Lotion

A lotion is a low-viscosity topical preparation intended for application to unbroken skin. By contrast, creams and gels have higher viscosity.

Lotions are applied to external skin with bare hands, a brush, a clean cloth, cotton wool, or gauze. While lotion may be used as a medicine delivery system, many lotions, especially hand lotions and body lotions are meant instead to simply smooth, moisturize and soften the skin. These may be used in anti-aging lotions, which can also be classified as a cosmetic in many cases, and may contain fragrances. The Food and Drug Administration voiced concern about lotions not classified as drugs that advertise anti-aging or anti-wrinkle properties.

Dermatologists can prescribe lotions to treat or prevent skin diseases. It is not unusual for the same drug ingredient to be formulated into a lotion, cream and ointment. Creams are the most convenient of the three but are inappropriate for application to regions of hairy skin such as the scalp, while a lotion is less viscous and may be readily applied to these areas (many medicated shampoos are in fact lotions). Historically, lotions also had an advantage in that they may be spread thinly compared to a cream or ointment and may economically cover a large area of skin, but product research has steadily eroded this distinction. Non-comedogenic lotions are recommended for use on acne prone skin.

Lotions can be used for the delivery to the skin of medications such as:

Since health care workers must wash their hands frequently to prevent disease transmission, hospital grade lotion is recommended to prevent skin dermatitis caused by frequent exposure to cleaning agents in the soap. A 2006 study found that application of hospital grade lotion after hand washing significantly reduced skin roughness and dryness.

Care must be taken not to use consumer lotions in a hospital environment, as the perfumes and allergens may be a danger to those who are immunodeficient.

Most lotions are oil-in-water emulsions using a substance such as cetearyl alcohol to keep the emulsion together, but water-in-oil lotions are also formulated. The key components of a skin care lotion, cream or gel emulsion (that is mixtures of oil and water) are the and oily phases, an emulgent to prevent separation of these two phases, and, if used, the drug substance or substances. A wide variety of other ingredients such as fragrances, glycerol, petroleum jelly, dyes, preservatives, proteins and stabilizing agents are commonly added to lotions.

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