LEVIGATIONCompiled by:-

Dr. Hafiz Rahat Riaz Rana(917)

Dr. M Husnain(871)

Dr. M Ahmad(883)

Supervised by:-

Dr.Khizar Hayat

CONTENTS

Definition

Levigating agent

Process

Method

Purpose

Advantage

Application

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.

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.

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.

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.

METHODS

• On small scale we use mortar and pestle.

• On large scale we use series of tanks called edge runner mill

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.

PESTLE AND MORTAR

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.

EDGE RUNNER MILL

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.

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.

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.

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