Some Further Experiences with the Production of Colloidal Lead or Salts of Lead

Abstract

In 1926, one of the authors in collaboration with Dr. Stenstrom (1) published an account of some experiences with the production of colloidal lead for intravenous injection in the treatment of malignancy. This work was interrupted and it was not until recently that further work was undertaken in an endeavor to find a more suitable colloid of lead or lead salt which would be more stable and less toxic. The method originally described by Bell (2) (3) is the Bredig method of arcing between lead electrodes in an aqueous solution of gelatin and calcium chloride. This yields a colloidal solution of metallic lead, the particles of which are of various sizes, necessitating centrifuging in order to remove the coarse grains. The solution is black but exposure to air soon causes it to become gray and eventually white with consequent rapid settling out of the precipitate. Furthermore in our experience this solution did not yield as concentrated solution as might be desired. Modifying this method by substituting various other chlorides such as iron, sodium and potassium, the above authors were able to produce more concentrated solutions. The use of potassium chloride yielded the best solution with respect to concentration and stability and this solution was used for most of the work.