Comparison of in vitro pharmacodynamics equivalence of generic and branded antimicrobials

Akemfua Fualefac, Michel Kengne, Valentine Ndikum, Achiangia Patrick Njukeng, Ubald Tamoufe, Daniel Ter Goon, Cedric Mbakam Happi, Joel Ngoupa, Awung Nkeza, Marcellin Ndoe Guiaro and Julius Mbekem Nwobegahay

Microbiology Research International
Published: October 26 2018
Volume 6, Issue 4
Pages 49-53


There has been an enormous increase in the clinical use of generic drugs. However, this has not been accompanied by frequent and systematic evaluations of their therapeutic efficacy compared with branded products. Although essential to reduce health budget costs and to promote pharmaceutical competition, generic drugs remain a topic of intense controversy. Generics are usually intended to be inter-changeable with branded products; however, there have been allegations that some have a lower therapeutic equivalence than their branded counterparts The main objective of this study was to compare the in vitro potency of generic and branded antibiotics on E. coli and S. aureus. A sample of generic and corresponding branded Ciprofloxacin, Ceftriazone, Gentamicin and Doxycycline were used to prepare antibiotic disk for Kirby-Bauer disk diffusion susceptibility antimicrobial assay on E. coli ATCC 25922 and S. aureus ATCC 25923. The inhibition zones were measured and relative potencies were calculated. Antimicrobial activity against S. aureus ATCC 25923 ranged from 92.50 to 100% for generic agents; and 96.89 to 100% for branded drugs. The potency range for E. coli ATCC 25922 were 86.61 to 104.35% for generics and 83.33 to 103.23% for branded antimicrobials. There was no significant difference between the potency of the generic and the branded antimicrobial agents on the bacterial strains in the study. Each generic antimicrobial agent presented relative potency that was within the 80 to 125% acceptable range. The in vitro pharmacodynamics potency of generic antimicrobials from health facilities and legal distributors are equivalent to their corresponding branded agents.

Keywords: Antibiotics, antimicrobial activity, potency equivalence, generic antibiotics, branded antibiotics.

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