Water-swellable polymers
US8628798B2 · kind B2 · utility
4Cited by
286References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 10, 2012 |
| Grant date | Jan 14, 2014 |
| Priority date | — |
| Expiry date | Aug 30, 2032 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G2210/00
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
A water-swellable linear polyurethane polymer is formed by reacting a polyethylene oxide (e.g. PEG 4000 to 35,000), a difunctional compound (e.g. a diamine or diol such as 1,10-decanediol) with a diisocyanate. The ratio of the three components is generally in the range 0.1-1.5 to 1 to 1.1-2.5. The polyurethane is water-swellable in the range 300 to 1700% and soluble in certain organic solvents such as dichloromethane. It can be loaded with pharmaceutically active agents, particularly of high molecular weight, to produce controlled release compositions, such as pessaries etc.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.