Anna Rita Bilia
University of Florence, Italy
Title: Natural Products Loaded In Nanocarriers: An Opportunity To Increase Stability, Oral Bioavailability And Bioefficacy
Biography
Biography: Anna Rita Bilia
Abstract
Natural products represent a main source of drugs due to their enormous structural and chemical diversity. They may have additive/synergistic or antagonistic effects, or possess unique mechanisms of action (i.e. taxol activity on tubulin polymerization), others can modulate multiple targets or activating multiple pathwaysdriving fundamental biological processes. A paradigmatic example is curcumin, it is a highly pleiotropic molecule with anti-inflammatory, anti-oxidant, chemopreventive, chemosensitization, and radiosensitization activities. In spite of these advantages, several questions concerning the role of natural compounds in the treatment of some diseases remain unanswered, principally due to the transferability of in vitro to in vivo and ultimately to human studies: mostly of promising molecules in cell-based assays fail in phase II and phase III. This passage from impressive in vitro activity to less or no significant in vivo efficacy is generally due to their poor water solubility, high lipophilicity resulting in poor absorption and hence poor systemic bioavailability, resulting in less or no therapeutic effects. Another problem is their instability in biological milieu, premature drug loss through rapid clearance and biotransformation. Over the last ten years, our laboratory has formulated biocompatible and iodegradablenanocarriers encapsulating various imperative natural products including artemisinin and derivatives, curcumin, andrographolide, salvianolic acid, verbascoside, flavonoids. The developed new dosage forms, namely micelles, vesicles, nanoparticles, microemulsions, solid lipid nanoparticles and structured lipid capsules performed several sound characteristics and functions, which are currently unavailable in conventional formulations of natural drugs, such as enhanced solubility and stability, effect of targeting and increasing bioavailability.
Acknowledgments: this work was supported by Ente Cassa di Risparmio di Firenze