Disperse system in pharmaceutics

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Disperse system

Introduction

• The disperse system refers to a system in which one substance is particularly distributed inthroughout the a second substance

• The system find wide application like

• various manfacuring process , pharmaceutical operations like- particle size redctuion, coating of drugs,microcapsulation.

Why disperse system

• The disperse system is  hetrogenous. Each of two phases exist in liquid,gas ,solid phases.

• The one  phases called is dispese phase or discontinuous phase

• The other is called dispersion medium

Component of disperse system

Three type of component occurs in disperse system as given below

• Dispersed phase –internal phase
• Dispersion medium- external phase
• Dispersing agent- for maintaining homogeneity of disperse system

Direction – the commonly known direction is “SHAKE WELL BEFORE USE”

Classification of disperse system

There are  different type of classification is available for the disperse system given blow

•  based on physical state of  disperse system
•  based on size of disperse phase
•  based on affinity of disperse phase
•  based on coarse disperse system

A) based on physical state of  disperse system

1. Suspension   
2. emuision   
3. aersol

 Suspension -state is solid/liquid Dispersion

 Emuision - liq./liq. Dispersion

 Aersol –drug either in liquid or solid form within gaseous phase

B) based on size of disperse phase

1. Molecular Dispersion
2. colloidal Dispersion 
3. coarseDispersion

Molecular Dispersion –homogenous and true solution (size-<1nm) ex.potassium ion dissolve in water

Colloidal Dispersion –intermediate between true solution and colloidal solution(size-0.5 μm -1nm) ex.collidal silver solution

Coarse Dispersion –particle invisible under ordinary light microscope(size->0.5 μm )

 C) based on affinity of disperse phase

1. Lyophilic 
2. Lyophobic

Lyophilic - Dispersed phase  has affinity towordsDispersion medium

Lyophilic - Dispersed phase  has no affinity towordsDispersion medium

D) based on coarse disperse system

1. Emulsion  Suspension
2. Emulsion - Dispersion phase is liqiud
3. Suspension - Dispersion phase is solid