Thymol-Loaded Eudragit RS30D Cationic Nanoparticles-Based Hydrogels for Topical Application in Wounds: In Vitro and In Vivo Evaluation

Abstract

Natural medicines formulated using nanotechnology-based systems are a rich source of new wound-treating therapeutics. This study aims to develop thymol-loaded cationic polymeric nanoparticles (CPNPs) to enhance the skin retention and wound healing efficacy of thymol. The developed materials exhibited entrapment efficiencies of 56.58 to 68.97%, particle sizes of 36.30 to 99.41 nm, and positively charged zeta potential. In Vitro sustained release of thymol up to 24 h was achieved. Selected thymol CPNPs (F5 and C2) were mixed with methylcellulose to form hydrogels (GF5 and GC2). An In Vivo skin-retention study revealed that GF5 and GC2 showed 3.3- and 3.6-fold higher retention than free thymol, respectively. An In Vitro scratch-wound healing assay revealed a significant acceleration in wound closure at 24 h by 58.09% (GF5) and 57.45% (GC2). The potential for free thymol hydrogel, GF5, and GC2 to combat MRSA in a murine skin model was evaluated. The bacterial counts, recovered from skin lesions and the spleen, were assessed. Although a significant reduction in the bacterial counts recovered from the skin lesions was shown by all three formulations, only GF5 and GC2 were able to reduce the bacterial dissemination to the spleen. Thus, our study suggests that Eudragit RS30D nanoparticles-based hydrogels are a potential delivery system for enhancing thymol skin retention and wound healing activity.

Development and Characterization of Microparticles with Actinidia arguta Leaves Extract by Spray-Drying: A New Mind-Set Regarding Healthy Compounds for Oral Mucositis

“…Concerning the loading capacity, the kaempferol-3- O -(acetyl-rhamnoside)-hexoside showed the highest value (0.00320%), followed by 4- O -caffeoylquinic acid (0.00225%) and 1- O -caffeoylquinic acid (0.00205%). These parameters are crucial to evaluate the encapsulation efficiency that expresses the amount of extract entrapped in microparticles [ 32 , 36 ]. Many conditions such as compounds solubility in the encapsulating agent or in the aqueous phase, aggregation or precipitation of molecules, or even spray-drying conditions (e.g., flow rate, inlet, and outlet temperature) can affect the encapsulation efficiency [ 36 , 37 , 38 ].…”

“…These parameters are crucial to evaluate the encapsulation efficiency that expresses the amount of extract entrapped in microparticles [ 32 , 36 ]. Many conditions such as compounds solubility in the encapsulating agent or in the aqueous phase, aggregation or precipitation of molecules, or even spray-drying conditions (e.g., flow rate, inlet, and outlet temperature) can affect the encapsulation efficiency [ 36 , 37 , 38 ]. In the present study, even though the spray-drying conditions were adjusted to prevent the phenolic compounds’ degradation, it is possible that adjustments should be optimized.…”

“…Concerning empty microparticles ( Figure 6 b), the obtained spectrum displayed significant peaks at wavelengths 1100–1200 cm −1 (quaternary ammonium group), 1700–1750 cm −1 (C=O stretching band related to the ester carbonyl groups), 1400–1500 cm −1 (C=C stretching band), and 2900–3000 cm −1 (C–H stretching band). Eudragit RS 30 D, widely employed in pharmaceutical formulations, serves as enteric coating material and matrix for controlled-release drug delivery systems [ 36 ]. This copolymer primarily consists of ethyl acrylate and methyl methacrylate monomers, combined with a quaternary ammonium group integrated into its structure [ 52 ].…”

Eucalyptus torquata L. flowers: a comprehensive study reporting their metabolites profiling and anti-gouty arthritis potential

“…Several medicinal plants and phytochemicals play a major role in the treatment of a wide array of diseases and pathological conditions, among them oxidative stress related disorders 5 – 11 . High levels of oxygen reactive species and free radicals end up in a state of cellular oxidative stress, which mediate acute inflammation through cytokines stimulation and pro-inflammatory enzymes activation, such as lipoxygenase, cyclooxygenase, hyaluronidase, tyrosinase and xanthine oxidase 12 , 13 .…”