Study Set Content:
Bright red heat
800-1000 C
Yellow red heat
1000-1200 C
White heat
1200-1600 C
Many drugs found in the USP and NF contains various amounts of water. They exist as either
hydrates or water that are absorbed.
sets standards for water content limitations for these substances to assure uniformity.
USP and NF
must be calculated for its active ingredient free from water content.
Raw materials
1mL of KFR =
15mL H2O
METHOD I:
Karl Fisher Titrimetry
METHOD II:
Azeotropic Distillation (USP) / Moisture method by toluene distillation (NF) – Xylene
method
Moisture is removed from the sample by distillation as an azeotrope (constant boiling point mixtures) with a
solvent.
METHOD II: Azeotropic Distillation (USP) / Moisture method by toluene distillation (NF) – Xylene
method
METHOD III:
Gravimetric method
Method of Choice
Gravimetric method
-Dried at 105˚C for 5 hours
Gravimetric method
For drugs containing no constituents, other than water, volatile
@ 105˚C
For drugs containing ether-soluble constituents volatile
@ 105˚C
SIX METHODS USED TO DETERMINE WATER CONTENT
METHOD I: Karl Fisher Titrimetry
METHOD II: Azeotropic Distillation (USP) / Moisture method by toluene distillation (NF) – Xylene
METHOD III: Gravimetric Method – Method of Choice
Dew point
Electrolytic Hygrometric
- Are values which are used as parameters to measure the physical and chemical properties of fatty substances, fatty oils, waxes, balsams and resins.
Constants
- Along with the organoleptic studies of these substances they’re used as basis to determine the purity and quality of these substances.
Constants
Common constants used in measuring quantitatively the properties of fatty substances:
- Acid value
- Saponification value
- Ester value
- Iodine value
- Hydroxyl value
- Acetyl value
Also known as acid number or acidity index
Acid Value
