Today over three quarters of world population relies on herbal plants and products for health care, as they symbolize safety in contrast to synthetics. In India nearly 9,500 registered herbal industries and a multitude cottage level herbal unit depends upon continuous supply of medicinal plants for manufacturing herbal medical formulation. In fact, the major wild resource of medicinal plant required for herbal Industry is facing shortage due to non-availability of genuine plants due various problems like over-exploitation, deforestation, loss of habitat, extinction of rare plants, indiscriminate harvesting impairing the availability of raw drugs. The demand of medicinal plant is ever increasing but fails to meet supply with authentic drug giving rise to adulteration and irrational substitution affecting efficacy and safety of herbal medicines.

The concept of substitution in Pharmcognosy or herbal science mainly refers it as a part of adulteration which may be deliberate or accidental. Usually this practice includes substitution of original crude drug partially or fully with other substances which is either from or inferior in chemical properties and therapeutics.

Unlike above, in Ayurveda the concept of substitution differs in a way that the substitute drug possesses similar ‘guna’ i.e. the Rasapanchakas (Ayurveda Pharmacology) on the level of attributes with that of the original drug. That means the substitutes seemed to be intentionally selected and utilize rationally to achieve the desired effect. Usage of Pratinidhi is alternate to rare/extinct/difficult to unobtainble original drug. It can overcome the depletion of rare drugs, thus lend a support in conservation and sustainability of medicinal plants and provide a quality herbal formulation with economic feasibility.

Pratinidhi Dravyas are substitute drugs utilize for the drugs which are not available. It mainly deals with rational substitution intentionally selected of crude drugs required for medicinal purpose. This concept is referred from one of the Laghutrayi, Bhavapraksh written in 16th century A.D. As the list of substitute is first of its kind and this Nighantu is considered as latest among classical work in Dravyaguna Shastra.

As the main requirement for an appropriate Pratinidhi Dravya is to possess similar gunas to that of original drug, the Abhava Pratinidhi dravyas were compared on basis of their Rasapanchak i.e. Guna (properties), Rasa (taste), Vipaka (post digestion and metabolism effect), Veerya (potency) along with Karma (actions) and Roghanata (Indications).

Pratinidhi drugs serves to overcome the problem of un-available drugs due to scarcity, rare or difficult to procure. This in a way helps to produce good quality herbal products and lend a support in conservation and sustainability of medicinal plants. With proper revalidation of existing documented examples there is always a scope to find out new substitutes for Abhava Dravyas of todays time.
 
Pratinidhi Dravyas for Sthavar Dravyas (Substitute Drugs of Plant Origin)

Pratinidhi Dravya for Jangam Dravyas (Substitute Drugs of Animal Origin)

Pratinidhi Dravya for Ahariya Dravya (Substitute for Food Substances)