Compositions and methods for improved skin care

Abstract

Compositions and methods for administering collagen to a human subject have been developed. The collagen-containing lipid vesicles of the invention provide a delivery system for human collagen which eliminates problems associated with chemical and physical instability of the collagen as well as immune responses to non-human collagen.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S) [0001] This application claims the benefit of provisional patent applications Ser. No. 60 / 723,043, filed Oct. 3, 2005; and Ser. No. 60 / 833,045, filed Jul. 25, 2006, which are hereby incorporated by reference in its entirety, including any figures, tables, or drawings.BACKGROUND OF THE INVENTION [0002] The skin is the largest organ in the human body and consists essentially of two primary layers—the epidermis and the dermis. The epidermis is the outermost layer and, among other things, controls water loss from cells and tissue. The dermis is the layer below the epidermis and contains blood vessels, lymph vessels, hair follicles and sweat glands. Below the dermis is the hypodermis. Although the hypodermis is considered to be part of the integumentary system, it is not generally considered to be a layer of the skin. The hypodermis is used mainly for fat storage. [0003] The outermost epidermis is made up of stratified squamous epithelium with an...

AI Technical Summary

Benefits of technology

[0034] In one embodiment, the present invention provides a skin care composition with cross-linked hyaluronic acid that further comprises a safe and effective amount of collagen, wherein the formulation facilitates the active ingredients passing through the epidermis and thus being released within the dermis of the skin. In a further embodiment, the human collagen and / or crosslinked HA may be delivered to the epidermis as well. Accordingly, the present invention is useful in regulating and / or improving the condition of the skin (including the appearance and / or feel of the skin) by efficiently delivering hyaluronic acid and / or collagen to the appropriate location within the skin.

[0035] In addition, the use of human collagen (e.g., recombinant human collagen or human collagen isolated from human tissue or cultured human fibroblasts), or a fragment thereof, is advantageous for avoiding undesired side effects such as allergic or autoimmune reactions. Advantageously, hyaluronic acid does not present a significant risk of an allergic reaction.

Problems solved by technology

Over time however, due to aging and other external factors, the body's natural supply of hyaluronic acid is slowly absorbed and disappears gradually.

The effectiveness of such administration is limited by the relatively rapid breakdown of this compound caused by enzymes that exist naturally in the body.

These injections are similar to collagen injections and, apart from being non-allergenic, have the same limitations and drawbacks.

With age or injury, the collagen in a person begins to weaken and lose its elasticity.

In the skin, this process eventually results in the appearance of wrinkles.

In young skin, the collagen remains intact and elastic, however, as the skin ages, the support structure weakens, the skin loses elasticity and the collagen support wears down from the cumulative stress of, for example, facial expressions.

This causes lines and wrinkles to appear in the skin.

Procedures involving injecting collagen are not without risk.

For example, bovine collagen injections can cause allergic reactions such as redness, swelling, firmness, itching and, in rare instances, abscess formation.

Also, the injection process itself poses certain challenges.

The locating of the needle tip at the proper depth within the dermis is also difficult for the practitioner.

However, there is no visual reference point, other than the end of the syringe body, from which the practitioner can easily determine the extent that the needle extends into the dermis.

Thus, the needle tip may be placed too deep, or too shallow, for the intended application.

These qualities are not always present in individuals, and this has limited the availability of collagen therapy to patients.

Unfortunately, such topical collagen therapy has proven less than effective as conventional forms of collagen do not appear to penetrate into the dermis.

As noted above, the skin consists of multiple layers and is extremely complex in terms of its function as well as its chemical make-up.

Transdermal (through the skin) application of medicines and other substances poses a wide range of formulation hurdles.

The ability to deliver desired substances to a layer within the skin is equally, if not even more, difficult.

Each of these methods has disadvantages, particularly with respect to the delivery of collagen and / or hyaluronic acid.

However, although phospholipids are suitable for certain pharmaceutical applications, phospholipid liposome technology has been beset by serious problems, for example, phospholipids turn over rapidly in vivo and are unstable in storage.

Also, they are labile and expensive to purify or synthesize, and the manufacture of phospholipid liposomes is difficult and costly to scale up.

Although liposomes are well known in the art, there are no previous reports of their use to efficiently deliver collagen and / or hyaluronic acid in a skin care formulation.