Bleomycin for Injection, USP is a mixture of cytotoxic glycopeptide antibiotics isolated from a strain of Streptomyces verticillus. It is freely soluble in water.
It is available as a lyophilized powder for intramuscular, intravenous or subcutaneous injection. Each vial contains sterile bleomycin sulphate equivalent to 15 units or 30 units of bleomycin.
Sulfuric acid or Sodium hydroxide used, if necessary to adjust the pH.
Bleomycins are a group of related basic glycopeptides which differ in the terminal amine substituent of the common structural unit, bleomycin acid. The main components of Bleomycin for Injection are bleomycins A2 and B2. Chemically, bleomycin A2 is N1-[3-(dimethylsulfonio)propyl]-bleomycinamide and bleomycin B2 is N1-[4-(aminoiminomethyl)amino]butyl]-bleomycinamide.
The molecular formula of bleomycin A2 is C55H84N17O21S3 and a calculated molecular weight of 1414. The molecular formula of bleomycin B2 is C55H84N20O21S2 and a calculated molecular weight of 1425. The structural formula of bleomycins A2 and B2 are shown below.
Note: A unit of bleomycin is equal to the formerly used milligram activity. The term milligram activity is a misnomer and was changed to units to be more precise.