The present invention relates to a salt selected from the group comprising the N-methyl-D-glucamine salt (NMG), the diethylamine salt (DEA) salt, the magnesium salt, the tromethamine salt, the choline salt, the L-arginine salt, the zinc salt, and the 4-(2-hydroxyethyl)morpholine (HEM) salt of compounds of the general formula (I) wherein X is selected from the group consisting of CH2, S, or O; D is O or S; R8 is hydrogen or alkyl; E is an optionally substituted phenylene group; Y is a monocyclic or bicyclic substituted or unsubstituted 6-9 membered ring system which may contain one or more heteroatoms selected from N or S and which contains at least one aromatic ring; n is 0 or 1; and q is 0 or 1; with the proviso that compounds wherein X═CH2, q=0, Y=unsubstituted phenyl and E=unsubstituted phenylene are excluded; or a hydrate thereof.