Method for preparing capsules consisting of a liquid active material core enclosed in a mineral coating
US6537583B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 19, 2001 |
| Grant date | Mar 25, 2003 |
| Priority date | — |
| Expiry date | Jul 19, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2984
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
The invention concerns a method for preparing mineral capsules consisting of aqueous liquid core enclosed in mineral coating, said method consisting in: 1) emulsifying an aqueous fluid in a phase non-miscible with said aqueous fluid so as to disperse it therein in the form of droplets; 2) contacting, in the resulting emulsion, at least a zirconium, silicon, aluminium and/or a transition metal capable of being hydrolysed or subjected to condensation polymerisation in temperature and pH conditions suitable for forming a precipitate consisting of the corresponding oxide or hydroxide; 3) recuperating the resulting mineral capsules and, if required, purifying them. Said method is characterised in that the formation of the mineral precipitate in the second step is carried out in the presence of an amphiphilic surfactant system present in the emulsion and capable of concentrating the deposit of mineral particles of said precipitate formed in the interface of the aqueous droplets and the hydrophobic phase and of effectively blocking their diffusion inside the droplets.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.