Kupipakwa Rasayana Preparation Method
All the RASA AUSHADHI (the ingredients of metallic and mineral origin) are mixed together to form a fine powder. Then, KANCH KUPI (glass flask) is filled to its 1/3rd with the mixture of RASA AUSHADHI. The glass flask is covered using a cloth, which is smeared with the paste of clay in seven layers. This is kept aside to allow it to dry.
Then, the flask is buried in BALUKAYANTRA up to the neck and it is heated. The AGNI or heat should be given in three stages, MRIDVAGNI (mild flame), and MADHYAMAGNI (mid-flame) followed by TIKSHNAAGNI (high flame).
Sometimes, there may be a choking of the opening of the flask due to the thick coating of subliming GANDHAKA or Sulfur, which is one of the common ingredients of most Kupipakwa Rasayana. This can be prevented by inserting a red hot iron rod into the flask through the opening to stir the contents now and then.
Then, the mouth of the bottle is sealed using chalk pieces wrapped around strips of cloth. These cloth strips should be smeared with a solution of jaggery or clay. Then, the flask is removed and allowed to cool so that the materials inside the flask get separated and accumulate in the lower and upper halves of the flask.
Then, the flask should be broken carefully in the middle to collect the separated materials. The material at the bottom is discarded and the material deposited near the neck of the flask should be scraped and collected to obtain the final product.