Neosporin Description
Neosporin Ophthalmic Ointment (neomycin and
polymyxin B sulfates and bacitracin zinc ophthalmic
ointment) is a sterile antimicrobial ointment for
ophthalmic use. Each gram contains: neomycin sulfate
equivalent to 3.5 mg neomycin base, polymyxin B sulfate
equivalent to 10,000 polymyxin B units, bacitracin zinc
equivalent to 400 bacitracin units, and white
petrolatum, q.s.
Neomycin sulfate is the sulfate salt of neomycin B and
C, which are produced by the growth of Streptomyces
fradiae Waksman (Fam. Streptomycetaceae). It has a
potency equivalent of not less than 600 µg of neomycin
standard per mg, calculated on an anhydrous basis. The
structural formulae are:
Neosporin Clinical Pharmacology
A wide range of antibacterial action is provided by
the overlapping spectra of neomycin, polymyxin B
sulfate, and bacitracin.
Neomycin is bactericidal for many gram-positive and
gram-negative organisms. It is an aminoglycoside
antibiotic which inhibits protein synthesis by binding
with ribosomal RNA and causing misreading of the
bacterial genetic code.
Polymyxin B is bactericidal for a variety of
gram-negative organisms. It increases the permeability
of the bacterial cell membrane by interacting with the
phospholipid components of the membrane.
Bacitracin is bactericidal for a variety of
gram-positive and gram-negative organisms. It interferes
with bacterial cell wall synthesis by inhibition of the
regeneration of phospholipid receptors involved in
peptidoglycan synthesis.
Microbiology: Neomycin sulfate, polymyxin B sulfate, and
bacitracin zinc together are considered active against
the following microorganisms: Staphylococcus aureus,
streptococci including Streptococcus pneumoniae,
Escherichia coli, Haemophilus influenzae, Klebsiella/Enterobacter
species, Neisseria species, and Pseudomonas aeruginosa.
The product does not provide adequate coverage against
Serratia marcescens.
Neosporin Indications and Usage
Neosporin Ophthalmic Ointment is indicated for the
topical treatment of superficial infections of the
external eye and its adnexa caused by susceptible
bacteria. Such infections encompass conjunctivitis,
keratitis and keratoconjunctivitis, blepharitis and
blepharoconjunctivitis.
Neosporin Contraindications
Neosporin Ophthalmic Ointment is contraindicated in
individuals who have shown hypersensitivity to any of
its components.
