Pharmaceutical composition

A continuous method of forming particles which comprise microcrystals with a non-hydroscopic inner crystalline core comprising co-precipitant molecules and an outer coating comprising at least one bioactive molecule, comprising the following steps:

• (a) providing a continuous stream of an aqueous solution comprising non-polymeric co-precipitant molecules and bioactive molecules, each co-precipitant molecule substantially having a molecular weight of less than 4 kDa, wherein the aqueous solution is capable of forming a co-precipitate which comprises the co-precipitant and bioactive molecules with a melting point of above about 90° C.;
• (b) rapidly admixing the continuous stream of bioactive molecule/co-precipitant molecule solution with a greater volume of a continuous stream of a substantially water miscible organic solvent such that the co-precipitant and bioactive molecules co-precipitate from solution forming particles which comprise microcrystals with a non-hydroscopic inner crystalline core comprising co-precipitant molecules and an outer coating comprising at least one bioactive molecule, wherein the continuous streams are mixed in a continuous flow process;
• and
• (c) optionally isolating the particles from the organic solvent,
• wherein following mixing with the bioactive molecule the co-precipitant will be at between about 5 and 100% of its aqueous saturation solubility.