The invention provides an oral pharmaceutical composition, optionally in dose unit form, comprising a lipophilic drug substance in dispersion in a physiologically tolerable aqueous carrier, preferably an aqueous gel, wherein said drug substance contains a functional electrostatic group having a pKa value of from 2 to 10, characterised in that said aqueous carrier has a pH at least 0.3 below or above said pKa value, said pH being below said pKa where said group is acidic and above said pKa where said group is basic.