Quimica Farmaceutica

Cosmetic Pharmaceuticals in Dermatology
Katherine D. O'Rourke, MD

The last several years have shown an astronomic growth in the cosmetic pharmaceutical industry. This growth is in response to aging baby boomers and improvements in the technology used in topical therapy delivery. A plethora of products is now available making claims regarding antiaging capabilities. These products includethose containing ingredients such as alpha- and beta-hydroxy acids, retinoids, and topical antioxidants. Research on these products still remains somewhat limited, and large, placebo-controlled, randomized studies have yet to be done. However, many peer-reviewed articles have been published, suggesting penetration of these products resulting in changes of the epidermis and dermis. Another pertinentissue looming overhead includes US Food and Drug Administration regulation of these products. Cosmetics are not required to comply with the same regulations imposed on drugs, hence the immense number of new products annually. This contrasts them with drugs, which would require extensive premarketing research to prove their efficacy and safety. The Food and Drug Administration continues to pursuethis issue, actively debating their classification. Many products are available that fall under this umbrella, and their therapeutic indications will be discussed in detail. A newer topical scar preparation is available to improve the cosmetic appearance and texture of scars. This product contains Allium cepa, an onion extract, and is an alternative to silicone sheeting and hydrocolloid dressings.This product will also be addressed.

Alpha-Hydroxy Acids
Many products are available over the counter at neighborhood pharmacies and through dispensing physicians. Unfortunately, because these products are not regulated on a federal level, there is no standardization between products. The bioavallability on the individual products depends on the free acid available, and the vast majority ofcompanies do not report this in product labehng. The claims by the manufacturers of these products to reduce signs of aging and to lessen fine lines and wrinkles has greatly enticed the public. The products dispensed by physicians are often stronger in concentration and are
Curr Probl Dermatol, November/December 2000

frequently used in association with other available prescription products.Physicians may use this as a pretreatment regimen before use of surgical modalities such as chemical peeling and laser resurfacing. The introduction of these products in 1974 by Van Scott and Yu 1 showed improvement in patients with ichthyosis who used alpha-hydroxy acids (AHAs). Since then, the AHAs have been shown to have effects on both the epidermis and the dermal matrix. Epidermal effects includesdesquamation, which is thought to be due to a diminished cellular cohesion between keratinocytes. This exfoliative effect has been useful to dermatologists who combine products such as glycolic acid with other topical modalities such as retinoids and hydroquinones for treating hyperpigmentary disorders and photoaging. The desquamation allows for penetration of these other topicals, which resultsin enhanced efficacy and augmented effect. The dermal effects include increased synthesis of collagen, glycosaminoglycans, and possibly elastic fibers. A recent study by Kim et al2 showed an increased production of collagen and fibroblast proliferation in both in vivo and in vitro systems, which may account for the reversal of photoaging. Glycolic acid, perhaps the best-known AHA, has many uses indermatology. Because of its role in decreasing keratinocytes cohesion, it has been claimed to be a useful adjuvant for the treatment of acne. Glycolic acid in combination with topical retinoids may be synergistic in combating comedonal acne. Pigmentary disorders such as melasma, postinflammatory hyperpigmentation, and mottled dyschromia from photodamage can all be addressed with the use of...