Analytical eco‐scale and quality by design‐oriented liquid chromatography method for simultaneous quantification of metoprolol succinate, telmisartan, and cilnidipine in their fixed‐dose combination

Abstract

AbstractA new combination of metoprolol succinate, telmisartan, and cilnidipine is recently approved to treat hypertension effectively. A reversed‐phase liquid chromatography method was developed to quantify the said compounds, combining analytical eco‐scale and quality‐by‐design approach. The former one revealed an excellent green score for the present method. Later, method variables were assessed for risks and optimized using the quality‐by‐design‐oriented method development. The optimization process included using a Box‐Behnken design, and the obtained response surfaces for resolution amongst target peaks were mapped systematically. The optimal separation conditions employed a mobile phase of methanol: 0.01 M KH2PO4 buffer of pH 3.0 (70:30, %v/v) flowing at a rate of 1.0 mL/min on a C18 column with diode array detection at 240 nm. All three analyte peaks were well separated from each other with a resolution greater than 2.0. The analytical method was linear (2.5‐80 μg/mL) for target compounds with accuracy (>99%), and precision (<1%) results complying with regulatory requirements. The results of detection and quantitation limits, solution stability, and system suitability limit were good and acceptable. The current method selectively quantified the analytes from commercial dosage forms. Overall a green analytical method is developed and suitable for estimating metoprolol, telmisartan, and cilnidipine simultaneously in their combined pharmaceutical formulations.