Process for preparation of microcapsules
US4622244A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 23, 1984 |
| Grant date | Nov 11, 1986 |
| Priority date | — |
| Expiry date | Aug 23, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2989
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
Microcapsules particularly those less than 300 microns in size are provided which are adapted for injection by conventional means to afford controlled release of the encapsulated drug material, such as a narcotic antagonist, an antibiotic or the like, over a prolonged period. The microcapsules are characterized by a solid core material of a solid, injectable drug material and a wall material engulfing the core material and composed of a polymer material such as a bioabsorbable polymer material. The microcapsules are made by providing a system containing a mixture of particles of a solid, injectable drug material and a solution of a bioabsorbable polymer material in a solvent in which the drug material is substantially insoluble. The system is treated to induce phase separation of the bioabsorbable polymer material from the solution by the addition to the system of a phase separation agent at a temperature at least as low as -30.degree. C. Phase separation may also be carried out at room temperature, but in either event, isolation of the microcapsules formed during the phase separation should be carried out at a temperature at least as low as -30.degree. C. The system is maintained …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.