Water-swellable polymers
US9987364B2 · kind B2 · utility
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289References
10Claims
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Key dates
| Filing date | Dec 6, 2013 |
| Grant date | Jun 5, 2018 |
| Priority date | — |
| Expiry date | Jun 9, 2034 |
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.