A HUMAN NECESSITIES
A61 MEDICAL OR VETERINARY SCIENCE; HYGIENE
A61K PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
A61K31/00 Medicinal preparations containing organic active ingredients
A61K31/33 Heterocyclic compounds
A61K31/395 having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins
A61K31/495 having six-membered rings with two; or more; nitrogen atoms as the only ring heteroatoms, e.g. piperazine; or tetrazines
A61K31/505 Pyrimidines; Hydrogenated pyrimidines, e.g. trimethoprim