Ammonium lactate is a formulation of lactic acid neutralized with ammonium hydroxide (i.e., Lac-Hydrin). It is indicated for the treatment of mild to severe xerosis (dry skin) and ichthyosis vulgaris (hyperkeratotic disorder) and for temporary relief of itching associated with these conditions. The formulation is available as a cream or lotion either by prescription or over-the-counter (OTC). The lotion formulation of Lac-Hydrin 12% was approved by the FDA in April 1985 and Lac-Hydrin 12% cream was later approved in August 1996. Generic versions of 12% ammonium lactate cream and lotion are available. However, generic versions (i.e., Amlactin) are classified as a cosmetic and have not been shown to be bioequivalent or therapeutically equivalent to Lac-Hydrin. Therefore, Amlactin 12% is not an FDA-approved generic substitute for Lac-Hydrin 12%.
General Administration Information
For storage information, see the specific product information within the How Supplied section.
Route-Specific Administration
Topical Administration
Cream/Ointment/Lotion Formulations
-Ammonium lactate cream or lotion is applied topically to the skin (for external use only). Before applying the cream or lotion, the affected areas should be clean and dry.
-Wash hands before and after application of the cream or the lotion.
-Do not apply the cream or lotion to the eye; avoid contact with the eyes, mouth, lips, and other mucous membranes.
-Cream: To apply the cream, massage gently and thoroughly into the affected skin areas.
-Lotion: Shake well before application to the skin. To apply the lotion, massage gently and thoroughly into the affected skin areas.
Common adverse reactions associated with ammonium lactate topical cream or lotion are generally mild and include transient burning or stinging, pruritus, and rash including erythema and skin irritation at the application site. In patients treated with Lac-Hydrin 12% cream or lotion for ichthyosis, the following dermatological reactions are generally higher than for patients treated for xerosis: rash including erythema and skin irritation (10 to 15%), burning/stinging (10 to 15%), and pruritus (5%). In patients treated with Lac-Hydrin 12% cream or lotion for xerosis, the approximate incidence of adverse effects were: transient burning (3%), stinging (2 to 3%), dry skin (xerosis) (2%), and rash or erythema (2%). Less common adverse effects reported with Lac-Hydrin 12% lotion include exfoliative dermatitis (skin peeling in 1 of 60 patients), irritation, eczema, petechiae, dryness, and skin hyperpigmentation.
Ammonium lactate is for external use only. Contact with eyes, lips, or mucous membranes should be avoided. Ammonium lactate may cause irritation when applied to the face, especially in patients with fair or sensitive skin. A mild, transient stinging may occur when ammonium lactate is applied to a skin abrasion or inflamed areas. Patients should be cautioned to avoid artificial or natural sunlight to treated areas of skin, including the face, which may be more sensitive to the effects of sunlight (UV) exposure.
The safety and efficacy of ammonium lactate have not been established in neonates, infants, or children less than 2 years old. Potential systemic toxicity from percutaneous absorption of lactic acid has not been studied, but may be a potential concern because of the increased surface area to body weight ratio in young children.
Ammonium lactate is classified as FDA pregnancy category B. There are no adequate and well-controlled studies in pregnant women. According to the manufacturer, it should be used during pregnancy only if clearly needed.
Although lactic acid is a normal constituent of blood and tissues, it is not known to what extent ammonium lactate affects normal lactic acid levels in human milk. According to the manufacturer, caution should be exercised when the cream or lotion is administered to breast-feeding women. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally ingested drug, healthcare providers are encouraged to report the adverse effect to the FDA.
For the treatment of ichthyosis vulgaris:
Topical dosage (12% lotion or cream):
Adults: Apply twice daily to the affected skin areas and rub in thoroughly. Clinical improvement may not be evident for several weeks. If the skin condition worsens with treatment, the medication should be discontinued promptly.
Children and Adolescent 2 to 17 years: Apply twice daily to the affected skin areas and rub in thoroughly. Clinical improvement may not be evident for several weeks. If the skin condition worsens with treatment, the medication should be discontinued promptly.
For the treatment of xerosis:
Topical dosage:
Adults: Apply twice daily to the affected skin areas and rub in thoroughly. Clinical improvement may not be evident for several weeks. If the skin condition worsens with treatment, the medication should be discontinued promptly.
Children and Adolescents 2 to 17 years: Apply twice daily to the affected skin areas and rub in thoroughly. Clinical improvement may not be evident for several weeks. If the skin condition worsens with treatment, the medication should be discontinued promptly.
Maximum Dosage Limits:
-Adults
No maximum dosage information available.
-Geriatric
No maximum dosage information available.
-Adolescents
No maximum dosage information available.
-Children
Children 2 and older: No maximum dosage information available.
Children under 2 years old: Safety and efficacy have not been established.
-Infants
Safety and efficacy have not been established.
-Neonates
Safety and efficacy have not been established.
Patients with Hepatic Impairment Dosing
No dosage adjustment is needed.
Patients with Renal Impairment Dosing
No dosage adjustment is needed.
*non-FDA-approved indication
There are no drug interactions associated with Ammonium Lactate products.
Lactic acid is an alpha-hydroxy acid that acts as a keratin-softening agent by increasing the hydration of human skin and reducing epidermal keratinization. Lactic acid is reported to be one of the most effective naturally occurring humectants in the skin. Glycerin and propylene glycol are also humectants. Humectants draw water into the stratum corneum to hydrate the epidermis, while emollients retain water that is already present. Mineral oil and petrolatum are emollients; they act as occlusive agents and moisturizers, helping to relieve pruritus and other symptoms of dry skin. Urea is a mild keratolytic. Urea also increases water uptake in the stratum corneum and has a direct effect on the stratum corneum elasticity by binding to epidermal protein. Cetyl alcohol acts as an emulsion stabilizer and thickening agent.
Ammonium lactate is applied topically to the skin.
Affected cytochrome P450 isoenzymes: none
-Route-Specific Pharmacokinetics
Topical Route
Absorption of Lac-Hydrin 12% cream into human cadaver skin was approximately 6.1% of the topically applied dose after 68 hours.