Liniment

Liniment (from Latin: linere, meaning "to smear, anoint"), also called embrocation and heat rub, is a medicated topical preparation for application to the skin. Some liniments have a viscosity similar to that of water; others are lotion or balm; still others are in transdermal patches, soft solid sticks, and sprays. Liniment usually is rubbed into the skin, which the active ingredients penetrate. Liniments are typically sold to relieve pain and stiffness, such as from muscular aches and strains, and arthritis. These are typically formulated from alcohol, acetone, or similar quickly evaporating solvents and contain counterirritant aromatic chemical compounds, such as methyl salicylate, benzoin resin, menthol, and capsaicin. They produce a feeling of warmth within the muscle of the area they are applied to, typically acting as rubefacients via a counterirritant effect. Methyl salicylate, which is the analgesic ingredient in some heat rubs, can be toxic if used in excess. Heating pads are also not recommended for use with heat rubs, because the added warmth may cause overabsorption of the active ingredients.