Nanoporous silicon to enhance oral delivery of poorly water-soluble drugs

Abstract With the abundance of poorly water-soluble candidates currently under investigation in the drug development pipeline, there is a significant imperative to develop methodologies to control and improve their in vivo behavior. Porous silicon (PSi) has received considerable attention for the delivery of a range of poorly water-soluble therapeutics, which are typically loaded by solvent partitioning. As a result of the steric crowding of the drug molecules in the pores, the drugs remain ‘frozen’ in highly soluble molecular or amorphous forms. Experimental evidence confirming this phenomenon has been obtained using techniques, such as powder X-ray diffraction, differential scanning calorimetry, Fourier transform infrared spectroscopy, and in vitro dissolution. Complementary in vivo studies have demonstrated the significant improvement in pharmacokinetics achievable using orally dosed PSi carrier particles, highlighting the significant potential of PSi as a delivery system for poorly water-soluble drugs. In this chapter, we provide an insight into the oral delivery challenges of poorly water-soluble drugs and how PSi can be implemented to improve their drug delivery, exemplified through in vitro and in vivo findings.