Clinical Efficacy and Safety of a Multimodality Skin Brightener Composition Compared With 4% Hydroquinone
March 2013 | Volume 12 | Issue 3 | Supplement Individual Articles | 21 | Copyright © March 2013
Elizabeth T. Makino BS CCRA MBA,a James H. Herndon Jr. MD,b Monya L. Sigler PhD,b Vincent Gotz MS MBA,c John Garruto BS,a and Rahul C. Mehta PhDa
aSkinMedica, an Allergan Company, Carlsbad, CA bThomas J. Stephens & Associates, Inc, Carrollton, TX cProPharmaCon, LLC, Carlsbad, CA
There are numerous common skin disorders involving hyperpigmentation, including solar lentigines, postinflammatory hyperpigmentation, melasma, freckles, and dyschromia from photoaging. While these conditions are of an aesthetic nature, there is great interest in newer, safer, and more effective treatment modalities. Topical hydroquinone (HQ) has been the gold standard of skin lighteners for many years. However, regulatory authorities around the world are now questioning its safety. A randomized, double-blind, half-face study was conducted in females with moderate to severe facial hyperpigmentation to assess the efficacy and tolerability of 3 new skin brightener formulations containing SMA-432, a prostaglandin E2 inhibitor, compared with 4% HQ. Each subject was assigned 2 of the 4 test materials and was instructed to apply the product on the assigned side of the face twice daily for 12 weeks. Evaluation visits were conducted at baseline and at 4, 8, and 12 weeks. At each visit, subjects were evaluated by a blinded investigator for clinical efficacy and tolerability using grading scales. Standardized digital photography and Chroma Meter assessments were also taken. Self-assessment questionnaires were completed at weeks 4, 8, and 12. Sixty-eight Caucasian subjects (136 half faces) completed the study. All test materials significantly reduced Overall Hyperpigmentation and improved the Investigator's Global Hyperpigmentation Improvement rating at weeks 4, 8, and 12 compared with baseline. SMA-432 exhibited a dose-dependent improvement in hyperpigmentation. There were no major tolerability issues with any of the test materials. Self-assessments were generally favorable for all test materials. At the completion of the trial, subjects rated one of the tested multimodality brightener compositions as the most favorable product and 4% HQ as the least favorable. This study demonstrated that the new non-HQ-containing skin brightener formulations were as effective and equally well tolerated as the gold standard, 4% HQ, in females with facial hyperpigmentation.
J Drugs Dermatol.
2013;12(3 suppl 1):s21-s26.
The amount and type of melanin pigments, which are polymers produced inside the melanosomes, determine skin color.1,2 While there is tremendous diversity worldwide in the color of human skin, uniform or even skin color (particularly across the face) in an individual is considered a sign of health, attractiveness, and youthfulness and, as such, is aesthetically desirable.3,4 Skin issues involving hyperpigmentation typically arise because of injury and/or advancing age. Exposure to sunlight is the most common cause of hyperpigmentation and is likely a postinflammatory response to ultraviolet (UV) damage to the skin.5,6 Inflammation may lead to hyperpigmentation via several mechanisms, including direct stimulation of melanocytes by inflammatory mediators and reactive oxygen species (ROS) and release of endocrine inducers of pigmentation such as α-melanocyte-stimulating hormone.6 The resulting melanin production provides protection against future insult, as melanin has both UV-absorption and ROS-scavenging activities.7
Altered production of cutaneous melanin causes problems of an aesthetic nature. Such disorders of hyperpigmentation, including melasma, postinflammatory hyperpigmentation, solar lentigines, freckles, and dyschromia from photoaging, are very common in humans, and there is a broad interest in newer, more effective treatment modalities. Traditionally, the gold standard topical agent for skin lightening was hydroquinone (HQ) 4%, until regulatory agencies around the world began questioning its safety.8,9 Adverse effects, including skin irritation, contact dermatitis, and exogenous ochronosis may occur with use of this compound. The US Food and Drug Administration has initiated studies to better understand the long-term safety of topical HQ and has not made a determination on its safety10; however, many user interest groups have taken the position that products containing HQ should not be used because of potential safety concerns. As a result, there exists a large and growing market for alternative products that effectively lighten the skin.