Improvements in or relating to the manufacture of preparations containing vitamin

摘要

The concentration of vitamin H (preventing skin diseases) from fractions obtained, for instance from yeast or by digesting liver with papain, is effected by treating a crude solution by electrodialysis between a number of diaphragms arranged between the electrodes of an electrolytic cell. In an example, liver residue is digested with papain, phosphotungstic acid is added to the solution, and the precipitate is decomposed with baryta, yielding a dark-brown crude vitamin H solution of 4000 rat. units in 200 c.c.; the solution is diluted to 620 c.c. and electrodialyzed between platinum foil electrodes separated by parchment diaphragms into a total of ten cells. Current is supplied at 220 volts. After 24 hours the cell having pH 3,8 shows 200 rat. units, those at pH 2,5 and 3,0 have 1,000 rat. units each, that at pH 2,6 has 800 rat. units, and that at pH 2,3 has 320 rat. units, the other cells having little activity. The active solutions may be purified further in known manner, for instance by extraction with butyl alcohol and precipitation of inactive substances with acetone.