HOW TO INCREASE SOLUBILITY OF P'CEUTICAL COMPOUND VIA SUPER CRITICAL RECRYSTALLIZATION.

1. SOLUBILIZATION ENHANCE METHOD
SUPER CRITICAL RECRYSTLIZATION
CHANDA MALVIYA
M. PHARMA I SEM
PHARMACOLOGY
VNS COLLEGE OF PHARMACY

2. OUTLINES
• WHAT IS SUPER CRITICAL FLUID [SCF]?
• SCF PROPERTIES
• COMMON SOLVENT USE IN SCF
• WHY USE CO2
• IMPORTANT PARAMETER
• ADVANTAGES OF SCF
• SOLUBILITY OF NAPHTHALENE
• MIGLYOL TREATED WITH CO2 TO INCREASE SOLUBILITY

3. WHAT IS SCF
CRITICAL CONDITION : where the liquid and vapor phase of a substance become in
distinguish.
A supercritical fluid is any substance at a temperature and pressure above its critical point, where
distinct liquid and gas phases do not exist.

4. SCF PROPERTIES
Liquid like densities
Reduce surface tension
Gas like viscosity
COMMON SOLVENT USE IN SCF
CO2 - mostly used
Nitrous oxide
Ethylene
Propylene
n- heptane
Ethanol
Ammonia

5. TABLE : 1
SUBSTANCE Tc [K] Pc [atm] DENSITY
CO2 304 73 0.47
ETHANE 305.5 48.2 0.20
ETHANOL 516.6 63 0.28
PROPANE 370 42 0.22

6. WHY CO2 USE IN SCF
Low critical pressure [73 atm] and temp.[31 C]
Non- toxic
Non- flammable
Available at high pure form
Low cost
They can remove quite easily from extract
It has polarity like liquid pentane at super critical condition that’s why suitable for lipophilic
compound.
DRAWBACK : CAN’T EXTRACT POLAR SOLUTE.

7. IMPORTANT PARAMETER
• THRESHOLD PRESSURE : at normal temp. or pressure solubility of substance will be ‘0’ that mean
no miscibility.
• If pressure increase beyond the critical pressure solute , so would be dissolve its’s become soluble.
• Where the solubility beyond the 1 called threshold pressure.[that mean where the solute starts soluble]

8. USE OF CO-SOLVENT
• ROLE : to modify the property of solvent.
• Modification of polarity of solvent, so that the solvent can solubilize polar solvent as well.
• Ex : 1-10% methanol is added to CO2 in order to increase it’s polarity.
[ By the use of co- solvent you can increase polarity of CO2, solubilization capacity will be increase]
ADVANTAGES OF SC
Beyond critical point solvent has better or higher capacity to dissolve solute.
If pressure reduce solubility of solute become less because this property solute can easily
separate/remove from the SCF.
They can penetrate easily the solid matrix and dissolve solute.

9. SOLUBILITY OF NAPHTHALENE

10. MIGLYOL TREATED WITH CO2 TO INCREASE SOLUBILITY