Locula 20% Eye Drop contains Sulphacetamide 20% w/v, a sulfonamide antibiotic indicated for the treatment of bacterial infections of the eye. Sulphacetamide acts by inhibiting bacterial dihydropteroate synthase, thereby interfering with folic acid synthesis essential for bacterial growth and replication. This ophthalmic solution is primarily used in managing conjunctivitis, keratitis, blepharitis, and other superficial ocular infections caused by susceptible strains of bacteria. Locula 20% Eye Drop is administered topically, providing targeted antimicrobial activity with minimal systemic absorption. The formulation is intended for use under strict aseptic conditions to prevent contamination. Patients should be advised to avoid touching the dropper tip to any surface, including the eye or hands, to maintain sterility. Common side effects may include mild ocular irritation, burning sensation, or transient blurred vision upon instillation. Hypersensitivity reactions, though rare, necessitate discontinuation of therapy. This medication is contraindicated in individuals with known sulfonamide hypersensitivity. Locula 20% Eye Drop should be used with caution in patients with renal impairment or those using other sulfonamide-containing products. Proper diagnosis and susceptibility testing are recommended prior to initiation to ensure efficacy and reduce the risk of resistance development.