Use of ionic cloud point modifiers to prevent particle aggregation during sterilization

US5298262A · kind A · utility

Assignee

• Sterling Winthrop Inc. · US

Inventors

• George C. Na · Fort Washington, US
• Natarajan Rajagopalan · Kothagudem, IN

Key dates

• Filing date: Dec 4, 1992
• Grant date: Mar 29, 1994
• Expiry date: Dec 4, 2012

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S977/847
• WIPO field: Pharmaceuticals
• WIPO sector: Chemistry

Abstract

This invention discloses a composition comprised of nanoparticles having a surface modifier adsorbed on the surface thereof and an anionic or cationic surfactant as a cloud point modifier associated therewith, which cloud point modifier is present in an amount sufficient to increase the cloud point of the surface modifier. A preferred surface modifier is tyloxapol. Preferred anionic surfactants are dioctylsulfonesuccinate, sodium dodecyl sulfate and sodium oleate. Preferred cationic surfactants are dodecyltrimethylammonium bromide and cetrimide tetradecyl ammonium bromide. This invention further discloses a method of making nanoparticles having a surface modifier adsorbed on the surface and an anionic or cationic surfactant as a cloud point modifier associated therewith, comprised of contacting said nanoparticles with the cloud point modifier for a time and under conditions sufficient to increase the cloud point of the surface modifier.