[Degradation of liquid preparations of four fluoroquinolones by factorial experiment. ]

The effects of light, pH and ionic strength on the degradation of four fluoroquinolones (norfloxacin, NFX; ofloxacin, OFX; ciprofloxacin, CPX; lomefloxacin, LEMX) solutions were studied. Using 2(3) factorial experiment and F test, it was confirmed that the degradation of NFX, OFX, CPX and LEMX was affected very markedly by light, but almost not affected by the ionic strength of the solution. The degradation of OFX and CPX was affected very markedly by pH, but the degradation of NFX and LEMX was almost not affected by pH. The degradation of OFX and CPX was affected very markedly by the combined action of light and pH, but the degradation of NFX and LEMX was almost not affected by the combined action of light and pH.