Study Set Content:
- Also known as ethereal oils or essential oils.
Volatile oils
They are mixtures of hydrocarbon terpenes, sesquiterpenes and polyterpenes and their oxygenated derivatives obtained from various parts of the plant.
volatile oils
evaporate on exposure to air at ordinary temperature and are the odorous constituents.
Volatile oils
Chemical components of volatile oils
- Hydrocarbons
- Alcohols
- Aldehydes
- Ketones
- Phenols
- Acids
- Sulfuric compounds
- determines the purity and value based on certain physical characteristics or properties.
Analysis of volatile oils
Organoleptic examinations:
- Odor
- Appearance and color
Physico-chemical properties:
Specific gravity
Rotatory power
Refractive index
Solidifying points
Solubility
Behavior during distillation
The highest temperature at which it solidifies.
Congealing point
The congealing point of the liquid is the same as the
melting temperature of the solid
but since the liquid may be cooled to a temperature below its congealing point without assuming the solid form, the method described is used to determine the
- congealing point of a liquid or of a melted solid.
Generally most volatile oils are soluble to organic solvents:
- Alcohol
- Ether
- Chloroform
- hexane
- Carbon disulfide
- Benzene
Specific assays for Volatile oils
- Assay of Alcohol content
- Assay of Phenol content
- Assay of Ester content
- Are obtained from plant, animal or synthetic sources.
Alkaloids
- Contains organic nitrogen within their chemical structures that are usually distinguished as primary, secondary or tertiary.
Alkaloids
Possess physiological activity.
Alkaloids
Assay for Alkaloids and preparations are utilized for:
- Standardization
- Determination of purity
- Commercial evaluation
- Pharmacological evaluation
Methods used to determine the presence of alkaloids quantitatively:
- Gravimetric
- Volumetric
- Spectrometric
- Electrometric
- Physiological
The amount of alkaloids that exists may be subjected to variations in different samples of the same drug:
- Age of plant when collected
- Season of the year
- Type of soil and climate
- Conditions when the raw material is collected
Quality of alkaloids present in Galenical preparations is also subject to variations:
- Quality of drug employed
- Menstruum used in the extract of the alkaloid
- Amount of decomposition of the alkaloid during the process of extraction and storage
Factors that contributes to the deterioration of alkaloidal preparations:
- Nature of the alkaloid
- pH value of the preparation
- Heat
- Light
