Report concerning results of laboratory proficiency testing on microbial enumeration level from pharmaceutical products

Authors: Simona Sturzu, Daniela Tirsinoaga, Ioana Tihulca, Mariana Dumitrache, Alina K. Draghici
Affilation: Institute for Control of Veterinary Biological Products and Medicines

The present study describes the results obtained by the Microbiological Control Laboratory from Institute for Control of Biological Products and Veterinary Medicines after participating in the proficiency testing scheme study on low – level microbial enumeration from pharmaceutical products. The proficiency testing scheme was organized by LGC Standards, Great Britain, organization with competences in managing of the proficiency testing scheme for laboratories. Membrane filtration is a microbiological technique used for the microbial enumeration test, which consist in the transfer of the appropriate amounts from the sample, prepared according to the provisions of the European Pharmacopoeia, through a membrane filter, incubating it on appropriate culture media, followed by reading and interpretation of the results. The result obtained by the Microbiological Control Laboratory was 34 CFU / vial, and the value attributed by LGC Standards was 30 CFU / vial.The Z- scores were 0,16 and the performance of Microbiological Control Laboratory was very good for low-level microbial enumeration from sample.

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Report concerning results of proficiency testing laboratory on assay of tobramycine and nystatin by microbiological method

Authors: Simona Sturzu, Daniela Tirsinoaga, Ioana Tihulca, Alina Karina Drăghici
Affiliation: Institute for Control of Veterinary Biological Products and Medicines, Bucharest

The present study describes the results obtained by the Microbiological Control Laboratory from Institute for Control of Biological Products and Veterinary Medicines after participating in the proficiency testing scheme study on microbiological assay of nystatin and tobramycin. The proficiency testing scheme was organized by European Directorate for the Quality of Medicines and Health Care. The microbiological method consisted of a cylinderplate agar diffusion assay using Bacillus subtilis ATCC 6633 for tobramycin and Saccharomyces cerevisiae for nystatin as the test microorganism. The means of results were 108.70 % of label claim for nystatin and 104.70% of label claim for tobramicin. The Z scores were 0.14 for tobramycin and 1.40 for nystatin, the assigned value used for booth samples was 105.4% for tobramycin and 101.7% for nystatin. The performance of Microbiological Control Laboratory was very good for both samples.

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