Simultaneous determination of quinine and chloroquine anti-malarial agents in pharmaceuticals and biological fluids by HPLC and fluorescence detection

Abstract

Even nowadays millions of people suffer and even die each year from malaria and hundreds of millions of people especially in tropical countries. Quinine (Q) a natural occurring alkaloid and chloroquine (CQ) a synthetic drug are widely used as anti-malarial agents. Herein an isocratic reversed-phase high performance liquid chromatographic (RP-HPLC) method is described for the simultaneous determination of quinine and chloroquine, at low concentrations, in pharmaceuticals and biological fluids. The present method is characterized by higher sensitivity and analytes are separated in less time than the already published methods. The analytical column, an MZ Kromasil, C 18, 5 μm, 250 × 4 mm, was operated at ambient temperature with backpressure values of 230 kg/cm 2. Mobile phase consisted of methanol–acetonitrile–0.1 mol/L ammonium acetate, (45:15:40 v/v) at a flow rate of 1.0 mL/min. Fluorescence detection was performed at excitation 325 nm and emission 375 nm, respectively. Salicylic acid was used as internal standard at a concentration of 0.5 ng/μL, resulting in a detection limit of 0.3 ng, while upper limit of linear range was 0.7 ng/μL for quinine and 0.5 ng/μL for chloroquine. Separation was completed within 5 min. The statistical evaluation of the method was examined performing intra-day ( n = 8) and inter-day calibration ( n = 8) and was found to be satisfactory, with high accuracy and precision results. Solid phase extraction provided high relative extraction recoveries from biological matrices: 92.1% for quinine and 105.4% for chloroquine from blood serum and 101.8% for quinine and 90.7% for chloroquine from urine.