ABSTRACT
OBJECTIVE: To investigate the absorption kinetics of fenofibrate nanosuspension in rat intestine. METHODS: The intestine of rats was cannulated for in situ recirculation. UV spectrophotometry was used to determine the concentrations of phenol red while HPLC was used to determine the concentrations of fenofibrate and fenofibric acid. RESULTS: The fenofibrate nanosuspension exhibited substantial absorption enhancement in entire intestine compared to the crude drug solution. The difference in drug absorption at concentrations from 50 to 200 μg · mL-1 between fenofibrate nanosuspension and crude drug solution was not significant. Different pH values of K-R buffer had no effect on the intestinal permeability (Papp) and absorption rate constant (KR) for the two dosage forms. The absorption rate constants (h-1) of fenofibrate nanosuspension at duodenum, jejunum, ileum and colon were (0.373 ± 0.0021), (0.329 ± 0.0008), (0.362 ± 0.0014), and (0.347 ± 0.0079), respectively. CONCLUSION: Fenofibrate nanosuspension can be well absorbed in the whole intestinal segments. The absorption of fenofibrate nanosuspension in rat intestine is a first order process with passive diffusion mechanism.