Gold nanoparticles are one of the most extensively investigated metallic nanoparticles for several applications. It is less toxic than other metallic nanolattices. The exceptional electrical and thermal conductivity of gold make it possible to be administered as non-invasive radiofrequency irradiation therapy that produces sufficient heat to kill tumor cells. Nanoparticles are generally administered intravenously instead of orally due to negligible oral absorption and cellular uptake. This study evaluated the oral bioavailability of gold nanoparticles coated with chitosan (C-AuNPs), a natural mucoadhesive polymer. We employed traditional method of evaluating bioavailability that involve estimation of maximum concentrations and area under the curve of 3 nm chitosan coated gold nanoparticles (C-AuNPs) in the rat plasma following intravenous and oral administrations (0.8 mg and 8 mg/kg body weight respectively). The oral bioavailability of C-AuNPs was found to be 2.46% (approximately 25 folds higher than polyethylene glycol (PEG) coated gold nanoparticles, reported earlier). These findings suggest that chitosan coating could be better than PEG coating for the enhancement of oral bioavailability of nanoparticles.
Keywords: AUCINF, area under curve extrapolated till infinite time; AUCcall, area under curve calculated till last quantifiable time point; AUCiv, Area Under the Plasma Concentration-Time Curve of intravenous administration; AUCpo, Area Under the Plasma Concentration-Time Curve of oral administration; Area under curve; Bioavailability; C-AuNPs, gold nanoparticles coated with chitosan; CL, clearance; Chitosan; Chitosan coated gold nano-particles (C-AuNP); Cmax, maximum concentration of gold nanoparticles in blood; F_AUCINF, bioavailability calculated from Area Under the Plasma Concentration-Time Profile from Time 0 to Infinity; Gold nanoparticles (AuNP); Rat plasma; T ½, biological half-life (time required to eliminate half amount of drug from body); Vd, volume of distribution.