Otosporin Ear Drops are indicated for the treatment of otitis externa due to, or complicated by, bacterial infection. Route of Administration Topical In Vitro Activity Otosporin Ear Drops are active against a wide range of bacterial pathogens. The range of activity includes:- Gram-Positive Organisms: Staphylococcus epidermis and Staphylococcus aureus : Gram-Negative Organisms: Enterobacter Spp. Escherichia Spp. Haemophilus Spp. Klebsiella Spp. Proteus Spp. Pseudomonas aeruginosa Otosporin Ear Drops are not expected to be active against streptococci, including Streptococcus pyogenes . Hydrocortisone possesses anti-inflammatory, anti-allergic and antipruritic activity.