Scientific Research and Essays

  • Abbreviation: Sci. Res. Essays
  • Language: English
  • ISSN: 1992-2248
  • DOI: 10.5897/SRE
  • Start Year: 2006
  • Published Articles: 2754

Full Length Research Paper

Survey of the efficacy and quality of some brands of the antibiotics sold in Calabar Metropolis, South-south region of Nigeria

A. O. Nkang1, I. O. Okonko1*, J. A. Lennox2, E. T. Babalola3, O. G. Adewale4, B. O. Motayo1,5, O. K. Mejeha6, O. A. Adekolurejo7 and J. T. Amande8,9
1Department of Virology, Faculty of Basic Medical Sciences, University of Ibadan College of Medicine, University College Hospital (UCH), Ibadan, University of Ibadan, Ibadan, Nigeria. 2Department of Microbiology, Faculty of Sciences, University of Calabar, Calabar, Nigeria. 3Department of Microbiology, College of Applied Sciences, Crawford University, Igbesa, Ogun State, Nigeria. 4Department of Biochemistry, Olabisi Onabanjo University, Ikene, Ogun State, Nigeria. 5Microbiology Laboratory, Department of Pathology, Federal Medical Centre, Idi-aba, Abeokuta, Ogun State, Nigeria. 6Department of Microbiology, Federal University of Technology (FUTO), Owerri, Imo State, Nigeria. 7Department of Zoology, Faculty of Science, University of Ibadan, Ibadan, Nigeria 8Department of Microbiology, Faculty of Science, University of Uyo, Uyo, Akwa Ibom State, Nigeria.  9Department of Botany and Microbiology, Faculty of Science, University of Ibadan, Ibadan, Nigeria.
Email: [email protected]

  •  Accepted: 14 January 2010
  •  Published: 28 February 2010


This study reports the survey of the level of efficacy of some brands of the antibiotics sold in Calabar, Nigeria. This survey was carried out using the agar diffusion technique. Ten brands of 5 different antibiotics were bought from different pharmacy shops in Calabar metropolis and tested against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus pyogenes to determine their efficaciesThe test antibiotics were 2 brands each of ampicillin, chloramphenicol, erythromycin, septrin and vancomycin. This survey measured the ability of these antibiotics to inhibit bacterial growth in vitro. The potency or activity per milligram of a chemotherapeutic agent is expressed on the basis of the lowest concentration of minimal inhibitory concentrations (MICs) or higher zones of inhibition. From the results, the overall mean zones of inhibition for the test organisms ranged from 20.2 – 33.3 mm, with 21.9 mm for E. coli, 26.4 mm for K. pneumoniae, 20.2 mm for P. aeruginosa, 33.3 mm for S. aureus and 21.7 mm for S. pyogenes. Our study showed that there were no significant differences (P > 0.05) between the mean zones of inhibition of the test antibiotics and standard controls tested against the test organisms except for P. aeruginosa and K. pneumoniae. The 2 brands of ampicillin and erythromycin were significantly (P = 0.027; P = 0.038) less effective against P. aeruginosacompared to the standard controls while for K. pneumoniae, the 2 brands of chlorampenicol and erythromycin were significantly (P = 0.049; P = 0.057) less effective compared to the standard controls. The results showed that the level of potency of these antibiotics vary according to the different manufacturers. Indeed, the findings of this survey confirm that some of the brands of antibiotics (ampicillin, chloramphenicol and erythromycin) sold in Nigeria may be fake or adulterated and do not contain the acclaimed quantity of active ingredients, which is a reflection of what goes on in many developing countries, in particular, in sub-Saharan Africa.


Key words: Active ingredients, antibiotics, efficacy, quality, selective toxicity, survey, zones of inhibition.