Enhancement of oral bioavailability of fenofibrate by solid self-microemulsifying drug delivery systems

A solid form of self-microemulsifying drug delivery system (Solid SMEDDS) was developed by spray-drying with dextran as the inert solid carrier, to improve the oral bioavailability of a poorly water-soluble drug, fenofibrate. The optimized liquid SMEDDS, composed of Labrafil M 1944 CS/Labrasol/Capryol PGMC (15/75/10%v/v) with 10% w/v fenofibrate gave a z-average diameter of around 240 nm. There was no significant difference in the mean droplet size and size distribution of the emulsions obtained from the liquid and solid forms of SMEDDS. Solid state characterizations of solid SMEDDS showed that the crystal state of fenofibrate in solid SMEDDS was converted from crystalline to amorphous form. Solid SMEDDS had significantly higher dissolution rates than the drug powder, due to its fast self-emulsification in the dissolution media. Furthermore, the AUC value of solid SMEDDS was twofold greater than that of the powder, indicating this formulation greatly improved the oral bioavailability of drug in rats. Thus, these results suggest that solid SMEDDS could be used as an effective oral solid dosage form to improve dissolution and oral bioavailability of fenofibrate.