Eye drops are sterile liquids for instillation into the conjunctiva sac worldwide; they are formulated and packaged in order to maintain their sterility throughout the period of use. This study was conducted to evaluate the pharmaceutical quality and antimicrobial effectiveness ophthalmic drops offered for sale in Nigeria. A total of thirty-three (33) sterile eye drops of 11 different brands (3 of each) were examined; these include Gentamicin, Chloramphenicol, Ciprofloxacin, Betaxolol, Betamethasone, Artificial tears, Hypromellose, Diclofenac, and Timolol were purchased in pharmacy stores and the other two which are natural drops were purchased from the market and bus vendor (Oster and Quick action). A standardized (using 0.5 Mac Farland turbidity standard) clinical isolates of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus were added (according to British and United State Pharmacopoeia) to newly opened eye drops and stored at room temperature away from light. At 1hour, 3days, 7days, 14days, 21days and 28days samples were collected, plated and the number of viable microorganisms was counted after 48hrs incubation at 37oC. Seven 7 (Gentamicin, Betamethasone, Chloramphenicol, Hypromellose, Artificial tears, Ciprofloxacin and Betaxolol)out of the test eye drops had significant antimicrobial activity with their anti-infective having the highest rapidity in bactericidal activity; Timolol and Diclofenac showed a reduced and poor antimicrobial activity. The findings had shown 77.8 of the test eye drops passed the antimicrobial effectiveness test while 22.2% failed. Quick action and Oster were found to contain heavy microbial growth. In conclusion, the ophthalmic drops offered for sale in Nigeria from approved medicine stores are of acceptable standard
