Patent ID: 6056791
Filing Date: 2000-05-02
Classification: A61K,B01J

Abstract:
A process for the production of dry particles or powders, comprising the steps of:(a) providing in a pressure vessel a non-gaseous substance or mixture of substances to be treated,(b) adiusting a temperature of the substance or mixture of substances to a range between about 50.degree. K above or below the melting point under atmospheric pressure and below a decomposition temperature of the substance or mixture of substances,(c) selecting a highly compressible fluid having a melting point of at least about 40.degree. K lower than the melting point of the substance or mixture of substances, the selected fluid being highly compressible under conditions of 0.5.T.sub.critical to 2.0.T.sub.critical and 0.3.P.sub.critical to 8.0.P.sub.critical with regard to said highly compressible fluid,(d) pressurizing the substance or mixture of substances provided in the pressure vessel at the temperature in (b) by introducing said highly compressible fluid under conditions of 0.5.T.sub.critical to 2.0.T.sub.critical and 0.3.P.sub.critical to 8.0.P.sub.critical with regard to said highly compressible fluid until a liquid solution has formed containing 10-95% of the substance or mixture of substances,(e) conveying to and passing the solution through a decompression device for rapid decompression, wherein conditions are selected such that the temperature falls, downstream of the decompression device, below the solidification point of the substance or mixture of substances and essentially all of the highly compressible fluid turns gaseous and dry particles of the substance or mixture of substances form, and(f) removing from the stream of decompressed highly compressible fluid the dry particles which have formed.