Simultaneous determination of lisinopril and H2 antagonists in API, formulations and human serum by using two different HPLC systems

An isocratic reversed phase high-performance liquid chromatographic method has been developed for the simultaneous determination of lisinopril and H-2 antagonists (cimetidine, ranitidine, and famotidine) in bulk, dosage formulations, and human serum at 225 nm. Chromatographic separation was achieved using mobile phase, acetonitrile:water (70:25 v/v) adjusted to pH 3.0 via phosphoric acid 85% with flow rate of 1 ml/min at room temperature. Calibration curves were linear over range of 0.7-12.50 mu g/ml for H-2 antagonists and 2.5-100 mu g/ml for lisinopril with a correlation coefficient +/- A 0.999. Limit of detection and limit of quantitation were in the ranges of 0.07-10.4 ng/ml. Intra- and inter-day precision and accuracy results were 98.0-102%.