Thin-layer and gas chromatographic screening programs for new drug substances

Procedures are described for evaluation of the thin-layer and gas chromatographic properties of new raw material drug substances over a broad spectrum of conditions. Chromatographic profiles are established for each drug, and these are used as starting points for analytical procedures for the drug, its synthetic precursors, and its degradation products. Thin-layer chromatography is performed initially by use of three absorbents and a series of six solvents. Gas chromatography is performed initially by temperature programming on a series of six different columns, followed by isothermal experiments. Evaluation of resulting chromatograms from both techniques determines whether more experiments are necessary or whether an analytical method can be developed based directly on one of the results of the initial screening.