Zero order release and temperature-controlled microcapsules and process for the preparation thereof
US7179407B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 24, 2003 |
| Grant date | Feb 20, 2007 |
| Priority date | — |
| Expiry date | Oct 20, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2991
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
A microcapsule composition comprising a core material in a matrix of polymorphic shell material, releases said core material in an aqueous environment in accordance with zero order linear release profile. A preferred composition comprises a core material having a degree of water solubility entrapped in a beta crystalline matrix of water insoluble shell material which matrix may, optionally, be surrounded by a contiguous core material-free layer of water insoluble shell material. Also disclosed is a process for the preparation of microcapsules comprising subjecting a flowable mixture of core material and a first amount of water insoluble shell material to a pressure force to form a pressure-treated mixture, and passing said pressure-treated mixture through a spray nozzle into a chilling zone to form a solidified composition. A special embodiment of the method providing for the long term moisture stability of the resulting microcapsules subjects the microcapsules prepared in the first step to a second coating with a second amount of water insoluble shell material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.