Agricultural Research Service

Filed:

August 18, 1998

Abstract:

The invention relates to microscopic-sized starch-based shells (microspheres) and their use in forming microcapsules having utility as delivery systems for drugs, pharmaceuticals, cosmetics, and other active agents. These shells are prepared by blending a solubilized polysaccharide with a lipophilic material to produce spherical droplets of the lipophilic material coated with the polysaccharide, diluting the emulsion with a solvent, and isolating the polysaccharide shells from the diluted emulsion. The coated droplets of the invention may be stored in aqueous suspension, or alternatively as a dry product that is suspended in a pharmaceutically acceptable vehicle or carrier immediately prior to administration such as by intravenous, subcutaneous, or intramuscular injection. The composition may also be administered orally, or by applying to the skin surface. The coated droplets can also be used to deliver essential oils and flavoring materials in food products, deliver agents for waxes and other lipophilic materials in water-based coating formulations.

Inventors:

George F. Fanta Biomaterials Processing Research Peoria, Illinois 61604 (309) 681-6356/ fax: (309) 681-6691	Frederick C. Felker (Same address as first inventor) (309) 681-6663
Kenneth Eskins (deceased)	Clarence A. Knutson (Same address as first inventor) (309) 681-6330

Industry Keywords:

pharmaceutical, food additive, cosmetics, hydrophilic drugs, lipophilic drugs, polysaccharide, microcapsular, aqueous compositions

The invention relates to microscopic starch-based shells, or microcapsules. The microcapsules are formed by first processing starch and either a fat or oil in the presence of water in a steam-jet cooker, and then diluting the mixture with an excess of water. Microscopic starch shells, having a fat or oil core, rise to the surface. When a volatile fat or oil is used in the process, the core will evaporate, leaving empty shells that can be refilled with another agent that would not have survived the steam-jet cooking. The microcapsules disperse easily in water and can be used for a variety of purposes including lubricants, cosmetics, oil-based food flavorings, and for delivery of oil-soluble pharmaceuticals that are given either by injection or topically. Chemical modification of the starch shells would be possible for certain pharmaceutical and industrial applications.

Reference:

"Starch Microcapsules for Delivery of Active Agents," Patent Number 6,238,677, issued
May 29, 2001.  S.N. 09/745,043, filed on December 20, 2000, is a continuation of Patent Number 6,238,677.