Method Development and Validation of Stability Indicating RP-HPLC Method for Simultaneous Estimation of Escitalopram Oxalate and Clonazepam in Bulk and its Pharmaceutical Formulations

Abstract

This article refers to simple isocratic reverse-phase high-performance liquid chromatographic method (RP-HPLC) developed for the simultaneous quantification of Escitalopram Oxalate (EST) and Clonazepam (CZP) in active pharmaceutical ingredient and pharmaceuticals. The separation of the two drugs was attained using a C₁₈ column (250mm×4.6mm, 5µ) as a stationary phase. The mobile phase was used as a mixture of methanol; acetonitrile; and 0.05M potassium dihydrogen orthophosphate buffer (pH 4 adjusted by orthophosphoric acid) with an isocratic ratio of 40:20:40 v/v. Detection was made by using PDA detector at 210 nm. Escitalopram Oxalate (RT= 4.428 minutes) and Clonazepam (RT= 6.532 minutes) were separated in a single chromatographic run with resolution of 8.719. The calibration plot indicated good linear relationship with r2 = 0.998 for Escitalopram Oxalate in concentration range of 32 µg/ml - 48 µg/ml and r2 = 0.999 for Clonazepam in concentration range of 16 µg/ml - 24 µg/ml. The retrievals for Escitalopram Oxalate and Clonazepam were found to be 99.75% and 99.00%, respectively. The established analytical method was validated and found acceptable as per ICH guidelines for linearity, precision, accuracy, specificity, limit of detection, limit of quantification, robustness and stability. Escitalopram Oxalate and Clonazepam individually as well as in combination were exposed to different stress conditions like acid, base, thermal, photolytic and oxidation degradation and peaks of a degraded product were well determined from peaks of pure drug. This method is modest, quick and appropriate for routine quality control analysis.
 Keywords: Reverse Phase – HPLC; Escitalopram Oxalate; Clonazepam; Validation; Degradation study.

Development and Evaluation of Novel Estimation Techniques for in Vitro Dissolution Study and Validation Protocol for Escitalopram as Antidepressant Drug and Their Formulation

“…The various RP-HPLC methods have been studied for the analysis of escitalopram in bulk and various dosage forms [3][4][5][6][7][8][9][10][11][12][13]. However, the reported methods are less specific and also time-consuming.…”

“…Literature survey reveals spectrophotometric, RP-HPLC [3][4][5][6][7][8][9][10][11][12][13], and HPTLC [14] methods for these compounds either individually or in combination with other dosage forms. The literature review does not show any stability indicating RP-HPLC method for quantification of escitalopram.…”

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

“…Various high-performance liquid chromatography (HPLC) methods have also been reported for the determination of EST or CZP, either alone or in combined dosage forms [8][9][10][11][12]. A stability-indicating HPLC method was used for the simultaneous estimation of EST and CZP in bulk drug and tablet formulations [8]. Some HPLC methods have also been used to estimate CZP alone in tablet formulations [9,10].…”

“…Reported HPLC methods for the determination of EST or CZP were linear, accurate, precise, and robust [9][10][11][12]. However, a single HPLC method was stability-indicating one [8]. In addition, the reported HPLC method for the simultaneous determination of EST and CZP was not rapid and time-saving compared to the developed HPLC method [8].…”

“…However, a single HPLC method was stability-indicating one [8]. In addition, the reported HPLC method for the simultaneous determination of EST and CZP was not rapid and time-saving compared to the developed HPLC method [8]. The statistical optimization of any of the reported analytical methods of EST and CZP determination was not performed in literature.…”