Dravya Sangrahana (collection) and Samrakshana (preservation)
Collection and preservation of Ayurvedic raw material is well explained in Ayurvedic texts. Ayurveda is a science of life and art of living the knowledge of life science bestowed health and longevity in the form of preventive and curative measures. Dravyaguna is a branch of science which deals with all drugs used in the treatment of diseases, their source, collection, preservation, preparation dosages and uses.
Collection of specific drugs played utmost role in Ayurveda. In Ayurveda has considered that all the drugs are made up of pancha mahabhoota. Therefore, due consideration should be given to the type of land, soil, direction, users, etc. The herbs should also have some characters, not affected by smoke, rain, air or water and also collected in respective season. Drugs must have single predominant taste, well developed, strong such drug may be collected preserve for therapeutic utility.
After collection of the drugs as mentioned above, preservation and protection is equally important. Otherwise the drugs once spoiled cannot be used in treatment. Drugs are maintained in a sound condition by adopting proper storage and a study of the causes of deterioration enables one to perceive the general principle which must govern the condition of storage. Drugs need preservation for future use in treatment.
Optimal timing for usage
There is a limitation for the development of every food and medicinal plant. Time consideration is important for plants. Any plant unless fully grown and completely developed does not acquire its attributes of properties and actions mentioned in the books are those of the mature plants, immature plants, if used, do not show the desired effects. Some drugs matue in summer, some in winter and rest in the rainy season, flowering and fruiting makes the plant rich in its properties.
Latex of a plant should be collected before sunrise. Milky juice of cactus is never collected before the plant is two to three years old. Consideration of time for such collection method is important. To observe the effect of a drug on the body, every second, minute, hour, morning, afternoon, evening, month, year, etc. ae considered. Similarly, in the patient, various stages of digestion like aam, semi-digestion, full digestion, prerigor sage, pyretic stage, etc. are also important.
Drugs – their collection & preservation
Ayurveda has considered that all the drugs are made up of Panchamahabhootas.
Substances of any use, medicinal or dietary are intimately related to the type of land in which they are produced. Therefore, due consideration should be given to the type of land, i.e., soil, land, which ultimately determines the Gunakarma of Dravyas, produced in it, it is classified into 5 types. Though soil is Panchamahabhoota, its composition in relation to individual Mahabhoota varies at different places, hence the change in properties and action.
Parthiv – This type of soil containing stones, is hard, black, with tall tries and grass.
Aapya – This soil is of different colours, full of small stones, brownish white coloured and grassy.
Tejas – Dry, ash coloured, trees scatered dry, hollow and grassy.
Vavyaveeya – This soil is soft but uneven, water tasteless, trees of useless varities, large mountains and blackish colour.
Soil & water are responsible for the formation of Rasa just as Panchamahabhootas forms various dravyas, herbs, shrubs and climbers continuously ingest water. Water is devoid of Rasa but it is expressed in climbers and plants because of contact with the soil. Therefore, soil and environment become important factor while considering the dravyas.
As all the medicinal dravyas from various sources are related to soil, its study for fertility and usefulness becomes essential.
Infertile land, uneven pits, deep trenches, collection of dirty and waste water, heaps of ant hills, funeral place, temples and desert land are indicative of infertile land.
Fertile land – land having even surface, salt less near pond or late, where grass grows, soft black, white or red color without cultivation containing only medicinal plants and no other vegetation, jungle and sadharan land is considered to be fertile.
The possibility of underground gold, silver, iron or copper can be judged by the habitat and growth of plants in that region. It is also rational to think that the same Guna acquired from the metals into the plants would be useful as medicine.
Irrespective of the type of the crude drug and the area of collection, these can be two options that the drug should be collected when they contain maximum concentration of active constituents. The advantage of the environmental conditions is also taken into consideration while collecting the crude drugs. The drug which constitute leaf and the flowering tops are collected just before they reach flowering stage (maturity).
eg; Senna digitalis, vinca, belladonna, etc., the leaves of the aloe are collected when they are sufficiently thick, flowers need to be collected just before pollen or before their full blooming.
eg; saffron, clove buds, chamomite, etc. the barks are generally collected in the spring or early summer when the combium is active as it is easy to detach them from the stem. Sometimes, they are collected in autumn (wild cherry) or in rainy season (cinnamon), fruits are collected just before their dehiscence of bael and tamarind after their fully maturity while caraway, fennel and coriander are collected when they are fully ripe. Rhizomes are collected after full vegetative growth of plants, ginger and turmeric. The roots are collected in spring. Before the vegetative procedure stops, Rhizomes and roots are collected when they store ample of reserve food material and maximum contents of chemical constituent. The unorganized drug such are resins, gums and lattices are collected as soon as they ooze out of the plant. The general opinion is that the time of collection should coincide with the time when the active ingredients are at their maximum level. They should also be free from insect infestation.
Drugs need preservation for future use in treatment. The should be easily available. A drug used as medicine should not come in contact with bacteria, insects, poison, instruments, smoke, sunshine, air, fire and water. Plants with deep and thick rooks, fulfilling the essential properties of rasa, guna, colour, smell and proportion and plants grown in favourable season are suitable for proper preservation and treatment of diseases.
In India, the Himalayas lie towards the north and there is a belief that moon which is the guardian of the north is the ruler of plant kingdom. Therefore, plants gown in the Himalayas and in the northern region, are considered of the best quality and their use is advocated.
The use of Tinospora cordifolia, Asparagus racemosus and Herpestis moniera are advocated in fresh form and therefore should not be preserved.
Honey, piper longum and embelia ribes should be used after preserving these for one year. The time is required for their maximum efficacy.
Method of drug preservation
For collecting the plants grown in suitable soil as mentioned above, a person should pluck or uproot the plant after a bath wearing white clothes, mind stabilized by reciting shlokas, praying to gods, Ashwinikumaras, cow, brahmin and faithfully facing the north or east direction. East indicates vitalizing the plant energy through the sun and north is the symbol of the moon, the ruler of plants. Similarly, regarding time, pushya nakshatra, ashwin nakshatra and mriga nakshatra are considered to be superior. Moon being the ruler of pushya and mriga nakshatra, it (moon) transferred its properties into the plant during these nakshatra. This must be related to aptopadesha.
Just as man is controlled by cosmos, plants ae also under the influence of the cosmos. Therefore, the study of environment for their preservation is essential. Plants collected in the rainy season always tend to perish, therefore rainy season is unsuitable for preservation. Also perennial plants are immature in their Rasas during rainy season. Generally some are plucked at the end of winter and some at the end of autumn since they are fully enriched with their Rasas.
Specific period of preservation
While preserving the plant, its useful parts should also be given due importance. Generally, the part or the specific portion which is considered for use, must grow full – maturity.
According to Rajagnighantu, Tuber – Hemant, Root – Shishir, Flower – Vasant, Leaves – Greeshma & Panchang Sharad.
According to some other acharyas, root – pravrutt, leaves – varsha, bark – sharad, latex – hemant, juice vasant, fruit greeshama.
Useful parts- Period
Branches- Rainy season or autumn
Leaves- Rainy season or autumn
Root- Summer or winter
Bark, Tuber & Latex- End of summer or the beginning of winter, latex of calotropies procera to be collected at the beginning of summer and End of winter.
Flower, fruit- Blossom and fruiting period of the specific plants.
Veerya in drug procurement
Above mentioned seasonal view may not be useful while considering veerya. Instead of considering specific parts in specific season for drug collection due importance should be given to its veerya. Sheeta veerya drugs which possess madhur snigdha & sheeta gunas should be collected during visargakala while ushna veerya drug which possess tikta, ruksha & ushna, properties must be collected in adan kala.
Consideration of karma in drug procurement
Similar to veerya, consideration of the action of drug is also important. To bring about effective purgation, the drug must be collected from the soil containing prithvi & jala mahabhootas which have a tendency to move downwards. Similarly, for emesis, the drug should be collected from soil predominantly containing agni and vayu mahabhootaswhich tend to move downwards. Drug acting for both the purposes must be collected from soil containing akash Mahabhoota so that the expected action is achieved.
Sharangdhar mentions that for emetic and purgative action drug should be collected at the end of vasant ritu and for rest of the action in the sharad rutu but the best period is when they are enriched with their Rasa.
Collection of dietary item
Food contains different part of plants like fruit, tuber, seed, panchang, etc. – Sushruta has laid down the following guidelines:
Fruit – Only ripe (not raw or over ripe), fruit are collected. the exception is Aegle marredes which is collected in a raw form which is very effective fruits which are diseased, insect affected, untimely grown, affected by fire or cold or artificially ripened ae not to be collected.
Vegetables – over ripe, worms and insect affected, spoilt, grown in dirty soil, untimely tasteless and dried vegeable should not be collected (exception is raddish). Vegetables which are soft, maatue, unspoilt, grown in proper season and soil are wet are advocated for consumption.
Kanda – Tuber which are raw, untimely grown, old, diseased and eaten by insects should be discarded. They should be well nourished, timely grown and pest-free.
Cereals – Cereals which are affected by too much heat or cold fire, poisonous gases, insect affected, wet grown in unsuitable soil, untimely, with other cereals and valueless should be discarded and those of suitable quantity must be collected.
Collection of drugs of animal origin
Similar consideration must be given to the collection of drugs of animal origin. Animals from whom blood, hair or nails are to be collected, must be fully grown. (These animals mature at ¼ th the age of the total life span of the species.. this span varies with different species.) Similarly, milk, urine, etc. of animals should be collected after complete digestion of their food.
Preservation of drugs
After collection of the drug as mentioned above, preservation and protection is equally important, otherwise the drugs once spoiled cannot be used in treatment for this season, the drugs in the store room must be protected from wet soil, dust, water, fire, smoke, dirt, vapour, rats, cockroaches, ants, flies, etc. Even the containers like vessels, jars, drum, etc. must be such that they will not affect the rasa, properties and action of drugs.
Efficacy of sheeta veerya drugs increases if kept in cold storage or refrigerator. At least it will not decrease. In olden days, such medicines were kept in earthen pots, coconut kernel, covering of hard fruits and brass vessels. But now many varieties of containers are available where it can be protected in a better way.
Potency period of the drug
The main aim of collection and preservation of the drug is to maintain its potency by conserving its properties and action. Even the best selected and protected medicine loses its effectiveness after a certain period. Generally they are potent for one year. Therefore, a proper label giving the date of manufacture, batch number and the expiry date must be attached.
The successful preservation of drug depends on air, changing seasons, container and packaging. Then the potency of a drug will be preserved for a longer period. Sunshine, humid air, rainy season, torn or open container immediately depotentiate the drug, making it ineffective.
Preservation of fresh and dried specimens
Different methods are followed for preserving dry and green plants. This is useful for identification.
Leaves of the plant in intact condition must be pressed between two sheets of blotting paper to absorb humidity. Then they must be stuck or stitched to the paper, treated with liquid hydrogen perchloride or clipped in gelatine and then dried. This process helps preservation for a longer period.
Better than this method is the preparation of mega slides. It maintains the natural colour, appearance and shape of the specimen and hence it is more suitable.
Method of preserving the specimen of plants in natural state
(Dr. Mrs. Shyamalatai Chitale’s technique)
- Branch of a tree or a creeper bearing leaves and flowers or small sprout with the primary root is collected and immediately dipped for 5 minutes in the mixture mentioned below. If the flowers and leaves are too delicate for the mixture then the sample must be sprinkled with the mixture and then spread on blotting paper for 1-2 hours under pressure. The mixture is prepared by 5 to 1- gms. of tannin powder dissolved in 500 ml of water boiled and filtered and preserved in glass or stainless steel container or jar with a tight lid.
- 10 gm. of camphor & 10 gm. of menthol are mixed with equal quantity of castor oil and kerosene to make up to one litre. Camphor & menthol take 10-15 minutes to dissolve uniformly in the mixture. The solution should be applied to a paper with help of a brush and then spread over the sample. Another paper is kept on the sample after spreading it with the mixture. Then the sample is wrapped between the two papers. A hot iron is used to dry the sample by pressing the upper paper which is removed repeatedly to test the dryness of sample. Then it is transferred between the cloth fold and again a hot iron press is used to absorb the remaining moisture by the cloth. Left over solution makes the sealing of the sample in a polythene bag , difficult.
- A sample prepared in the manner described above is scaled in a polythene bag for the process, a sample is kept between two polythene sheets of required thickness and then transferred between the fold of the cloth bag. A hot iron press is applied over the cloth. The two polythene paper stick together because of the pressure and heat applied. While sealing the polythene bag it is repeatedly observed that excess of heat is prevented which may burn or wrinkle the polythene bags. Practice, experience and a use of proper hot press makes the sealing optimum. Principles of this method and its advantages – Tannic acid is the best preservative of the colour even then excess of acid may change the colour, for example, Hibiscus rosa sinesis change from red to voilet many times. Citric acid is used along with tannic acid to preserve the red colour. Application of lemon juice over the hibiscus flower for 3-4 minutes induces dehydration and pressure the rend colour of the flowers.
- Pressure and artificial heat of the hot press dehydrates the sample rapidly. Infiltration of this oily mixture helps to preserve and protect the colour of the plants. Oily mixture also makes the sample transparent for examination of the internal structure as well as protect it from insects and fungi.
- Oil mixture makes the sample soft and elastic sealed polythene bag protects it from becoming friable and also makes it easier to observe the sample from both dorsal and ventral surfaces. This transparent sample can be better studied under the microscope. Overall, it helps to identify the sample in an easy way.
Chitale’s technique is the best modern preservative method to study plants. Even then the old method of preservation should be known and was as follows:-
Collected fresh and wet leaves after cleaning and drying were kept between two sheets of blotting paper under pressure in a frame. Humidity is absorbed by the blotting paper and the required aeration is given by opening the press intermittently. Wet paper is also changed frequently. By this process, the sample dries subsequently it can be glued or tied to drawing paper before this process it is treated with a solution of 1:1000 hydrogen perchloride to protect it from insects, mites and fungus.
In this method, even after following all the precautions, the natural colour fades and gets spoiled by air after some days. Rainy season is not suitable for preservation by this method as no precaution can prevent fungal growth in this season. Best season is between October & June.
The process of preservation of fresh plants
Green wet plants dipped in 5-10% formalin in an air tight jar remains for many years in the original form which can be used for identification of the plant. For medicinal use, these plants are incorporated in formulations which are based on honey oil or ghee, fruits and vegetables are preserved in air tight jars, wet plants can be preserved in polythene bags for a long duration (needs scientific research).
While preserving fresh power or tablets the old ones must be discarded completely to prevent the danger of using non-effective drugs. Wet & fresh vegetables can be preserved for 7-8 days in air tight plastic bags.
Ref: Sushruta sutra 37/12-13
Drugs whether fresh or old and emitting a contrary smell or in any way affected as regards their natural sap or juice should not be used for pharmaceutical purposed. The virtues of such medicinal drugs and substance such as vidanga, pippali, madhu improve (after a year). Accordingly, all drugs and medicinal herbs excepting the preceding ones should be used fresh and unsoiled or uninjured by insects.
Guidelines regarding collection of individual plant parts
1. Stem – This is ideally collected when the plant has reached maturity and full growth. The special period for the harvesting of stem is when the interior part is collected after 20 years. Guduchi should be at least 2 years old before collected.
2. Stem bark – should be collected in Sharad rutu.
3. Fruit – are collected according to yielding season and when they achieve full growth and maturity. Eg: Amalaki fruits which can be dried and preserved. those which are used fresh.
4. Branches – should be collected when the tree is shedding its leaves as in cold season. eg: Teja patra.
5. Root – Grishma season
6. Flowers – should be collected during vasantha ruthu since this is the flowering season. However, there are many exceptions like Kutaja tree flowers during the Varsha rutu and jasmine flowers during Grishma rutu.
Generally speaking, flowers should be collected according to the season when they bloom.
7. Leaves – tender leaves should be collectd during vasantha ruthu and well grown mature leaves should be collected during vasantha ruthu. Generally the leaves should be collected before the following season:
Special direction for collection
When the roots are very big and thick the roots bark should be collected. eg., Brahat panchamula are to be collected the innermost part of the stem, i.e. the sara has to be collected.
Collection of herb according to their potency
Collection schedule of different part of the drug
- Underground parts should be collected after shedding to facilitate regeneration.
- Generally collected in autumn in 1st year of growth or in spring before the beginning of 2nd year growth as root and other underground parts are the storage organ and accumulate active principle during the summer.
- Do least cligging for the collection of underground parts.
- Tubers/bulbs should be collected during flowering because this aids in identification of the species.
- Bark should be harvested from mature plants during spring or autumn because this time when the flow of sap is at maximum and bark radically detached from the wood.
- Collected from the branches instead of main trunk.
- Do not harvest when plant is sprouting.
- Do not peel whole bark of plant.
- Strip the bark longitudinally and not all over the circumference to trunk / branches.
- Cut into small pieces to facilitate complete drying .
- Do not remove all the branches of plant.
- Harvest only mature branches for stem.
- Dry the herbs properly before packing and storing.
- Leaves, flowers, fruit seeds and floral should be harvested when they are mature.
A preservative is a substance which is added to pharmaceutical formulations to prevent or inhibit the growth of micro organism in the preparations. They are added to all formulations which are to be stored for long period of time and the ingredients of which support microbial growth. The emulsions and suspensions (eg., Phanta, Kvatha) containing H2O and carbohydrates as emulsifying and suspending agents respectively must be suitably preserved because water and carbohydrates provide very good medium for the multiplication of bacteria and molds.
A preservative is unnecessary in multi dose containers prepared by heating with bactericide because they already contain a lethal substance, nor they are necessary in preparations which contain medicament having bactericidal properties.
Choice of preservative
- It should be effective against a wide rage of microorganisms.
- It should be compatible with other ingredients of the formation.
- It should be soluble in aqueous phase when used in emulsion.
- It should be non-toxic.
- It should be free from odour and taste.
- It should preserve the preparation and remain stable for the shelf life of the products.
No single preservative possess all the qualities, therefore it becomes necessary to use a combination of preservatives to prevent the growth of microorganisms. The most commonly used preservatives are as follows:-
- Benzoic acid and sodium benzoate 0.1 to 0.2%
- Salicylic acid 0.1%
- Phenol 0.2 – 0.5%
- Chlorocresol 0.05 – 0.1%
- Alcohol 15 – 20%
- Chlorobutanol 0.5%
- Phenylmercuric nitrate 0.002 – 0.005%
- Scorbic acid & its salt 0.05 – 0.2%
- Benzalkonium chloride 0.004 – 0.02%
- Methyl paraben & propyl paraben 0.1 – 0.2%