Ultrasmall, non-aggregated porous particles of uniform size for entrapping gas bubbles within and methods
US5741522A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 5, 1995 |
| Grant date | Apr 21, 1998 |
| Priority date | — |
| Expiry date | Jun 5, 2015 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61K49/223
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
This invention relates to the preparation, composition and applications of suspensions of ultra-small, substantially non-aggregated, non-crystalline particles of predetermined uniform size which, when suspended in a liquid, contain entrapped gaseous bubbles. These gaseous bubble particles are prepared by simultaneous co-precipitation of two compounds. In accordance with the present invention, the two compounds chosen for co-precipitation are such that one is substantially more soluble than the other in a given vehicle. When this vehicle is used for washing the co-precipitated particles, part of the soluble material is dissolved leaving a porous matrix. The porous particles then are dried and stored. The porous particles, which can be resuspended immediately prior to use, contain entrapped gas in the evacuated crevices or pores which is not displaced for a period of time because of surface tension of the suspending vehicle. These ultrasmall, substantially non-aggregated porous particles therefore can be used to advantage as ultrasound contrast agents as well as other applications.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.