Biodegradable low molecular weight triblock poly (lactide-co-glycolide) polyethylene glycol copolymers having reverse thermal gelation properties
US6117949A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 1, 1998 |
| Grant date | Sep 12, 2000 |
| Priority date | — |
| Expiry date | Oct 1, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L71/02
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
A water soluble biodegradable ABA- or BAB-type triblock polymer is disclosed that is made up of a major amount of a hydrophobic polymer made of a poly(lactide-co-glycolide) copolymer or poly(lactide) polymer as the A-blocks and a minor amount of a hydrophilic polyethylene glycol polymer B-block, having an overall weight average molecular weight of between about 2000 and 4990, and that possesses reverse thermal gelation properties. Effective concentrations of the triblock polymer and a drug may be uniformly contained in an aqueous phase to form a drug delivery composition. At temperatures below the gelation temperature of the triblock polymer the composition is a liquid and at temperatures at or above the gelation temperature the composition is a gel or semi-solid. The composition may be administered to a warm-blooded animal as a liquid by parenteral, ocular, topical, inhalation, transdermal, vaginal, transurethral, rectal, nasal, oral, pulmonary or aural delivery means and is a gel at body temperature. The composition may also be administered as a gel. The drug is released at a controlled rate from the gel which biodegrades into non-toxic products. The release rate of the drug may …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.