Polyethylene glycol ethers of alkyl alcohols having the general formula CH.sub.3(CH.sub.2).sub.xCH.sub.2(OCH.sub.2CH.sub.2).sub.nOH wherein x is 8 to 20 (of which ceteareth-20, steareth-20 and steareth-100 are preferred), poloxamer 185, poloxamer 407, N,N-dimethyl dodecylamine N-oxide, and mixtures thereof, are employed to increase follicular delivery and/or follicular residence time of certain water soluble ornithine decarboxylase inhibitors of which 2(difluoromethyl)-2,5-diamino pentanoic acid and its pharmaceutically acceptable salts, hydrates, optical enantiomers and racemic mixture are preferred.