Abstract
Surface-active agents, including silicone, and sorbitan and polypropylene compounds, were examined for anti-foaming action in vitro and surface tension. To determine the anti-foaming action, 0.1ml of the diluted agent was added to 3.5ml of 1% saponine (Merck) solution contained in a glass vessel with No.4 glass filter. The mixture was bubbled by sucking under negative pressure at-250mmHg for seven minutes at 38°C. The foam-breaking action was measured by reading a decrease in height of the foam five minutes after addition of 0.1ml of the diluted agent to saponin foam bubbling at a height of 66 mm at 38°C. The surface tension of the saponin solution after addition of the diluted agent was measured by means of a Du No-U tensiometer.
The anti-foaming actions of various silicone agents and a polypropylene compound were distinctly greater than those of all sorbitan compounds. Some commercial silicone agents for bloat treatment had not so great actions. All the surface-active agents tested decreased the surface tension of the saponin solution. The correlation between surface tension and anti-toaming action, nowever, was not apparent in any of the surface-active agents. The anti-foaming actions of soybean oil, cotten-seed oil, turpentine, liquid paraffin, and glycerine were less marked than those of the surface-active agents.
A new surface-active agent, a polypropylene compound with the proprietary name pronon, was less toxic for mice or young rabbits when administered in a dose of 0.1 g or more per kg of body weight daily for 14 or 24 days. Moreover, this compound seemed to be palatable for these animals.
