Standardization of Lokanatha Rasa – A Classical Mercurial Preparation
Herapathdeniya SKMK
Paranagama PA
Ranasingha Shirani JG
ABSTRACT
Rasa Shastra is a main pharmaceutical branch in Ayurveda. Lokanatha Rasa (LKN), is a mercurial preparation, indicated for various liver and spleen disorders. This study was aimed to conduct standardization of LKN used in Ayurveda treatments using physicochemical and modern technical parameters, employing advanced instruments like particle size analyzers, XRD, SEM, and ICP-MS. Organoleptic characteristics of the ingredients and final product in the powder form were tested based on classical parameters such as Varna, Gandha, Sparsha, Varitharathwa, Rekapoornathwa and Gatha Rasathwa. Results showed the total ash value of 85.25±0.1%, water-soluble ash value of 9.08±0.04% and acid-insoluble ash value of 3.50±0.2% which are within the acceptable range for a mineral powder form preparation. Loss on drying of 0.34±0.2% shows low moisture content and pH of 8.1±0.1 shows an alkaline pH suitable for the gastric mucosa. Microbial testing indicated absence of E. coli, Coliforms, Pseudomonas and Salmonella, with acceptable limits for aerobic plate count, yeast and molds. The average particle size of the LKN samples was <4.57 µm. FTIR analysis revealed characteristic absorbance peaks between 1792cm-1 and 417cm-1, while SEM micrographs revealed various crystallite shapes (rod, round, square, and cubic). XRD confirmed the presence of inorganic mercury (HgS), with no elemental mercury. ICP-MS analysis revealed absence of Arsenic and Cadmium, Lead level below the WHO limits and Mercury level above the WHO limits. However, an ICP-MS analysis indicates the total mercury level of a product. But in this preparation, Mercury is present as HgS, which is proven as a non-toxic compound to the human body in previous research studies. These findings establish a fingerprint profile for LKN, aiding its standardization and quality control.
Key words –Lokanatha Rasa, Mercury, Rasa Shastra, ICP-MS, X-ray diffraction