Comparative analysis of blood concentrations for orally administered micronized and non-micronized florfenicol in Sprague-Dawley rats

Florfenicol is a fluorinated analog of thiamphenicol and has been used for the treatment of animal respiratory infectious diseases with a mechanism of action that inhibits bacterial protein synthesis. The aim of this study was conducted to investigate the effect of micronized and non-micronized-florfenicol prepared with different comminution techniques on the change in the blood concentration of florfenicol in rats. Forty adult male Sprague Dawley rats (6 weeks of age, body weight 126.8±9.52 g) were randomly allocated to two treatments groups: MF treated with micronized florfenicol powder (particle size, over 90% was 10 ㎛) and NMF treated with non-micronized florfenicol powder (particle size, over 70% was 100 ㎛) were given 97.5 mg/kg body weight once daily for four days. The results showed that MF at day 2, 3 (p<0.05) and 4 (p<0.001) had a significantly increased serum concentration of florfenicol compared to NMF. The results show that the micronization of florfenicol may provide higher oral bioavailability of the drug compared to its normal form.