The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 08, 1998
Filed:
Nov. 01, 1995
Alok K Kulshreshtha, Arlington, TX (US);
Garnet G Smith, Colleyville, TX (US);
Scott D Anderson, Marlboro, MA (US);
Val J Krukonis, Lexington, MA (US);
Alcon Laboratories, Inc., Fort Worth, TX (US);
Abstract
A process employing a supercritical fluid anti-solvent for sizing prednisolone acetate is disclosed. The process optionally incorporates sterilization filters. Average particle sizes of about 1 .mu.m or less (number average) and narrow particle size ranges are obtainable. The process comprises the steps of (a) forming a solution by dissolving prednisolone acetate in acetone such that the concentration of prednisolone acetate is approximately 80% or less of its solubility in acetone; and (b) transporting the solution formed in step (a) through an orifice having a diameter of 50-100 .mu.m into a mixer/expander containing compressed CO.sub.2, wherein the compressed CO.sub.2 is at a temperature from about 40.degree. to 80.degree. C. and has a density less than the density of the solution by at least 0.3 g/cc, to expand the solution so that the acetone dissolves in the CO.sub.2 and the prednisolone acetate precipitates.