Abstract

ANTIMICROBIAL POTENCY OF COMMERCIAL DRUGS (AMOXICILLIN, CIPROFLOXACIN, KETOCONAZOLE AND GRISEOFULVIN) OVER A PERIOD OF TIME AT A SELECTED PHARMACY

R.C. Jagessar*, G. Ceres, Y. Ramnarine and S. Craig

ABSTRACT

The potency of Amoxicillin, Ciprofloxacin, Ketoconazole and Griseofulvin against S. aureus, E.coli, K. Pneumoniae and C. albicans was evaluated over five months period at a selected Pharmacy, using the Disc Diffusion assay under asceptic conditions. In addition, the potency of combined suspension of Amoxicillin and Ciprofloxacin was evaluated over a five months period. It was found that uncombined suspension of Amoxicillin and Ciprofloxacin showed a decrease in potency over the five month period. For the 1st batch of tablets purchased, the largest AZOI of 151.5 mm2 was induced by Ciprofloxacin against E.coli. This was followed by AZOI of 907.5 mm2, induced by Amoxicillin against E.coli. Ketoconazole and Griseofulvin induced zero AZOI against C. albicans. Over a five month period, there was a significant decreased in antimicrobial potency. AZOI of 490.63 mm2 and 889.93 mm2 (for the 4th batch) were observed for Amoxicillin and Ciprofloxacin respectively over the five month periods. Also, the combination of Amoxicillin and Ciprofloxacin resulted in an increase in antimicrobial potency. For example, AZOI of 961.63 mm2 and 1256.00 mm2 was obtained for the 1st combined batch against E. coli and S. aureus respectively. There was also a decrease in antimicrobial potency for the combined suspension over a five month period. Interestingly, there was an increase in antimicrobial potency of the combined suspension against K. pneumoniae over a five month period. A decrease in the potency of drugs is a contributing factor to antimicrobial resistance.

Keywords: Amoxicillin, Ciprofloxacin, Ketoconazole, Griseofulvin, S. aureus, E.coli, K. pneumoniae and C. albicans, potency.