Progress in Quantitative Methods for Azelnidipine and Chlorthalidone: An Analytical Basis for a Recently Approved FDC

Background: Products with multiple active substances mixed in a single dosage form are fixed-dose combinations. These are justified for a variety of reasons. These include a) increasing therapeutic efficacy, b) lowering adverse drug effects, c) pharmacokinetic advantages, d) lowering pill load, e) lowering individual drug doses, and f) lowering drug resistance development. Objective: A recently approved fixed dose combination of azelnidipine (8 mg) and chlorthalidone (6.25 or 12.5 mg) is indicated to treat hypertension. Individual quantification methods for azelnidipine and chlorthalidone are available, but no practical and acceptable analytical approach for their combination has been documented. As a result, the goal of this literature review was to gather information on numerous analytical instrumental approaches utilized to quantify azelnidipine and chlorthalidone in diverse matrices individually. The scientific community could use this information to design a new analytical method for analysing the recently approved combination. Methods: Authors have explored various scientific databases to obtain information on analytical methods. Results: The methods listed for azelnidipine and chlorthalidone are spectroscopy, highperformance liquid chromatography, hyphenated techniques, high-performance thin-layer chromatography, thin-layer chromatography, and a few other approaches. For azelnidipine and chlorthalidone, there were 26 and 46 research papers reported, respectively.