Polymeric matrix particle compositions containing coacervate polymer shell
US5492646A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 15, 1993 |
| Grant date | Feb 20, 1996 |
| Priority date | — |
| Expiry date | Nov 15, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC11D17/0039
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
This invention relates to the encapsulation of active ingredient within polymeric material so as to protect the active ingredient from the ambient environment, for instance atmospheric moisture when the product is exposed to the air, or the liquid phase of a liquid detergent when the product is incorporated in such a detergent. A dispersion in oil of an aqueous solution of a matrix polymeric material containing enzyme or other active ingredient is subjected to distillation to provide a substantially anhydrous dispersion in oil of particles of matrix polymer containing active ingredient, and during or after the distillation the polymer solution is converted into a solid polymer. In the invention, we use a matrix polymer that is so hydrophobic that it partitions preferentially into the oil rather than into the aqueous solution of encapsulating polymer. Because the aqueous solution is incompatible with both the hydrophobic oil and the matrix polymer, there is increased tendency for the encapsulating shell to be formed around a layer of oil, rather than in direct contact with a matrix polymer particle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.