Thin-Layer Chromatography of Darvon Compound-65A casual glance through any recent issue of this Journal reveals that more and more undergraduate laboratory experiments are being oriented toward drugs (1-5). Our organic laboratory experiments are also tending in that direction (6). In light of the new interests in Darvon (7), we decided that the thin-layer analysis of Darvon drugs would be appropriate.Darvon Compound-65, an effective analgesic, consists of four components (8): caffeine (I), phenacetin (II), aspirin (III), and propoxyphene hydrochloride (IV), itself known