Estimation of potency of antibiotics by means of microbiological methods – preparation of pharmacopoeial antibiotic modules
Keywords:
CSP, antibiotic module, the potency of antibiotics, inter-laboratory tests, pharmacopoeial methodAbstract
Introduction and objective: Medicinal products containing antibiotics constitute an important and complex group of therapeutic preparations. One of the most important parameters is estimating the antimicrobial activity by means of microbiological methods, or assessing the potency of antibiotics, with reference to proper standards. The Department of Antibiotics and Microbiology of the National Medicines Institute (NMI) has participated in inter-laboratory proficiency tests aimed at estimating the potency of new pharmacopoeial antibiotic modules since 2000. The tests are conducted by the European Directorate for the Quality of Medicines (EDQM) – European Pharmacopoeia Commission, and the results are analyzed and drawn up in report form. The aim of this paper is to present the results of estimating the potency of antibiotic modules.
Materials and methods: The potency of substances, prospective modules, of the following antibiotics was estimated: amphotericin B, bacitracin zinc, dihydrostreptomycin, erythromycin, colistin sulphate, colistimethate sodium, nystatin, polymyxin B sulphate, rifamycin sodium and spiramycin. The potency of antibiotics is estimated by comparing the inhibition of growth of sensitive standard micro-organisms produced by known concentrations of the examined antibiotic and a reference substance. The test micro-organisms sensitive to the examined antibiotics were recommended by pharmacopoeia and were supplied by the American Type Culture Collection (ATCC). The potency of antibiotics was estimated by means of pharmacopoeial microbiological methods, mainly a diffusion method, and a turbidimetric method in case of estimating the potency of rifamycin sodium. The examination was conducted in a way which permitted the validation of the mathematical model on which the power equation is based.
Results: The microbiological potency of 14 substances was determined. The substances were then accepted as modules of 10 different antibiotics with high precision: + / - one standard deviation (SD) (in only two cases + / - 2 SD) of the average value received from all laboratories taking part in proficiency tests. The average value was accepted by the EDQM as the official biological potency for a given module batch.
Conclusions: The estimation of the potency of a variety of antibiotics in the Department of Antibiotics and Microbiology of the NMI by means of an accredited pharmacopoeial method is a high-level scheme approved by the EDQM.
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References
Tyski S, Pajchel G. Zasady i metody kontroli leków antybiotykowych dopuszczonych do obrotu w Polsce. Mikrobiologia Medycyna 1999: 1, 35-40.
Zapaśnik M, Pajchel G, Tyski S. Determination of antimicrobial agents content in multiantibiotic drugs. Acta Poloniae Pharmaceutica 1999; 56 (suplement), 71-76.
European Pharmacopoeia, monografia 2.7.2. “Microbiological assay of antibiotics”, ver. 01/2009:20702.
Charton E, Daas AGJ, Sandrin J, Miller JHMcB. Collaborative studies for the establishment of reference substances for the microbiological assay of antibiotics. Pharmeuropa 2001; 13, 703-714..
Charton E, Daas AGJ, Sandrin J, Miller JHMcB. Collaborative studies for the establishment of reference substances for the microbiological assay of antibiotics. Pharmeuropa Bio 2003-2; 1-8.
Rautmann G, Daas A, Buchheit K-H. Collaborative study for the establishment of the second international standard for amphotericin B. Pharmeuropa Bio & Scientific Notes, 2010-1; 1-13.
Rautmann G, Charton E, Daas A, Buchheit K-H. Collaborative study for the establishment of the third international standard for nystatin. Pharmeuropa Bio & Scientific Notes, 2010-2; 68-85.
European Pharmacopoeia, monografia 5.3. “Statistical analysis of results of biological assays and tests”, ver. 01/2008:50300.
German R, Bukowska B, Pajchel G, Grzybowska W, Tyski S. Extremely long time stability study of selected antibiotic standards. J. Pharm. Biomed. Anal. 2010; 51, 758-763.
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