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:
Dec. 13, 2011
Filed:
Apr. 09, 2009
Lester Moore, Fort Collins, CO (US);
Richard L. Norton, Ft. Collins, CO (US);
Lester Moore, Fort Collins, CO (US);
Richard L. Norton, Ft. Collins, CO (US);
Tolmar Therapeutics, Inc., Fort Collins, CO (US);
Abstract
The invention provides methods of extracting a biodegradable polyester with a supercritical fluid effective to obtain a purified biodegradable polyester, such as a purified biodegradable poly(lactide-glycolide) (PLG). The supercritical fluid can be carbon dioxide at an elevated pressure, or can be carbon dioxide with one or more cosolvents. Methods for carrying out stepwise purification of the biodegradable polyester at multiple pressures or multiple temperatures, or both, are also provided. When the polyester is PLG, a purified PLG copolymer is obtained having a narrowed molecular weight distribution with respect to the unpurified polyester. The purified PLG copolymer can have a polydispersity index of less than about 1.7, less than about 2% monomers, and less than about 10% oligomers. The purified PLG copolymer can exhibit a reduced initial burst effect when incorporated into a controlled release formulation such as a flowable implant adapted to be injected into body tissues.