Classification of Crude drugs - PowerPoint Presentation

Slide1

Classification of Crude drugs

L.A.

Dilbreen

H. A.

BarzanjiSlide2

1-

Alphabateical

classification

The

crude drugs are arranged according to the

alphabetic order

of their Latin or English names.

Some

of the pharmacopoeia and reference books which classify crude drugs according to this system

are:

Indian pharmacopoeia(IP)

British pharmacopoeia (BP)

British

herbal

pharmacopoeia (BHP)

United

States Pharmacopoeia and national

formulary (USP/NF)

British

pharmaceutical

codex

European pharmacopoeia(EP)

Encyclopedia

of common natural ingredients used in drugs and

cosmetics

e.g

. Acacia,

benzoin

, cinchona, dill, ergot

……..zedoarySlide3

2- Taxonomical

(biological)

classification

The drugs are classified according to plants or animals from which they are obtained in phyla,

division, class, order

,

families

,

genus

,

species

,

subspecies

, etc.

This classification is based on the consideration of natural relationship or

phylogeny

among plants or animals. The crude drugs of

plant origin

are classified on the basis of one of the accepted systems of botanical classification.

A large number of plant families have certain

distinguishing characteristics

that permit crude drugs from these families to be studied at one time

. thus

drugs obtained from plants having

alternate leaves,

cymose

flowers and fruits that are berries or capsules

(

hyoscyamus

,

datura

, belladonna and

stramonium

) are considered with other members of

Solanaceae

).Slide4

In case of animals, all arthropods are grouped, as are all mammals, fish and other

phylogenetic

types.This system of classification are criticized for

its failure to recognize the organized and unorganized nature of the crude drug.

At

first sight, this classification looks appealing, but many drugs are not entire plants and represent parts of the plants that have been processed systemically.

Further

, the system

fails to take into account the chemical nature

of active constituents and

therapeutic significance of crude drugs.Slide5

e.g.

Phylum

: Spermatophyta

Division:

Angiospermae

Class:

Dicotyledons

Order: Rosales

Family :

Leguminosae

Genus:

Glycerrhiza

Species:

Glycerrhiza

glabra

Slide6

3- Morphological

classification

:

The crude drugs are grouped according to the part of the plant or animal represented into organized and unorganized drugs.

The

organized drugs

are divided into parts of plants like

leaves, flowers, fruits, seeds

,

etc.

the

unorganized drugs

are

dried latex, gums, extracts

, etc.Slide7

Seeds: Castor,

nux-vomica

Leaves: senna, eucalyptus

Barks: cinchona, cinnamon

Woods:

Quassia

, Sassafras

Roots:

Rauwolfia

, Ipecacuanha

Rhizomes: Ginger, ValerianFlowers: Clove, PyrethrumFruits: Coriander, FennelEntire drugs: Ephedra, ErgotSlide8

Dried lattices: Opium,

Papain

Resins: Balsam of Tolu,

Benzoin

Dried juices: Aloes, Kino

Gums: Acacia, Guar

Dried extracts: Gelatin, Agar

This system of classification is more convenient for practical study especially

when the chemical nature of the drug is not clearly understood

.Slide9

4- Chemical classification

:

The crude drugs are divided into different groups according to the chemical nature of their most important constituent.

Since

the pharmacological activity and therapeutic activity of crude drugs are based on the nature of their chemical constituents, it would be appear that chemical classification of crude drugs is the preferred method of study. Slide10

Glycosides: Digitalis,

liquorice

Alkaloids: Ergot, CinchonaTannins:

Myrobalan

,

Ashoka

Volatile oils: Peppermint, Eucalyptus

Lipids:

Castor oil, Cod liver oil

Carbohydrates: Acacia, Honey

Resins: Balsam of Tolu, JalapVitamins and Hormones: Oxytocin

, InsulinProteins and Enzymes: Gelatin, CaseinSlide11

5- Pharmacological

(Therapeutic) Classification

:

This system of classification involves the grouping of crude drugs according to

the pharmacological action

of their active constituent or

their therapeutic uses

.

Cascara, Castor oil, Senna, Jalap, Colocynth are grouped together as

purgatives

or

laxatives because of their common pharmacological action. The drug differing in mechanism of action

, but with the same pharmacological effect are grouped together.Some of the drugs could be classified under two pharmacological leadings

, since they exhibit two different actions, for example, Cinchona is classified both as antimalarial and bitter tonic.Slide12

Ex. drugs acting on GIT

Bitters

: Cinchona, GentianCarminative: Dill, Cardamom

Emetics: Ipecacuanha

Bulk laxatives: Agar, Ispaghula

Purgatives: Senna, Castor oilSlide13

Production of crude drugs:

The crude drug that that reaches the pharmaceutical manufacturing line will have passed through various stages, all of which influence the nature and amount of active constituents present

.Slide14

1- Source materials

:

It is imperative that

correct identification

of the source material is made.

Adulteration

may be

accidental

, particularly if collection is made from wild plants, or

it may be deliberate.

Failure

in this area can result in poisoning (e.g. hemlock fruits mistaken for other

umbilliferous fruits) or

inactive products (e.g. substituition of St. John’s

wort with other vegetable material when demand exceed supply). Slide15

For

pharmacopoeial

drugs, precise macroscopic and microscopic characters are available. For isolation of specific constituents, the source can vary, e.g.

hyoscine

obtained from a number of

solanaceous

species. Slide16

2- Environmental

conditions:

Plant

growth and development, and often the nature and quantity of secondary metabolites, are affected by:

Temperature

Rainfall

Day-length and radiation characteristic

AltitudeSlide17

3- Cultivation

and wild

plants

Crude drugs are now obtained most exclusively cultivated plants. These include cardamoms, Indian hemp, ginger and peppermint and spearmint for oil production.

In other cases both wild and cultivated plants are used.

There is a turning into cultivation because wild plants are

insufficient to meet the demand

sparse distribution

inaccessibility

collection is difficult

governmental control (e.g. in case of opium)

some wild plants are in danger of over-exploitation

.Slide18

4- Collection:

Drugs may be collected from wild or cultivated plants, and the task may undertaken by

casual, unskilled native

labour

(e.g.

ipecacuanha

) or by

skilled workers in a highly scientific manner

(e.g. digitalis, belladonna, cinchona

).

The season at which each drug is collected is usually a matter of considerable importance,

as the amount, and sometimes the nature, of active constituents is not constant throughout the year. e.g. rhubarb is reported to contain

no anthraquinone derivatives in

winter but anthranols which, on the arrival of

warmer weather, are converted by oxidation into anthraquinones

.Slide19

The

age

of plant is also of considerable importance and governs not only the

total quantity

of active constituents produced but also the relative

proportions

of components of the active mixture.

e.g

.

Mentha

piperita give relatively high proportion of

pulegone in young plants: replaced by menthone

and menthol as

leaves mature.Slide20

Generally speaking,

leaves are collected as the flowers are beginning to

open

Flowers just before they are fully expanded

The underground organs as the aerial parts die down

Leaves, flowers and fruits should not be collected when covered with dew or rain.

Any which are

discoloured

or attacked by insects or slugs should be rejected.

Even

with hand picking,

it is difficult, certainly expensive

, to get leaves, flowers or fruits entirely free from other parts of the plant. In cases such as senna

leaf and digitalis the official monographs allow a certain percentage of stalks to be present or a limited amount of ‘foreign matter’. Similarly, with roots and rhizomes a certain amount of areal stem is often collected and is permitted in the case of Senega

root.Slide21

Special machines are used to harvest ergot and lavender flowers.

Barks

are usually collected after a period of

damp weather

, as they then separate mostly from the wood.

For separation of

gums

,

gum resins

, etc.,

dry weather is obviously indicated and care should be taken to exclude vegetable debris as far as possible

.Underground organs must be freed from soil. Shaking the drug before, during and after drying, or brushing it , may be sufficient to separate a sandy soil, but in cases of clay or other heavy soil; washing is necessary.

Before drying, any wormy or diseased rhizomes or roots should be rejected.

All large organs should be sliced to facilitate drying.Seeds such as nux

vomica and cocoa, which are extracted from mucilaginous fruits, are washed free from pulp before drying.Slide22

5- Drying

If enzymatic action is

to be encouraged

,

slow drying

at a moderate temperature is necessary. e.g. ‘vanilla pods’ and ‘gentian roots’.

If

enzymic

action is

not desired

, drying should be take place as soon as possible

after collection.Drugs containing volatile oils are liable to lose their aroma if not dried or if the oil is not distilled from them

immediately, and all moist drugs are liable to develop mould

. For these reasons, drying apparatus and stills should be situated as near to the growing plants as possible.Slide23

The duration of drying process varies from a

few hours to many weeks

, and in the case of

open-air drying

depends very largely on the weather. In suitable climates open-air drying is used for such drugs as clove, colocynth, cardamom and cinnamon.

Even in warm and dry climates arrangements have to be made for getting the drug under the cover of sheds or tarpaulins at night or during wet

weather.

For

drying in sheds the drugs may be suspended in bundles from the roof, threaded on strings, as in the case of Chinese rhubarb

, or more commonly placed on trays made of sacking or tinned wire-netting.

Papers spread on a wooden framework are also used, particularly for fruits from which it is desired to collect the seedsSlide24

Drying by

artificial heat

is more rapid than open-air drying and is often necessary in tropical countries (e.g. west Africa, where the humidity is very high).

In Europe

continuous belt driers

are used for large crops such as digitalis.

Alternatively heat may be applied means of

open fires

(e.g. nutmegs),

stoves

or hot-water pipes.

In all drying sheds there must be a space of at least 15 cm between superimposed trays, and air must circulate freelySlide25

As a general rule, leaves,

herbs and flowers

may be dried between 20 and 40

o

C

, and

barks and roots

between

30 and 65

o

C.

If leaves and other delicate structures are over dried, they become very brittle

and tend to break in transit.Exactly how far drying is to be carried is a matter for practical experience. Slide26

6- Storage

Long storage

, although often unavoidable, is

not to

be recommended,

Drugs such as Indian hemp and sarsaparilla deteriorate even when carefully stored.

Few cases such as cascara bark need long storage before indicated to be used.

It has been reported that the content of

taxol

in

Taxus

baccata leaves stored at room temperature for one year decreased by30-40% , storage in freezer and out of direct sunlight produced no adverse deterioration.

Similarly the alkamides of the popular immunostimulant

herb Echinacea purpurea decrease rapidly on storage. Slide27

drugs stored in the usual containers: sacks, bales, wooden cases, cardboard boxes and paper bags reabsorb about

10-12% or more of moisture

.Plastic sacks will effectively

seal

the contents.

Drugs such as

digitalis and Indian hemp

should

never be allowed to become moist

or they lose a considerable part of their activity. They may kept in sealed containers with a dehydrating agent.Slide28

Volatile oil should be stored in sealed, well-filled containers in a cool, dark place.

Similar remarks apply to fixed oils, particularly cod-liver oil.

In order to reduce undesirable microbial contamination and to prevent the development of other living organisms, some plant materials may require

sterilization

before storage

.