- Tobramycin is an aminoglycoside antibiotic marketed for topical ophthalmic use.
- Due to tobramycin’s broad spectrum of activity, it has proven useful in controlling both superficial and deep infections of the eye and ocular adnexa (i.e., blepharitis, conjunctivitis, keratitis, and endophthalmitis).
- Tobramycin is significantly more effective than gentamicin sulfate clinically, and the former exhibits a greater antibacterial efficacy, in the eye, against the combined conjunctival pathogens.
Benzalkonium chloride (Category III antiseptic)
- Benzalkonium chloride (BAK), a quaternary ammonium salt, is the most common preservative used in eye drops.
- Benzalkonium chloride is effective against both Gram-positive and Gram-negative bacteria as well as fungi.
- It may also act as a corneal penetration enhancer, leading to great ocular penetrance of active ingredients in BAK-preserved formulations.