Prolonged release biodegradable microspheres and method for preparing same
US7691412B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 10, 2002 |
| Grant date | Apr 6, 2010 |
| Priority date | — |
| Expiry date | Feb 24, 2027 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61K9/1647
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
The invention concerns a method for preparing a pharmaceutical composition in the form of microspheres with prolonged release of a water-soluble active principle. The invention is characterized in that it comprises the following successive steps: dissolving an active principle in an appropriate amount of water; emulsifying the resulting aqueous solution of active principle with a d,l-lactide-co-glycolide matrix copolymer, of average molecular weight ranging between 40000 and 80000, dissolved in a chlorinated hydrocarbon, resulting in a first microfine and homogeneous emulsion; emulsifying said resulting first emulsion in an external aqueous phase, containing a surfactant, a viscosity-enhancing agent and an osmotic agent; extraction-evaporation of the solvent to obtain microspheres which are recuperated after filtering, washing and drying. The invention also concerns microspheres obtainable by implementing said method, having continuous release over a period of more than two months, advantageously over a period of at least three months.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.