Why is Neosporin OTC?

The current thread on antibiotics reminded me of this question:

Why is Neosporin sold over the counter, without clear instructions to use it for X period of time before discontinuing? It does say to apply “1 to 3 times daily”, but not for any particular number of days. Isn’t this a situation that would tend to promote antibiotic resistance (since plenty of users might just apply it for one day, or even just one instance)? Is there something about the particular antibiotics in there that makes it impossible for bacteria to develop resistance to them?

Probably because it’s topical. You are not treating an internal infection, but the bacteria that happen to have colonized an open wound. A much less isolated population.

It may well cause antibiotic resistance. It is circumstantially implicated in a severe strain of MRSA.