Simultaneous Estimation of Escitalopram and Clonazepam in Tablet Dosage Forms Using HPLC-DAD Method and Optimization of Chromatographic Conditions by Box-Behnken Design

Abstract

The study aimed to develop a new reverse-phase high-performance liquid chromatography (RP-HPLC) method with diode array detection (DAD) detection for simultaneous estimation of escitalopram (EST) and clonazepam (CZP) in tablet dosage forms with a quality by design (QbD) approach. The chromatographic conditions were optimized by Box-Behnken design (BBD) and developed method was validated for the linearity, system suitability, accuracy, precision, robustness, sensitivity, and solution stability according to International Council for Harmonization (ICH) guidelines. EST and CZP standard drugs peaks were separated at retention times of 2.668 and 5.046 min by C-18 column with dimension of 4.6 × 100 mm length and particle size packing 2.5 µm. The mobile phase was methanol: 0.1% orthophosphoric acid (OPA) (25:75, v/v), with a flow rate of 0.7 mL/min at temperature of 26 °C. The sample volume injected was 20 µL and peaks were detected at 239 nm. Using the standard calibration curve, the % assay of marketed tablet was founded 98.89 and 98.76 for EST and CZP, respectively. The proposed RP-HPLC method was able to detect EST and CZP in the presence of their degradation products, indicating the stability-indicating property of the developed RP-HPLC method. The validation parameter’s results in terms of linearity, system suitability, accuracy, precision, robustness, sensitivity, and solution stability were in an acceptable range as per the ICH guidelines. The newly developed RP-HPLC method with QbD application is simple, accurate, time-saving, and economic.

A Method for Improving Microbial Conversion of Diosgenin and Separation and Identification of the Product

“…The interactions between sucrose and NH 4 H 2 PO 4 and between NH 4 H 2 PO 4 and wheat bran were not significant. However, the interaction between sucrose and wheat bran had a notable effect on the diosgenin yield, with a p-value = 0.0209, indicating that the effects of sucrose and wheat bran on the yield are not simple linear relationships [30]. The strength of various additives' influence on the diosgenin yield, judged by the F value, are NH 4 H 2 PO 4 > wheat bran > sucrose.…”

The Applicability of Chromatographic Retention Modeling on Chiral Stationary Phases in Reverse-Phase Mode: A Case Study for Ezetimibe and Its Impurities

“…The main advantage of employing an "enhanced approach" through software-assisted method development is acquiring an understanding of the process through the identification of critical method parameters (CMPs or ECs) and critical quality attributes (CQAs), which are essential for establishing a control strategy. There are numerous examples from recent years about the applicability of experimental design-based retention modeling in chromatographic method development and optimization using both empirical-model-based, statistical- [2,4,[12][13][14][15][16][17][18][19][20][21] and theoretical-model-based, or mechanistic [8,[22][23][24][25][26] approaches.…”