Process for improving crystallinity
This invention provides a process for increasing the crystallinity of at least one solid material which is less than 100% crystalline, comprising contacting said solid material with solvent in which the solid material is insoluble or poorly soluble (a non-solvent); and applying ultrasound to the solid material when in contact with said non-solvent.
1. A process for increasing the crystallinity of a crystallizable solid, comprising contacting said crystallizable solid with a non-solvent; and
applying ultrasound to the crystallizable solid when in contact with said non-solvent;
wherein the crystallizable solid is selected from the group consisting of an active pharmaceutical ingredient, an active agrochemical ingredient, a pharmaceutical excipient, an agrochemical excipient and appropriate mixtures of two or more thereof; and wherein the process further comprises:
(i) forming a solution of the crystallizable solid in a solvent;
(ii) subjecting the solution, after step (i), to a process selected from the group consisting of rapid precipitation, freeze drying, lyophilisation, rapid expansion of supercritical solutions, spray drying or mixtures thereof, wherein the said dissolved crystallizable solid is converted into a substantially dry solid material;
(iii) isolating, after step (ii), the substantially dry crystallizable solid from the liquid and/or gaseous components of the process of step (ii);
(iv) treating, after step (iii), said substantially dry crystallizable solid from step (iii) with a non-solvent therefor;
(v) applying ultrasound, after step (iv), to the crystallizable solid from step (iv) when it is in contact with said non-solvent; and
(vi) optionally, after step (v), separating and/or drying the resultant crystallizable solid from step (v).
2. A process according to claim 1 , wherein the crystallizable solid is a particulate solid material having a mass median aerodynamic diameter of up to about 10 μm.
3. A process according to claim 1 , wherein prior to the application of the above process, the crystallizable solid is less than 50% crystalline.
4. A process according to claim 1 , wherein the crystallizable solid is a pharmaceutically active ingredient selected from the group consisting of anti-allergics, bronchodilators, anti-inflammatory steroids and mixtures thereof.
5. A process according to claim 1 , wherein the crystallizable solid is obtained from spray-drying.
6. A process according to claim 1 , wherein the crystallizable solid produced by the process is at least 90% crystalline.