Simultaneous estimation of naproxen and dexamethasone sodium phosphate in pharmaceutical dosage form by RP-HPLC

Abstract

A modified simple, selective, rapid, precise reversed phase high performance liquid chromatography method has been developed and validated for the simultaneous estimation of naproxen and Dexamethasone Sodium. The separation was made in a HYPERSIL C18, 250 X 4.6 mm, 5? column using Mixed Phosphate buffer (1.36 gms of potassium Dihydrogen phosphate and 0.6gms of DiPotasssium hydrogen phosphate in 1 Liter water pH 6.8±0.1): Methanol in the ratio 45: 55 at 273 nm. The mobile-phase flow rate and the sample volume injected were 1 ml/min and 20 ?l, respectively. Retention time of naproxen and Dexamethasone Sodium was found to be 3.383 and 4.896 minutes respectively. The standard and sample preparation required less time and no tedious extraction were involved. A good linear relationship (naproxen r=0.999 & Dexamethasone r=0.998) was observed between the concentration range of 20-80 ?g/mL. The assay of naproxen was found to be 99.84% & the assay of Dexamethasone was found to be 99.85%.From the recovery studies it was found that about 101% of drug was recovered which indicates high accuracy of the method. It is suitable for the routine analysis of naproxen and Dexamethasone in pharmaceutical dosage form. The limit of detection (LOD) and limit of quantification (LOQ) for naproxen was found to be 3.7367?g/mL & 11.3236?g/mL. The limit of detection (LOD) and the limit of quantification (LOQ) for Dexamethasone were found to be 0.5502?g/mL &1.66736?g/mL. It was concluded that in the present developed HPLC method, the standard and sample preparation required less time and no tedious extraction were involved.