Arka and its pharmaceutical attributes in Indian alchemy (Rasashastra): A comprehensive review

Rasashastra, a branch of Ayurvedic system of medicine, deals with the pharmaceutical procedures of drugs of metallic, mineral and poisonous origin. These drugs are processed by some unique prescribed pharmaceutical techniques including Shodhana (purification process), Jarana (incineration) and Marana (calcination) that renders them fit for internal administration. Some specific groups of drugs of herbal origin viz. Marak gana (group of calcifying herbs), Dugdha varga (group of latex bearing plants), etc. are used for these procedures which primly include medicinal plants.Arka, (Calotropis procera Ait. and Calotropis gigantea L.R.Br.) one of such plant from the semi-poisonous group finds manifold usage in these purification procedures and incineration techniques for many Rasaushadhis. Still, single hand information on the collective information regarding the use of Arka in various processing techniques in Rasashastra is deficient. Hence, a thorough review from available 37 texts related to Rasashastra was made and the necessary supplementary references of nano particles was found out through available resources from internet. After a critical analysis, a total of 133 references were found wherein the usage of Arka has been highlighted in different pharmaceutical processes in texts of Rasashastra. Among them, thirty eight are related to procedures of shodhana and marana of Parada (mercury), nineteen deal with procedures concerned with Maharasa, six and three respectively in case of Uparasa and Sadharana (mineral origin) rasa along with fifty five processing techniques of  varied  dhatus (metals).