Methods for a particle precipitation and coating using near-critical and supercritical antisolvents

Abstract

Improved methods and apparatus for particle precipitation and coating using near- or supercritical fluid conditions are described. A fluid dispersion having a continuous phase dispersant and at least one precipitatable substance therein is contacted with a supercritical fluid (SCF) antisolvent so as to generate focused high frequency antisolvent sonic waves, breaking up the dispersion into extremely small droplets; the enhanced mass transfer rates between the droplets and the antisolvent causes precipitation of very small particles on the order of 0.1-10 .mu.m. In coating processes, a turbulent fluidized flow of core particles is created using an SCF antisolvent in an enclosed zone. The core particles are contacted therein at near- or supercritical conditions by a fluid dispersion containing a dispersant together with a precipitatable substance. The antisolvent depletes the dispersant and the substance is precipitated onto the fluidized core particles. In another aspect of the invention, a process for preparing and administering a medicament using only a single container is provided. In such method, a fluid dispersion having a dispersant with the medicament therein is contacted with an antisolvent at near- or supercritical conditions within a use container, so as to directly precipitate small particles of the medicament in the container. The antisolvent is then removed and the use container is sealed with the medicament particles therein. Thereafter, dose(s) of the medicament can be withdrawn from the use container and administered to a patient.

Dependencies are inferred from the claim text.