Bacitracin and mupirocin are two common antibiotics used to produce ointments for infections of small cuts, scrapes, etc.

Many people think these two are the same, with not much difference between them.

While the fact is: bacitracin is a mixture, a combination of at least 9 bacitracins, and 60-80% of commercially manufactured bacitracin is bacitracin A, while the content of mupirocin is not that complex, it is only pure mupirocin, no other related substances.

As we can see from their chemical structures above, bacitracin is a cyclic peptide, while mupirocin is a linear acid.

mupirocin is a naturally-occurring antibiotic that displays a broad-spectrum activity against many gram-positive bacteria and certain gram-negative bacteria in vitro. It primarily works by inhibiting bacterial protein synthesis.

#1 Different Usage

Mupirocin is an antibacterial pseudomonic acid antibiotic produced by Pseudomonas fluorescens.

It is mainly used for skin infections such as impetigo, and other primary or secondary superficial skin infections, such as ecthyma, eczema, folliculitis, furunculosis, atopic dermatitis, epidermolysis bullosa, and minor wounds, burns, or ulcers.

While bacitracin is used for infection prevention, especially for wounds on the skin such as small cuts or burns.

And bacitracin is also used for infantile streptococcal pneumonia and empyema when used intramuscularly.

Bacitracin is also formulated as an ointment with neomycin and polymyxin B for over-the-counter use

#2. Different Working Mechanism

Mupirocin works by preventing bacteria from growing.

It inhibits protein synthesis in bacteria by binding to isoleucyl transfer RNA synthetase.

While bacitracin prevents the formation of the bacterial cell wall and oxidatively cleaves DNA, thus it kills the bacteria and prevents wounds from infections.

#3 Different Dosage forms

There are mainly 4 dosage forms of Mupirocin:

1. Mupirocin Calcium Ointment

2. Mupirocin Cream

3. Mupirocin Nasal Ointment

4. Mupirocin Ointment.

Dosage forms for bacitracin include:

1. Injections:

2. Ointment for skin

3. Ophthalmic ointment.

As we can there are only topical dosage forms for mupirocin but without injections.

Neither does Mupirocin have eye ointments, while bacitracin has injections as well as ophthalmic ointments. 

The reason that mupirocin can not be made into eye ointments is that: once mupirocin is applied to the eyes, there will be severe symptoms such as burning and tearing.

It will take days or even weeks for this uncomfortableness to disappear. (If contact with the eyes occurs, thoroughly wash your eyes with water or go to a doctor immediately).

However, there is mupirocin ointment for intranasal use, while there are no bacitracin dosage forms suitable for intranasal use.

#4 Different Costs

The unit price for mupirocin API is around 2000usd per kg, almost 3 times that of bacitracin, about 700 USD per KG for commercial order quantities.

It is the same case when they are made into formulations.

Mupirocin formulations are also more expensive than bacitracin.

Check the price below:

the lowest Bactroban price is 320.38usd and the lowest price for bacitracin ointment is 50.83usd.

Conclusion: Mupirocin is more expensive than bacitracin.

Mupirocin can not be used for eye infections but has no problems with nose infections, while bacitracin can be used for eye infections and has dosage forms of injections.