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Novel core-shell dual-mesoporous silica nanoparticles (DMSN) were successfully prepared as a carrier in order to improve the dissolution of fenofibrate and obtain an oral highly bioavailable controlled-release drug delivery system using the osmotic pump technology. Fenofibrate was loaded into DMSN by an adsorption method. The solid state properties of fenofibrate in DMSN, before and after drug loading, were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption/desorption analysis (BET), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD) and differential scanning calorimetry (DSC). In vitro release tests showed that DMSN increased the dissolution rate of fenofibrate and produced zero-order release in push-pull osmotic pump tablets (OPT). The relative bioavailability of OPT was 186.9% in comparison with the commercial reference product. In summary, osmotic pump technology in combination with solid dispersion technology involving nanometer materials is a promising way for achieving the oral delivery of poorly water-soluble drugs.

In this study, a novel three-dimensional ordered macroporous gelatin (3DOMG) was fabricated as a carrier for increasing the solubility of poorly water-soluble drugs, offering sustained release and a high oral bioavailability. Polymethyl methacrylate nanospheres (257 nm) were used as a colloidal plastic framework to synthesize 3DOMG. Fenofibrate (FNB) was selected as a model drug and loaded onto 3DOMG by the adsorption equilibrium method. Detailed characterization showed that the FNB absorbed onto 3DOMG was in a microcrystalline state. A fluorescence experiment and the prepared drug microcrystal network gave further information on the physical state of the drug. A degradation experiment proved that 3DOMG was readily biodegradable. In vitro release testing showed that 3DOMG increased the dissolution rate of FNB and produced a sustained release. An in vivo pharmacokinetic study confirmed that 3DOMG improved the oral bioavailability compared with that of commercial sustained-release capsules. These findings confirm that 3DOMG can be regarded as a promising carrier for an oral drug delivery system.

Starch macrocellular foam (SMF), a novel natural bio-matrix material, was prepared by the hard template method in order to improve the dissolution rate and oral bioavailability of poorly water-soluble drugs. Nitrendipine (NDP) was chosen as a model drug and was loaded into SMF by the solvent evaporation method. SMF and the loaded SMF samples (NDP-SMF) were characterized by scanning electron microscopy, differential scanning calorimetry, X-ray powder diffraction and Fourier transform infrared spectroscopy. In vitro drug release studies showed that SMF significantly increased the dissolution rate of NDP. In vivo studies showed that the NDP-SMF tablets clearly increased the oral bioavailability of NDP in comparison with the reference commercial tablets. All the results obtained demonstrated that SMF was a promising carrier for the oral delivery of poor water-soluble drugs.