The basic aim of the treatment of Ayurvedic medicine is in correcting the imbalance of the three biological humors. The scholars of Ayurveda developed particular procedures for testing the potency of the drugs.
Dravya is described as substance used for medicinal action. According to Ayurvedic theory, every component of the universe is substance (dravya) and has medicinal value. Drugs derived from herbs, minerals and animal source, all are dravya. Charaka Samhita describes substance (dravya) to be the core of Ayurvedic pharmacy.
Taste has got significant place in Ayurvedic medicine. The diagnosis of a particular disease is based on imbalance in three biological humours (vata, pitta, and kapha). The treatment is based on six tastes (sweet, sour, salt, pungent, bitter and astringent). Three tastes increases each of the biological humours and three decreases them. This is a basic concept of Ayurveda but exceptions are always there.
Property (guna) is a vast topic. Ayurveda described 41 guna, which are described as physical properties of the drugs. Among 41 guna, every guna plays a specific role in designing Ayurvedic drug formulations.
Virya (potency) is described as active constituent of the drugand is responsible for pharmacological activity of the formulation. The drugs have cold and hot potencies. Vipaka and prabhava parameters are comparable with metabolism and therapeutic activity of the drug. Karma parameter describes pharmacological activity of a drugs in a detailed fashion.
The pharmacological, toxicological & clinical efficacy of a drug are attributed to rasa , guna,virya,vipaka & prabhava. The pharmacological (pharmacodynamic & pharmacokinetic) actions of Ayurvedic drugs are difficult to be explained in terms of clinical pharmacology. Ayurvedic drugs are not the single chemical entity as found in case synthetic drugs.
The substance (padartha) that explains about the very much difference between two substances is known as Vishesha. Vishesha is better known as dissimilar or opposite or different.
According to Chakrapani: Bye the use of similarity (Samanya) and dissimilarity (vishesha) at a particular time, samana tissue (dhatu) is increased by samany substance (dravya) and vishesha tissue (dhatu) is decreased by vishista substance or dravya (Pravruttirubhayastu – ubhayasya samanyasya visheshasya).
One of the fundamental principles of Ayurvedic way of treatment is the Fundamental principle of similarity (Samanya) and dissimilarity (vishesha). Substances can always be increased by consumption of similar food-stuffs and can always be decreased or depleted by by consumption of dissimilar food-stuffs. The human body responds to samanya or vishesha in the identical fashion.
In our article on Samanya Vigyaniyam (Fundamental principle of Similarity), we have described how mamsa can increase mamsa. For details you are requated to refer to the article. However, there are certain barriers or conditions which can cause exception to the fundanetal rule of Fundamental principle of Similarity. As an instance, Amla or Indian gooseberry) is sour in taste so it should increase the Pitta by similarity in quality of sourness between Amala and Pitta (Gunansamanya). Opposite to this, it does not happen due to cold nature of Amala, a property just opposite to hot character of the Pitta.
Ghrita is cool and unctuous in nature and it should counteract the heat or agni. On the other side, ghrita increases the agni or digestive fire and pitta by prabhava (specific action). It is absolutely must to study the Fundamental principle of decrease or increase due to activities. As an instance, sleep increases kapha, it means due to lack of exercise and activities, the biological water, kapha is not consumed in the human body and increases, in turn. By the fundamental rule of Samanya (similarity) and Vishesh (dissimilarity), a drug used in rational manner strengthens the humours that have become feeble (due to Samanya) and reduce the humours that increases out of proportion to create the dis-equlibrium (due to Vishesh). A practical application of Samanya (similarity) and Vishesh (dissimilarity) principle is a important component in selecting a effective schedule of treatment.