Nanoparticle tools for maximizing oral drug delivery

The biological permeability and water solubility of drugs can pose substantial obstacles to oral drug delivery, the most common mode of drug administration for improving human health. Solubility determines the amount of drug that can be dissolved in solution, whereas permeability is the ability to permeate across biological membranes, determining therapeutic efficacy and safety. Some biological barriers, such as gastrointestinal pH, enzymes, and mucus, may affect the dissolution or absorption of therapeutic drugs. Physical or chemical approaches can be used to modify the water solubility or enhance the permeability. Moreover, nanocarriers, which can increase drug stability through encapsulation, enhance absorption due to their extensive surface area, and facilitate the targeted administration of medications to certain areas, could be useful for drug delivery systems. Nanoparticles can increase drug solubility by particle size reduction, complexation, and drug encapsulation and increase permeation by retention in tumors, opening of tight junctions, membrane fluidization, or intestinal mucoadhesion. Despite the many advantages of nanoparticle drug formulations, they also have several limitations, such as complicated manufacturing processes, nanotoxicity, and stability issues. In this article, we provide a comprehensive description of nanoparticle tools for maximizing oral drug delivery.