judged by the concentration of antibiotic which caused a rapid fall in opacity of the culture , polymyxin b sulphate and colistin sulphate had similar activities , but the sulphomethyl compounds differed considerably : sulphomyxin sodium induced lysis of the culture at a concentration four times that of the parent compound , whereas colistin sulphomethate sodium induced a delayed fall in opacity consistent with recruitment of activity as the inactive sulphomethyl derivative was broken down to the parent compound .
C0009317
colistin sulphate
C0009316
colistin