Microbiological Evaluation of Secnidazole Tablets Using Dilution Method: A Quality Control Study in Karachi, Pakistan

Abstract

Aims: This study was conducted to evaluate the microbiological integrity and therapeutic reliability of Secnidazole tablets available in the pharmaceutical market of Karachi, Pakistan. Given Secnidazole critical role in treating protozoal and anaerobic infections, ensuring consistent antimicrobial performance across commercial formulations is essential. The research specifically aimed to assess the antimicrobial potency of these tablets using the broth micro dilution method.

Methodology: Ten Secnidazole tablet samples were procured from various manufacturers operating in or supplying to Karachi, representing a diverse spectrum of production standards. Each tablet was pulverized and dissolved in dimethyl sulfoxide (DMSO), then diluted to a working concentration of 10 μg/mL. The antimicrobial activity of the resulting solutions was tested against three representative pathogens: Escherichia coli (Gram-negative), Staphylococcus aureus (Gram-positive), and Candida albicans (fungus). The broth microdilution technique was employed to determine the minimum inhibitory concentration (MIC), defined as the lowest concentration at which visible microbial growth was inhibited after 24 hours of incubation at 37°C.

Results: All tested samples exhibited effective antimicrobial action against the selected microorganisms. MIC values ranged from 0.25 to 1.0 μg/mL for E. coli, 0.5 to 2.0 μg/mL for S. aureus, and 1.0 to 4.0 μg/mL for C. albicans. These results indicate that the Secnidazole formulations possess adequate potency and conform to acceptable microbiological standards. Notably, some samples demonstrated enhanced efficacy, suggesting possible differences in formulation quality among manufacturers.

Conclusion: The findings affirm that the broth microdilution method is a reliable and practical tool for evaluating the microbiological quality of Secnidazole tablets. The consistent antimicrobial performance across all samples supports their clinical effectiveness and underscores the importance of routine quality control in pharmaceutical production. This study provides valuable insights for healthcare professionals, regulatory authorities, and manufacturers, reinforcing the need for stringent testing protocols to ensure the safety, efficacy, and therapeutic consistency of antimicrobial medications in Karachi, Pakistan and beyond.