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.
