• Journal of Microbiology and Biotechnology
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• v.16 no.4
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• pp.590-596
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• 2006

Clavulanic acid (CA) produced by Streptomyces clavuligerus is degraded during the bacterial cultivation. The degradation was examined in three different aspects, including physical, chemical, and enzymatic effects, in order to understand the degradation during the cultivation. The result showed that CA was unstable in the production medium containing ammonium salts and amino acids, owing to ammonium ions and amine groups. In addition, the degradation was not only due to instability of CA by metabolites and proteins, but also enzymes from S. clavuligerus such as $\beta-lactamase$ and penicillin-binding proteins. However, the degradation caused by these enzymes was not highly significant compared with the degradation during the cultivation, owing to irreversible reactions between CA and enzymes.

• YAKHAK HOEJI
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• v.49 no.5
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• pp.392-398
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• 2005

In this study, we evaluated the stability of amoxicillin (AMX) and clavulanic acid (CLA) in aqueous solution, and compared the stability of AMX and CLA in commercial combination products. In aqueous solutions, the degradation of AMX ($t_{90}=8.88\;day\;at\;10^{circ}C$) and CLA ($t_{90}=3.53\;day\;at\;10^{circ}C$) occurred rapidly. From the pH-rate profile, AMX and CLA were the most stable at the range of pH 5.5 and 6.0. After reconstitution of commercial dry syrups, the contents of AMX and CLA in suspensions were gradually decreased for 7 days. However, AMX and CLA in dispersible tablet were not changed at all. The contents of CLA in the dispersible tablet ($87.92\%$) and dry syrups (2.16 and $3.91\%$) were remained in the accel­erated stability test ($75\%\;RH,\;at\;40^{circ}C$) after 10 hours. And the colors of the dry syrups were rapidly changed from white to yellow. From these results, we concluded that the dispersible tablet could overcome the stability problems of dry syrups.