MAY 2015 • Vol. 21 No. 5
New York Society of Cosmetic Chemists
www.nyscc.org
Applications of Maleic Anhydride Chemistry in Skin Care, Biomedical Devices, and Transdermal Delivery Part III
‌ by Roger L. McMullen
I
n the first two articles of this series we discussed several applications of maleic anhydride chemistry to phenomenon occurring in skin. Numerous examples of the use of maleic anhydride and its derivatives can be found in patent publications and the literature. Polymers of maleic anhydride are especially well known for their bioadhesive properties, and are used extensively in the biomedical industry. Somewhat related, the same types of polymers found their way into personal care adhesive strips designed to remove unwanted keratotic debris. In a much different application, maleic anhydride derivatives made headway into antiperspirant formulations where they help to reduce the concentration of aluminum salts. Transdermal drug delivery is another explosive area where hydrogels made of maleic anhydride polymers act as key ingredients of the delivery formulation. In this third and last article of this series, we touch upon some of the other applications of maleic anhydride and its derivatives in skin care. In the first section, we focus on the chemical modification of maleic anhydride with skin care active ingredients, which are delivered to the skin surface, made possible by a biological binding mechanism of the maleic anhydride portion of the molecule with the skin, followed by subsequent release of the active. Throughout the remainder of the article, further emphasis is placed on the use of maleic anhydride derivatives in various skin care formulations as skin care emollients, adjuvants in skin cleansing formulations, soap bar stability agents, antioxidant stabilizers, auxiliary agents for alpha hydroxy acids, sunscreen formulating agents, rheology modifiers, and skin tightening agents.
1. Delivery of active ingredients
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here are many compounds in the cosmetic industry that are used to improve the health state of skin. These active ingredients typically have some biological activity and can modulate important processes in the skin. Examples of such ingredients include antioxidants, biologically active peptides, and sunless tanning agents. Other active ingredients such as sunscreens, anti-acne agents (e.g., retinol), antiperspirant actives, whitening agents, and dandruff products are regulated by the FDA and are considered OTC drugs. The delivery of these molecules to skin is paramount to their ability to be functional. Often times this includes choosing the correct formulation vehicle, and sometimes can even mean encapsulating products in a variety of vesicles for effective delivery. The lack of affinity to the skin can (Continued on page 6)
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