This document discusses the preservation of crude drugs and herbarium specimens. It notes that proper storage conditions like low temperature, low humidity, and low light are important to prevent deterioration. Drugs containing things like essential oils or glycosides deteriorate more quickly. The document also discusses techniques for pressing, drying, and storing plant specimens to preserve them. Factors like temperature, humidity, air, and light can all impact how long drugs and specimens last and special care must be taken in storage and transportation.

1. Preservation
Prepared By :
Neama Mohamed
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2.  The act or process of keeping something safe from damage or
deterioration.
Preservation
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3. Preservation of crude drugs on storage
 Storage of crude drugs is very important for stability as well as
quality maintenance. There are great differences in the stability
of crude drugs because of slow enzymatic changes in the
constituents.
 Drugs containing glycosides and esters are usually less stable
than those containing alkaloids.
 Drugs with essential oils deteriorate rather quickly through
evaporation, oxidation, and polymerization of the substances
constituting the essential oil. Tannins, on the other hand, have
an almost unlimited durability.
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4. Preservation techniques
 The two main steps in preserving floral collections are
pressing and drying.
 Correct pressing→ prevents plant parts from curling or
wrinkling during the drying process, and allows the requisite
plant parts to be visible for identification.
 Care in pressing specimens →will result in more useful and
visually appealing herbarium specimens.
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5. Pressing
The process consists of laying the plant specimens in folded sheets
of newsprint separated by cardboard sheets, and placing them in a
pressing frame, which is then tightened with straps.
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7. Drying
Drying involves an adequate length of time and exposure to ‘‘dry’’
air, and maintenance of the specimens in the press, e.g., changing
the newsprint to speed up the drying process and cinching the
press daily as the specimens dry.
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8. Storage conditions
 Herbarium specimens will last for hundreds of years if properly
cared for. The best conditions for storage include low temperature
(from 50–65ºF), low humidity, low light, and infrequent handling.
Roaches and certain beetles will destroy plant specimens. You can
kill insects in dried plant specimens by freezing them for three or
four days, and keep them pest-free in a tightly-sealed plastic bag.
There are various ways to achieve these conditions. In a
herbarium, plants are stored in folders within airtight cabinets.
Any dried plant material is frozen before entering the herbarium,
and the space is periodically treated with a pyrethrin spray (an
organic insecticide made from chrysanthemums).
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9. Factors affecting storage
 Stability of drugs depends on both environmental factors such
as temperature, air, light and humidity, and drug-related
factors such as the active ingredient itself, the dosage form
(tablet, solution, etc.) and the manufacturing process.
 It is therefore necessary to respect storage instructions given in
this guide or by manufacturers (on notices and labels) if the
recommendations are not identical.
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10. Temperature
The temperature in the store should not be above 25 °C.
Storage temperatures are defined by European pharmacopoeia as
follows:
freezer - 15 to 0 °C
refrigerator + 2 to + 8 °C
cool + 8 to + 15 °C
ambient temperature + 15 to + 25 °C
During transit and transportation temperatures may attain 50 to 60 °C
inside vehicles, shipping containers or on docks and, in this case,
shelf life and expiry dates may no longer be guaranteed.
Freezing may be detrimental, particularly for solutions, leading to the
deterioration or precipitation of active ingredients as well as the
breaking of ampoules and vials.
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11.  Vaccines, immunoglobulins and antisera are products that are
sensitive to heat and light. Even though new techniques
produce vaccines that are less sensitive to heat (called
"thermostable"), they still have to be stored in the refrigerator
between 2 °C and 8 °C, and the cold chain must be strictly
respected during transport.
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12. Air and Humidity
 In a store, relative humidity should not be above 65% (there
are several devices for humidity measurement).
 Air is a factor of deterioration due to its content of oxygen
and humidity. All containers should remain closed. In airtight
and opaque containers (hospital type), drugs are protected
against air and light. Opening containers long before the use
of drugs should be avoided.
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14. Light
 Drugs should be protected from light, particularly
solutions. Parenteral forms should be preserved in their
packaging. Coloured glass may give illusory protection
against light.
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15. Control of infestation
 Food grains are kept in storage facilities for longer periods.
Grain infestation during storage causes a significant loss in
quality and market value. Various chemical methods have been
implemented to control insect infestation in stored grains.
However, the chemical fumigants for insects have been limited
due to the resistance of insects, environmental concerns, and
adverse effects on human health. Therefore, there is a need for
viable alternatives for insect disinfestation, which can be
residue-free and acceptable at the national and international
markets.
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16.  The new techniques used in the grain industry for insect
control during storage gave promising results with high
mortality. New methods, such as cold plasma, are
becoming a safer tool for the disinfestation of stored
grains. The new techniques are rapid and can be applied to
bulk material without affecting the quality of grains.
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