Process for the preparation of a complete extract of pilewort roots

Claim 1

A process for the extraction of the active substances from tuberised pilewort roots, said process comprising the following stages: (a) macerating the pilewort roots, which have previously been dried and ground to a powder, in 35°-45° C. petroleum ether, extracting them with this solvent, so as to remove all the substances soluble therein, separating the resulting solid residue from the solvent and drying it; (b) macerating the dried residue in an aqeuous lower alcohol and extracting it with a supplementary amount of this aqueous alcohol; (c) subjecting the resulting alcoholic extract to two successive concentrations in each of which the quantity of alcohol is approximately halved, allowing the extract to cool after each concentration, and removing precipitated impurities by filtration; (d) treating the filtrate with papaine and concentrating it to a solids content of 40 to 50%; (e) adding an equal volume of an aqueous lower alcohol to the viscous solution thus obtained, allowing the mixture to stand in the cold, and removing the insoluble products by decantation, filtration or centrifugation; and (f) distilling off the alcohol so as to give an aqueous extract.