Method for preparation of polymer microparticles free of organic solvent traces
US5858531A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 24, 1996 |
| Grant date | Jan 12, 1999 |
| Priority date | — |
| Expiry date | Oct 24, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2989
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
The present invention relates to a new method for the production of polymer microparticles. The method is carried out in the absence of organic solvent, and consists in the steps of (a) combining first and second polymers, the first and second polymers being immiscible, (b) heating the combination obtained in step (a) so as to melt the first and second polymers; (c) stirring the melted polymers obtained in step (b) under conditions effective to produce a biphasic system comprising a dispersed phase consisting of a dispersion of the first polymer and a matrix continuous phase comprising the second polymer, the dispersed phase containing microparticles of the first polymer dispersed in the matrix continuous phase; (d) solidifying the biphasic system obtained in step (c) so as to keep the microparticles of the first polymer dispersed in the matrix continuous phase; and (e) separating and isolating the microparticles of the first polymer from the matrix continuous phase, wherein the first polymer forming said dispersed phase is water-insoluble, while the second polymer forming the continuous phase is water-soluble.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.