It facilitates automatic application and scanning in situ. The composition of the mobile phase for the development selleck catalog of the chromatographic method was optimized by testing different solvent mixtures of varying polarity. Acetonitrile-0.2% acetate (6:4, 7:3, v/v) and methanol-0.2% acetate (8:2, 9:1, v/v) were tried. The best results were obtained using acetonitrile-methanol�C0.1% acetic acid (3.5:2.6:3.9, v/v). This mobile phase showed good resolution of losartan potassium peak from other formulation components or excipients tested. Densitometric scanning of all the tracks showed compound with Rf value 0.61 (single violet spot), identified as losartan potassium. The present method is quicker as the time needed for development of plate is reduced considerably to less than half an hour for chamber saturation.
The method was successfully used in the analysis of losartan potassium from the tablet dosage forms, and in case of Cozaar Tablets without interference of the formulation excipients. Figure 1 Typical chromatogram of losartan potassium and internal standard Recovery study Results showed high extraction efficiency of losartan potassium from formulation components. The recovery of losartan potassium ranged from 96.58 to 98.27%, average of 97.33%. This confirms that the proposed method can be used for determination of losartan potassium in tablet formulation. Precision and accuracy Five microliter aliquots of samples containing 5.0, 15.0, and 30.0 ng losartan potassium were analyzed according to the proposed method. In order to control the scanner parameters, one spot was analyzed several times.
By spotting and analyzing the same amount several times the precision of the automatic spotting device and the derivatization technique, was evaluated. The coefficient variation (% C.V.) for the analysis of eight replicates indicated good precision for the proposed TLC method (% C.V. consistently less than 5) and scanning eight spots in one run is the method of choice. Results obtaining were of good accuracy and high precision. The accuracy was found to be in the range of 88.76�C98.88% and % C.V. in range of 1.02-6.81. The results are presented in Tables Tables11�C3. Table 1 Precision and accuracy data of HPTLC method performed on losartan potassium Table 3 Precision data of the HPTLC assay for losartan potassium Table 2 Accuracy and precision of the assay Limit of detection and limit of quantification The limit of detection was 3.
0 ng/ml and the limit of quantification was 16.0 ng/ml and the solutions were stable for the 3 days. CONCLUSIONS The developed HPTLC technique is precise, specific, accurate, and sensitive. It proves that the method is repeatable and selective for the analysis of losartan potassium as bulk drug and in pharmaceutical formulations without any interference from the excipients. ACKNOWLEDGEMENT AV-951 Author wish to thank to J.S.S.Mahavidyapeetha, Mysore for providing this facility to carry out this work.