摘要 |
A method of preparing particles of a substance, for example selected from a flavor, fragrance, pigment, dye, biologically active compound or a plastics material, comprises contacting the substance of a formulation (which may include the substance in conjunction with a second solvent) with a first solvent which comprises a C1-C4 hydrofluorocarbon, especially tetrafluoroethane, and subjecting the resultant mixture to a separation process, for example, by allowing the mixture to be sprayed as a mist ( 14 ) from a high pressure environment in a first vessel ( 2 ) to a low pressure environment in a second vessel ( 8 ), thereby to cause separation of a least some of the substance from the first solvent and the formation of fine particles ( 20 ) of the substance. |