Preparation of microparticles for controlled release of water-soluble substances
US5478564A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 1993 |
| Grant date | Dec 26, 1995 |
| Priority date | — |
| Expiry date | Jun 17, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2985
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
The subject of the present invention is a process for preparing microparticles of the microsphere type of a water-soluble substance and a biocompatible and biodegradable polymer controlling the kinetics of release of the said substance consisting of a matrix of the said polymer within which the said water-soluble substance is regularly dispersed, characterized in that PA1 a) the said polymer is dissolved in a first volatile organic solvent immiscible with water, PA1 b) the said water-soluble substance is dissolved in a second solvent which is miscible with the said first solvent, is a solvent for the polymer, and miscible with water, PA1 c) the solution of the said substance and the solution of the said polymer are mixed, PA1 d) an organic phase of the polymer and of the said substance is obtained which is then emulsified in an immiscible dispersant medium consisting of an aqueous phase containing an emulsifying agent, PA1 e) the two solvents are then removed from the microspheres being formed with stirring, the first solvent being removed by evaporation, the second solvent and part of the first solvent which is miscible therewith being removed by passage towards the aqueous phase …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.