Development and validation of the analytical method for the estimation of a combination of 5-fluorouracil and imiquimod by rp-hplc

A simple, precise, and accurate reverse phase high performance liquid chromatographic method (RP-HPLC) was developed and validated for the estimation of the combination of 5- Fluorouracil (5-FU) and Imiquimod in active pharmaceutical ingredients (APIs). The method was carried out on Phenomenex C18 (250 x 4.6mm I.D., 5μm) using isocratic elution mode. The mobile phase was used as Acetonitrile: 10mM potassium dihydrogen orthophosphate: triethylamine (40:59.9:0.1, v/v, pH 4.5 with orthophosphoric acid) and Water: ACN (50:50 v/v) was used as a diluent. The concentration of solvents was 1–20μg/ml and the volume of injection was 20μl with the flow rate of 1.2ml/min. The retention times for 5-FU and Imiquimod were found to be 1.9±0.5 and 6.6±0.5 min respectively. The absorption maxima of 5FU and Imiquimod were found 267nm and 227nm respectively. The method was validated as per ICH guidelines. All the data were found within the specified limits. The limit of detection (LOD) and limit of quantification (LOQ) of 5- Fluorouracil were found to be 0.015μg/mL and 0.048 μg/mL, respectively, and Imiquimod was found to be 0.078μg/mL and 0.237μg/mL, respectively. The method developed in the present study was found to be sensitive, specific, and precise and can be applied for the simultaneous estimation of 5-FU and Imiquimod.