Page 235 - Cosmetology

methylpropanediol. A glycol that functions as a solvent. Methylpropanediol can enhance the penetration of
ingredients (such as salicylic acid) into the skin.

methylrosaniline chloride. See gentian violet extract.

methylsilanol mannuronate. See silicone.

methylsilanol PEG-7 glyceryl cocoate. Used as an emollient and thickening agent in cosmetics. See
glyceryl ester and silicone.

methylsufonylsulfate. See antioxidant.

methylsulfonylmethane. Also known as MSM. There is no published research to back up claims made
regarding any benefit this sulfur compound may have for arthritis or other physical ailments. There is no
research about its effect when applied topically. Sulfur is stored in every cell of the body, particularly in the
hair, nails, and connective tissue of joints and skin, where it is an important structural protein component. An
MSM manufacturer has sponsored two very small trials, but the results have not been published. Until
additional research is published, MSM enthusiasm should be tempered. MSM is available in capsules and
powder for oral intake or in creams for topical use. So far, there have been no reports of toxicity.

Mexoryl SX. Also called ecamsule, it is a synthetic sunscreen agent developed and patented by L’Oreal.
The technical name for Mexoryl SX is terephthalylidine dicamphor sulfonic acid. It has been used in the
company’s sunscreen products sold outside of the United States since 1993, and was first approved for use
in Europe in 1991. In July 2006 the FDA approved the use of Mexoryl SX in the U.S. in a single sunscreen
product, La Roche-Posay’s Anthelios SX SPF 15 (L’Oreal owns La Roche-Posay). The FDA did not approve
Mexoryl SX for use in any other sunscreen; only this one specific product. Anthelios SX will list Mexoryl SX
as ecamsule on the label along with other actives of avobenzone and octocrylene (both of those sunscreen
ingredients have been approved for use in the U.S. for years).

L’Oreal has been blitzing the media with press releases about this approval, most touting Mexoryl’s
improved stability compared to avobenzone or intimating that it is the best UVA sunscreen available.
According to sunscreen expert Ken Klein, president of Cosmetech Labs, who also teaches sunscreen
formulation classes for the Society of Cosmetic Chemists, although Mexoryl SX does not degrade after
hours of sun exposure at the same rate as avobenzone, it does indeed break down, losing 40% of its
protective properties. Studies have shown that after controlled doses of UV exposure, avobenzone breaks
down at a rate of 65%, so Mexoryl SX does have a slight stability edge. However, avobenzone can be made
more stable when combined with other active ingredients, specifically octocrylene. Outside of the U.S.,
Tinosorb is often used to enhance the stability of avobenzone. It is also important to note that all sunscreen
ingredients break down to some extent after sunlight exposure, which is why reapplication of sunscreen is
critical to maintaining protection. Interestingly, the press releases touting Mexoryl’s superiority as a UVA-
protecting sunscreen ingredient don’t mention titanium dioxide and zinc oxide, which have long been
available worldwide in sunscreen formulations and offer an even greater range of protection with almost no
possible risk of irritation, a pervasive problem for synthetic sunscreen agents such as Mexoryl SX. In terms
of protection, UVA rays have a range of 320—400 nanometers. Although Mexory protects within this range
titanium dioxide and zinc oxide protect the entire UVA and UVB spectrum from 230 to 700 nanometers.
Mexoryl SX is an effective UVA sunscreen agent to consider but not the only one to look for.

mica. Earth mineral used to give products sparkle and shine.

micrococcus lysate. Earth mineral used to give products sparkle and shine.Enzyme derived from bacteria.
It can break down foods and is present in the human body. It has no known benefit in skin care.

microcrystalline wax. A plastic-type, highly refined wax derived from petroleum. Used as a thickener and to
give products a semi-solid to solid smooth texture.

Microcystis aeruginosa. Latin name for spirulina. See algae.

milk protein. See protein.

milk vetch root. There is a good deal of research showing this root to have antioxidant properties, but there
is little evidence it has that function when applied topically.