Comparison of the microbiological turbidimetric and hydroxylamine colorimetric methods in stability study of cefadroxil monohydrate powder

ABSTRACT

Comparison between the chemical and microbiological methods for the analysis of cefadroxil in powder for reconstitution stored at different temperature was carried out. Results indicated that the values of the antibiotic percent obtained by chemical method differ than those obtained microbiologically of the same samples. Microbiological assay of stored samples at 25 gave information that the product is valid up to 30 months while the chemical method indicated that the same sample valid for 12 months only. Sample stored at 37C seemed valid after storage for 12 months using microbiological method but the chemical assay indicated that it was not valid after 6 months. Chemical and microbiological assay indicated that stored samples at 56C were not valid but there was difference between values obtained by chemical and microbiological methods. Microbiological assay of stored sample valid for 2 months but chemical assay showed them not valid at all. This indicated that the chemical method considered invalid for stability study and/or assessment of validity of product containing cefadroxil