GLC determination of erythromycin in enteric-coated tablets

Application of Different Analytical Techniques and Microbiological Assays for the Analysis of Macrolide Antibiotics from Pharmaceutical Dosage Forms and Biological Matrices

Macrolides are a group of drugs whose activity stems from the presence of a macrolide ring, a large macrocyclic lactone ring to which one or more deoxy sugars may be attached. They are produced by Streptomyces species and used primarily against gram-positive bacteria. The determination of antibiotics, including macrolides, is mainly carried out by microbiological assays. However, microbiological assays tended to lack specificity. And hence to overcome this problem, lots of chemical and instrumental methods have been developed to determine macrolides separately as well as simultaneously. Different chromatographic, spectrophotometric, and electrochemical methods used for the determination of macrolides have been reviewed in this paper.

Analysis of macrolide antibiotics

The following macrolide antibiotics have been covered in this review: erythromycin and its related substances, azithromycin, clarithromycin, dirithromycin, roxithromycin, flurithromycin, josamycin, rokitamycin, kitasamycin, mycinamycin, mirosamycin, oleandomycin, rosaramicin, spiramycin and tylosin. The application of various thin-layer chromatography, paper chromatography, gas chromatography, high-performance liquid chromatography and capillary zone electrophoresis procedures for their analysis are described. These techniques have been applied to the separation and quantitative analysis of the macrolides in fermentation media, purity assessment of raw materials, assay of pharmaceutical dosage forms and the measurement of clinically useful macrolide antibiotics in biological samples such as blood, plasma, serum, urine and tissues. Data relating to the chromatographic behaviour of some macrolide antibiotics as well as the various detection methods used, such as bioautography, UV spectrophotometry, fluorometry, electrochemical detection, chemiluminescence and mass spectrometry techniques are also included.

Analysis of oral suspensions containing sulfonamides in combination with erythromycin ethylsuccinate

The sulfonamides and erythromycin ethylsuccinate in combination oral suspensions were determined by high-performance liquid chromatography and automated turbidimetry, respectively. The chromatographic procedure was rapid, specific, and stability-indicating for sulfisoxazole acetyl and the trisulfapyrimidines using a reversed-phase system with UV detection at 254 nm. Erythromycin ethylsuccinate did not interfere with the sulfonamide analysis and these compounds were assayed with relative standard deviations (RDS) ranging from +/- 2.1 to +/- 3.1%. Erythromycin ethylsuccinate was determined as erythromycin with RSD values of +/- 1.3 or 3.5% without interference by the sulfonamides present.

High-performance liquid chromatographic determination of erythromycin

An isocratic, reversed-phase high-performance liquid chromatographic (HPLC) method has been developed for the determination of erythromycin. The method uses a muBondapak C18 reversed-phase column with a mobile phase composed of acetonitrile-methanol-0.2 M ammonium acetate-water (45:10:10:35). The relative standard deviation of the method for quantification of erythromycin is about 0.6%, and the method is capable of selectively quantifying erythromycins A, B, C and at least nine other erythromycin epimers and degradation compounds in 15 min of chromatographic time. The bio-equivalent potencies of erythromycin powders calculated from the HPLC data agreed well with those of the microbiological assay method. The HPLC method developed is also applicable for the analysis of various derivatives of erythromycin.