Pharmacologic experiments on D. D. S. carried out in our laboratory presented the following results :
1) D. D. S, inhibits the growth of staphylococcus in vitro in 0.1-0.5 mg %, but effective only in higher concentration upon the tubercle or the smegma bacillus.
2) Below the concentration of 1mg %, it shows no influence upon the development of chick embryo heart tissue cultured in the test tube.
3) The per os administered D. D. S. concentration in the various organs of rabbits reach the highest after 3 hours. The concentration in the liver and kidney is as much as two or three times as that in the blood. In the skin and nerve it reaches to 0.2mg% and produces the therapeutic significance.
4) The blood concentration of D. D. S, in patients administered per os three times a day shows no marked up and down throughout 24 hours.
5) The 70-90% of per os administered dose of D. D. S. is excreted in urine, of which 90% is excreted as D. D. S..
6) Between D. D. S. and blood proteins, absorption takes place in acid medium and both absorption and chemical combination occur in alkaline medium.