Chimie médicale

In vitro Activity and Evaluation of Quality of Some Selected Penicillins on the Ghanaian Market using Developed HPLC Methods

Abstract

Rita Frema Boadu, Christian Agyare, Martin Adarkwa-Yiadom, Francis Adu, Vivian Etsiapa Boamah and Yaw Duah Boakye

The use of antibioticsin health delivery is inevitable since it is one of the most prescribed medications. The quality and efficacy of these medications are crucial in health systems since they can affect the quality of healthcare delivery. The study was designed to determine the quality and activity of some penicillins on the Ghanaian market. A total of 54 samples (29 capsules and 25 suspensions) of different brands and batches were collected from different pharmacies in Accra and Kumasi, Ghana, from October 2011 to May 2012. The activity (zones of inhibition) and minimum inhibitory concentration (MIC) of the samples were determined by the agar-well diffusion and micro-dilution methods respectively against two typed strains of Gram-negative and Gram-positive bacteria. Quality of the samples was determined quantitatively by developed and validated HPLCmethods. The MICs of flucloxacillin and cloxacillin samples were ≥ 1400 μg/mL, whiles that of amoxicillin samples were ≥ 200 μg/mL, with reference to the standard antibiotics which gave MICs of 200 to 800 μg/mL against all the test bacteria with the suspensions exhibiting higher antimicrobial activity. Specificity, linearity, precision and accuracy of the developed HPLC method were determined. HPLC analysis of the samples revealed that 75% of amoxicillin capsule samples and 92.3% of amoxicillin suspension samples contained the right amount of active pharmaceutical ingredient (API) with percentages ranging from 93.2 to 104.3% and 81.0 to 104.1% respectively. For samples of flucloxacillin capsules, 62.5% of the samples showed API content from 96 to 120.5%. All the suspension samples have their API within BP and USP specification of 114.4 to 120.0%. Capsules (58.6%) of all the samples contained the right API whereas 64% of them were recorded for suspensions. Out of the 54 samples evaluated, 61.1% were within the BP and USP specifications. The biological assay revealed higher MIC values for all the penicillin samples evaluated compared with the reference samples. Among the samples evaluated, amoxicillin showed better quality of 82.8% as compared to flucloxacillin (31.3%) and cloxacillin (44.4%) samples. Efforts should therefore be made to improve the quality and storage conditions of these antibiotics and also constant monitoring and surveillance of activity and potency of these antibiotics should be done.