Development of kojic acid loaded collagen-chitosan nanoparticle as skin lightener product: in vitro and in vivo assessment.

In the present study, an ionic gelation and ultrasonic approach was performed to produce kojic acid (KA) loaded chitosan(CS)/collagen(CN) nanoparticle(NP) (CSCN-NP) which aimed to increase the dermal delivery and anti-pigmentation effect. To optimize the CSCN-NP the effect of the amount of CN was investigated. The results showed that increasing CN from 0 to 500 mg increased the mean particle size and entrapment efficiency of KA-CSCN-NP from 266.07 ± 9.30 nm to 404.23 ± 9.44 nm and 17.37 ± 2.06% to 82.34 ± 2.16%, respectively. Differential scanning calorimetry confirmed the amorphous form of KA in CSCN-NP, while scanning electron microscopy revealed that the nanoparticles were spherical. There was no chemical interaction between KA and the other components base on attenuated total reflectance-Fourier transform infrared spectroscopy. The skin permeability test showed that KA-CSCN-NP gel delivered more KA to the dermal layers (29.16 ± 1.67% or 537.26 ± 537.26 µg/cm2) and receiver compartment (15.04 ± 1.47% or 277.15 ± 27.22 µg/cm2) compared to KA plain gel. In vitro cytotoxicity assay demonstrated that the improved KA-CSCN-NP was non-toxic. Dermal irritating test on Wistar rats showed that the KA gel was non-irritating. Furthermore, KA-CSCN-NP was found to inhibit melanin formation to a greater extent than free KA and significantly inhibited L-dopa auto-oxidation (94.80 ± 2.41%) compared to pure kojic acid solution (75.28 ± 3.22%). The observations of this study revealed that the produced KA-CSCN-NP might be used as a potential nano-vehicle for KA dermal administration, thereby opening up innovative options for the management of hyper-melanogenesis problems.

Methylene blue-loaded niosome: preparation, physicochemical characterization, and in vivo wound healing assessment.

Following skin injury, the overproduction of reactive oxygen species (ROS) during the inflammatory phase can cause tissue damage and delay in wound healing. Methylene blue (MB) decreases mitochondrial ROS production and has antioxidant effects. The authors aimed to prepare MB-loaded niosomes using the ultra-sonication technique as a green formulation method. A Box-Behnken design was selected to optimize formulation variables. The emulsifier to cholesterol ratio, HLB of mixed surfactants (Span 60 and Tween 60), and sonication time were selected as independent variables. Vesicle size, zeta potential (ZP), and drug entrapment capacity percentage were studied as dependent variables. The optimized formulation of niosomes showed spherical shape with optimum vesicle size of 147.8 nm, ZP of - 18.0 and entrapment efficiency of 63.27%. FTIR study showed no observable interaction between MB and other ingredients. In vivo efficacy of optimized formulation was evaluated using an excision wound model in male Wistar rat. Superoxide dismutase (SOD, an endogenous antioxidant) and malondialdehyde (MDA, an end product of lipid peroxidation) levels in skin tissue samples were evaluated. After 3 days, MDA was significantly decreased in niosomal gel-treated group, whereas SOD level was increased. Histological results indicate rats that received niosomal MB were treated effectively faster than other ones. Graphical abstract.