used. The ratio found through method was 1:2 for NIN.…”

“…[7][8][9][10][11] NIN has special application in the pharmaceutical industry by visualization of amino and azo group-containing compounds on TLC plates and in kinetic studies. [12][13][14] A literature survey revealed that various analytical methods have been reported to quantify pregabalin, including spectrophotometery, [15][16][17][18][19] specrtofluorimetery, [20][21] high pressure liquid chromatography with UV detection, [22][23] HPLC mass spectrometry, 24 HPLC with fluorescence detection 25 and HPLC with pre-column 26 and post-column 27 derivatization. Liquid chromatographic methods involve expansive equipment while spectrofluorimeters are not commonly available.…”

A Novel RP-HPLC method for simultaneous estimation of Dorzolamide and Timolol maleate in ophthalmic products

“…A combination of DA and TM at various concentrations has been available in the market, requiring the simultaneous analysis of TM and DA in ophthalmic drops and ocular matrices. Pharmaceutical industries pay a great deal of importance to simultaneous analysis and a simple and straightforward method as such method reduces human hours in analyzing the product and implicates less environmental impact [3][4][5][6]. Literature survey reveals that there are few methods available for the determination of these drugs individually and simultaneously.…”