Background: Test methods to inform hazard characterization and labeling of pesticides to protect human health are typically conducted using laboratory animals, and for skin irritation/corrosion the rabbit Draize test is currently required by many regulatory agencies. Although the Draize test is generally regarded to provide protective classifications for human health, new approach methodologies (NAMs) have been developed that offer more human relevant models that circumvent the uncertainty associated with species differences that exist between rabbits and humans. Despite wide applicability and use of these test methods across a broad range of chemicals, they have not been widely adopted for testing pesticides and pesticidal formulations. One of the barriers to adoption of these methods in this sector is low concordance with results from the Draize rabbit test, particularly for chemicals within the mild to moderate irritation spectrum.
Methods: This review compares and contrasts the extent to which available models used in skin irritation testing mimic the anatomy and physiology of human skin, and how each aligns with the known key events leading to chemically-induced adverse skin irritation and corrosion. Doing so fully characterizes the human relevance of each method.
Results: As alternatives to the rabbit Draize test, several protocols using ex vivo, in chemico, and in vitro skin models are available as internationally harmonized test guidelines. These methods rely on a variety of models of human skin, including excised rodent skin, synthetic biochemical models of barrier function, cell culture systems, and reconstructed human tissue models. We find these models exhibit biological and mechanistic relevance aligned with human skin irritation responses. Further, recent retrospective analyses have shown that the reproducibility of the Draize test is less than 50% for mild and moderate responses, with many of the replicate predictions spanning more than one category (e.g., a moderate response reported in one study followed by a non-irritant response reported in another study).
Conclusions: Based on this comparative evaluation, we recommend top-down and bottom-up testing strategies that use the most human relevant in vitro test methods for skin irritation and corrosion classification of pesticides and pesticide formulations. To further discriminate among mild and non-irritant formulations, optimization of a cytokine release protocol and subsequent analyses of reference formulation test results is recommended.

With the growing importance of alternative test methods that implement the 3Rs principles (Reduction, Refinement and Replacement) and the global importance of biological safety assessment data for medical devices is increasing. We have developed and optimized the \'KeraSkin™ Skin Irritation Test (KeraSkin™ SIT) for medical device\' for regulatory application in biological evaluation according to ISO 10993-23. We conducted a round robin study to optimize and evaluate the performance of KeraSkin™ SIT for medical devices using KeraSkin™ Reconstructed Human Epidermis (RhE), which is developed and manufactured in Korea. This round robin study was performed to assess the transferability, reproducibility (within and between laboratories) and predictive capacity in 1 lead laboratory and 3 participating laboratories based on OECD Guidance Document 34. The predictive capacity, the results showed 83.3 % of sensitivity, 100 % of specificity and 91.6 % of accuracy. In conclusion, the results demonstrate that \'KeraSkin™ SIT for medical device\' provides a robust test method for detecting irritant activity of medical device extracts and can be utilized for identifying low levels of potent irritants in medical device extracts. Therefore, it fulfills the requirements to be included as a \'me-too\' test method to EpiDerm™ and SkinEthic™ skin irritation test in ISO 10993-23.

Following the publication of the above article, the authors contacted the Editorial Office to explain that they had identified a pair of duplicate images in the control (Vehicle) group of mouse images in Fig. 1A on p. 1792. Specifically, the same image (corresponding correctly to the \'Day 5\' experiment) was inadvertently chosen to represent the cutaneous manifestations of mice in the Vehicle group on \'Day 3\' and \'Day 5\' in Fig. 1A. This error arose as a consequence of repetitive application and duplication procedures within the image set, resulting in the inadvertent reuse of the same photo. Additionally, due to minimal alterations observed in the skin condition of mice from the control group following treatment, each mouse exhibited a similar appearance; this similarity further contributed to the delayed identification of this error during the paper revision stage. Consequently, this duplication of the same image was made as a result of insufficient scrutiny. The revised version of Fig. 1, showing the correct image for the \'Day 3\' experiment in Fig. 1A, is shown on the next page. The authors can confirm that the error associated with the assembly of this figure did not have any significant impact on either the results or the conclusions reported in this study, and all the authors agree with the publication of this Corrigendum. The authors are grateful to the Editor of International Journal of Molecular Medicine for allowing them the opportunity to publish this; furthermore, they apologize to the readership of the Journal for any inconvenience caused. [International Journal of Molecular Medicine 43: 1789‑1805, 2019; DOI: 10.3892/ijmm.2019.4098].

BACKGROUND: Retinoids, defined as synthetic or natural derivatives of vitamin A, have been extensively studied as anti-aging molecules that are widely applied in cosmetics. However, due to their physicochemical property, retinoids are highly unstable and extremely sensitive to light, oxygen, and temperature. Moreover, topical application of retinoids often leads to cutaneous irritation. These instabilities and irritant properties of retinoids limit their application in cosmetic and pharmaceutical products.
OBJECTIVE: Our study aimed to provide a systematic review to summarize the mechanisms underlying the instability and irritant properties of retinoids, as well as recent developments in addressing these challenges.
METHODS: A comprehensive PubMed search was conducted using the following keywords: retinoids, chemical instability, skin irritation, retinoid derivatives, nano lipid-based carriers, liposomes, penetration-enhancer vesicles, ethosomes, niosomes, nanoemulsions, solid lipid nanoparticles, vitamins, soothing and hydrating agents, antioxidants and metal chelator and retinol combinations. Relevant researches published between 1968 and 2023 and studies related to these reports were reviewed.
RESULTS: The development of new retinoid derivatives, the utilization of new delivery systems like nano lipid-based carriers and the combination with other compounds like vitamins, soothing agents, antioxidants and metal chelator have been explored to improve the stability, bioavailability, and toxicity of the retinoid family.
CONCLUSIONS: Through advancements in formulation techniques, structure modification of retinoid derivatives and development of novel nano lipid-based carriers, the chemical instability and skin irritation of retinoids has been mitigated, ensuring their efficacy and potency over extended periods.

After EU ban on animal testing for cosmetics in 2013, there has been an increasing global interest in alternatives test methods. To development for alternatives test method, we need to get the toxic data about in vitro and in vivo of chemicals. However, database sometimes provide limited in vivo and in vitro data on chemicals. Further, the data generated using the OECD TG439 (in vitro skin irritation) are scattered in difference databases, and it is not easy to navigate through them. Therefore, we complied \'Reference Chemical Database System for Skin Irritation Alternative Test (RCDS-Skin Irritation)\' to allow easy, one-stop access to test chemical information. We established the systematic RCDS-Skin Irritation by collecting physiochemical properties, CAS number, human data, and in vivo (OECD TG404) data from overseas chemicals database including European Chemicals Agency (ECHA) etc., and in vitro data using Reconstructed human Epidermis (RhE) (OECD TG439). As a result, we developed the RCDS-Skin Irritation that contains information on 149 chemicals including the data we generated by performing tests using EpiDerm™ SIT, SkinEthic™ RHE and KeraSkin™ SIT. Therefore, the RCDS-Skin Irritation established based on our study will provide insight for safety assessment of chemicals and for development of alternative test methods.

Resveratrol could be applied in wound healing therapies because of its antioxidant, anti-inflammatory and antibacterial effects. However, the main limitation of resveratrol is its low aqueous solubility. In this study, resveratrol was included in hydroxypropyl-β-cyclodextrin complexes and further formulated in Pluronic F-127 hydrogels for wound treatment therapy. IR-spectroscopy and XRD analysis confirmed the successful incorporation of resveratrol into complexes. The wound-healing ability of these complexes was estimated by a scratch assay on fibroblasts, which showed a tendency for improvement of the effect of resveratrol after complexation. The antimicrobial activity of resveratrol in aqueous dispersion and in the complexes was evaluated on methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, and Candida albicans strains. The results revealed a twofold decrease in the MIC and stronger inhibition of the metabolic activity of MRSA after treatment with resveratrol in the complexes compared to the suspended drug. Furthermore, the complexes were included in Pluronic hydrogel, which provided efficient drug release and appropriate viscoelastic properties. The formulated hydrogel showed excellent biocompatibility which was confirmed via skin irritation test on rabbits. In conclusion, Pluronic hydrogel containing resveratrol included in hydroxypropyl-β-cyclodextrin complexes is a promising topical formulation for further studies directed at wound therapy.

UNASSIGNED: The present work is focus on development of anti-psoriasis activity of Karanjin (isolated from Pongamia pinnata seed oil) loaded liposome based lotion for enhancement of skin permeation and retention.
UNASSIGNED: Karanjin was isolated using liquid-liquid extraction method and characterised by HPLC analysis and partition coefficient. Further, isolated Karanjin was loaded into liposomes using thin-film hydration technique and optimised by Box-Behnken design. Selected optimised batch was characterised their mean diameter, PDI, zeta potential, and entrapment efficiency, morphology (by TEM), FTIR and ex-vivo skin retention. Additionally, Karanjin loaded liposomes were formulated into lotion and characterise their rheological, spreadability, texture, ex-vivo skin permeation & retention, stability and anti-psoriatic activity in mouse tail model.
UNASSIGNED: The yield of Karanjin from seed oil was 0.1% w/v and have lipophilic nature. The optimised liposomal formulation showed 195 ± 1.8 nm mean diameter, 0.271 ± 0.02 PDI, -27.0 ± 2.1 mV zeta potential and 61.97 ± 2.5% EE. TEM image revel the spherical shap of liposome surrounded by single phospholipid bilayer and no interection between drug and excipients. Further, lotion was prepared by 0.1% w/v carbopol and found to 615 mPa.sec viscosity, good thixotropic behaviour, spreadability and texture. There was 22.44% increase in drug permeation for Karanjin loaded liposomal lotion compared to pure Karanjin lotion, confirm by ex-vivo permeation and retention. While, in-vivo study revel the liposomal lotion of Karanjin was found to have 16.09% higher drug activity then 5% w/w conventional Karanjin lotion.
UNASSIGNED: Karanjin loaded liposomal lotion have an effective anti-psoriatic agent and showed better skin permeation and retention than the conventional Karanjin lotion.

Transdermal rotigotine (RTG) therapy is prescribed to manage Parkinson\'s disease (Neupro® patch). However, its use is suffered from application site reactions. Herein, drug nanocrystalline suspension (NS)-loaded hydrogel (NS-HG) employing polysaccharides simultaneously as suspending agent and hydrogel matrix was constructed for transdermal delivery, with alleviated skin irritation. RTG-loaded NS-HG was prepared using a bead-milling technique, employing sodium carboxylmethyl cellulose (Na.CMC) as nano-suspending agent (molecular weight 90,000 g/mol) and hydrogel matrix (700,000 g/mol), respectively. NS-HG was embodied as follows: drug loading: ≤100 mg/mL; shape: rectangular crystalline; crystal size: <286.7 nm; zeta potential: -61 mV; viscosity: <2.16 Pa·s; and dissolution rate: >90 % within 15 min. Nuclear magnetic resonance analysis revealed that the anionic polymers bind to RTG nanocrystals via charge interaction, affording uniform dispersion in the matrix. Rodent transdermal absorption of RTG from NS-HG was comparable to that from microemulsions, and proportional to drug loading. Moreover, NS-HG was skin-friendly; erythema and epidermal swelling were absent after repeated application. Further, NS-HG was chemically stable; >95 % of the drug was preserved up to 4 weeks under long term (25 °C/RH60%), accelerated (40 °C/RH75%), and stress (50 °C) storage conditions. Therefore, this novel cellulose derivative-based nanoformulation presents a promising approach for effective transdermal RTG delivery with improved tolerability.

UNASSIGNED: Ducrosia anethifolia is an aromatic desert plant used in Saudi folk medicine to treat skin infections. It is widely found in Middle Eastern countries.
UNASSIGNED: A methanolic extract of the plant was prepared, and its phytoconstituents were determined using LC-MS. In-vitro and in-vivo antibacterial and antibiofilm activities of the methanolic extract were evaluated against multidrug-resistant bacteria. The cytotoxic effect was assessed using HaCaT cell lines in-vitro. Diabetic mice were used to study the in-vivo antibiofilm and wound healing activity using the excision wound method.
UNASSIGNED: More than 50 phytoconstituents were found in the extract after LC-MS analysis. The extract exhibited antibacterial activity against both the tested pathogens. The extract was free of irritant effects on mice skin, and no cytotoxicity was observed on HaCaT cells with an IC50 value of 1381 µg/ml. The ointment formulation of the extract increased the healing of diabetic wounds. The microbial load of both pathogens in the wounded tissue was also reduced after the treatment. The extract was more effective against methicillin-resistant Staphylococcus aureus (MRSA) than MDR-P. aeruginosa in both in vitro and in vivo experiments. Further, skin regeneration was also observed in histological studies.
UNASSIGNED: The results showed that D. anethifolia methanol extract supports wound healing in infected wounds in diabetic mice through antibacterial, antibiofilm, and wound healing activities.

BACKGROUND: Niacin, an established therapeutic for dyslipidemia, is hindered by its propensity to induce significant cutaneous flushing when administered orally in its unmodified state, thereby constraining its clinical utility.
OBJECTIVE: This study aimed to fabricate, characterize, and assess the in-vitro and in-vivo effectiveness of niacin-loaded polymeric films (NLPFs) comprised of carboxymethyl tamarind seed polysaccharide. The primary objective was to mitigate the flushing-related side effects associated with oral niacin administration.
METHODS: NLPFs were synthesized using the solvent casting method and subsequently subjected to characterization, including assessments of tensile strength, moisture uptake, thickness, and folding endurance. Surface characteristics were analyzed using a surface profiler and scanning electron microscopy (SEM). Potential interactions between niacin and the polysaccharide core were investigated through X-ray diffraction experiments (XRD) and Fourier transform infrared spectroscopy (FTIR). The viscoelastic properties of the films were explored using a Rheometer. In-vitro assessments included drug release studies, swelling behavior assays, and antioxidant assays. In-vivo efficacy was evaluated through skin permeation assays, skin irritation assays, and histopathological analyses.
RESULTS: NLPFs exhibited a smooth texture with favorable tensile strength and moisture absorption capabilities. Niacin demonstrated interaction with the polysaccharide core, rendering the films amorphous. The films displayed slow and sustained drug release, exceptional antioxidant properties, optimal swelling behavior, and viscoelastic characteristics. Furthermore, the films exhibited biocompatibility and non-toxicity towards skin cells.
CONCLUSIONS: NLPFs emerged as promising carrier systems for the therapeutic transdermal delivery of niacin, effectively mitigating its flushing-associated adverse effects.