The present invention relates to calcium salts of compounds of the general formula (I) wherein X is selected from the group consisting of CH 2 , S, or O； D isOorS； R 8 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 = CH 2 , q =0 , Y= unsubstituted phenyl and E = unsubstituted phenylene are excluded； or a hydrate thereof.
