Larry Richard Robinson

Reduction in the appearance of facial hyperpigmentation by topical N-acetyl glucosamine.

Glucosamine has been reported to inhibit melanin production in melanocyte culture. It thus has a potential to reduce hyperpigmentation via topical use. Due to stability limitations of glucosamine, we chose to clinically evaluate the stable derivative N‐acetyl glucosamine (NAG). Based on in vitro Franz cell testing, NAG is a good skin penetrant. In an 8‐week, double‐blind, placebo‐controlled, left‐right randomized, split‐face clinical test, topical 2% NAG reduced the appearance of facial hyperpigmentation. In a second clinical study involving the topical combination of 2% NAG with 4% niacinamide, an agent previously shown to be clinically active, the effect on hyperpigmentation was greater. Both of these agents are well tolerated by the skin. This high tolerance coupled with relative ease of formulation and stability in solution make NAG, especially in combination with niacinamide, a suitable cosmetic ingredient for use in skin care products dealing with issues of skin hyperpigmentation.

Reduction in the appearance of facial hyperpigmentation after use of moisturizers with a combination of topical niacinamide and N‐acetyl glucosamine: results of a randomized, double‐blind, vehicle‐controlled trial

Background  Topical niacinamide and N‐acetyl glucosamine (NAG) each individually inhibit epidermal pigmentation in cell culture. In small clinical studies, niacinamide‐containing and NAG‐containing formulations reduced the appearance of hyperpigmentation.

Reduction in the appearance of facial hyperpigmentation by topical N-undecyl-10-enoyl-l-phenylalanine and its combination with niacinamide

Objectives  N‐undecyl‐10‐enoyl‐l‐phenylalanine (Sepiwhite®, N‐undecylenoyl phenylalanine), a reported alpha‐melanocyte‐stimulating hormone (MSH) receptor antagonist, has been observed to reduce melanin production in cultured melanocytes. In other testing, niacinamide has been found to inhibit melanosome transfer in cultured cells and to reduce the appearance of hyperpigmented spots in clinical studies. Since these two agents function by different mechanisms, we conducted two studies to determine if their combination is more effective than niacinamide alone in reducing facial hyperpigmentation.