[Densitometric determination of propyphenazone, paracetamol, guaiacol glycerol ether, caffeine and acetylsalicylic acid in analgesic-antipyretic preparations with thin-layer chromatography].

Optimum conditions for a simultaneous determination of propyphenazone, paracetamol, guaiacol glycerol ether, caffeine and acetylsalicylic acid were described for preparations with analgesic-antipyretic activity, which don't allow a direct determination of the active principle because of interference phenomena. Using an external standard for calibration the determination was carried out by adsorption measurement (reflectance detection) in situ. Beside the determination of the drug content the method can be used to identify substances according to their RT and RF-values as well as by on-plate spectra taken.