Development and Validation of Analytical Method for Quantification of Losartan Potassium in Solid Dosage Form

The aim of this study was to develop and validate a simple, robust, reliable and an accurate isocratic reverse phase high-performance liquid chromatography (RP-HPLC) method for quantification of Losartan potassium in solid dosage form using DAD Detector. Elution was carried out with mobile phase comprising of 0.01 M monobasic potassium dihydrogen phosphate buffer (adjusted at pH 3.0 ± 0.05 with ortho-phosphoric acid) and methanol (40: 60), through octadecyl silyl (C18) column (15 cm x 4.6 mm x 5 μl), at flow rate of 1 ml/min. The detection was carried out at 230 nm. The developed method was validated according to International Conference on Harmonization (ICH) guidelines (ICH 2005). The assay was linear in concentration range of 1-3 µgmL-1 with Correlation coefficient of 0.999. The limit of detection was 0.036 µgmL-1 and limit of quantification was 0.110 µg/ml. Similarly, method accuracy was asses by comparing the %RSD of BP method with the %RSD of the method developed which shows RSD for standard method was 1.012% while for developed method it was 1.516% and combined RSD of both two methods was found 1.823% that was as per the precision criteria of accuracy i.e. <2%. The result of intraday study was 0.129% and Intermediate precision among inter day and brand to brand was 0.332%. Moreover, the devised method seems to be linear over broad range of LK concentration (1-3 µgmL-1) with appreciable repeatability and reproducibility (RSD <2.00). The results of present study indicate that the method is efficient, specific, sensitive and suitable to be used for the determination of losartan potassium in solid dosage forms using isocratic mode in comparison to gradient mode used by United States pharmacopoeia (USP 2016).