Levigation

Levigation

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

2. Contents Definition Levigating agent Process Method Purpose Advantage Application

3. 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.

4. 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.

5. 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.

6. 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.

7. methods On small scale we use mortar and pestle. On large scale we use series of tanks called edge runner mill

8. 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 .

9. PESTLE AND MORTAR

10. 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.

11. EDGE RUNNER MILL

12. 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 .

13. 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.

14. 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.

15. 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