NZ 599430 Disclosed is a site-specific, microparticulate pharmaceutical composition comprising: a therapeutic amount of a therapeutic agent, wherein the therapeutic agent comprises an Endothelin (ET) receptor antagonist a Transient Receptor Potential (TRP) channel antagonist, or a combination thereof and a pharmaceutically acceptable carrier, wherein the carrier comprises a plurality of microparticles, the composition being characterised by: dispersal of the therapeutic agent throughout each microparticle sustained release of the therapeutic agent from the composition as a dispersion, its fluidity around the cerebral artery at risk for vasospasm following local delivery via injection and a local therapeutic effect that is effective to reduce risk of vasospasm without entering systemic circulation in an amount to cause unwanted side effects. Also disclosed is the use of said microparticulate pharmaceutical composition in the manufacture of a medicament for the treatment of a cerebral artery at risk for cerebral vasospasm in a human subject, wherein the microparticulate pharmaceutical composition is formulated to be administered to the human subject locally via injection into a subarachnoid space in a cistern closest to a cerebral artery at risk for vasospasm.
