I looked up BNT, and it contains exactly the same ingredients as Oti-Pack E: enrofloxacin to treat bacterial infection, ketoconazole to help prevent fungal growth, and triamcinolone to reduce inflammation, in a lanolin base. Both BNT and Oti-Pack E are manufactured by compounding pharmacies, so they do not have the same type of regulation as products produced by a pharmaceutical company.
If you google BNT and Oti-Pack E, there are many stories of permanent deafness resulting from the use of these products. That could be because people only write about the bad things that happen as a result of using a medicine, but still, the numbers of adverse reactions are large.
And the lack of regulation of compounded products might cause warnings about adverse reactions to fall through the cracks. In addition, even if they gave warnings about each individual ingredient in the compounded medicine, drugs sometimes have reactions when used in combination that are unpredictable or unforeseen. Below is a quote from an article about compounded medications and product liability
https://www.ncbi.nlm.nih.gov/pubmed/25276868 (portions highlighted for emphasis):
My mission for today will be to collect articles on ototoxicity (the study of medicines that cause toxic reactions to the ears and hearing) and see if I can find out anything more about the possible side effects of these drugs. If I find anything else, I'll post it below.