LAB #3 Flashcards
What is the title of experiment number 3
Extraction and recrystallization
A process that selectively dissolves one or more compounds into an appropriate solvent the resulting solution is called an extract
Extraction
It refers to the transfer of compounds from one liquid solvent to another one
Extraction
Can be used to separate unwanted impurities or to separate mixtures of compounds
Extraction
The two solvents used for extraction must be____
Immiscible
Can be defined as the preparations of crude drugs which contain all the constituents which are soluble in the solvent
Extract
It is the solid residue obtain after extraction
Marc
It is the solvent used for extraction
Menstruum
Principles of extraction
To pull out a compound from one layer into another
A compound partitions more toward where it is more soluble (equilibrium)
Multiple extractions may be needed to completely extract a substance
Factors affecting extraction process
Nature of drug
Solvent
Temperature
pH
Particle size
Methods of extraction
Infusion
Decoction
Digestion
Maceration
Percolation
Continues hot extraction
These are prepared by macerating the crude drug for a short period of time with cold or boiling water
Fresh infusions
These are dilute solutions of the readily soluble constituents of crude drugs
Infusion
Two types of infusion
Fresh infusion
Concentrated infusion
Example given for fresh infusion
Infusion of orange
Example given for concentrated infusion
Concentrated infusion of quassia
In this process the crude drug is boiled in a specified volume of water for the fine time it is then cooled and strained for filtered
Decoction
This procedure is suitable for extracting water soluble heat stable constituents
Decoction
This is a form of maceration in which gentle heat is used during the process of extraction
Digestion
It is used when moderately and elevated temperature is not objectionable
Digestion
During this process the solvent efficiency of the menstruum is there by increased
Digestion
Example given for digestion
Extraction of morphine
In this process solid ingredients are placed in a stoppered container with a hole of the solvent and allowed to stand for a period of at least 3 days with frequent agitation until soluble matter is dissolved
Maceration
The mixture is then strained through sieves or nets where the mark pressed and the combined liquids clarified or cleaned by filtration or by decantation after standing
Maceration
It is continuous downward displacement of the solvent through the bed of crude drug material to get extract
Percolation
Most frequently used to extract active ingredients in the preparation of tinctures and fluid extracts
Percolation
It is the method of short successive maceration or process of displacement
Percolation
This is the instrument used in percolation
Percolator
Two kinds of percolator
Conical and cylindrical
Five steps in percolation
Size reduction
Imbibition
Packing
Maceration
Percolation
Enumerate the parts of soxhlet extractor
Cooling water out
Cooling water in
Condenser
Expansion adapter
Thimble
Siphon
Distillation path
Round bottom flask
Hot plate
It continuous the extraction of a component from a solid mixture
Soxhlet extractor
Flowchart for the separation of immiscible liquids
Extract
Separate
Dry
Evaporate
It is a liquid substance capable to dissolve other substances without chemical changes
Solvent
Type of solvents
Molecular structure of solvents
Inorganic solvents
Organic solvents
It is the ability of a substance to dissolve another substance is determined by compatibility of their molecular structures
Molecular structure of solvents
Types of molecular structure of solvents
Polar protic solvents
Dipolar aprotic solvents
Non-polar solvents
It consists of a polar group OH and a nonpolar tail
Polar protic molecule
The structure may be represented by a formula R-OH
Polar protic solvents
It dissolves other substance with polar protic molecular structure
Polar protic solvents
These are miscible with water or they are hydrophilic
Polar protic solvents
Examples of polar protic solvents
Water
Acetic acid
Methanol
Ethanol
N-propanol
N-butanol
Possess a large bond dipole moment
Dipolar aprotic molecules
They do not contain OH group
Dipolar aprotic solvents
Examples of dipolar aprotic solvents
Acetone
Ethyl acetate
Dimethyl sulfoxide
Acetonitrile
Dimethylformamide
They are hydrophobic or immiscible with water
Nonpolar solvents
They are lipophilic as they dissolve nonpolar substances such as oils fats and greases
Nonpolar solvents
Examples of nonpolar solvents includes
Carbon tetrachloride
Benzene
Diethyl ether
Hexane
Methylene chloride
The most popular inorganic solvents
Water and aqueous solutions containing special additives including surfactants detergents PH buffers and inhibitors
Other inorganic solvents includes
Liquid anhydrous ammonia
Concentrated sulfuric acid
Sulfuryl chloride fluoride
It is a type of volatile organic compound which vaporize at room temperature
Organic solvents
They are useful for dissolving certain materials and substances and are often used in the manufacture of pharmaceutical products footwear paints varnishes and adhesives
Organic solvents
Types of organic compounds used as solvents includes
Aromatic compounds
Alcohols
Esters and ethers
Ketones
Amines
Nitrated and halogenated hydrocarbons
In choosing the solvents what should be the miscibility of the solvents
2 immiscible solvents, a polar one and a nonpolar one
These are less dense than water and thus the water tends to move to the bottom
Nonpolar hydrocarbons and ethers
These are more dense than water so the water will be on top
Chlorinated solvents
It is defined as a drug because it stimulates the central nervous system causing increased alertness
Caffeine
It gives most people a temporary energy boost and elevates smooth
Caffeine
Is caffeine soluble in water
Yes
Staffing is soluble in water but it is more soluble in
DCM or dichloromethane
