Ionic beads for controlled release and adsorption

US5840293A · kind A · utility

Assignee

• Advanced Poymer Systems, Inc. · US

Inventors

• Sergio Nacht · Los Altos, US
• Richard Won · Palo Alto, US
• Martin Katz · Menlo Park, US
• Tai C. Cheng · Mountain View, US
• Christine Liau · La Palma, US
• Robert Eury · Rue de l'Église, US
• Michael Froix · Menlo Park, US

Key dates

• Filing date: May 17, 1994
• Grant date: Nov 24, 1998
• Expiry date: May 17, 2014

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61K2800/92
• WIPO field: Pharmaceuticals
• WIPO sector: Chemistry

Abstract

Ionic compositions comprise an active ingredient absorbed within a network of internal pores defined by a plurality of polymeric particles. The particles are preferably crosslinked polymeric beads having a diameter in the range from about 5 to 100 microns and a surface charge density from about 0.1 to 10 meq/qm hydrogen ion capacity. The active ingredients are released from the ionic polymer beads over time when orally administered, applied to a keratinic material, typically human skin or hair or otherwise delivered to a target environment. The use of a cationic charge promotes adhesion of the beads to the keratinic material.