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:
Aug. 04, 1998
Filed:
Jan. 15, 1997
Ellington M Beavers, Meadowbrook, PA (US);
Djoerd Hoekstra, Malvern, PA (US);
Yee San Su, Fort Washington, PA (US);
Nicole Willard, Collegeville, PA (US);
Biocoat Incorporated, , PA (US);
Abstract
A free acid form of a polysaccharide is produced from its alkali-metal salt. In one example, free-form hyaluronic acid is produced by preparing a solution of an alkali-metal salt of hyaluronic acid, dispersing into the solution a strong acid, enclosing the dispersion within a semi-permeable membrane, dialyzing the dispersion in water, and harvesting the product from within the membrane. The strong acid can be hydrochloric acid, sulfuric acid, nitric acid, orthophosphoric acid, or oxalic acid, for example. The semi-permeable membrane has a molecular weight cut-off large enough to pass the strong acid, and preferably much larger. The invention provides a simple and economical way to produce a product which is not commercially available.