Method and apparatus for the formation of particles

Apparatus for use in a method of forming particles of a substance, comprising a particle formation chamber;

• a mechanism for controlling the temperature in the chamber at a desired level;
• a mechanism for controlling the pressure in the chamber at a desired level;
• a first fluid inlet for the separate introduction into the chamber of (i) a first supercritical fluid and (ii) a solution or suspension of the substance in a vehicle;
• a pump for conveying the solution or suspension to the first fluid inlet;
• and a second fluid inlet for introducing simultaneously an impinging flow of a second supercritical fluid into the particle formation chamber separately from the first supercritical fluid, at an angle to, and directed at, the direction of flow of the first supercritical fluid, the apparatus being such as to allow dispersion of the solution or suspension, and extraction of the vehicle, to occur substantially simultaneously and substantially immediately on introduction of the fluids into the particle formation chamber, by the action of either or both of the two supercritical fluids.

Apparatus for use in a method of forming particles of a substance, comprising a particle formation chamber;

• a mechanism for controlling the temperature in the chamber at a desired level;
• a mechanism for controlling the pressure in the chamber at a desired level;
• a first fluid inlet for the introduction into the chamber of a first supercritical fluid and a solution or suspension of the substance in a vehicle;
• and a second fluid inlet for introducing simultaneously an impinging flow of a second supercritical fluid, at an angle to, and directed at, the direction of flow of the first supercritical fluid, the apparatus being such as to allow dispersion of the solution or suspension, and extraction of the vehicle, to occur substantially simultaneously and substantially immediately on introduction of the fluids into the particle formation chamber, by the action of either or both of the two supercritical fluids, wherein the second fluid inlet allows the introduction of the second supercritical fluid in a direction substantially opposite to the direction of flow of the first supercritical fluid.