Development, structural characterization, in vitro release and oral bioavailability studies of novel surface-modified natural Fiber Interlaced Liposomal Vitamin C

Abstract

New design techniques are required to improve the stability of vitamin C (VC), which is essential for human health but is sensitive to environmental factors, in the stomach and its release in the body. The purpose of this study is to develop and characterise a fibre interlaced liposome (FIL) as a vehicle for better delivery of VC, with fruit fibres providing surface protection against degradation, which was confirmed by various studies. The optimised formulation was evaluated for its structural and surface morphological properties through zeta potential, FTIR, XRD, SEM, TEM, and DSC analyses. In vitro release studies were also conducted, and FIL-VC displayed a sustained release of VC (19.31%) compared to the control (67.54%) during the period of 8 h. FIL-VC demonstrates better release in simulated intestinal fluids (95.34%) than in gastric fluids (21.15%), indicating better stability and absorption in the gastrointestinal tract. In a randomized, double-blind, active-controlled, two-way crossover clinical study, FIL-VC showed 5.77-fold higher relative oral bioavailability in comparison with the unformulated VC. The AUC_0−t for VC in FIL-VC (23.80 μg mL⁻¹) was found to be significantly higher compared to unformulated VC (4.13 μg mL⁻¹) after the oral administration of a single dose. These data show that FIL formulation resulted in a sustained release of VC with increased bioavailability, which could be beneficial for extended-release applications.