Preparation and evaluation of BSA-based hydrosol nanoparticles cross-linked with genipin for oral administration of poorly water-soluble curcumin

•Hydrosol system was used to encapsulate curcumin for improving its water solubility.•Food-grade colloidal delivery system was used for curcumin encapsulation and preparation of water-dispersible curcumin.•No stabilizers were added and BSA act as a protective colloid.•Genipin as a natural cross-linking agent, was replaced instead of toxic glutaraldehye.•Particles diameter was highly pH-dependent.•BSA-based nanoparticles with less than <200 nm were prepared.

One of the most interesting functions of albumin is the ability to interact with bioactive compounds. This study describes preparation of protein-based nanoparticles (NPs) for the preparation of solid dispersion of curcumin (CN). Fabrication of hydrosol system of dispersed CN in bovine serum albumin (BSA) was approached, followed by cross-linking with glutaraldehyde (Gta). Response surface methodology (RSM) was used to investigate the influence of input factors (pH, CN content and organic phase ratio (r)), on the particle size and CN entrapment efficiency (EE). Particle size, EE and CN loading efficiency (LE) at optimum condition (pH 7, r 10% and 3.4 mg of CN content), were found to be in the range of 153-184.4 nm, 72.54%, and 14.508 μg/mg, respectively. In the optimum formulation, genipin (Gnp) was used at three different levels (0.1-0.2 and 0.3% w/w of BSA), as a safe, natural cross-linker instead of toxic Gta, to address the limitation of oral delivery purpose. AFM and SEM analysis revealed the spherical and smooth surface of Nps. Ninhydrin (NHD) assay and FT-IR analysis confirmed the cross-linking between BSA and Gnp. In vitro release studies ensure the efficiency of the formulation for sustained release of soluble CN.