^"DailyMed: View Drug Label: Lac-Hydrin (ammonium lactate) Lotion". Lac-Hydrin specially formulates 12% lactic acid, neutralized with ammonium hydroxide, as ammonium lactate to provide a lotion pH of 4.4-5.5. … Lactic acid is an alpha-hydroxy acid. It is a normal constituent of tissues and blood. The alpha-hydroxy acids (and their salts) may act as humectants when applied to the skin.