Chromatographic and UV-spectrophotometric study of H-2-receptor antagonists

The histamine H-2-receptor antagonists cimetidine, famotidine, nizatidine, ranitidine hydrochloride have been extracted from pharmaceutical preparatio ns with methanol or concentrated acetic acid and identified on the basis of their infrared spectra, TLC of 0.2-1% solutions on silica gel 60F(254) pla tes with ethyl acetate-acetone-water, 50 + 40 + 10, as mobile phase enabled separation of all four compounds. The spots were detected under UV light a t lambda = 254 nm and in iodine vapor. After isolation by preparative TLC, and extraction from the adsorbent, the UV spectra were also recorded. Altho ugh the USP 23 HPLC method for analysis of nizatidine could also be used to separate famotidine and cimetidine, nizatidine and ranitidine hydrochlorid e had the same retention time.