levigation

Question 1

intro

Answer 1

 The process of particle size reduction by first forming a paste of solid by adding the minimum amount
of suitable non-solvent (levigating agent) and then triturating the paste in the mortar or on the slab by
using the pestle or spatula.
 Levigation is commonly used in small scale preparation of ointments to reduce the particle size and
grittiness of the added powders.
 A mortar and pestle or an ointment tile is used for this purpose.
 A paste is formed by combining the powder and a small amount of liquid (the levigating agent) in
which the powder is insoluble
 The paste is then triturated in the mortar by the pestle or on the ointment tile by a spatula to reduce the
particle size.
 The levigated paste is then added to the ointment base and the mixture is made uniform and smooth
by rubbing it together with a spatula on the ointment tile.
 The most common levigating agents are mineral oil, water, alcohol and glycerin.
 The process of levigation is also known as wet grinding and is used to reduce the particle size of a
substance to finer state of subdivision
 This process is often used to incorporate solid substances into dermatological and ophthalmic
ointments and suspensions.

Question 2

application

Answer 2

 Size reduction
 Preparation of ointments and pastes.
 Commonly used levigating agents are mineral oil and glycerin.
 This process is used in making suspensions.