The present invention is the process for bio synthesis of novel nano arsenic trioxide defined by its low toxicity, higher bio availability and nano particle size with the aid of buttermilk, goat urine, dolichos biflorous and other plant materials such as ginger, momordica charantia and musa paradisica. The invention is carried out in different steps involving purification of crude form of arsenic trioxide by boiling it with buttermilk, goat urine and extract of dolichos biflorous in subsequent steps, followed by the trituration of the bio purified arsenic trioxide with extracts of ginger and momordica charantia in subsequent steps and heating of the dry product obtained after trituration with musa paradisica resulting in the production of novel nano arsenic trioxide. The said novel product is effective in the treatment of various diseases including different types of cancer in animals, humans. The novel nano arsenic trioxide obtained through the present inventive process is less toxic with higher bio availablility. Its applicability extends to treatment of plants, agriculture, nano technology and other fields where arsenic trioxide can be used.
