Abstract
Background: Mercurial preparations are used as medicines in Ayurveda. Many procedures are mentioned in the texts to purify and detoxify mercury before its use as a medicine. Gandhaka Jarana viz. treating Parada with Gandhaka is one of them. It is claimed that, it not only implants the property of bioavailability to Parada but also increases its therapeutic efficacy. As per textual claims of Rasashastra, there is difference in the products of respective Gandhaka Jarana. To know details and rationality of Gandhaka Jarana, it was decided to screen and review the studies related with it.

Materials and Methods: Few studies were carried out in the department of Rasashastra and Bhaishajya Kalpana of our institute like concept of Gandhaka Jarana, pharmaceutical procedures, chemical characterization, experimental and toxicity studies, study of therapeutic efficacy, etc for dissertation and thesis work. These studies were collected through departmental library, screened and reviewed. Along with this published research articles related with Gandhaka Jarana were reviewed. Results and

Conclusion: Gandhaka Jarana having definite role in the mercurial preparations. The screened and reviewed studies showed that increase in number and quantity of Gandhaka Jarana induces major differences in the finished mercurial products. Rasasindura prepared Samaguna Gandhaka Jarana and Shadguna Gandhaka Jarana shows major difference in the analysis of finished product. Analytical studies of Makaradhwaja revealed that Makaradhwaja prepared by Triguna Balijarana shows 300.1 ppm of gold in finished product, whereas 12131 ppm of gold in Shadguna Balijarita Makaradhwaja. Scholars have also mentioned that increase in the number of Gandhaka Jarana of Makaradhwaja reduces the concentration of Parada (Mercury) in the finished product. Clinical and experimental studies of the same products also indicate that increase in number of Gandhaka Jarana increases the efficacy of product. All reviewed studies in different aspects viz. analytical, experimental, and clinical shows that Gandhaka Jarana has a definite role in the mercurial medicinal preparations.

Key words: Cinnabar, Gandhaka Jarana, Mercury, Mercury sulfide, Kupipakwa Rasayana