Extraction & Sample Preparation Method Flashcards
What are the three different medicinal extracts?
Gelenical
Menstruum
Marc
What is a galenical?
Medicinal extract derived from nature
What is menstruum?
Solvent(s) used in extraction process
What is Marc?
Waste (insoluble) after extraction
What are the process that can be used for extraction process?
Infusion Decoction Maceration Percolation Counter current
What are the different types of extracts?
Liquid extracts
Tinctures
Soft extracts
Dry extracts
Are liquid extracts more diluted than tinctures?
NO- tinctures are more diluted
What are the 3 steps of extraction process?
1- communition- inc SA of plant material E.g. by grinding
2- incubation with menstruum- penetration and dissolution
3- separation of Marc and API- E.g. filtration
What can be done to make the process more efficient?
1- wet particles with alcohol or water
2- add organic solvent to permeate cell walls
3- inc temp to ince rate of dissolution
4- outward dissolution of solution
What is method of infusion?
Drug is stood in cold/ hot water for a short time
What is the menstruum used in infusion?
Cold or boiling water
What is the method of decoction?
Simmering / boiling plant extracts in water for specific amount of time
What is the menstruum used in decoction?
Boiling water
Is the solid material in infusion hard or soft
SOFT
If the solid material in decoction hard or soft ?
HARD
Is the active principle in infusion volatile ?
Volatile or non volatile
Can active principle in decoction be volatile?
NO- has to be non volatile
Infusion extracts from soluble constituents of crude drugs prepared by diluting conc infusion should be used within……?
12 hours
What is the method of maceration?
Prolonged infusion (days) often in aq alcohol and closed container
What is percolation?
Maceration & then flow of fresh solvent passing over ground material at specified rate
What is Continuous hot extraction?
Repeated infusion with hot solvent
What should be considered when deciding which extraction method to use?
Hard- percolation/ decoction
Soft- meceration
Volatile- cold infusion
Cost
To prepare sample, need to ……?
Purify drugs of interest
Concentrate, derivative and stabilise analyte
Purpose of purification methods?
Isolate pure drug from crude forms
Remove interfering constituents for analysis
Techniques used for purification for immiscible liquids (2 layers)?
Separating funnel
Counter current distribution
Purification methods used for miscible liquids?
Crystallisation
Fractional distillation
Is water and organic solvent miscible?
NO- immiscible
What is distribution ratio?
Solute in org phase / solute in water phase
Organic layer is heavier so will sink to the bottom- T or F?
FALSE- org layer is lighter so floats
Problems with immiscible liquids?
- emulsion due to shaking
- where is the boundary?
When extracting drug- trying to get it in org or aq layer?
ORG layer as org solvent is volatile- easier to recover
Charged drug will partition into……?
Aq layer
What are the basic techniques to remove solvent?
Rotary evaporation
Fractional distillation
Crystallisation
Sublimation
What does rotary evaporation involve?
Round bottom flask heated gently- boils at low temp
Solvent drawn up, condenses and falls in the other flask
Solid left in the flask
Spin gives max SA
What does fractional distillation involve?
Two extracts with diff boiling points
One collected in flask and one left behind
What does sublimation involve?
Dries out water from extracts from solid to vapour state
