Development and Validation of a Stability-Indicating Assay of Etofenamate by RP-HPLC and Characterization of Degradation Products

Ramalingam Peraman

doi:10.3797/scipharm.1305-19

Abstract

A validated stability-indicating RP-HPLC method for etofenamate (ETF) was developed by separating its degradation products on a C18 (250 mm × 4.6 mm 5 μm) Qualisil BDS column using a phosphate buffer (pH-adjusted to 6.0 with orthophosphoric acid) and methanol in the ratio of 20:80 % v/v as the mobile phase at a flow rate of 1.0 mL/min. The column effluents were monitored by a photodiode array detector set at 286 nm. The method was validated in terms of specificity, linearity, accuracy, precision, detection limit, quantification limit, and robustness. Forced degradation of etofenamate was carried out under acidic, basic, thermal, photo, and peroxide conditions and the major degradation products of acidic and basic degradation were isolated and characterized by 1H-NMR, 13C-NMR, and mass spectral studies. The mass balance of the method varied between 92–99%.

Highlights

Etofenamate (ETF) is chemically 2-{[3-(trifluoromethyl)phenyl]amino}benzoic acid 2-(2hydroxyethoxy)ethyl ester, which exists as viscous a liquid and is used as an analgesic, antirheumatic, antipyretic, and anti-inflammatory [1]
It was noted that % aqueous in the mobile phase had shown a drastic effect on the retention time of ETF
The conditions were optimized on the C18 (Agilent, 250 x 4.6 mm, 5 μ) column with UV- PDA detection with the mobile phase consisting of a phosphate buffer and methanol in the ratio of 20:80% v/v

Summary

Introduction

Etofenamate (ETF) is chemically 2-{[3-(trifluoromethyl)phenyl]amino}benzoic acid 2-(2hydroxyethoxy)ethyl ester, which exists as viscous a liquid and is used as an analgesic, antirheumatic, antipyretic, and anti-inflammatory [1]. No stability studies on ETF have been reported, the present work was designed to develop a sensitive, precise, and selective stability-indicating RP-HPLC method for the estimation of ETF in dosage forms and to isolate and characterize the major degradants by spectral studies. Forced Degradation Studies of Etofenamate (ETF) Forced degradation of ETF was performed under neutral, acid, alkaline, oxidative, thermal, and photolytic stress conditions [8].

Results

Conclusion