Abstract: 3-[(3aR,4R,5S,7aS)-5-{(1R)-1-[3,5-bis(Trifluoromethyl)phenyl]ethoxy}-4-(4-fluorophenyl)-octahydro-2H-isoindol-2-yl]cyclopent-2-en-1-one (Compound I) has surprisingly improved solubility, bioavailability and stability in an ampiphilic vehicle that can include propylene glycol, a propylene glycol sparing agent, an antioxidant, or a mixture thereof. In one embodiment of the present invention is a solution comprising the active or a pharmaceutically acceptable salt or solvate thereof, and an amphiphilic agent, said amphiphilic agent being a fatty acid ester of glycerol, propylene glycol or sorbitol.