Liquid chromatographic determination of penicillins by postcolumn degradation with sodium hypochlorite using an hollow-fibre membrane reactor

Chromatographic analysis of penicillins in pharmaceutical formulations and biological fluids

Natural penicillin (benzylpenicillin) is the oldest antibiotic observed by Alexander Fleming in 1928. To broaden its spectrum of activity, natural penicillin was modified, giving rise to a group of antibiotics under the name 'penicillins'. Although an increasing number of bacteria appear to be resistant to them, penicillins are used to treat a variety of bacterial infections including Gram-positive, Gram-negative aerobic and anaerobic bacteria. Consequently, they are widely used in human and veterinary medicine to prevent and treat diseases. This review covers the analytical methodologies, mainly chromatographic, employed to the penicillins determination in pharmaceutical formulations, biological fluids and in production-scale fermentations reported in the literature. Results of published assays are comparatively presented focusing on sample preparation regarding isolation and purification, chromatographic conditions and method validation. Information on chemical structure, spectrum of activity and action mechanism of common penicillins has also been given.

High performance liquid chromatography of penicillins with penicillin-enhanced luminol chemiluminescence detection

A high performance liquid chromatographic method with chemiluminescence detection for the determination of penicillin G and ampicillin is reported. The method is based on the enhancement of the luminol chemiluminescence with beta-lactam antibiotics. The linear relationship was obtained between the peak height and the concentration of penicillin G or ampicillin up to 15 nmol per 20 microL injection. Detection limits were 1 nmol for penicillin G and 0.5 nmol for ampicillin with a signal-to-noise ratio of 2. Relative standard deviations for five replicate measurements of 4 nmol/injection each of penicillin G and ampicillin were 2.1 and 2.3%, respectively.