The aim of this study was to evaluate the oral bioavailability of liposomal vitamin C and non-liposomal vitamin C in healthy, adult, human subjects under fasting conditions through an open label, randomized, single-dose, two-treatment, two-sequence, two-period, two-way crossover, study. The vitamin C loaded liposome was well characterized using transmission electron microscopy (TEM), dynamic light scattering (DLS) and zeta potential measurements for evaluating morphology, particle size and stabilities, respectively. Microscopic image shows the core-type structure that confirms the characteristic pattern of liposome. The encapsulation efficiency (EE%) and the particle size were 65.85 ± 1.84% and below 100 nm, respectively. The results of the clinical studies of liposomal vitamin C by oral delivery to be 1.77 times more bioavailable than non-liposomal vitamin C. The liposomal vitamin C demonstrated higher values of Cmax, AUC0-t and AUC0-∞ related to non-liposomal vitamin C due to liposomal encapsulation. No adverse events were reported. It could be concluded that liposomal encapsulated ascorbic acid (vitamin C) shows well-organized morphological pattern, uniform particle size and highly efficient, which leads to have enhanced bioavailability.
Keywords: Vitamin C; bioavailability; liposomes; nutraceuticals; pharmacokinetics.