Improving oral delivery.

It is estimated that 90% of all medicines are oral formulations and their market share is still increasing, due to sound advantages for the patient, the pharmaceutical industry and healthcare systems. Considering biopharmaceutical issues such as physicochemical requirements of the drug and physiological conditions, however, oral delivery is one of the most challenging routes. Recognising solubility, permeability and residence time in the gastrointestinal milieu as key parameters, different characteristics of drugs and their delivery systems such as size, pH, density, diffusion, swelling, adhesion, degradation and permeability can be adjusted to improve oral delivery. Future developments will focus on further improvement in patient compliance as well as the feasibility of administering biotech drugs via the oral route.