Preparation of ionically cross-linked polyphosphazene microspheresy by coacervation
US5807757A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 2, 1996 |
| Grant date | Sep 15, 1998 |
| Priority date | — |
| Expiry date | Jul 2, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2989
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
A method is provided for preparing polyphosphazene microspheres wherein the polyphosphazene microspheres are produced by coacervation. A solution containing a polyphosphazene is admixed with a solution containing a salt of a monovalent ion such as a salt of a Group I element (for example, NaCl) to form a dispersion containing polyphosphazene coacervate microdroplets. The dispersion then is admixed with a solution containing a salt of a multivalent ion, such as a salt of a Group II element (for example, CaCl.sub.2) to form a suspension of polyphosphazene microspheres. The polyphosphazene microspheres then are recovered from the suspension. Such method enables one to obtain high yields of microspheres having a controlled size distribution. Polyphosphazene microspheres containing biological material can be produced by providing a biological material in the polyphosphazene solution that is mixed with the solution containing a salt of a monovalent ion. The biological material may be an antigen or other biological material selected from proteins, nucleic acids, polysaccharides and synthetic compounds having biological activity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.