Analysis of losartan and carvedilol in urine and plasma samples using a dispersive liquid-liquid microextraction isocratic HPLC-UV method

Background: A simple, precise and sensitive HPLC method has been developed for simultaneous determination of carvedilol and losartan in human plasma and urine samples. The analytes were extracted by a dispersive liquid-liquid microextraction method. A mobile phase of 15 mM sodium dihydrogen phosphate buffer (pH 4.0)/acetonitrile/2-propanol (70/27.5/2.5, v/v/v) was used to separate the drugs using a Waters (R) ODS column (250 X 4.6 mm) and detected by a UV detector at 222 nm. Results: The developed method is selective for studied drugs possessing a linearity range of 0.1-1.0 and 0.05-0.75 mu g/ml, respectively, for losartan and carvedilol with precision <15%. The accuracy is better than 15% and the mean recovery of carvedilol and losartan was 98.9 and 100.2% for plasma and 100.7 and 100.5% for urine samples, respectively. Conclusion: The developed method is applicable for therapeutic drug monitoring and PK analyses.