Activity of amorolfine or ciclopirox in combination with terbinafine against pathogenic fungi in onychomycosis-Results of an in vitro investigation.

BACKGROUND: Onychomycoses are difficult-to-treat fungal infections with high relapse rates. Combining oral and topical antifungal drugs is associated with higher success rates. Additive or synergistic modes of action are expected to enhance treatment success rates. OBJECTIVES: Investigation of the combined effects of antifungal drugs in vitro with different modes of action and application on clinical isolates from mycotic nails. METHODS: Isolates of Trichophyton rubrum, Trichophyton interdigitale and Scopulariopsis brevicaulis were collected from infected toenail specimens of patients with onychomycosis. Susceptibility testing was performed in 96-well polystyrene plates using a standard stepwise microdilution protocol. Additive or synergistic activity at varying concentrations was investigated by the checkerboard method. RESULTS: Combining terbinafine with amorolfine tended to be more effective than terbinafine in conjunction with ciclopirox. In most combinations, additive effects were observed. Synergy was detected in combinations with involving amorolfine in S. brevicaulis. These additive and synergistic interactions indicate that combined therapy with topical amorolfine and oral terbinafine is justified. Sublimation of amorolfine (and terbinafine) may enhance the penetration in and through the nail plate, and support treatment efficacy. CONCLUSIONS: These in vitro results support the notion that combining oral terbinafine and topical amorolfine is beneficial to patients with onychomycosis, particularly if the pathogen is a non-dermatophyte fungus such as S. brevicaulis.

In vitro determination of the combination of ciclopirox and terbinafine in the treatment of dermatophytosis.

INTRODUCTION: The cases of dermatophytosis are increasing and they are associated with a higher number of therapeutic failures leading the doctor to prescribe combinations of antifungals as therapy. The objective was to evaluate the interaction of terbinafine and ciclopirox, the most commonly antifungals used in the clinic, in dermatophyte isolates. METHODOLOGY: The minimum inhibitory concentrations (MIC) of ciclopirox and terbinafine were determined by the broth microdilution method according CLSI and the checkerboard assay was used to evaluate the interaction between the antifungal agents. RESULTS: For terbinafine the mic50 was 0.125 ug/mL and mic90 was 0.250 ug/mL. For ciclopirox the values were 2.0 ug/mL for mic50 and 4.0 ug/mL for mic90. No synergistic interaction was observed for the dermatophyte isolates tested. CONCLUSION: These results suggest that the use of terbinafine in combination with ciclopirox, which is widely used in the clinic, may not be a good choice for the treatment of onychomycosis.

Ciclopirox platinum(IV) conjugates suppress tumors by promoting mitophagy and provoking immune responses.

Mitophagy is an important target for antitumor drugs development. A series of ciclopirox (CPX) platinum(IV) hybrids targeting PTEN induced putative kinase 1 (PINK1)/Parkin mediated mitophagy were designed and prepared as antitumor agents. The dual CPX platinum(IV) complex with cisplatin core was screened out as a candidate, which displayed promising antitumor activities both in vitro and in vivo. Mechanistically, it caused serious DNA damage in tumor cells. Then, remarkable mitochondrial damage was induced accompanied by the mitochondrial membrane depolarization and reactive oxygen species generation, which further promoted apoptosis through the Bcl-2/Bax/Caspase3 pathway. Furthermore, mitophagy was ignited via the PINK1/Parkin/P62/LC3 axis, and exhibited positive influence on promoting the apoptosis of tumor cells. The antitumor immunity was boosted by the block of immune check point programmed cell death ligand-1 (PD-L1), which further increased the density of T cells in tumors. Subsequently, the metastasis of tumor cells was inhibited by inhibiting angiogenesis in tumors.

New Formulation-Microporation Combination Approaches to Delivering Ciclopirox across Human Nails.

Topical treatments for onychomycosis are of interest to those seeking to avoid systemic drug interactions and to improve systemic safety. This work aimed to develop aqueous-based, simple, and cost-effective vehicles that provide high solubility for ciclopirox and enable the delivery of an active through channels created by nail microporation. Following solubility tests, aqueous gels and thermogels based on hydroxypropylmethylcellulose and poloxamer 407, respectively, were loaded with 8% and 16% ciclopirox. Their performance was then compared to the marketed lacquer Micolamina® in in vitro release tests with artificial membranes and in in vitro permeation tests with human nail clippings with and without poration. Finally, a microbiological assay compared the best gel formulations and the reference product. Little correlation was observed between the in vitro release and the permeation data, and the drug release was highly membrane-dependent. Ciclopirox nail retention in single-dose, porated nails tests was larger than in daily-dosing, non-porated nail conditions. The series of new gel and thermogel vehicles delivered ciclopirox more effectively than Micolamina® in single-dose, porated nail experiments. The inhibition of Trichophyton rubrum activity was significantly increased with microporated nails when the gel formulations were applied but not with Micolamina®. Overall, the results suggest that the new vehicles could be successfully combined with nail microporation to improve the drug delivery and efficacy of topical antifungal medication while reducing the dosing frequency, facilitating patients' adherence.

Modeling, the Optimization of the Composition of Emulgels with Ciclopirox Olamine, and Quality Assessment.

The design and development of pharmaceutical products require specific knowledge, time, and investment. Response surface methodology (RSM) is a widely used technique in the design of experiments (DoE) to optimize various processes and products. The aim of this study was to model and produce experimental emulgels containing 1% ciclopirox olamine and to evaluate their physical, rheological, and mechanical properties and their ability to release ciclopirox olamine. The objective was to optimize the composition of the experimental emulgel containing 1% ciclopirox olamine by applying a central composite design based on selected criteria. The surfactant (polysorbate 80) had the greatest influence on the physical, rheological, and mechanical properties of the emulgels, as well as on the release of ciclopirox olamine from these systems. During the optimization process, an emulgel of optimal composition was generated containing 38.27% mineral oil, 6.56% polysorbate 80, and 55.17% hydrogel containing 1% ciclopirox olamine, meeting specified criteria (dependent variables) including the maximum flux of ciclopirox olamine, the minimum sol-gel transition temperature (Tsol/gel), and the minimum particle size of the oil phase. The oil phase particle size (D50) of this emulgel was determined to be 0.337 µm, the system Tsol/gel was 9.1 °C, and the flux of ciclopirox olamine from this gel matrix was calculated to be 1.44 mg/cm2. This emulgel of optimal composition could be used to treat fungal skin diseases.

Transungual Penetration and Antifungal Activity of Prescription and Over-the-Counter Topical Antifungals: Ex Vivo Comparison.

INTRODUCTION: Topical antifungals for toenail onychomycosis must penetrate the nail to deliver an inhibitory concentration of free drug to the site of infection. In two ex vivo experiments, we tested the ability of topical antifungals to inhibit growth of Trichophyton rubrum and Trichophyton mentagrophytes, the most common causative fungi in toenail onychomycosis. METHODS: Seven topical antifungals were tested: three U.S. Food and Drug Administration-approved products indicated for onychomycosis (ciclopirox 8% lacquer; efinaconazole 10% solution; tavaborole 5% solution) and four over-the-counter (OTC) products for fungal infections (tolnaftate 1% and/or undecylenic acid 25% solutions). The ability to inhibit fungal growth was tested in the presence and absence of keratin. Products were applied either to human cadaverous nails or keratin-free cellulose disks prior to placement on an agar plate (radius: 85 mm) seeded with a clinical isolate of T. rubrum or T. mentagrophytes. After incubation, the zone of inhibition (ZI), defined as the radius of the area of no fungal growth, was recorded. RESULTS: In the nail penetration assay, average ZIs for efinaconazole (T. rubrum: 82.1 mm; T. mentagrophytes: 63.8 mm) were significantly greater than those for tavaborole (63.5 mm; 39.1 mm), ciclopirox (7.4 mm; 3.6 mm) and all OTC products (range: 10.5-34.2 mm against both species; all P < 0.001). In the cellulose disk diffusion assay, efinaconazole and tavaborole demonstrated maximal antifungal activity against both species (ZIs = 85 mm); average ZIs against T. rubrum and T. mentagrophytes were smaller for ciclopirox (59.0 and 55.7 mm, respectively) and OTC products (range: 31.2-57.8 mm and 25.7-47.7 mm, respectively). CONCLUSIONS: Among all antifungals tested, the ability to penetrate human toenails to inhibit growth of both T. rubrum and T. mentagrophytes was greatest for efinaconazole, followed by tavaborole. These results indicate superior transungual penetration of efinaconazole compared to the other antifungals, suggesting lower keratin binding in the nail.

Ciclopirox inhibits SARS-CoV-2 replication by promoting the degradation of the nucleocapsid protein.

The nucleocapsid protein (NP) plays a crucial role in SARS-CoV-2 replication and is the most abundant structural protein with a long half-life. Despite its vital role in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) assembly and host inflammatory response, it remains an unexplored target for drug development. In this study, we identified a small-molecule compound (ciclopirox) that promotes NP degradation using an FDA-approved library and a drug-screening cell model. Ciclopirox significantly inhibited SARS-CoV-2 replication both in vitro and in vivo by inducing NP degradation. Ciclopirox induced abnormal NP aggregation through indirect interaction, leading to the formation of condensates with higher viscosity and lower mobility. These condensates were subsequently degraded via the autophagy-lysosomal pathway, ultimately resulting in a shortened NP half-life and reduced NP expression. Our results suggest that NP is a potential drug target, and that ciclopirox holds substantial promise for further development to combat SARS-CoV-2 replication.

Penetration Profiles of Four Topical Antifungals in Mycotic Human Toenails Quantified by Matrix-Assisted Laser Desorption Ionization-Fourier Transform Ion Cyclotron Resonance Imaging.

INTRODUCTION: Onychomycosis is a fungal infection of the nails that can be challenging to treat. Here, matrix-assisted laser desorption ionization-Fourier transform ion cyclotron resonance (MALDI-FTICR) imaging was applied to the quantitative analysis of the penetration profile of the antifungal compound, amorolfine, in human mycotic toenails. The amorolfine profile was compared with those of three other antifungals, ciclopirox, naftifine, and tioconazole. METHODS: Antifungal compounds (amorolfine 5% lacquer, ciclopirox 8% lacquer, naftifine 1% solution, and tioconazole 28% solution) were applied to mycotic nails (n = 42). Nail sections were prepared, and MALDI-FTICR analysis was performed on the sections at a spatial resolution of 70 µm to compare the distribution profiles. Based on the minimum inhibitory concentrations of the four test compounds needed to kill 90% (MIC90) of the fungal organism, Trichophyton rubrum, the fold differences between the MIC90 and the antifungal concentrations in the nails (termed the multiplicity of the MIC90) were calculated for each. RESULTS: The penetration profiles indicated higher concentrations of amorolfine and ciclopirox in the deeper layers of the nails 3 h after treatment, compared with naftifine and tioconazole. The mean concentrations across the entire nail sections at 3 h were significantly different among the four antifungals: amorolfine, 2.46 mM; ciclopirox, 0.95 mM; naftifine, 0.63 mM; and tioconazole, 1.36 mM (p = 0.016; n = 8 per compound). The median multiplicity of the MIC90 at 3 h was 191-fold for amorolfine, tenfold for ciclopirox, 52-fold for naftifine, and 208-fold for tioconazole. CONCLUSION: In this study, MALDI-FTICR was successfully applied to the quantitative analysis of antifungal distribution in human mycotic nails. The findings suggest that amorolfine penetrates deeper layers of the nail and accumulates at concentrations far exceeding the MIC needed to exert antimycotic activity.

Susceptibilidad in vitro a antifúngicos de especies de Cándida / In vitro antifungal susceptibility of Candida spp

Resumen Objetivo. Analizar la susceptibilidad in vitro de aislamientos de Candida spp. provenientes de onicomicosis obtenidos entre 2016 y 2019, para contribuir con el conocimiento sobre la necesidad o no de realizar pruebas de susceptibilidad a los microorganismos aislados antes de prescribir el tratamiento. Métodos. El estudio consistió en identificar 23 aislamientos de Candida spp. utilizando el sistema automatizado Vitek2® (bioMérieux, Francia). Se determinó la susceptibilidad in vitro de estos aislamientos ante dos antifúngicos tópicos (amorolfina y ciclopirox) y dos antifúngicos sistémicos (fluconazol e itraconazol) por el método de microdilución en caldo M27-A3 del Instituto Estándares para el Laboratorio Clínico (CLSI por sus siglas en inglés) de los Estados Unidos de América. Resultados. La mayoría de los aislamientos correspondieron a Candida parapsilosis (34,8 %), seguido por C. albicans (30,3 %), C. guilliermondii (17,4 %), C. tropicalis (8,7 %), C. dubliniensis (4,4 %) y C. krusei (4,4 %). No se encontraron diferencias estadísticamente significativas entre las CIMs de los diferentes antifúngicos y en promedio hubo susceptibilidad para todos los antifúngicos analizados. Sin embargo, para fluconazol se encontró un aislamiento con CIM alta de C. guilliermondii y un aislamiento resistente de C. parapsilosis. Conclusiones. Las directrices internacionales recomiendan pruebas de susceptibilidad para Candida spp. de hemocultivos o tejidos tras infecciones sistémicas. En todas las demás candidiasis se identifica la especie y se revisan sus patrones de susceptibilidad en la literatura. Por lo tanto, es de importancia conocer que aislamientos de onicomicosis de Candida no-albicans, especialmente de C. guilliermondii y C. parapsilosis, presentan una susceptibilidad disminuida a ciertos antifúngicos que se utilizan como tratamiento, por lo que se recomienda realizar pruebas de susceptibilidad en caso de no tener una buena respuesta al tratamiento en casos de onicomicosis por estas levaduras.

Abstract Aim. The purpose of this investigation was to determine the in vitro susceptibility patterns of Candida spp. isolated from onychomycosis, in order to contribute with strategies for optimal clinical laboratory management of patients with onychomycosis infected with these yeasts. Methods . A total of 23 isolates of Candida spp. were identified with the automatized system Vitek®2 (system bioMérieux, France). In vitro susceptibility patterns were evaluated with two topic antifungals (amorolfine and ciclopirox) and two systemic antifungals (fluconazole and itraconazole) using the Clinical Laboratory and Standards Institute (CLSI) broth microdilution M27-A3 guidelines. Results . Most of the isolates were identified as Candida parapsilosis (34,8 %), followed by C. albicans (30,3 %), C. guilliermondii (17,4 %), C. tropicalis (8,7 %), C. dubliniensis (4,4 %) and C. krusei (4,4 %). There were no statistically significant differences among the MICs of the antifungals tested. However, there was one isolate of C. guilliermondii with high MIC for fluconazole and one fluconazole resistant isolate of C. parapsilosis. Conclusions. Susceptibility tests are only recommended internationally for Candida spp. isolated from blood stream or tissue in systemic infections. In every other candidiasis there is only a species identification, while its susceptibility pattern for treatment is reviewed in literature. Therefore, it is important to report that Candida no-albicans isolates from onychomycosis, especially C. guilliermondii and C. parapsilosis, have a reduced susceptibility to some antifungals commonly used for treatment. According to the obtained in vitro results, we recommend performing antifungal susceptibility testing in those cases of onychomycosis caused by Candida spp. no responsive to treatment.