Porous substances and methods for producing the same
A physiologically active porous substance of the present invention obtained by treating a physiologically active solid substance with a carbon dioxide in a supercritical or subcritical state or a liquid carbon dioxide has a significantly improved dissolution rate and can easily be handled.
1 . A method for producing a physiologically active porous substance comprising treating a physiologically active solid substance with carbon dioxide in a supercritical or subcritical state or liquid carbon dioxide;
wherein said substance is not dissolved completely in said carbon dioxide in a supercritical or subcritical state or liquid carbon dioxide.
2 . The method according to claim 1 comprising the steps of (1) placing a physiologically active solid substance in a pressure-resistant container, (2) keeping the temperature of said pressure-resistant container at a level allowing carbon dioxide to be in a supercritical or subcritical state, (3) filling carbon dioxide into said pressure-resistant container, (4) stopping filling the carbon dioxide at the time point when the pressure in said pressure-resistant container reaches a level allowing carbon dioxide to be in a supercritical or subcritical state, (5) depressurizing after completing the carbon dioxide treatment and then collecting the resultant physiologically active porous substance.
3 . The method according to claim 1 wherein the supercritical carbon dioxide is carbon dioxide in a state exceeding both the critical pressure of about 7.38 MPa and the critical temperature of about 304.1 K.
4 . The method according to claim 1 wherein the subcritical carbon dioxide is carbon dioxide in a state exceeding either the critical pressure of about 7.38 MPa or the critical temperature of about 304.1 K.
5 . The method according to claim 1 comprising the steps of (1) placing a physiologically active substance in a pressure-resistant container, (2) keeping the temperature of said pressure-resistant container at the critical point or below, (3) filling carbon dioxide into said pressure-resistant container, (4) stopping filling the carbon dioxide under the condition where the pressure in said pressure-resistant container does not exceed the critical point of carbon dioxide, (5) depressurizing after completing the carbon dioxide treatment and then collecting the resultant physiologically active porous substance.
6 . The method according to claim 2 wherein the supercritical carbon dioxide is carbon dioxide in a state exceeding both the critical pressure of about 7.38 MPa and the critical temperature of about 304.1 K.
7 . The method according to claim 2 wherein the subcritical carbon dioxide is carbon dioxide in a state exceeding either the critical pressure of about 7.38 MPa or the critical temperature of about 304.1 K.
8 . The method according to claim 5 wherein the supercritical carbon dioxide is carbon dioxide in a state exceeding both the critical pressure of about 7.38 MPa and the critical temperature of about 304.1 K.
9 . The method according to claim 5 wherein the subcritical carbon dioxide is carbon dioxide in a state exceeding either the critical pressure of about 7.38 MPa or the critical temperature of about 304.1 K.