Production, Characterization and Evaluation of Kaempferol Nanosuspension for Improving Oral Bioavailability

Context: Kaempferol has a large particle size and poor water solubility, leading to poor oral bioavailability. The present work aimed to develop a kaempferol nanosuspension (KNS) to improve pharmacokinetics and absolute bioavailability. Methods: A nanosuspension was prepared using high pressure homogenization (HPH) techniques. The physico-chemical properties of the kaempferol nanosuspension (KNS) were characterized using photon correlation spectroscopy (PCS), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR) and x-ray diffractometry (XRD). A reverse-phase high performance liquid chromatography (RP-HPLC) method for the analysis of the drug in rat plasma was developed and validated as per ICH guidelines. In vivo pharmacokinetic parameters of oral pure kaempferol solution, oral kaempferol nanosuspension and intravenous pure kaempferol were assessed in rats. Results and discussion: The kaempferol nanosuspension had a greatly reduced particle size (426.3 +/- 5.8 nm), compared to that of pure kaempferol (1737 +/- 129 nm). The nanosuspension was stable under refrigerated conditions. No changes in physico-chemical characteristics were observed. In comparison to pure kaempferol, kaempferol nanosuspension exhibited a significantly (P<0.05) increased in C-max and AUC(0-infinity) following oral administration and a significant improvement in absolute bioavailability (38.17%) compared with 13.03% for pure kaempferol. Conclusion: These results demonstrate enhanced oral bioavailability of kaempferol when formulated as a nanosuspension.