Pharmaceuticals

1. OUR LADY OF FATIMA UNIVERSITY
COLLEGE OF PHARMACY
Pharmaceutical Analysis I
EXERCISE NO. 10
Analysis of Oils
Post - Laboratory Discussion

2. OBJECTIVES
 To determine the difference between fixed oils and
volatile oils
 To conduct acid value determination on oil sample
 To conduct saponification value and iodine value
determination on oil sample
 To perform ester content determination on volatile
oil sample
 To perform phenol content determination on volatile
oil sample
 To determine conformance of the sample to the
pharmacopeial specifications

3. Introduction
According to dictionary.com, OILS refer to any of a
large class of substances typically unctuous, viscous,
combustible, liquid at ordinary temperatures, and soluble
in ether or alcohol but not in water: used for anointing,
perfuming, lubricating, illuminating, heating, etc.
Chemistry describes oil as any
nonpolar chemical substance that is a viscous liquid
at ambient temperatures and is both hydrophobic
(does not mix with water, literally "water fearing") and
lipophilic (mixes with other oils, literally "fat loving").

4. Introduction
What are the sources? Name few examples
• Plants
• Animals
• Petroleum
• Fixed oils - esters of glycerin with fatty acids of
high molecular weight by aliphatic long chain,
particularly palmitic, stearic and oleic acids.
• Liquid and solid esters of glycerin differentiate
fats from fixed oils

5. Introduction
• Essential oils – do not contain glycerin esters but a
variety of organic compounds characterized by its
strong, aromatic odor.
• Chemical constants
• Assay

6. Answers
• Preparation of Oil samples before analysis
Oil samples are prepared by
Water bath at 50°C
Hot water jacket
Fats and waxes (hot titration)
Alcohol-ether mixture: as solvent
Mix 25 ml each of ethyl alcohol and ether
Neutralize with sodium hydroxide
The acidity is due to the alcohol
Useful for rosins and balsams (soluble in ether layer)

7. Answers
a. ACID Value
• number of mL of 0.1 N alkali required to neutralize the free acids in 10.0 g of
substance
• number of mg of potassium hydroxide required to neutralize the free acids in 1.0 g
of the substance
• Esters hydrolysis
• Chemical treatment, bacterial action and catalytic action
• 
• 
Liberated acid
or free acid
that is
determined
by the titrant
NaOH

8. Answers
a. ACID Value
• Sample used is Olive oil
• Olive oil is the oil obtained solely from the fruit of the olive tree (Olea
europaea L.), to the exclusion of oils obtained using solvents or re-esterification
processes
** Virgin olive oils are the oils obtained from the fruit of the olive tree solely by
mechanical or other physical means under conditions, including thermal
conditions, that do not lead to alterations in the oil
• Oleic acid
• Specific gravity of 0.910 – 0.915
• Acid value – nmt 5.0 ml of 0.1 N NaOH for 10 gram-sample
• Iodine value of – 79-88
• Saponification value – 190 – 195

9. Answers
b. SAPONIFICATION Value
• number of mg of potassium hydroxide required to
neutralize the free acids and saponify the esters
contained in 1.0 g of the substance
• Mixtures of glyceryl esters
• It is a measure of the average molecular weight (or chain
length) of all the fatty acids present (less than 16 or more
than 18)
• SV is inversely proportional to the average weight of fatty
acids
• When SV goes out of the limits
• Indication of adulteration

10. Answers
b. SAPONIFICATION Value
• Sample used is Olive oil
• Alcoholic KOH: as solvent for oil and product
• Dissolve 2.10 g of KOH in 2 ml distilled water and
sufficient alcohol to make 60 mL
• Long glass tubing – prevents escape of alcohol
• Heating oil with alkali – saponification (Clear and free
from oil globules)
• 0.5 N HCl – titrant not H2SO4 because the
procedure requires heating
• Blank determination  to eliminate errors

11. Answers
c. IODINE Value
• number of g of iodine absorbed, under the
prescribed conditions, by 100 g of the substance.
• Iodine value is an indication of
• Degree of unsaturation
• Basis for classifying oil: Drying, Semi drying, non
drying
• Methods of Iodine Value Determination
• Method I – Hanus method
• Method II – Wij’s method

12. Answers
c. IODINE Value
• Iodine Flask – container of sample
• CCl4 – solvent to oil sample
• Iodobromide TS – soluble form of iodine
• Protected from light – avoid side reactions
• KI TS – reacts with IBr to form KBr
• Na2S2O3 VS – titrate the liberated iodine
• Blank test – correct errors due to
• CO2
• Alkalinity imparted by the glass

13. Answers
OTHER Constants
• The peroxide value is the amount of peroxide
oxygen per 1 kilogram of fat or oil.
• Peroxide value is a parameter for primary
oxidation products, hydroperoxides BUT PV
decreases with secondary oxidation products
increases

14. Answers
OTHER Constants
• Anisidine value 100 times the optical density
measured at 350 nm in a 1 cm cuvette of a solution
containing 1.00 g of the oil in 100 mL of a mixture
of solvent and reagent according to the method
used.
• Anisidine value is for secondary oxidation
products, that is, hydroperoxides to aldehydes.
• ToTox (total oxidation) is the indicator of the
overall oxidation of the oil.
** together with Acid Value, these four are the
standards parameters for fish oil quality.

15. Answers
OTHER Constants
• Total Oxidation Value is defined by the formula:
2PV + AV
• TotOx (total oxidation) is the indicator of the
overall oxidation of the oil.
** together with Acid Value, these four are the
standards parameters for fish oil quality.

16. Sample monograph

17. Sample monograph

18. Sample monograph

19. Answers – Volatile oils
-Essences or aromatic substance
-Contains: hydrocarbons, acids, alcohols,
aldehydes, ketones, phenol, sulfur
compounds
• Specific gravity Distillation range
• Refractive index Solubility
• Specific rotation
• Congealing point

20. Answers – Volatile oils
-Method of Extraction
https://extraessay.top/adw/

21. Answers – Volatile oils
-Ester Value (fixed oils) no of mg KOH required
to saponify the esters in 1 g sample
-In essential oil (EO) EV is expressed as
percentage of total esters present in the
sample

22. • volatile oil distilled with steam from the dried Flower
buds of Syzygium aromaticum
• It containsNLT 85.0% of total phenolic
substances,chieFy eugenol (C10H12O2)
• Syzygium aromaticum(L.) Merr. (Fam.Myrtaceae)
• Uses: ±flavouring, aromatherapy, antiseptic, remedy
for toothache
• Relevant Constituents:–eugenol (75–90)–eugenyl
acetate (10–15)–β-caryophyllene (3)
Clove oil

23. Answers – Volatile oils

24. • Cassia flask
• 100 or 200 ml cap with 0.1 ml divisions
• KOH TS
• Reacts with phenol to form
potassium eugenolate
• Water bath
• Saponify any eugenyl acetate
• Products are soluble in water
• Undissolved components rise to the top
• To separate eugenol from aqueous solution, acidify
with sulfuric acid
Assay for Phenol Content

25. Reference/s:
• Articles of botanical origin -
https://www.usp.org/sites/default/files/usp/document/our-
work/DS/2015-dsc-chapters-561-616-1010-1092.pdf
• Fats and Fixed oils -
http://ftp.uspbpep.com/v29240/usp29nf24s0_c401.html
• S. Ahmed, M. Hasan. Standardization of crude drugs: A precise
review. 2015. retrived from
https://www.researchgate.net/publication/282353527_Standar
dization_of_crude_drugs_A_precise_review

26. Any questions??