Ayurvedic Pharmacy

Chapter 27

Ayurvedic Pharmacy

INTRODUCTION

Ayurveda means the science of life. Since ancient times a variety of pharmaceutical have been used in Ayurvedic system of medicine and some of them are in practice even today, obtaining maximum therapeutic benefit and making recipe palatable. Different pharmaceutical processes are prescribed in ayurveda, called Aushadhana kalpna (medicinal formulations), which are prepared for the convenience of administration through various routes in different forms for different disease condition. These processes not only help in the isolation of the therapeutically active parts of the drugs, but also easily administrable, palatable, digestible, therapeutically more tolerable and more preservable. Ayurvedic dosage forms (formulations) can be grouped into four types depending upon their physical nature:

• Solid dosage forms, e.g. vatika, gutika, guggulu 

• Semisolid dosage forms, e.g. kalka, avaleha 

• Liquid dosage forms, e.g. asava, arista, swarasa, taila

• Powder dosage forms, e.g. churna

All the ayurvedic preparations consist of two words. The first word may indicate either the disease for which the preparation is used (Jwarantaka vati), or the property of the preparation (Kaameshwara modaka), or the drug contained (Arjuna arishta), or the name of some god or saint (Narayana taila) and the second word always indicates the type of preparation (Jwarantaka vati, Kameshwara modaka, Arjuna arishta, Narayana taila).

 MARKET POTENTIAL

• There is more recognition for nonallopathic system of medicines in the country now than in the past few decades. The concept of alternative system of treatment notably herbal and Ayurvedic medicines therapy is gaining ground and attracting attention worldwide. There is more and more scientific research being conducted in our country for treatment of various diseases by ayurvedic and herbaltherapy. A large number of diseases have ayurvedic treatment much superior to the other system of medicines, and this has been recognized world over.

• Thus, ayurvedic medicines/drugs are becoming popular day-by-day, and demand for its usage is increasing not only in the country but also worldwide for the inherent quality of having negligible side/after effects, which has made great potential for its production. A large number of medicinal plants, herbs, shrubs, etc., are available in our country in the hilly/forest regions. In order to boost the production of ayurvedic/herbal drugs, Govt. of India has also set up a board namely Indian System of Medicine and Homoeopathy to encourage production of ayurvedic medicines especially in the regions, where basic raw materials are available in plenty. Thus, there is a great potential for ayurvedic medicines not only in the country but for export purpose also.

 ASAVA AND ARISTA

Definition

• Asavas and Aristas are medicinal preparations made by soaking the drugs, either in powder form or in the form of decoction (kasaya) in a solution of sugar or jaggery, as the case may be for a specified period of time, during which it undergoes a process of fermentation generating alcohol, thus facilitating the extraction of the active principles contained in the drugs. The alcohol, so generated, also serves as a preservative.

Method of Preparation for Arista

• The drugs are coarsely powdered and kasaya is prepared. The kasaya is strained and kept in the fermentation pot, vessel or barrel. Sugar, jaggery or honey, according to the formula, is dissolved, boiled, filtered and added. Drugs mentioned as praksepa dravyas are finely powdered and added. At the end, dhataki puspa, if included in the formula, should be properlycleaned and added. The mouth of the pot, vessel or barrel is covered with an earthen lid and the edges sealed with clay-smeared cloth wound in seven consecutive layers. The container is kept either in a special room, in an underground cellar or in a heap of paddy to ensure a constant temperature is maintained during fermentation, since varying temperatures may impede or accelerate the fermentation.

• After the specified period, the lid is removed, and the contents examined to ascertain whether the process of fermentation (sandhana) has been completed. The fluid is first decanted and then strained after two or three days. When the fine suspended particles settle down, it is strained again and bottled.

Method of Preparation for Asava

• The required quantity of water, to which jaggery or sugar as prescribed in the formula, is added, boiled and cooled. This is poured into the fermentation pot, vessel or barrel. Fine powder of the drugs mentioned in the formula is added. The container is covered with a lid and the edges are sealed with clay-smeared cloth wound in seven consecutive layers. The rest of the process is as in the case of Arista.

General Precautions

• If the fermentation is to be carried in an earthen vessel, it should not be new. Water should be boiled first in the vessel. Absolute cleanliness is required during the process. Each time, the inner surface of the fermentation vessel should be fumigated with pippali churna and smeared with ghee before the liquids poured into it. In large-scale manufacture, wooden vats, porcelain-jars or metal vessels are used in place of earthen vessels.

Characteristics

• The filtered Asava or Arista should be clear without froth at the top. It should not become sour (cukra). The preparation has the characteristics of aromatic alcoholic odour.

Preservation

• Asavas and Aristas can be kept indefinitely. They should be kept in well stoppered bottles or jars. Examples: Asavas—Arvindasava, kumaryasava, vasakasava. Aristas—Dasmularista, asvagandhadyarista, ashokarista.

ARKA

Definition

• Arka is a liquid preparation obtained by distillation of certain liquids or of drugs soaked in water using the Arkayantra or any convenient modern distillation apparatus.

Method of Preparation

• The drugs are cleaned and coarsely powdered. Some quantity of water is added to the drugs for soaking and kept overnight. This makes the drugs soft and when boiled releases the essential volatile principles easily. The following morning it is poured into the Arkayantra and the remaining water is added and boiled. The vapour is condensed and collected in a receiver. In the beginning, the vapour consists of only steam and may not contain the essential principles of the drugs. It should therefore be discarded. The last portion also may not contain therapeutically essential substance and should be discarded. The aliquots collected in between contain the active ingredients and may be mixed together to ensure uniformity of the arka.

Characteristics

• Arka is a suspension of the distillate in water having slight turbidity and colour according to the nature of the drugs used and smell of the predominant drugs. Examples: Ajamodarka, jatamamsyarka, satapusparka.

AVALEHA OR LEHA

Definition

• Avaleha or lehya is a semisolid preparation of drugs, prepared with addition of jaggery, sugar or sugar candy and boiled with prescribed drug juice or decoction. They are also known as modaka, guda, khanda, rasayana, leha, etc.

Method of Preparation

• These preparations are made up of kasaya or other liquids, jaggery or sugar or sugar candy, powders or pulps of certain drugs, ghee or oil and honey. Jaggery, sugar or sugar candy is dissolved in the liquid, strained to remove the foreign particles and boiled over a moderate fire. After the paka is ready or in other words, when it sinks in water without getting easily dissolved, it is removed from the fire. With continuous and vigorous stirring, fine powders of drugs are added in small quantities to form a homogeneous mixture. Required amount of ghee or oil is added while the preparation is hot and mixed well. Honey is added at last when the mass is cool and mixed uniformly

Characteristics

• The lehya should neither be hard nor be a thick fluid. When pulp of the drugs is added and ghee or oil is present in the preparation, this can be rolled between the fingers. Growth of fungus over it or fermentation is, among others, signs of deterioration. When metals are mentioned, the bhasmas of the metals are used. In the case of drugs like bhallataka, purified drugs alone are included in the preparation. The colour and smell depend on the drugs used.

 LEPA

• DefinitionMedicinal preparations in the form of a paste used for external application are called lepas.

Method of Preparation

• The drugs are made into a fine powder and it is mixed with some liquid or other medium, according to the requirement of the preparations and made into a soft paste. The commonly used media for mixing are water, cow’s urine, oil and ghee.

Characteristics and Preservation

• They are stored in airtight containers. The lepas prepared from vegetable powders will retain their potency for 30 days, and those prepared using mineral and metallic preparations last indefinitely. Examples: Sinduradi lepa, dasanga lepa, etc.

VATI AND GUTIKA

Definition

• Medicines prepared in the form of tablet or pills are known as Vati and Gutika. These are made of one or more drugs of plant, animal or mineral origin.

Method of Preparation

• The drugs of plant origin are dried and made into fine powders separately. The minerals are made into bhasma orsindura, unless otherwise mentioned. In cases where parada and gandhaka are mentioned, kajjali is made first and other drugs are added, one by one according to the formula. These are put into a khalva and ground to a soft paste with the prescribed fluids. When more than one liquid is mentioned for grinding, they are used in succession. When the mass is properly ground and is in a condition to be made into pills, sugandha dravyas, like kasturi, karpura, which are included in the formula, are added and ground again. The criterion to determine the final stage of the formulation before making pills is that it should not stick to the fingers when rolled. Pills may be dried in shade or in sun as specified in the texts. In cases where sugar or jaggery (guda) is mentioned, paka of these should be made on mild fire and removed from the oven. The powders of the ingredients are added to the paka and briskly mixed. When still warm, vatakas should be rolled and dried in shade.

Characteristics and Preservation

• Pills and vatis should not lose their original colour, smell, taste and form. When sugar, salt or ksara is an ingredient, the pills should be kept away from moisture. Pills made of plant drugs when kept in airtight containers can be used for two years. Pills containing minerals can be used for an indefinite period.

Examples: Gandhaka vati, khadiradi gutika, etc.

VARTTI, NETRABINDU AND ANJANA

Definition

• Medicines used externally for the eye come under category of Vartti, netrabindu and anjana.

Method of Preparation

• Vartties are made by grinding the fine powders of the drugs with the fluids in the formula to form a soft paste. This is then made into thin sticks of about 2 cm in length and dried in shade.

• Netrabindu is prepared by dissolving the specified drugs in water or kasaya and used as eye drop. Anjanas are very fine semisolids of drugs to be applied with netra salaka.

Characteristics and Preservation

• Colour and smell depend on the drugs used. These can be preserved for one year if kept in airtight container. In case of formulations in which minerals are used, the drugs are preserved indefinitely.

BHASMA

Definition

• Bhasmas are the powdered forms of a substance obtained by calcination. It is applied to the metals, mineral and animal products which are prepared by two special processes, Sodhana and Marana in closed crucibles in pits and with cow dung cakes (puta).

Method of Preparation

• Sodhana: The process of purification is called sodhana in ayurveda. The process of purification is of different types, which depends upon the type of drugs used. The first one is Samanya sodhana and the second is Visesa sodhana, the first is applicable to a large number of metals or minerals by heating the thin sheets of the metals and immersing them in gomutra, taila, takra, etc., for removing toxicity— the latter is applicable only to certain drugs and in certain preparations.

• Marana: This stage is regarding the preparation of bhasma. The drug that is purified by sodhana process is ground with juices of the specified plants or decoction of drugs mentioned for a particular mineral or metal in a khalva (mortar and pestle). After the specified period of time, small cakes (cakrikas) are made and dried well under sunlight. The dried cakes are kept on a shallow earthen plate in single and closed with another plate. The edge of the plates are wound with clay-smeared cloth in seven consecutive layers and dried. The closed earthen container is kept in a pit half filled with cow dung. After keeping inside the pit the remaining portion of the pit is filled with cow dung cakes, and fire is put on all the sides. Once the burning is over, it is allowed to cool and the earthen container is removed. The contents of the earthen container is taken out and ground into a fine powder in a khalva. The process of marana is repeated as many times as prescribed in the procedure. The fine powders are packed in airtight glass or earthen containers.

• Bhasmas are yellowish, black, white, grey, reddish black and red coloured powders and do not have any characteristic taste. They are stable preparations and maintain their potency for indefinite period.

• Examples: Svarna bhasma, tamra bhasma, etc.

SATTVA

Definition

• Sattva is water extractable solid substance collected from a drug.

Method of Preparation

• The drug is cut into small pieces, macerated in water and kept overnight. Then it is strained through cloth, and the solid matter is allowed to settle. The supernatant liquid is decanted and the sattva is washed by repeating the process by adding water and decanted.

Preservation and Characteristics

• This can be preserved in a closed container. The colour varies from drug to drug. Example: Guduchi sattva.

GUGGULU

Definition

• Guggulu is an exudate (niryasa) obtained from the plant Commiphora mukul. Preparations having the exudates as main effective ingredient are known as guggulu. There are five different varieties of guggulu described in the texts. However, two of the varieties, namely mahisaksa and kanaka guggulu are usually preferred for medicinal preparations. Mahisaksa guggulu is dark greenish brown and kanaka guggulu is yellowish brown in colour.

Process of Sodhana

• Sand stone, glass, etc., are first removed 

• Then broken into small pieces 

Thereafter it is bundled in a piece of the cloth and boiled in dola yantra containing any one of the following fluids: 

• Gomutra 

• Triphalakasaya 

• Vasapatra kasaya 

• Vasapatra svarasa 

• Nirgnndipatra svarasa with haridra churna and 

• Dugdha

• The boiling is continued till the guggulu becomes a soft mass. It is then taken out of the cloth and spread over a smooth wooden board smeared with ghee or oil.

• By pressing with fingers the sand and other remaining foreign impurities are removed. It is taken out and again fried with ghee and ground in a stone mortar (khalva). This is called sodhita guggulu.

• The other method is to suspend the bundle of guggulu in dola yantra so as to remain immersed in the specified fluid as it is boiled. The boiling of guggulu in dola yantra is carried until all the guggulu passes into the fluid through the cloth. The residue in the bundle is discarded. The fluid is filtered and again boiled till it forms a mass. This mass is dried in sunlight and then pounded with a pestlein a stone mortar, adding ghee in small quantities till it becomes waxy.

Characteristics

• Sodhita guggulu is soft, waxy and brown in colour. Characteristics of preparations of guggulu vary depending on the other ingredients added to the preparations.

Preservation and Storage

• It should be kept in glass or porcelain jars free from moisture and stored in a cool place. The potency is maintained for two years when prepared with ingredients of plant origin, and indefinitely when prepared with metals and minerals.

• Examples: Triphala guggulu, yogaraja guggulu, laksa guggulu, etc.

KVATHA CHURNA

Definition

• Certain drugs or combination of drugs are made into coarse powder (javkut) and kept for preparation of kasaya. Such powders are called kvatha churna.

Method of Preparation

• Drugs are cleaned and dried. They are coarsely powdered (javkut), weighed as per formula and then mixed well.

Characteristics and Preservation

• Kvatha churnas retain potency for one year and should be kept in an airtight container. They are also called srta, niryuha and kasaya. Kvatha churna can be used for preparing kasaya, hima, phanta, etc. Examples: Amrtottara kvatha churna, ardhabilva kvatha churna, etc.

STANDARDIZATION OF AYURVEDIC PREPARATIONS

Ayurvedic medicines are manufactured under different pharmaceutical process to result in various dosage forms, such as extracts, tinctures, decoctions, pills, powders, tablets, capsules and semisolid pastes, jellies, syrups, etc. The general standardization protocols to determine the percentage of active medicaments could not be followed for ayurvedic herbal preparations. The procedures have to be modified in order to make the preparation safe. This is because of few reasons like:

• Ayurvedic preparations are polyherbal or herbo-mineral preparations.

• Even a single herb used in the preparation contains multiple constituents.

• Bio-active chemical constituents are not known in the herbal preparations, and even if it is known and compared with a marker, it does not necessarily reflect its connection with biological effects.

• The principle of holistic approach does not permit assaying a single marker.

So the approach has to be made from raw materials to finished products for the successful out come.

Raw Material Standardization

• Collection: Plants should be collected when their active principles are maximum.

• Botanical identity: Plants should be identified by botanist/taxonomist to distinguish from its related species.

• Identification of adulterants and substitutes: Quantitative microscopy, macroscopic and microscopic characters.

• Analytical data: (i) Ash values, (ii) Solubility profiles, (iii) Extractives values, (iv) Loss on drying, (v) Acid values, (vi) Saponification values and (vii) Foreign matter.

• Chemical identity tests: Tests for chemical constituents like alkaloids, glycosides, saponins, tannins, etc.

• Instrumental analysis: Main active constituents are quantified using chromatographic techniques and spectrophotometric methods.

• Pesticide/herbicide residues: Check whether these remedies are well within the limits.

• Absence of mycotoxins or aflatoxins: These toxins should be absent.

• Efficacy and toxicity testing. 

 Standardization of Manufacturing Process

Next to the raw material standardization the manufacturing process should be taken into considerations. Various process evaluation parameters in general are as follows:

For liquid/extractive formulations

• Solvent blend composition 

• Ratio of crude drug to solvent 

• Temperature 4. Length of time of extraction 

• Method of collection of extractives

• Method of concentration

• Light sensitivity during processing 

• Storage conditions, precautions during processing

For solid dosage formulation (powders, pills, capsules, tablets, etc.)

• Particle size distribution of drugs 

• Blending order and time of blending 

• Granulating fluid, binder concentration, granulating time 

• Drying temperature and time 

• Moisture content 6. Tablet Hardness 

• Tablet characters, such as disintegration, friability, etc. 

• Tablet weight and thickness control 

• Spray rate of film coating solution

Semisolid formulations

• Solvent blend composition 

• Extraction process parameters, such as amount of solvent, temperature, length of time, method of collection of extractives, etc. 

• Method of concentration 

• Semisolid blending time 

• Blend homogeneity 

• Viscosity/Rheological characters 

• Light sensitivity, storage and other precautions during processing

Finished products standardization

• Organoleptic properties: Colour, odour, taste and touch

• Physical characteristics: Viscosity, particle size, specific gravity, refractive index, etc.

• Chemical characteristics: pH, chemical tests/chemical identity/assay

• Biological characteristics: Efficacy and toxicity tests

• Microbiological parameters: Total viable count, yeast and mould counts, tests for the absence of pathogenic microorganisms

• Stability testing: To define shelf life of the product

• Storage condition

• Packaging systems/unit