Microsphere reservoirs for controlled release application
US5725869A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 24, 1996 |
| Grant date | Mar 10, 1998 |
| Priority date | — |
| Expiry date | Oct 24, 2016 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61K9/1652
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
Microspheres, optionally containing an ingredient to be dispensed through controlled release, are prepared by solvent evaporation of an oil-in-water emulsion formed from an organic solvent containing a polymer and a plasticizer and an aqueous solution containing one or more emulsifying agents. The microcapsules formed have a size of between about 3 and about 300 microns in diameter and are porous and spongy in structure as opposed to the hollow core, relatively solid surface structure of microspheres formed by solvent evaporation without utilizing a plasticizer. The microspheres can have a relatively high loading rate of an ingredient to be dispensed combined with a relatively low release rate and are useful for instance for agricultural chemicals, pharmaceuticals or medicines, cosmetics or fragrances.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.