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The slides helps to know the methods available for drug evaluation
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PHYS
ICAL M
ETHOD O
F
DRUG EVA
LUAT
ION
Physical parameters
1.Mosture content
2.Ash values
3.Swelling factor
4.Extractive values
5.Melting point
6.Solubility
7.Optical rotation
8.Viscosity
ASH VALUES
The residue remaining after incineration is
the ash content of the drug.( inorganic
salts of carbonates, phosphates, silicates
of sodium, potassium, calcium and
magnesium) is known as ash content.
Ash value is a criterion to judge the identity
OR purity of the crude drug
TYPES OF ASH VALUES
1.Total ash value
2.Acid insoluble ash value
3.Sulphated ash value
4. Water soluble ash value
Total ash value:
Useful for detecting low grade products
Useful for detecting exhausted products
Useful for detecting excess of sandy
Useful for detecting earthy matter with
drug
DETERMINATION
1.Weigh accurately about 3gms of the powdered drug in a
tared silica crucible
2.Incinerate the powdered drug by gradually increasing the
heat until free from carbon and cool. Keep it in
desiccators
3. Weigh the ash and calculate the % of the total ash with
reference to the air dried sample
Acid insoluble ash value :
1. Used for the determination of earthy matter present on
roots, rhizomes, and also on the leaves
2. Crude drugs contain calcium oxalate crystals the amount
may varies depending on the environmental conditions
DETERMINATION
1. Boil the total ash obtained as above for 5 minutes with
25ml of dilute HCL
2.Filter and collect the insoluble matter on the ashless filter
paper , wash the filter paper with hot water, ignite in
tared crucible, cool and kept in desiccators
3.Weigh the residue and calculate the acid insoluble ash of
the drug
Sulphated ash value :
Used for the detection of low grade products
Water soluble ash value :
Used to detect either material exhausted by water or not
( Tea leaves, Ginger rhizomes)
SWELLING FACTOR
Significances :
Useful in the evaluation of crude drugs containing
mucilage
Useful for the detection of purity of the crude drug
DETERMINATION
1. Transfer 1 gm of the seeds to a 25ml
stoppered cylinder
2. Fill up to the 20ml mark on the cylinder
with water. Agitate gently and occasionally
during 24 hours and allowed to stand
3.Measure the volume occupied by the
swollen seeds
EXTRACTIVE VALUES
Significances :
1.Useful for the evaluation especially when the constituents of the drugs can not be readily estimated by any other means
2.It also helps to indicate the nature of chemical constituents present in the drug
3. Also helps in the identification of adulterants
TYPES
1.Water soluble extractive values
2.Alcohal soluble extractive values
3.Ether soluble extractive values
1.Water soluble extractive value is applied
for the drugs which contain water soluble
constituents such as tannins, sugars, plant
acids and mucilage.
2.Alcohol soluble extractive value is applied
for the drugs which contain alcohol soluble
constituents such as tannins, resins and
alkaloids
Official method for the assay of myrrh &
asafoetida
3.Ether soluble extractive value is
applied for the extraction of volatile
oils, fixed oils and resins.
1.Volatile ether soluble extractive
value
2.Non volatile ether soluble extractive
value
DETERMINATION
Water soluble extractive value:
1. Macerate about 5gm of the accurately weighed
coarse powder with 100ml of chloroform water in a
100ml volumetric flask for 24 hours .
2. Shake frequently for first 6 hours
3. Filter rapidly through filter paper and evaporate
25ml of water extract to dryness in a tared flat-
bottomed shallow dish.
4. Dry the residue at 105 and weigh. Keep it in a
desiccators
5. Dry the extract to constant weight ,finally , calculate
the % W/W of Water soluble extractive value with
reference to the air dried drug.
• Alcohol soluble extractive values
• Macerate about 5gm of the accurately weighed coarse
powder with 100ml of 90% alcohol in a 100ml stoppered
flask for 24 hours .
• Shake frequently for first 6 hours
• Filter rapidly through filter paper and collect the filtrate
evaporate 25ml of alcohol extract to dryness in a tared flat-
bottomed shallow dish.
• Dry the residue at 105 and weigh. Keep it in a
desiccators
• Dry the extract to constant weight ,finally , calculate
the % w/w of alcohol soluble extractive value with
reference to the air dried drug.
SIGNIFICANCE:
1.The method is generally used when standardization is not
done satisfactory by chemical or physical methods
2.When the quantity of the drug /sample are very less then
the drugs are evaluated by biological methods
These methods are performed on living animals,
isolating living organ and tissue, animal preparation, and
micro-organism
( Bioassay)
Following method is used as
1.Anti inflammatory activity
2.Analgesic activity
3.Antipyretic activity
4.Anti ulcer activity
5.Antidiabetic activity
6.Anthelmintic activity on earth worms
7.Cardiac activity- on frog and pigeon
8.Microbiological methods- living bacteria, yeast, molds are
used for the assaying vitamins and to determine the
activity of antibiotic drugs
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