Chloramphenicol (5% w/v) + Prednisolone (0.5% w/v) + Acetic acid (2% w/v) + Benzocaine (3% w/v) (Medical Monograph)

Overview

A fixed-dose combination topical otic/otic-sterile solution designed for the treatment of acute otitis externa and infected otitis media with perforation. It combines a broad-spectrum bacteriostatic antibiotic (Chloramphenicol), a potent corticosteroid (Prednisolone) for anti-inflammatory and anti-pruritic action, an acidifying/antimicrobial agent (Acetic acid), and a local anesthetic (Benzocaine) for symptomatic pain relief. This combination addresses infection, inflammation, and pain simultaneously, commonly used in Indian clinical practice for 'swimmer's ear' and other acute ear infections.

This combination exerts a multi-pronged therapeutic action. Chloramphenicol inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit. Prednisolone induces phospholipase A2 inhibitory proteins (lipocortins), suppressing prostaglandin and leukotriene synthesis, thereby reducing inflammation, edema, and itching. Acetic acid creates an acidic environment (lowers pH) hostile to bacterial and fungal growth, particularly Pseudomonas aeruginosa and Candida. Benzocaine blocks sodium ion channels in neuronal membranes, preventing the initiation and conduction of nerve impulses, providing local analgesia.