Continuous development HPTLC and sequential wavelength scanning for the simultaneous determination of nine clinically important β-blocking drugs

High performance thin-layer chromatography was used for the separation of nine therapeutically important and structurally similar β-adrenoceptor blocking drugs on silica gel plates. In situ scanning of the plate in the reflectance mode gave detection limits in the low nanogram range depending on the individual drug and the wavelength selected for its determination. Scanning the HPTLC plate at several wavelengths can be used to aid the identification of partially resolved components. Continuous development and continuous multiple development techniques are compared for the simultaneous separation of the drug mixture.