Among the new antibiotics investigated clinically in Houston during the past two years, colistin (Coly-Mycin) has been one of the most promising. This antibiotic was isolated in Japan by Yosuo Koyama in 1950 from culture filtrates of Bacillus colistinus, a bacterium closely related to Bacillus polymyxa, the source of the polymyxins. Its pharmacology has been studied in Japan, Italy, France, and, more recently, this country. A summary of the findings of these studies indicates that the chemical, pharmacological, and antimicrobial activity of colistin is closely related to the polymyxins, Clinically, however, colistin causes fewer undesirable side-effects.
Colistin is a complex polypeptide, with an empirical formula of C45H85O10N13 and a molecular weight of 969. Its acid salts are stable in solution even for very long periods; alkaline salts are less stable. It is available as colistin sulfate for oral and ophthalmic use, and as
YOW EM, TAN E, SHANE L, SCHONFELD S, ABU-NASSAR H. Colistin(Coly-Mycin) in Resistant Bacterial InfectionsA Clinical Appraisal. Arch Intern Med. 1961;108(5):664–670. doi:10.1001/archinte.1961.03620110004002