Liniment is a solution or mixture of various substances in oil, alcoholic solution of soap or emulsion intended for external application. They should comply with the labeling requirements of liquid dosage forms. They are applied to the unbroken skin with rubbing or massaged directly on the affected area as counterirritating or stimulating agents. Liniments have substances such as analgesics, antimicrobials, rubefacients, counterirritants, stimulants and soothing agents. Alcohol is primarily used as the solvent in liniments. It enhances the penetration of the medicaments into the skin and has counterirritant or rubefacient action. Counterirritants are used to mask pain from fibrositis, neuralgia and similar complaints by producing warmth, tingling and numbness. When rubbed onto the skin, they cause redness and hence are called as rubefacients. Cottonseed oil and arachis oil are less irritating to the skin than alcohol and spread more easily on the skin.

Example

Camphor liniment

 

	Camphor	20 g
	Arachis oil	80 g

 

Camphor is freely soluble in arachis oil. Camphor is dissolved in arachis oil in a closed vessel and mixed well. The resulting solution is packed in a suitable container.

 

Table 6.4 Examples of Marketed Products