Description:
Bacitracin Zinc and Polymyxin B Sulfate Ophthalmic Ointment USP, is a sterile antimicrobial ointment for ophthalmic use. Each gram contains: bacitracin zinc equivalent to 500 bacitracin units, polymyxin B sulfate equivalent to 10,000 polymyxin B units, mineral oil, and white petrolatum.
Bacitracin zinc is the zinc salt of bacitracin, a mixture of related cyclic polypeptides (mainly bacitracin A) produced by the growth of an organism of the licheniformisgroup of Bacillus subtilisvar Tracy. It has a potency of not less than 40 bacitracin units per mg. The structural formula for bacitracin A is:
Polymyxin B sulfate is the sulfate salt of polymyxin B1 and B2 which are produced by the growth of Bacillus polymyxa(Prazmowski) Migula (Fam. Bacillaceae). It has a potency of not less than 6,000 polymyxin B units per mg, calculated on an anhydrous basis. The structural formulae are: