Isocarbacyclin methylester (clinprost) (isocarbacyclin methylester; methyl 5-{(1S,5S,6R,7R)-7-hydroxy-6-[(E)- (S)-3-hydroxy-1-octenyl] bicyclo[3.3.0]oct-2-en-3-yl} pentanoate) and its active metabolite, isocarbacyclin (TEI-7165), are chemically stable PGI2 analogues. TTC- 909 is a drug preparation of clinprost incorporated into lipid microspheres (LM). The hypothetical sequence of events for TTC-909 to exert pharmacological effects is as follows: the LM would deliver clinprost to most tissues including the blood and the brain, clinprost would be released gradually from the LM, and then the clinprost would be hydrolyzed to TEI-7165 by esterase action to exert pharmacological activity. Both clinprost and TEI-7165 inhibit platelet aggregation and platelet adhesion in vitro and suppress prostaglandin F2 (PGF2 )-induced contraction of isolated canine arteries. TTC-909 also has vasodilative and anti-platelet activity in vivo, similar to PGI2. TTC-909 was shown to inhibit cerebral infarction, maybe by improving cerebral blood flow and by protecting against neuronal damage.