Comparative Assessment of Ciprofloxacin Ophthalmic Solutions Marketed in Nigeria: Physicochemical and Microbiological Evaluation
DOI:
https://doi.org/10.51412/psnnjp.2026.027Keywords:
ciprofloxacin, ophthalmic, pharmaceutical equivalence, physicochemicaAbstract
Background: Ciprofloxacin ophthalmic solutions are commonly used in the treatment of susceptible bacterial eye infections, so their quality must be reliable to ensure accurate dosing, acceptable ocular characteristics, and adequate antimicrobial performance. In Nigeria, comparing generic products with an innovator product is useful for medicine-quality monitoring and informed substitution. This study compared ten brands of ciprofloxacin eye drops available in Nigeria with an innovator product using physicochemical and microbiological tests.
Methods: Each sample was evaluated for appearance and clarity, volume, assay/content uniformity, viscosity, relative density, refractive index, surface tension, drop mass, drop volume, pH, electrical conductivity, and total dissolved solids. Antibacterial activity was determined against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus using susceptibility testing, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) procedures.
Results: Most of the products satisfied the individual quality characteristics assessed. However, noticeable differences occurred in viscosity, electrical conductivity, and total dissolved solids. Ciprofloxacin content ranged from 97.14% to 102.90%, and every brand showed antibacterial activity against the organisms tested. When the physicochemical and microbiological findings were considered together, only one brand satisfied the operational criteria used in this study for pharmaceutical equivalence with the innovator product.
Conclusion: The results indicate that ophthalmic products carrying the same active ingredient and labelled strength can still differ in formulation-related characteristics. Continued post-marketing surveillance and assessment using several complementary quality parameters are therefore important for maintaining the quality of ophthalmic generics and supporting appropriate substitution decisions.
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