Recombinant DNA technology (Immunological screening)
Cultivation and Collection of Drugs
1. C
Cultivation and Collection of
Drugs of Natural Origin
Presented By-
Diksha Kataria
Assistant Professor
Lord Shiva College of Pharmacy
2. Cultivation of Drugs
Though several countries in the world have a rich heritage of herbal
drugs, very few can put claim for their procurement only from
cultivated species. It is recent that some of these drugs have been
subjected to systematic cultivation based on modern scientific
information.
Our reliance on wild sources of crude drugs and the lack of information
of sound cultivation technology have resulted in gradual depletion of
raw material from wild sources.
Also, cultivation of drugs requires intensive care and management.
3. Advantages of Cultivation:
• It ensures quality and purity of medicinal plants.
• Collection of crude drugs from cultivated plants gives a better yield and therapeutic quality.
• Cultivation ensures regular supply of a crude drug.
• The cultivation of medicinal and aromatic plants also leads to industrialization to a greater
extent.
• Cultivation permits application of modern technological aspects such as mutation,
polyploidy and hybridization.
The high cost of cultivation drugs as compared to wild source and losses due to ecological
imbalance such as storms, earthquakes, floods, droughts etc. is a major disadvantage of
cultivation.
4. I. Methods of Propagation:
a) Sexual method
b) Asexual method
Sexual Method (Seed Propagation)-
In case of sexual method, the plants are raised from seeds and such plants are known as seedlings.
Advantages:
❖ Simple and easy method of propagation.
❖ Some species of trees, ornamental annuals and vegetables which cannot be propagated by
vegetatively should be propagated by this method. E.g. Papaya, Marigold, Tomato etc.
❖ New variety of crops are developed only by sexual method of propagation.
❖ The plants propagated by this method are long lived and are resistant to water stress.
❖ Seed can be transported and stored for longer time for propagation.
5. Disadvantages:
❖ Plants propagated by sexual method requires long period for fruiting.
❖ Plants grow very high, so they are difficult for intercultural practices like spraying,
harvesting etc.
❖ The plants which have no seeds cannot be propagated by this method. E.g. Banana, fig,
Jasmine, Rose etc.
❖ Characteristics of seedlings propagated by this method are not genetically true to type to that
of their mother plant.
Asexual Method (Vegetative Propagation)-
The vegetative part of a plant such as stem or root is placed in such an environment that it
develops into a new plant.
Advantages:
❖ Inferior quality fruit plants can be converted into good quality plants.
6. ❖ Vegetative propagation helps to alter the size of the plant, i.e., dwarfing effect. This helps for
spraying, intercropping & harvesting of crops easy and economical.
❖ The vegetative way propagated plants bear fruits early.
❖ It encourages disease-resistant plants.
❖ The horticultural crops which do not produce viable seeds are propagated by vegetative
method.
Disadvantages:
❖ By vegetative propagation new variety can not be developed.
❖ It is an expensive method of propagation and required specialized skill.
❖ The life span of vegetatively propagated plants is short as compared to sexually propagated
plants.
❖ As all the plants are homozygous the whole plantation may get attacked by a particular pest or
disease.
❖ Viral diseases can be transferred through vegetative parts.
7. II. Methods of Irrigation:
a) Hand watering
b) Flood watering
10. Collection of Drugs
After cultivation of drugs, they need to be collected and processed prior to marketing. While
preparing for commerce, several methods are adopted to meet the standard pharmacopeia
requirements. Generally these methods include proper collection, harvesting, drying and garbling.
Collection:
➢ The time of collection of drugs should be appropriate in order to maintain its quality and quantity.
➢ The collected plant parts should be kept away from soil to avoid any contamination.
➢ The collected part should be thoroughly cleaned and placed in basket or bags to avoid mixing with
foreign matter.
➢ The drugs which constitute leaf and flowering tops of plants are collected just before they reach
their flowering stage(maturity) while the leaves of aloe are collected when they are sufficiently
thick.
11. ➢ Flowers need to be collected just before pollination or many a times, before their full expansion.
They are collected in dry weather and preferably during morning hours.
➢ Barks are generally collected in spring or early summer when cambium is active, as it is easy to
detach them form the stem. Sometimes, they are collected in autumn or in rainy season.
3 different methods for collecting barks are
a) Felling- In felling method, the tree is cut at base and bark is peeled out.
b) Uprooting- The roots are dug out and bark is stripped off from roots and branches.
c) Coppicing- In coppicing method, the plant is allowed to grow for a definite period and then cut
off at a specific distance from soil. The stumps remaining in soil are allowed to grow into shoots
independently yielding aerial parts. These new parts are cut off and bark is collected from shoots.
➢ The fruits are collected either ripe or half ripe but fully grown.
➢ The roots are collected in spring before the vegetative process stops. The are sliced transversely or
longitudinally to facilitate drying.
12. ➢ Rhizomes are cut when they store ample of reserve food material and maximum of
chemical constituents.
➢ The unorganized drugs such as gums, resins, latices are collected as soon as they ooze out
of the plant.
Harvesting:
➢ It is an important operation in cultivation technology.
➢ Medicinal plants should be harvested during optimal season or time period to ensure
production of medicinal plants materials and herbal products of best possible quality.
➢ Harvesting can be done efficiently by the skilled workers.
➢ It is a laborious job so may not be economical.
➢ The underground drugs are harvested by mechanical devices such as diggers or lifters.
➢ The roots or tubers are washed in water to get rid of earthy matter.
➢ Flowers, seeds and small fruits are harvested by seed strippers.
➢ Drugs which constitute aerial parts are harvested by binders for economic reason.
13. Drying:
▪ A drug should be processed properly to preserve it for longer time. This process includes
several operations or treatments depending upon its source and chemical nature.
▪ Drying involves removal of excess moisture content from the drug in order to improve its
quality and inhibit the growth of micro-organisms.
▪ Drying also facilitates pulverizing or grinding of a drug.
▪ The drugs are also sliced or cut into smaller pieces to enhance drying.
▪ The flowers are shade dried to retain their color and volatile oil content.
Depending upon the type pf constituent a drug contains, a suitable method from the following can
be used-
i. Natural drying (sun drying)
ii. Artificial drying (mechanical dryers)
14. i. Natural drying- It maybe either in direct sun or in the shed. If the volatile principles and
color of the drug are to be retained, the drug should be dried in shed.
ii. Artificial drying- artificial means of drying includes drying in oven (tray dryers), vacuum
dryers and spray dryers
Garbling:
➢ The next step in the preparation of a crude drug for market after drying is garbling.
➢ This process is desired when sand, dirt & foreign organic parts of the same plant, not
constituting drug are required to be removed.
➢ The quality of the drug suffers if the extraneous matter is permitted.
Examples:
Excessive stems should be removed in case of Lobelia and stramonium.
Pieces of barks should be removed from Gum Acacia.
Pieces of iron should be separated by using magnet before crushing and shifting for Castor seeds.
15. Storage of crude drugs:
➢ Preservation of crude drugs needs should knowledge of their physical & chemical
properties.
➢ All the drugs should be preserved in well closed and filled containers away from direct
sunlight and in a cool place.
➢ They should be stored in the premises which are waterproof, fire proof and rodent proof.
➢ A number of drugs absorb moisture during their storage and become susceptible to the
microbial growth which should be prevented.
➢ Apart from protection against adverse physical and chemical changes, the preservation
against insect or mold attacks is also important.
➢ Fibre glass or glass lined containers should be used for storage.
➢ Wooden boxes, paper bags or newspaper should not be used for preservation of crude
drugs.
➢ Air condition facility with dehumidifier is a must in the store room.