CLINICAL PHARMACOLOGY
It is generally accepted that the water content of the stratum corneum is a controlling factor in maintaining skin flexibility. When the stratum corneum contains more than 10% water it remains soft and pliable; however, when the water content drops below 10% the stratum corneum becomes less flexible and rough, and may exhibit scaling and cracking and the underlying skin may become irritated.1,2
Symptomatic relief of dry skin is provided by skin protectants containing hygroscopic substances (humectants) which increase skin moisture. Lactic acid, an α-hydroxy acid, is reported to be one of the most effective naturally occurring humectants in the skin.3 The α-hydroxy acids (and their salts), in addition to having beneficial effects on dry skin, have also been shown to reduce excessive epidermal keratinization in patients with hyperkeratotic conditions (e.g.,ichthyosis).4
Pharmacokinetics
The mechanism of action of topically applied neutralized lactic acid is not yet known.
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