Rapid thin-layer chromatography of various weak analgesics in saliva.

A thin-layer chromatographic method was developed to analyze phenacetin, 4-amino-phenazone and N-methyl-4-aminophenazone (5 and 1.25 micrograms/ml); bucetin (4-ethoxy-beta-hydroxybutyranilide), propyphenazone and N-acetyl-4-aminophenazone (2.5 and 1.25 micrograms/ml); phenazone (15 and 1.25 micrograms/ml); and N-acetylsalicylamide (0.25 micrograms/ml). The method was designed to study the bioavailability of different commercial tablets from salivary concentration data.