Development of a skin cream designed to reduce dry and flaky skin

Synopsis--Dry and flaky SKIN can result from a low extensibility in the STRATUM CORNEUM. Because the EXTENSIBILITY of corneum depends upon its water content, HUMECTANTS are often added to skin products to increase the corneum water content. Measurements of extensibility and water holding capacity in isolated animal comeurn showed that conventional humectants such as glycerol, sorbitol or sodium lactate can be effective but that the effect is lost on rinsing the comeurn in water. It was found that isolated animal comeum adsorbed LACTIC ACID and that the resulting increase in extensibility was retained after rinsing in water. In consumer tests, hand skin dryness and flaking was assessed by trained observers. Two weeks' use of HAND LOTIONS, containing SODIUM LACTATE or lactic acid adjusted to pH 4, resulted in less hand skin dryness and flaking than the use of control lotions. A lactic acid lotion also resulted in less dryness and flaking than a sodium lactate lotion.