Neomycin sulfate an aminoglycosides antibiotic drug, its main component is neomycin B, C. Neomycin is an antibiotic separated from Streptomyces fradiae metabolite by Waksman and Lechevalier of University of Glasgow in 1949. Neomycin includes three components of A, B and C, neomycin A is also called neamine (NEAMINE), it is one of the B and C degradation products, there is 1700-unit of the vigour to Bacillus subtilis, but only 20-unit to pneumobacillus, so, the neomycin A is invalid in medical value. Generally, neomycin sulfate product contains neomycin B(NEOMYCINB, also called FRAMYCETIN) and neomycin C. B is the main component, B and C are stereisomers, and the optical active materials.
Neomycin sulfate is white or off-white powder, odourless, very easy to catch wet. The product has high dissolubility in water, but it is nearly insoluble in ethanol, diethyl ether or acetone, the molecular formula is C23H46N6 O13.3H2SO4, molecular weight is 908.87, and molecular structural formula is as follows:
Neomycin sulfate has a wider antibacterial spectrum, it has very strong antibacterial action to Gram-negative bacterium, partial gram-positive bacterium and mycobacterium tuberculosis. It has good antibacterial action to such like staphylococcus (methicillin drug-sensitive strain), Corynebacterium, escherichia coli, klebsiella, Proteus and other gnterobactericaeae. Its mechanism of action is to disturb the bacterioprotein synthesis, hinder the release of synthesized proteins, so as to increase the bacterial membranes permeability, causing outleakage of some important physiological chemicals, and resulting in cell death.
Neomycin sulfate is mainly used for producing topical ointment, liniment and eyewash, and also a small amount is added to cosmetics. Neomycin is most widely used in veterinary drugs, the research results on the pharmacokinetics and residue elimination rule of cattle, sheep, pig, chicken and other animals body show that: in each stage of withdrawal time, no neomycin is detected in animal's muscle, fat and liver. Therefore, neomycin is highly safe in the treatment and prevention of animal disease, nearly no absorption for oral administration, no residue in animal body, discharged by alimentary canal archetype without cross tolerance. This research result is approved by the FDA, it is just the FDA approval that neomycin becomes the choice drug for treating and preventing bacillary enteritis of beasts and birds in clinical veterinary drug, and it keeps 20% growth rate above at consecutive years at home and abroad market.
Pharmacodynamics-neomycin belongs to aminoglycosides antibacterial drug, its antibacterial spectrum is similar to the kanamycin. It has strong antibacterial action to the majority of gram-negative bacillus, such as, escherichia coli, proteusbacillus vulgaris, salmonella, pasteurella multocida, etc., and it is more sensitive to staphylococcus aureus. Pseudomonas aeruginosa, gram-positive bacterium (excepting for staphylococcus aureus), Rickettsia, anaerobion, fungus, etc. are resistant to the product.
Pharmacokinetics-a little of neomycin will be absorbed while being taken orally and partially, after oral administration, only 3% of gross is discharged from urine, and the majority is discharged from excrement without change directly. Intestinal mucosa inflammation or anabrosis can facilitate the absorption. It is absorbed very fast for parenteral administration, and its physiological disposition is similar to the kanamycin.
Compatibility of medicines: drug combination with such as, tetracyclines (oxytetracycline, doxycycline, aureomycin, tetracycline hydrochloride, etc.), macrocyclic lipoids (kitasamycin, Tilmicosin, Erythromycin) or atropine can be considered. When neomycin sulfate is combined with Vc, antibacterial effect weakens, when it is combined with florfenicol, curative effect drops, and its curative effect increases while being combined with same kind of medicine.