2.
Definition:
Galenicals
- Medicines prepared according to the formulae of
Galen.
- A medicinal preparation composed mainly of
herbal or vegetable matter.
- It is prepared by extraction of crude vegetable
drugs (active principles) with suitable solvent(s).
- The term is now used to denote standard
preparations containing one or more active
constituents of a plant and made by a process that
leaves
the
inert
and
other
undesirable
constituents
of
the
plant
un-dissolved.
2
3. Galenicals
Galen is a Greek anatomist
whose theories formed
the basis of European
medicine until the
Renaissance
(between 4 th and 17 th )
- Pharmaceutical preparations are
divided into:
1. Galenical preparation
2. Non-Galenical preparations
3
4. Galenicals
Nomenclature:
Galenicals : Owing to Galen who discovered it.
Menstrum : Solvent used for extraction (ex.
water, alcohol, ether)
Marc : The inert fibrous and other insoluble
materials remaining after extraction
Types: Infusions- Decoctions- Fluid extractsSemisolid extracts – Dry extracts- TincturesMedical oils…..
4
5. Galenicals
General method of Preparation:
1-
Comminution (reducing substances to small
size).
2Penetration of the crude drug by the
menstrum.
3- Dissolution of the active principles by the
menstrum.
4- Diffusion of the dissolved active principles
through the cell wall to the surrounding
menstrum.
5- Separation of the dissolved active principles
from
the marc by straining, filtration or expression.
5
6. 1- Infusion
Drug
Crude drugs of light structure without dense tissues
and containing water-soluble constituents.
The drug may be freshly broken, thinly sliced, cut
small, or coarsely powdered in order to facilitate the
solvent penetration.
Menstrum
Always water (cold or boiling).
Time
Determined according to the amount of drug
constituents to be extracted and the ease or difficulty
with which the water penetrate the drug.
Examples
Teas- Senna infusion- Infusion of senega
6
7. Follow: Infusion
Preparation
1.1- Fresh (Dilute) Infusion
The simplest of all methods of extraction
A definite weight of the crude drug in a certain state of
subdivision (cut small, powdered…) is prepared
The calculated amount of hot or boiling menstrum
(usually water) is added to the crude drug
Soak for a definite time
During the period of infusion, the heat should be
retained in the container and the content should be
stirred
After the time of infusion, the liquid is poured off or
strained
Do not press or squeeze the marc otherwise colloidal
cell contents may be forced out giving a cloudy infusion
Such fresh infusion should be used within712 hours
8. Follow: Infusion
1.2- Concentrated (stock) infusion
To avoid rapid decomposition to which the fresh
(dilute) infusions are subjected.
These preparations are not made by the
concentration
of
the
dilute
infusion
by
evaporation, since thermal treatment will result in
loss of the volatile principles.
Concentrated infusions prepared with alcoholic
menstrum or contain alcohol as a preservative.
Concentrated infusion are not intended to be
dispensed in the concentrated state, but upon
use, are diluted with at least seven times their
8
volume of water
9. Follow: Infusion
Many medicines which were prescribed required
infusions of ingredients such as bitter orange,
cloves or senna.
Originally the ingredients were left soaking in
hot water and then drained. Later, it was
discovered that it was more effective if the
ingredients were suspended near the surface of
the water, as that way more of the drugs were
extracted, this discovery led to the development
of the infusion pot.
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10. Follow: Infusion
Apparatus
Consist
of
covered
jar
( made of earthenware,
stainless-steel,
ceramic,
glass, porcelain…) to which
is fitted at certain height a
perforated tray upon which
the crude drug may be
allowed to rest in water
being poured over it.
The plant may be enclosed
loosely in a small muslin
bag and suspended in the
jar at a height where it will
be just covered by the
liquid.
10
11. Follow: Infusion
The perforated tray or muslin bag confers two
advantages:
A - Placing the drug near the top of the liquid
rather than at its bottom gives complete
extraction
because
when
the
menstrum
surrounding the drug becomes saturated, it will
sinks to the bottom due to its increased density
and another amount of fresh menstrum displace
it leading to circulatory diffusion.
B- At the end of infusion time, the drug can be
lifted out, leaving clear liquid which can be
strained quickly.
11
12. Examples of infusion
Concentrated infusion of Quassia ( ( خشب المر
Rx.
Quassia, cut small………………..80 gm
Alcohol (90%)…………………….250 ml
Distilled water, cold Q.S to……...1000 ml
Prepared by triple maceration.
1- Macerate Quassia with 650 ml of cold water for one hour, mix
occasionally, strain and reserve the clear liquid.
2- Repeat maceration process twice, using 500 ml of cold water for
each maceration.
3- Combine second and third maceration and evaporate to 100 ml.
4- Mix liquid 3 with liquid 1, add alcohol and adjust the volume to 1000
ml with cold distilled water
12
13. Examples of infusion
Dose: 2 to 4 ml
N.B: alcohol is added to the final product as a
preservative
Use: Anti-malaria, Appetite stimulant (bitter
stomachic).
Dilute infusion of Quassia
Rx.
Concentrated infusion of Quassia……… 125 ml
Distilled water, cold Q.S to………………..1000 ml
Preparation : Just mix
Dose : 15 to 30 ml
13
14. Examples of infusion
Dilute compound infusion of Gentian
Rx.
gm
Gentian, thinly sliced …………………….12.5 gm
Dried bitter orange peel, cut small……12.5 gm
Dried Lemon peel, cut small…………….12.5 gm
boiling water Q.S to……………………….1000
Preparation: Macerate the solid drugs with 1000 gm of
boiling water, then strain.
Dose: 15 to 30 ml
Use: Gentian is a bitter and is used to stimulate gastric
secretion, strengthen the digestive system and
improve the appetite.
It should be given from half to one hour before meals,
preferably with juice.
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16. Follow: Infusion
General Notes
The drug is usually coarsely ground. Very fine
powders should be avoided due to difficulty of
separation from the infusion.
Where no specific directions are given, the
following general formula and procedure should be
used : 50 gm Drug in 1000 ml boiling distilled water
(moisten 50 gm drug with 50 ml of cold water and
allow to stand for 15 minutes. Then, add boiling
water to make 1000 ml infusion).
Infusions of readily soluble active principles are
prepared by maceration in water cold.
16
17. General Notes
Hot water extract the desired constituents more
quickly than cold but has the disadvantages of:
1- extracting inert materials that may precipitate
upon cooling.
2- causing volatilization or destruction of certain
principles.
3- coagulation of albuminous matters within the
drug cell and thereby inhibit the extraction.
17
18. 2- Decoction
Definition:
- Solutions of the water soluble constituents of
plant drugs prepared by boiling the drug with
water.
For extraction of drugs with water soluble and
non- volatile constituents, and drugs of hard
and woody nature.
Should be freshly prepared.
18
19. Follow: Decoction
Preparation:
Previously sliced drug barks or wood (5 parts) is boiled with
water (100 or 120 parts) in a vessel of enameled iron or
earthenware for a definite length of time (15 min.) counting
from when the liquid starts to boil with occasional stirring.
To obtain highly concentrated decoction, boiling is continued
until the liquid reduced to a certain volume.
Allow to cool to about 40ºC, press the marc and mix the
resulting liquid to the decoction.
At the end of decoction time, decoction is strained through
fine muslin or flannel according to the nature of marc. Then,
sufficient water is passed through the strainer to produce a
definite volume.
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20. Follow: Decoction
Example : Cinchona bark
or wood ()خشب الكينا
(contains quinine)
Uses: treatment of fever,
malaria and as an appetite
Stimulant.
Also used in anemia,
indigestion,
gastrointestinal disorders,
general fatigue.
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21. Comparison between infusion and
decoction
Item
Infusion
Decoction
1- Plant
Soft structure (ex. Senna
leaves)
Boiling or cold water
Hard woody structure
(ex. Cinchona bark)
Boiling water
Infusing the drug with cold or
hot water
Calculated as soon as water
is added to drug
No adjustment
Boiling the drug with
water
Calculated as soon as
the water begins to boil
Adjustment is necessary
Infusion earthenware pot
Any covered apparatus
Used fresh within 12 hours
Used fresh and when
stored in refrigerator
used within few days
2- Menstrum
3- Procedure
4- Time
5- Adjustment
of final
volume
6- Apparatus
7- Storage
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