HPTLC with fluorescence densitometry for simultaneous determination of some angiotensin II receptor blockers in tablets and plasma.

A selective, accurate, precise, and highly sensitive HPTLC assay with reflectance/fluorescence densitometry was developed to separate and quantify some angiotensin II receptor blockers (ARBs), namely, losartan potassium, irbesartan, valsartan, and olmesartan medoxomil, in tablets and plasma. Separation of the target ARBs was performed on precoated silica gel HPTLC plates developed using chloroform-glacial acetic acid (7.5 + 2.5, v/v) mobile phase. The drugs were adequately resolved. After the exposure of the chromatograms to concentrated hydrochloric acid vapor for 10 min, the scanner was set in the reflectance/fluorescence mode with 255 nm excitation wavelength and >400 nm emission filter. The linear regression analysis data for the calibration curves of all studied drugs produced a good linear relationship with correlation coefficients ranging from 0.9991 to 0.9999 over the concentration range of 2-20 ng/band. LOD and LOQ values of all studied drugs ranged from 0.6 to 0.8 and from 1.7 to 2.4 ng/band, respectively. The developed method was successfully applied for analysis of the target ARBs in tablets and spiked human plasma samples with good precision and accuracy.