Method of Making Perfluorocarbon Emulsions With Non-Fluorinated Surfactants

Abstract

The present invention provides a method of making a FC emulsion. The method comprises mixing an FC immiscible hydrophilic liquid and a solid emulsifying agent by agitation at a temperature elevated above the phase transition temperature of the emulsifying agent and below the boiling temperature of the FC immiscible hydrophilic liquid, and adding FC to the mixture of step (a) and agitating at the elevated temperature to disperse droplets of FC in the FC immiscible hydrophilic liquid to form the FC emulsion. The invention also provides another method of making an FC emulsion, which does not require a solid emulsifying agent. The method comprises mixing an FC immiscible hydrophilic liquid and an emulsifying agent to form a first mixture; mixing a stabilizing agent with the first mixture to form a second mixture; and mixing FC with the second mixture to form a third mixture to disperse droplets of FC in the FC immiscible hydrophilic liquid and to form the FC emulsion, wherein the stabilizing agent reduces ability of the droplets to move within a continuous phase of the FC emulsion.

Description

CROSS-REFERENCE TO THE RELATED APPLICATIONS [0001] This application is a divisional of U.S. patent application Ser. No. 10 / 253,572, filed Sep. 24, 2002, which is incorporated herein by reference.FIELD OF THE INVENTION [0002] The invention relates generally to stable emulsions capable of gas-supersaturation, and methods of their preparation and use. Specifically, the present invention relates to stable fluorocarbon emulsions prepared with non-fluorinated emulsifying and stabilizing agents and methods of their preparation utilizing conventional mixing equipment. BACKGROUND OF THE INVENTION [0003] Fluorocarbons (fluorine substituted hydrocarbons) and perfluorocarbons (fluorocarbons in which all of the hydrogen atoms have been replaced with fluorine) have numerous applications in the biomedical field because of their unique chemical and biological properties. These compounds are clear, colorless, odorless, nonflammable, biocompatible, and have low reactivity. In addition, they are capab...

AI Technical Summary

Benefits of technology

The present invention provides stable fluorocarbon emulsions using non-fluorinated emulsifying agents and stabilizing agents that reduce the ability of the fluorocarbon droplets to move within the continuous phase of the emulsion. The emulsifying agents and stabilizing agents can be hydrogenated phospholipids or other non-fluorinated compounds. The emulsions can be made using a simple mixing process and can have a broad range of droplet sizes. The invention also provides methods for making the emulsions without the need for a solid emulsifying agent. The emulsified fluorocarbon droplets can be used in various applications such as industrial cleaning, coating, and delivery of oxygen.

Problems solved by technology

These compounds are clear, colorless, odorless, nonflammable, biocompatible, and have low reactivity.

One of the shortcomings of existing emulsions is their low stability.

These storage requirements seriously limit the field of application of such fluorocarbon emulsions.

However, most conventional emulsifying agents have a low affinity for fluorocarbons.

However, this method involves a complex multi-step procedure and requires high pressure homogenization or sonically-induced cavitations to effectively disperse fluorocarbons in water.

Fluorinated surfactants have been shown to improve the stability of FC emulsions (U.S. Pat. No. 6,113,919) However, this class of surfactants has also been shown to have a negative environmental impact that led to the withdrawal of some previously commercially available fluorinated surfactants.

However, the environmental concerns associated with such fluorinated compounds have greatly limited their use and availability in recent years.

Microemulsions, while stable thermodynamically, require a substantial amount of surfactants in their formulations, which may lead to bioincompatibiltiy for medical applications.

However, it is not clear whether such microemulsions are suitable for biomedical and cosmetic applications.

Still another group of FC emulsions limit the size of the FC droplets and do not provide an optimal therapeutic effect in topical applications.

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