Production of particles by spray-evaporation

摘要

A method of preparing particles of a substance, for example selected from a flavour, fragrance, pigment, dye, biologically active compound or a plastics material, comprises contacting the substance or a formulation (which may include the substance in conjunction with a second solvent) with a first solvent which comprises a C1-4 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 at least some of the substance from the first solvent and the formation of fine particles 20 of the substance. Specific compounds disclosed are phenyl acetic acid and lauric acid. Also disclosed are particles of a substance which incorporate a trace of a C1-4 hydrofluorocarbon.