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. 06, 1988
Filed:
May. 14, 1987
Franklin Lim, Richmond, VA (US);
Damon Biotech, Inc, Needham Heights, MA (US);
Abstract
Permeable capsules are loaded with a reservoir of the substance to be dispensed at a concentration sufficient to provide an osmotic pressure above threshold level, and the pore size of the capsule membrane is controlled so that the passage of the substance through the membrane becomes the rate-limiting factor in dispensing. Shape-retaining spheres are formed from a water-soluble polymer containing plural anionic or cationic groups and cross-linking surface layers of the spheres by contact with a polymer having plural groups of charge opposite that of the water-soluble polymer. After loading, the capsules are again treated with the same or a different cross-linking polymer to reduce the dimensions of the pores.