Levigation is a process used to reduce the particle size of solids by grinding them with a small amount of liquid, called a levigating agent. The levigating agent acts as a lubricant to make incorporating solids into mixtures easier. The process involves triturating powders using a mortar and pestle or edge runner mill along with a levigating agent. This results in a smooth paste with uniform fine particles. Levigation is used to prepare ointments, suspensions, emulsions and other pharmaceutical formulations.

3. LEVIGATION
Compiled by:-
Dr. Hafiz Rahat Riaz Rana(917)
Dr. M Husnain(871)
Dr. M Ahmad(883)
Supervised by:-
Dr.Khizar Hayat

4. CONTENTS
 Definition
 Levigating agent
 Process
 Method
 Purpose
 Advantage
 Application

5. DEFINATION
The formation of paste by adding the larger amount of water, by
reducing the size of particles into fine size, which is to be obtained or
desired.
Or
Powders, levigation is the process of reducing particle size of a solid
by triturating it in a mortar or spatulating it on an ointment slab or pad
with a small amount of a liquid or melted base in which the solid is not
soluble.

6. LEVIGATING AGENTS
The liquid, called a levigating agent, is somewhat viscous
and has a low surface tension to improve ease of wetting the
solid.
Levigating agents act as lubricating agents. They make
incorporating solids easier, and they usually give smoother
preparations.

8. LEVIGATING AGENTS
A levigating agent is generally not added when
• The solid being incorporated has very fine particles.
• The quantity of solid to incorporate is small.
• The ointment base is soft.
• The final preparation is intended to be a stiff paste.

9. PROCESS
• Triturate the powder or solid by using PESTLE AND MORTAR and EDGE
RUNNER MILL.
• Now ,add the levigating agent or liquid as lubricating agent.
• Mix the above compound thoroughly.
• Till particle size become uniform and it appear like a paste.
• In case of preparation of emulsions, this paste gives the sound of ”click” and
creamy white color.

11. METHODS
• On small scale we use mortar and pestle.
• On large scale we use series of tanks called edge
runner mill

12. SMALL SCALE
The paste is formed by the addition of non-solvent like
glycerin or mineral oil to solid substance. size
reduction takes place in mortar or pestle.

13. PESTLE AND MORTAR

14. LARGE SCALE
• Material which is used into the tank is suspended in liquid
and flow like a turbid liquid.
• The turbid liquid is allowed to flow from series of tank and
allowed to stand for some time and the heaviest particles
are precipitated down and light fine particles remain
suspended into the liquid.
• In the tank particles settle according to size and weight.

15. EDGE RUNNER MILL

16. PURPOSE
We use this process to get fine powder or particles. By
using this method we get smooth paste by grinding
the solid with water.

17. ADVANTAGE
• Preparation of terra-segilate in water allow larger particles
to settle down and fine particles remain suspended.
• Purification of drugs.
• Get various degree of fine powder.

18. APPLICATION
• This process is used for the incorporation of solid into ophthalmic
and dermatological suspensions and ointments.
• We use this process to get fine and uniform particles.
• This process is used to prepare emulsions, suspension, ointments
and other pastes.
• This process is used to prepare creams and lotions.
• This is used in many pharmaceutical balms.

21. REFERENCE
• A Practical Guide to Contemporary Pharmacy Practice by Judith E.
Thompson and Lawrence W. Davidow 3rd edition published by Wolters
Kluwer
• Ansel’s Pharmaceutical Dosage Forms and Drug Delivery Systems(NINTH
EDITION)
• Comprehensive physical pharmacy by M.Masood
• http://pharmlabs.unc.edu/labs/powders/properties.htm
• http://jeepakistan.blogspot.com/2011/04/levigation.html