SIMULTANEOUS ESTIMATION OF RELATED COMPOUNDS IN ESOMEPRAZOLE AND NAPROXEN TABLETS BY USING ION PAIR REVERSE PHASE HPLC Original Article

Objective: To develop and validate a novel gradient reverse phase HPLC method for quantitative estimation of Naproxen and Esomeprazole impurities in pharmaceutical dosage form. Methods: Chromatographic separation was achieved on X-Bridge C18,150x4.6 mm, 3.5 µm column. Detection wavelength was set at 302 nm. The mobile phase A consists of Buffer and Acetonitrile in the ratio of 90:10, where Buffer was prepared by dissolving di ammonium hydrogen phosphate (2.64 gm per Liter) and 1-hexane sulphonic acid sodium salt (1.0 gm per Liter), pH adjusted to 6.5±0.05 with orthophosphoric acid. A mixture of acetonitrile and 1-propanol in the ratio of 90:10 was used as mobile phase B. Flow rate was set to 0.7 mL/minute in gradient elution mode, with a retention time for Naproxen and Esomeprazole 29 and 46 minute respectively. Results: The calibration curve was linear over the concentration range of 4.621 µg/mL – 99.026 µg/mL for Naproxen and 0.254 µg/mL–3.806 µg/mL for Esomeprazole (r= 0.999). The proposed method was found to be (considered)accurate and precise and linear within the desired range. The limit of quantitation (LOQ) was calculated. The purity angle was found less than purity threshold for forced degradation peaks, which shows there was no interference from the common excipient, known impurities and degradents indicating separation, accuracy and reliability of the method. The method was validated as per ICH guidelines and found to be specific, accurate, linear, precise and stability indicating. Conclusion: A Novel, simple, selective and rapid reversed phase high performance liquid chromatographic (HPLC) method was developed and validated for the estimation of Naproxen and Esomeprazole impurities in pharmaceutical dosage form. Hence, the method can be used for routine analysis in various pharmaceutical industries.