Effects of oral administration of synthesized delta-amides of eflornithine in the rat.

The purpose of this study was to synthesize a series of delta-amide derivatives of the antitrypanosomal drug eflornithine (2,5-diamino-2-(difluoromethyl)pentanoic acid hydrochloride, DMFO, CAS 70052-12-9), to determine their physicochemical properties and to assess whether they convert to eflornithine in vivo and if so, whether higher systemic exposure to eflornithine could be achieved by increase intestinal absorption, suggesting an oral treatment to be possible. The derivatives were synthesized by amidation of eflornithine on its delta-amino group using acyl chlorides. The partition coefficients (log D, pH = 7.