Special ingredients may be added to basic moisturizer formulations to create “targeted moisturizer products” (1-3). Alpha-hydroxy acids, such as glycolic acid and lactic acid, have been added to many formulations to create exfoliant moisturizers, often marketed as anti-aging preparations (2,3,5). In order to reduce associated irritation, reduction in concentration or use of neutralizing additives (buffering) is common. However, as clinical efficacy correlates with availability of free acid, neutralization to a pH >4.8 results in loss of efficacy (2,3,5). Retinol (vitamin A) and retinyl palmitate are added to some anti-aging moisturizer preparations to improve photodamage by decreasing fine wrinkling and tactile roughness. Both are inactive “precursor retinoids,” requiring enzymatic conversions to produce retinoic acid from retinol; it is believed that the extent of retinol conversion to retinoic acid in skin is limited (2,3,5). Niacinamide (nicotinamide) is stable and compatible in moisturizer preparations due to its high water solubility, appears to produce an exfoliant effect, and may have anti-aging characteristics (5). The role of niacinamide in prevention of photocarcinogenesis and promotion of antineoplastic changes in keratinocytes in murine skin models is of considerable interest and is currently a focus of additional research (5,27,28). The addition of effective sunblock or sunscreen agents to moisturizer formulations is significant as photoprotection is important in the maintainance of epidermal integrity, dermal infrastructure and support, avoidance of small vessel damage and formation of telangiectasia, prevention of photocarcinogenesis, and reduction in pigmentation irregularities. Combination moisturizer-sunscreen formulations may
enhance compliance as both are applied together, usually early in the day, in a “one step” process.