Abstract

Facile and Manifest Liquid Chromatographic Method for the Simultaneous Determination of Enalpril Maleate and NSAIDs in API and Pharmaceutical Formulations

Najma Sultana, Safila Naveed and M Saeed Arayne

Patients diagnosed with hypertension are prescribed a large number of medications for appropriate therapy, increasing risk of side effects or drug interactions. Enalapril, ACE inhibitor is commonly used as a drug of choice for the treatment of hypertension. On the other hand, NSAIDs are generally used for the treatment of pain, fever and inflammation, particularly in arthritis. A simple, efficient, economical and least time consuming isocratic method for the simultaneous determination of enalapril (ENP) and non-steroidal anti-inflammatory drugs (flurbiprofen, diclofenac sodium, ibuprofen and mefanamic) in bulk, pharmaceutical formulations and human serum using high performance liquid chromatography (HPLC) has been developed and validated. ENP was separated from NSAIDs using a Purospher STAR C18 column (250×4.6 mm, 5 μm) and a mobile phase consisting of methanol, water (80:20, v/v, pH was adjusted by ortho phosphoric acid to 2.8 at a flow rate of 1.8 mL min-1 and at ambient temperature. Effluents from the column were monitored at 225 nm. The retention time of ENP was 4.1 minute and that for flurbiprofen, diclofenac sodium, ibuprofen and mefanamic acid was 5.4, 5.9, 6.4 and 8.7 mins respectively. LLOD and LLOQ of enalapril were 0.7 and 2.2 ng respectively and that of flurbiprofen, diclofenac sodium, ibuprofen and mefanamic were 0.24, 0.07, 0.1, 0.1 and 0.7, 0.2, 0.3 and 0.4 ng respectively. The method was validated according to ICH guidelines. Linearity of the method was studied in the concentration range 2.5-100 μg mL-1 for ENP and 0.625-25 μg mL-1 for (NSAIDs) where it demonstrated good linearity with r=0.9995, 0.9979, 0.9995, 0.9967, 0.9967 and 0.9995 (n=6), respectively, recovery was >97.8%. The developed method may successfully be applied for the quantitative analysis of ENP and NSAIDs alone or in combination from raw materials, in bulk drugs, dosage formulations and in serum.