The new pharmaceutical compositions contain, apart from one or more active ingredient(s), between 0.01 and 60% w/w of the compounds of formula I ##STR1##

with n and m18 and 46 and with molecular weights between 600 and 8000 for the enhancement of absorption of the active ingredient(s). Moreover, such compositions may contain also between 0.01 and 20% w/w of Phosphatidylcholine.