Introduction
The chief aim of Ayurvedic system of medicine is equilibrium among tissues, which is defined as Dhatusamya in Ayurveda. This is also known as Karya. For production of the Karya, six types of Karanas are described in the Ayurvedic medicine treatise, Caraka Samhita.
- Samanya
- Visesa
- Dravya
- Guna
- Karma
- Samavaya
These Karana are further divided into two distinct types, which is based on the existence
- Actual existence (Sattasiddha) is which have a really existing influence.
- Virtual existence (Bhattisiddha) is the object that is more intellectual rather than real.
Dravya, Guna, and Karma out of the six Karanas, falls in the category of Sattasiddha. In other words, they are defined Sat Karana. Rest of the three, Samanya, Visesa and Samavaya, out of the six Karanas, falls in the category of Bhatisiddha. This means three Karanas (Samanya, Visesa and Samavaya) do not exist with their individual existence. Their existence is seen to be with Dravya, Guna, and Karma (Sat Karana).
Samanya and Visesa forms the basics of treatment in Ayurvedic system of medicine. Samanya and Visesa are not in a position to act without Sat Karna (Dravya, Guna, and Karma). Hence, treatment in Ayurvedic system of medicine is based and carried only and only by Sat Karana.
Out of Dravya, Guna, and Karma, treatment is chiefly based on Guna. Dravya is said to be prime, it has no existence without Guna (Physical property) and Karma (pharmacological property). Dravya is the basic cause in which other Guna and Karma always remain with samvaya sambandha. In other words, Guna and Karma are never separate from the Dravya. Guna is in unmanifested form in Dravya and is manifested when combines with the body. The basic principle of Satkaryavada states that karya remains present in the karana before the stage of manifestation.”
Definition of Samavaya
Samavaya refers to permanent an inseparable and inherent relationship between two substances. This can be roughly defined as strong bond between two chemicals.
Charka Samhita says that dravya (substance) is highly organized moiety. Ayurvedic system of medicine believes in using drug as a whole rather than isolation of the active principles, a point related to organized nature of the dravya (substance). Here we can see samavaya relationship existing between array of phytochemicals present in the dravya or drug. When active constituent are isolated, dravya losses its organized character and chances of having side effects are high.
Parameters like taste, property are present in the dravya only. According to Ayurveda, a drug works on seven parameters and these have been provided to the dravya naturally. It again proves the significance of dravya. • In preparing Ayurvedic poly-herbal drug, dravya is main ingredient. Decoctions, infusions, and powders are prepared from drugs of natural source.
Dravyaguna involves study of rasa, guna, virya, vipaka and Prabhava. Dravya can be defined as store house of guna and karma, another point proving samavaya (inherent) relationship between dravya and guna plus karma. Dravya refers to medicine and guna and karma represents physical property and pharmacological property and these having definitely inherent relationship.
Dravya are Classified According to Specific Action
1. Dosha prashamana
In Ayurveda the disturbed biological humours vata, pitta and kapha are considered to be the root cause of all diseases. Texts have described various drugs or methods to pacify the disturbed humours. Oil application and internal administration is best option for pacifying vata humour.
2. Dhatu pradushaka
Some drugs aggravate the biological humours and disturb the function of body tissues. Ayurveda has described various diet incompatibilities and contraindications for drugs. For instance a drug aggravates pitta humour in a person or produces pathology in blood tissue; this is refereed to dhatu pardushana.
3. Swasthahita
Some drugs help in maintaining good health of human body and mind.
Dravya are classified according to therapeutic actions also. Drugs are used for pacifying disturbed biological humours (sanshamana dravya). Sometimes drugs are used for removing humours from the body (samshodhana dravya). In modern science drugs are classified according to therapeutic use. For example a drug used for lowering blood sugar is known as hypoglycaemic agent. All these are based on samvaya relationship between the dravya and guna+karma.
These ayurvedic formulations, single or polyherbal, have been standardized chemically. Standardization of Ayurvedic formulations requires a rational approach. In this regard, the basic fundamental aspects of Ayurvedic system of medicine should be preserved. The main barrier in Ayurvedic drug standardization is the biological source of the drug. The active ingredient can vary according to the geographical source of the herb or medicinal plant and it thus may not be easy to standardize the drugs chemically on chemical basis. Ayurveda gives importance in using drug as a whole, instead of isolating the active ingredients, a point based on samvaya realtion between the drug and the active ingredient.