文摘
This study aims to investigate the stability of florfenicol using previously developed derivative spectrophotometric methods (D1 and D2).MethodsThe studied stability-indicating pararmeters included alkali (NaOH, 1 M), acid (HCl, 1 M), pH changes (buffer pH 2.2–11), temperature (80 °C and 100 °C at pH 10) and light.ResultA constructed pH profile for the drug degradation rate revealed a significant effect of pH on the drug stability between pH ranges 8 and 11. The obtained profile indicated first order dependence of Kobs on [OH−]. Arrhenius plot at pH 10 was found linear at temperatures 80 °C and 100 °C with estimated activation energy of 19.35 kcal/mol. The calculated rate constant (Kobs), t½ and t90 at 25 °C were found to be 1.8 × 10−3 h, 385 h and 58.3 h, respectively. The photostability of florfenicol was also studied by exposing the drug solution to direct sunlight during mid-day time.ConclusionThe obtained results reflected the instability of florfenicol under the study conditions.