RESUMO
BACKGROUND: Since ancient times, the essential element sulphur has played an important role in different medical fields. It is one of the main materials used in herbo-mineral pharmaceutics in Ayurveda. However, for Ayurvedic pharmaceutical preparations, the purity of sulphur is crucial in avoiding any harmful reactions and to enhance the medicinal quality. Therefore, it is subjected to a process called 'gandhaka shodhana' using cow's milk, ghee or occasionally plant extracts. The plant, Eclipta alba (L.) Hassak, containing many bioactive compounds, is one of the extracts known to be used in the 'shodhana' process of sulphur. However, in comparison to the laboratory purification method of sulphur neither the effect of this 'shodhana' process in removing impurities from sulphur nor its effect on the structure and morphology of sulphur has been evaluated. OBJECTIVES: This study identifies physical, morphological, and structural changes that occur in sulphur when it is subjected to the 'shodhana' process compared to the changes that occur in sulphur obtained after simple laboratory purification. METHODOLOGY: Both samples were characterized using Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, X-ray Diffraction, Differential Scanning Calorimetry, Thermogravimetric Analysis, Fourier Transform Infrared spectroscopy, and Raman spectroscopy. Observed physical changes such as colour, allotropic form, odour, hardness, transparency, and lustre of the samples were also determined using recommended techniques. RESULTS: Although the laboratory purification method separates the sulphur from physical and chemical impurities, Ayurveda 'shodhana' process with E. alba converts the sulphur into a more pharmaceutically suitable form by making it more nebulous and introducing higher brittleness, FT-IR data shows removal of chemical impurities from sulphur during 'shodhana' process in contrast to laboratory purified sample.
