Abstract: Time-release pharmaceutical compositions, suitable for oral administration, are disclosed, which comprise as active ingredient 50 to 70% by weight of a compound of the formula (I) ##STR1## or the formula (Ia) ##STR2## wherein R is hydrogen or --CH.sub.2 COOH,R.sup.1 is hydrogen or alkyl having 1 to 4 carbon atoms,R.sup.2 is alkyl having 1 to 4 carbon atoms, alkoxycarbonyl having 2 to 5 carbon atoms, carbamoly or ureido,R.sup.3 is hydrogen or methyl, and the dotted line stands for two hydrogens or another bond, or a pharmaceutically acceptable acid addition or quaternary ammonium salt thereof, and which further include 4 to 8% by weight of a hydrophobic substance with a great specific surface;7 to 12% by weight of a lipoid;8 to 12% by weight of a polyoxy compound;4 to 9% by weight of a binding agent; and0.5 to 4% by weight of an acid stabilizer.