A lotion is a low- to medium-viscosity medicated or non-medicated topical preparation, intended for application to unbroken skin. Lotions are usually applied to external skin with bare hands, a clean cloth, cotton wool, or gauze. Solid particles incorporated in lotions should be in a finely divided state to avoid grittiness. Most lotions are o/w emulsions, but w/o lotions are also formulated.
The key components of a lotion are the aqueous and oily phases, an emulsifying agent 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, and stabilizing agents are commonly added to lotions for improved organoleptic and preservation characteristics.
Lotions can be used for the topical delivery of medications such as antibiotics, antiseptics, antifungals, corticosteroids, antiacne agents, and soothing/protective agents (such as calamine). Aside from medical use and skin care, lotions are often used as accessories to aid massage, masturbation, or sex. Noncomedogenic lotions, products that do not block the natural pores of the skin, are recommended for use on pimples or acne-prone skin.
These lotions are also termed as non-occlusive. Thus, they may reduce acne and/or reduce the incidence of pimples. The same drug substance can 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; whereas a lotion is less viscous and may be readily applied to these areas. Many medicated shampoos are, in fact, lotions. Lotions also have an advantage that they may be spread thinly compared to a cream or ointment and may economically cover a larger area of skin.