Cyclodextrin-Based Microemulsions, and Dermatological Uses Thereof

Abstract

Described herein are cyclodextrin-stabilized microemulsion systems useful for increasing the solubility, stability, bioavailability, or safety of an active agent for delivery to the skin. The microemulsions may reduce the occurrence of skin irritation or odor upon application. In certain embodiments, the active agent is substantially insoluble in water. The microemulsions may be formulated as semi-solids, for example creams, or as aerosol or non-aerosol foams. Also described are methods of treating skin disorders, comprising the step of applying to an affected area of a subject in need thereof a therapeutically-effective amount of an inventive microemulsion.

Description

RELATED APPLICATIONS[0001]This application claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 61 / 614,177, filed Mar. 22, 2012, the contents of which are hereby incorporated by reference.BACKGROUND[0002]Microemulsions are thermodynamically-stable, optically-clear emulsions having submicron-sized droplets suspended in a continuous phase. These emulsions form spontaneously, and typically consist of an aqueous phase, an organic phase, and a surfactant / co-surfactant component.[0003]Previous data suggest that volatile lower alcohols, such as ethanol, are required to maintain stable oil-in-water microemulsions. However, topical application of volatile lower alcohols has a drying effect on the skin. Additionally, volatile lower alcohols and compositions containing them are extremely flammable. For these reasons, volatile lower alcohol-containing microemulsions for topical application have seen limited commercial use.[0004]Developing a formulation for a water-immi...

AI Technical Summary

Benefits of technology

The patent describes a new formulation containing an active ingredient called retinol, which is made into a microemulsion. The microemulsion has a specific composition and is combined with a moisturizer or emollient, a surfactant, an antioxidant or preservative, a viscosity modifying agent, and a pH adjuster. The formulation is effective in treating skin disorders like acne and keratosis pilaris, as well as wrinkles and sun spots. The technical effects of the patent are improved skin penetration and effective treatment of skin issues.

Problems solved by technology

However, topical application of volatile lower alcohols has a drying effect on the skin.

Additionally, volatile lower alcohols and compositions containing them are extremely flammable.

For these reasons, volatile lower alcohol-containing microemulsions for topical application have seen limited commercial use.

Developing a formulation for a water-immiscible drug that displays desirable drug delivery and solubilization characteristics while meeting other formulation criteria, such as targeted drug concentration, drug stability, bioavailability, safety, and others, is challenging.

However, these systems have numerous shortcomings, such as low efficiency (e.g., low bioavailability of drug), heterogeneity, and instability of the delivery systems themselves.

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