PCT No. PCT/EP94/01489 Sec. 371 Date Nov. 7, 1995 Sec. 102(e) Date Nov. 7, 1995 PCT Filed May 9, 1994 PCT Pub. No. WO94/26267 PCT Pub. Date Nov. 24, 1994Compositions in the form of solid solutions containing a) 1-90% by weight of a coumarin derivative A from the group of alkoxycoumarins with a heterocyclic substituent or of hydroxycoumarins esterified with a sulfonic acid as active substance and b) 10-99% by weight of at least one water-soluble polymer B as carrier substance.