Definition of solubility and explain what is solubility? - It is the quantity of a particular solute dissolved in a particular solvent to form a saturated solution under specified conditions of pressure and temperature. Solubility is the property of liquid, solid or gaseous substances in which solute dissolved in a given solid, liquid or gaseous solvent to form a solution.
It is divided into various types based on the amount of solute dissolve in a given solvent.
Some of the types are as follows:
- Very soluble- Less than 1 part of solvent used to dissolve 1 part of solute.
- Free soluble- 1 to 10 part of solvent used to dissolve 1 part of solute.
- Soluble- 10 to 30 part of solvent used to dissolve 1 part of solute.
- Sparingly Soluble- 30 to 100 part of solvent needed to dissolve 1 part of solute.
- Slightly Soluble- 100 to 1000 parts of solvent used to dissolve 1 part of solute.
- Very slightly soluble- 1000 to 10,000 part of solvents used to dissolve 1 part of solute.
- Practically insoluble- More than 10,000 parts of solvents are used to dissolve 1 part of solute.
Factors :
- Temperature
- Pressure
- Nature of solvent and solute
Technique or methods used to enhance or increase solubility are:
- Particle size reduction
- Solid dispersion
- Hot melt extrusion
- Nano suspension
- Hot melt method (Fusion method)
- Precipitation technique
- Solvent evaporation method
- Media Milling (Nanocrystals or Nanosystems)
- High pressure homogenization
- Combined precipitation and homogenization
- Cryogenic techinques
- Super critical fluid process
- Microwave irradiation method
- Ultra-Rapid freezing
- Spray freezing into vapor over Liquid
- Kneading Method
- Super critical anti solvent technique
- Liophilization / Freeze drying technique
More Methods- Solubilization by surfactants, Solubilization by Salt formation, Nanotechnology approaches
Complexation, Modification of crystal habit by Polomorphs and Psedopolymorphs.
Complexation, Modification of crystal habit by Polomorphs and Psedopolymorphs.
Reference - (1) Kumar A et al. / Pharmacie Globale (IJCP) 2011, 3 (03)
1 Pharmacie Globale© (IJCP), Vol. 02, Issue 03
Available online at www.pharmacie-globale.info