*Lac-Hydrin is a formulation of 12% lactic acid neutralized with ammonium hydroxide, as ammonium lactate, with a pH of 4.4-5.4.Lac-Hydrin Cream also contains water, light mineral oil, glyceryl stearate, polyoxyl 100 stearate, propylene glycol, polyoxyl 40 stearate, glycerin, cetyl alcohol, magnesium aluminum silicate, laureth-4, methyl and propyl parabens, and methylcellulose. Lactic acid is a racemic mixture of 2-hydroxypropanoic acid and has the following structural formula:
Lactic acid is an alpha-hydroxy acid. It is a normal constituent of tissues and blood. The alpha-hydroxy acids (and their salts) are felt to act as humectants when applied to the skin. This property may influence hydration of the stratum corneum. In addition, lactic acid, when applied to the skin, may act to decrease corneocyte cohesion. The mechanism(s) by which this is accomplished is not yet known.
An in vitro study of percutaneous absorption of Lac-Hydrin Cream using human cadaver skin indicates that approximately 6.1% of the material was absorbed after 68 hours.
Lac-Hydrin Cream is indicated for the treatment of ichthyosis vulgaris and xerosis.
Use of this product should be discontinued if hypersensitivity to any of the ingredients is noted. Sun exposure (natural or artificial sunlight) to areas of the skin treated with Lac-Hydrin Cream should be minimized or avoided (see Precautions section).
General: For external use only. Stinging or burning may occur when applied to skin with fissures, erosions, or that is otherwise abraded (for example, after shaving the legs). Caution is advised when used on the face because of the potential for irritation. The potential for post-inflammatory hypo- or hyperpigmentation has not been studied.
Information for patients: Patients using Lac-Hydrin Cream should receive the following information and instructions:
Carcinogenesis, Mutagenesis, Impairment of Fertility: Carcinogenesis: A long-term photocarcinogenicity study in hairless albino mice suggested that topically applied 12% ammonium lactate cream enhanced the rate of ultraviolet light-induced skin tumor formation. Although the biologic significance of these results to humans is not clear, patients should minimize or avoid use of this product on areas of the skin that may be exposed to natural or artificial sunlight, including the face. Long-term dermal carcinogenicity studies in animals have not been conducted to evaluate the carcinogenic potential of ammonium lactate.
Pregnancy: Teratogenic effects: Pregnancy Category C. Animal reproduction studies have not been conducted with Lac-Hydrin Cream. It is also not known whether Lac-Hydrin Cream can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Lac-Hydrin Cream should be given to a pregnant woman only if clearly needed.
Nursing Mothers: Although lactic acid is a normal constituent of blood and tissues, it is not known to what extent this drug affects normal lactic acid levels in human milk. Because many drugs are excreted in human milk, caution should be exercised when Lac-Hydrin Cream is administered to a nursing woman.
Pediatric Use: The safety and effectiveness of Lac-Hydrin Cream have not been established in pediatric patients less than 12 years old. Potential systemic toxicity from percutaneous absorption has not been studied. Because of the increased surface area to body weight ratio in pediatric patients, the systemic burden of lactic acid may be increased.
In controlled clinical trials of patients with ichthyosis vulgaris, the most frequent adverse reactions in patients treated with Lac-Hydrin Cream were rash (including erythema and irritation) and burning/stinging. Each was reported in approximately 10-15% of patients. In addition, itching was reported in approximately 5% of patients.
In controlled clinical trials of patients with xerosis, the most frequent adverse reactions in patients treated with Lac-Hydrin Cream were transient burning, in about 3% of patients, stinging, dry skin and rash, each reported in approximately 2% of patients.
Apply to the affected areas and rub in thoroughly. Use twice daily or as directed by a physician.
Lac-Hydrin Cream is available in cartons of 280 g (2-140 g plastic tubes). Store at controlled room temperature, 15-30°C (59-86°F).
©1994 WESTWOOD-SQUIBB PHARMACEUTICALS INC.
Princeton, NJ, USA 08543 03-2954-0
A Bristol-Myers Squibb Company Revised August 1999