Tea contamination by mycotoxins and azole-resistant mycobiota - The need of a One Health approach to tackle exposures.

Despite tea beneficial health effects, there is a substantial risk of tea contamination by harmful pathogens and mycotoxins. A total of 40 tea samples (17 green (raw) tea; 13 black (fermented) tea; 10 herbal infusions or white tea) were purchased from different markets located in Lisbon district during 2020. All products were directly available to consumers either in bulk (13) and or in individual packages (27). Bacterial analysis was performed by inoculating 150 µL of samples extracts in tryptic soy agar (TSA) supplemented with 0.2 % nystatin medium for mesophilic bacteria, and in Violet Red bile agar (VRBA) medium for coliforms (Gram-negative bacteria). Fungal research was performed by spreading 150 µL of samples in malt extract agar (MEA) supplemented with 0.05 % chloramphenicol and in dichloran-glycerol agar (DG18) media. The molecular detection of the Aspergillus sections Fumigati, Nidulantes, Circumdati and Flavi was carried out by Real Time PCR (qPCR). Detection of mycotoxins was performed using high performance liquid chromatograph (HPLC) with a mass spectrometry detector. Azole resistance screening was achieved following the EUCAST guidelines. The highest counts of total bacteria (TSA) were obtained in green raw tea (81.6 %), while for coliform counts (VRBA) were found in samples from black raw tea (96.2 %). The highest fungal counts were obtained in green raw tea (87.7 % MEA; 69.6 % DG18). Aspergillus sp. was the most prevalent genus in all samples on MEA (54.3 %) and on DG18 (56.2 %). In the raw tea 23 of the samples (57.5 %) presented contamination by one to five mycotoxins in the same sample. One Aspergillus section Fumigati isolate from green tea beverage recovered form itraconazole-Sabouraud dextrose agar (SDA) medium, presented itraconazole and posaconazole E-test MICs above MIC90 values. Our findings open further discussion regarding the One-Health approach and the necessary investment in researching biological hazards and azole-resistance associated with the production and consumption of tea (in particular green tea).

Microbial Contamination in the Coffee Industry: An Occupational Menace besides a Food Safety Concern?

Respiratory abnormalities among workers at coffee roasting and packaging facilities have already been reported; however, little is known about microbiological contamination inside coffee production facilities. This study intends to assess the microbial contamination (fungi and bacteria) in two coffee industries from Brazil with a multi-approach protocol for sampling and for subsequent analyses using four main sources of samples: filtering respiratory protection devices (FRPD) used by workers, settled dust, electrostatic dust cloths (EDC) and coffee beans. The fungal contamination in the assessed industries was also characterized through the molecular detection of toxigenic species and antifungal resistance. Total bacteria contamination presented the highest values in FRPD collected from both industries (7.45 × 104 CFU·m-2; 1.09 × 104 CFU·m-2). Aspergillus genera was widespread in all the environmental samples collected and sections with clinical relevance (Fumigati) and with toxigenic potential (Nigri and Circumdati) were recovered from FRPD. Circumdati section was observed in 4 mg/mL itraconazole. Sections Circumdati (EDC, coffee beans and settled dust) and Nidulantes (EDC, coffee beans and FRPD) were detected by qPCR. Some of the targeted Aspergillus sections that have been identified microscopically were not detected by qPCR and vice-versa. Overall, this study revealed that microbial contamination is a potential occupational risk in the milling stage and should be tackled when assessing exposure and performing risk assessment. In addition, a multi-sampling campaign should be the approach to follow when assessing microbial contamination and FRPD should be included in this campaign. Occupational exposure to mycotoxins should be considered due to high fungal diversity and contamination. A One Health approach should address these issues in order to prevent consumption of coffee crops and beans infected by fungi and, more specifically, to avoid widespread azole resistance.

Insights into the Release Mechanisms of ITZ:HPMCAS Amorphous Solid Dispersions: The Role of Drug-Rich Colloids.

Understanding the dissolution mechanisms of amorphous solid dispersions (ASDs) and being able to link enhanced drug exposure with process parameters are key when formulating poorly soluble compounds. Thus, in this study, ASDs composed by itraconazole (ITZ) and hydroxypropylmethylcellulose acetate succinate (HPMCAS) were formulated with different polymer grades and drug loads (DLs) and processed by spray drying with different atomization ratios and outlet temperatures. Their in vitro performance and the ability to form drug-rich colloids were then evaluated by a physiologically relevant dissolution method. In gastric media, drug release followed a diffusion-controlled mechanism and drug-rich colloids were not formed since the solubility of the amorphous API at pH 1.6 was not exceeded. After changing to intestinal media, the API followed a polymer dissolution-controlled release, where the polymer rapidly dissolved, promoting the immediate release of API and thus leading to liquid-liquid phase separation (LLPS) and consequent formation of drug-rich colloids. However, the release of API and polymer was not congruent, so API surface enrichment occurred, which limited the further dissolution of the polymer, leading to a drug-controlled release. ASDs formulated with M-grade showed the highest ability to maintain supersaturation and the lowest tendency for AAPS due to its good balance between acetyl and succinoyl groups, and thus strong interactions with both the hydrophobic drug and the aqueous dissolution medium. The ability to form colloids increased for low DL (15%) and high specific surface area due to the high amount of polymer released until the occurrence of API surface enrichment. Even though congruent release was not observed, all ASDs formed drug-rich colloids that were stable in the solution until the end of the dissolution study (4 h), maintaining the same size distribution (ca. 300 nm). Drug-rich colloids can, in vivo, act as a drug reservoir replenishing the drug while it permeates. Designing ASDs that are prone to form colloids can overcome the solubility constraints of Biopharmaceutics Classification System (BCS) II and IV drugs, posing as a reliable formulation strategy.

Dynamics of Aspergillus fumigatus in Azole Fungicide-Containing Plant Waste in the Netherlands (2016-2017).

The treatment of patients suffering from Aspergillus diseases is hampered due to infections with Aspergillus fumigatus that are already resistant to medical azoles. Previous work has suggested that A. fumigatus likely gains resistance through environmental azole exposure in so-called hot spots. Here, we investigated A. fumigatus resistance dynamics over time at three sites at which farmers used azole fungicides for crop protection. Over 16 months, 114 samples were taken from stockpiles of decaying plant waste. A. fumigatus and azole fungicide residues were ubiquitously present in the plant waste. On average, 105A. fumigatus CFU/g was recovered, of which roughly half were itraconazole and tebuconazole resistant. Similar tandem repeat-mediated resistance mechanisms were found in colonies cultured from plant waste as reported in clinical azole-resistant isolates. Our results show a consistent high burden of azole-resistant A. fumigatus in azole-containing plant waste and underscores the need to further investigate resistance-reducing interventions and transmission routes.IMPORTANCEAspergillus fumigatus is consistently present independently on season at a high abundance in plant waste material throughout the sampling period. Our study confirmed that long-term storage sites of azole-containing decaying plant material can indeed be considered hot spots, which can sustain resistance development and maintenance in A. fumigatus Roughly half of individual isolates were azole resistant and carried genetic mutations that are highly similar to those found in patients with azole-resistant invasive aspergillosis. Our work suggests that environmental sources of azole resistance in A. fumigatus may be important, underscoring the need for further studies on environment-to-patient transmission routes.

Development of a Method for the Quantification of Clotrimazole and Itraconazole and Study of Their Stability in a New Microemulsion for the Treatment of Sporotrichosis.

Sporotrichosis occurs worldwide and is caused by the fungus Sporothrix brasiliensis. This agent has a high zoonotic potential and is transmitted mainly by bites and scratches from infected felines. A new association between the drugs clotrimazole and itraconazole is shown to be effective against S. brasiliensis yeasts. This association was formulated as a microemulsion containing benzyl alcohol as oil, Tween® 60 and propylene glycol as surfactant and cosurfactant, respectively, and water. Initially, the compatibility between clotrimazole and itraconazole was studied using differential scanning calorimetry (DSC), thermogravimetric analysis (TG), Fourier transform infrared spectroscopy (FTIR), and X-ray powder diffraction (PXRD). Additionally, a simple and efficient analytical HPLC method was developed to simultaneously determine the concentration of clotrimazole and itraconazole in the novel microemulsion. The developed method proved to be efficient, robust, and reproducible for both components of the microemulsion. We also performed an accelerated stability study of this formulation, and the developed analytical method was applied to monitor the content of active ingredients. Interestingly, these investigations led to the detection of a known clotrimazole degradation product whose structure was confirmed using NMR and HRMS, as well as a possible interaction between itraconazole and benzyl alcohol.

Metabolomics-assisted metabolite profiling of itraconazole in human liver preparations.

Itraconazole (ITZ) is a first-generation triazole-containing antifungal agent that effectively treats various fungal infections. As ITZ has a better safety profile than that of ketoconazole (KCZ), ITZ has been used worldwide for over 25 years. However, few reports have explored the metabolic profile of ITZ, and the underlying mechanism of ITZ-induced liver injury is not clearly understood. In the present study, we revisited ITZ metabolism in humans, using a non-targeted metabolomics approach, and identified several novel metabolic pathways including O-dearylation, piperazine oxidation, and piperazine-N,N'-deethylation. Furthermore, we explored the formation of reactive ITZ metabolites using trapping agents as surrogates, to assess the possibility of metabolism-mediated toxicity. We found that ITZ and its metabolites did not form any adducts with nucleophiles including glutathione, potassium cyanide, and semicarbazide. The present study expands our knowledge of ITZ metabolism and supports the suggestion that ITZ has a better safety profile than that of KCZ in terms of metabolism-mediated toxicity.

Simultaneous determination of voriconazole, posaconazole, itraconazole and hydroxy-itraconazole in human plasma using LCMS/MS.

INTRODUCTION: Invasive fungal infections are an increasing cause of mortality and morbidity in high risk patient populations such as those on immunosuppressive therapy. Triazole antifungals are recommended for the prevention and treatment of such infections. The aim of this study was to develop and validate a simple, sensitive and robust LCMS/MS method for the simultaneous analysis in human plasma of three frequently used antifungal drugs: voriconazole, posaconazole, and itraconazole. METHODS: Precipitation reagent, containing deuterated internal standards, is added to 50µL of plasma. The vials are vortexed before centrifugation. The organic supernatant is transferred to a polypropylene vial and 1µL is injected into the Waters Acquity® Ultra Performance Liquid Chromatography system coupled with a Waters Acquity® TQ Detector system. Chromatographic separation is achieved on a BEH C18 column using gradient elution with mobile phases consisting of 2mM ammonium acetate with 0.1% formic acid in water and methanol. Run time is <5min between injections. RESULTS: The evaluation of the LCMS/MS triazole method showed good precision (intra-assay CVs<6.7%, inter-assay CVs<8.3%). The lower limit of quantitation for all antifungal triazoles tested was 0.10mg/L. Passing Bablok comparisons of voriconazole (n=50) and posaconazole (n=50) showed good correlation with the current HPLC method (Voriconazole LCMS=0.94(HPLC)+0.03, r2=0.99; Posaconazole LCMS=1.18(HPLC)-0.04, r2=0.95). Passing Bablok comparisons of itraconazole and hydroxy-itraconazole (n=18) showed good agreement with an external referral laboratory's antifungal LCMS/MS method (Itraconazole LCMS=1.00(referral lab)+0.01, r2=0.99; Hydroxy-Itraconazole LCMS=1.05(referral lab)+0.04, r2=0.99). External quality assurance samples for posaconazole and voriconazole (n=12, UK NEQAS Antifungal Pilot Panel) were assayed 'blind' and results were in good agreement with consensus mean values (both r2=0.99). CONCLUSION: The rapid pre-analytical sample preparation procedure, short chromatographic time, limit of quantitation and linear range make this LCMS/MS method suitable for determination of plasma voriconazole, posaconazole, itraconazole and hydroxy-itraconazole levels in a high throughput laboratory.

Anti-Sporothrix brasiliensis activity of different pyrazinoic acid prodrugs: a repurposing evaluation

From drug repurposing studies, this work aimed to evaluate the activity of different pyrazinoic acid (POA) derivatives against Sporothrix brasiliensis. The POA esters were prepared and characterized as previously reported by classical esterification reactions, with good to excellent yields. Sporothrix brasiliensis isolates from cats (n=6) and standard strains of S. brasiliensis and S. schenckii were used to assess the antifungal activity of the POA derivatives through broth microdilution assay (CLSI M38-A2). Among the tested compounds, molecules 3 and 4 showed fungistatic and fungicidal activities against all Sporothrix spp. strains, and the obtained MIC and MFC values ranged from 2.12 to 4.24 mg/mL and from 1.29 to 5.15 mg/mL, respectively. Compound 2 and 5 were active as in vitro inhibitors of fungal growth, but showed weak fungicidal activity, while molecules 1 and POA itself were inactive. The results suggest the activity of POA derivatives against Sporothrix spp. may be dependent on the lipophilicity. In addition, the antifungal susceptibility of the isolates to itraconazole was performed, showing that two Sporothrix isolates from cats were itraconazole-resistant. Compounds 3 and 4 were also active against these itraconazole-resistant isolates, indicating a possible alternative route to the standard mode of action of itraconazole.

Downstream drug product processing of itraconazole nanosuspension: Factors influencing drug particle size and dissolution from nanosuspension-layered beads.

There is more research required to broaden the knowledge on the downstream processing of nanosuspensions into solid oral dosage forms, especially for coated nanosuspensions onto beads as carriers. This study focuses on bead layering as one approach to solidify nanosuspensions. The aim was to systematically investigate the influence of type of coating polymer (HPMC VLV vs. copovidone), bead material and bead size (sugar vs. MCC, and small vs. large) and coating thickness (50%-150% layering level) on the properties of a dried itraconazole nanosuspension. A stable itraconazole nanosuspension with a mean particle size below 200nm was prepared and a ratio of itraconazole and coating polymer of around 1:1 was identified. XRD and DSC scans revealed that itraconazole remained mostly crystalline after the bead layering process. The fastest dissolution rate was achieved using the small bead size, sugar beads, HPMC VLV as film-forming polymer and lowest layering level, with the best formulation releasing 94.1% (±3.45% SD) within the first 5min. A deterioration of the release profile with increasing layering level was only observed for MCC beads and was more pronounced when copovidone was used as a coating polymer. It was observed that bead layering is a suitable method to process an itraconazole nanosuspension into a solid form without compromising release.

Epidemiología, factores de riesgo y sensibilidad in vitro en candidemias por especies diferentes de Candida albicans / Epidemiology, risk factors and in vitro susceptibility in candidaemia due to non-Candida albicans species

Antecedentes. La infección fúngica invasora ha aumentado en los últimos años por el incremento de los factores de riesgo; la candidemia es la principal manifestación clínica. Candida albicans es la especie más frecuente, aunque actualmente se ha observado un aumento en otras especies del género. Objetivos. Analizar la epidemiología, los factores de riesgo y la sensibilidad antifúngica de los aislamientos en hemocultivos de especies de Candida diferentes de C.albicans en nuestro hospital en los últimos 12años. Métodos. Se estudiaron retrospectivamente las características epidemiológicas de 107 pacientes con candidemia ingresados en nuestro hospital. Se determinó la sensibilidad de las especies de Candida al fluconazol, el itraconazol, el voriconazol, la anfotericinaB, la 5-fluorocitosina, la caspofungina, la micafungina y la anidulafungina mediante el método de microdilución Sensititre Yeast One (Izasa, España). Resultados. De los 109 aislamientos, 59 correspondieron a las siguientes especies de Candida (diferentes de C.albicans): 25 Candida parapsilosis complex, 14 Candida glabrata complex, 13 Candida tropicalis, 4 Candida krusei, una Candida lipolytica, una Candida membranaefaciens y una Candida pulcherrima. El factor de riesgo más frecuente en adultos y niños con candidemias por estas especies fue ser portador de catéter. El 8,5% de estos aislamientos fueron resistentes al fluconazol. Conclusiones. El resultado de nuestro trabajo confirma la necesidad de conocer la epidemiología de las especies de Candida diferentes de C.albicans, su sensibilidad in vitro y los factores de riesgo asociados, especialmente en pacientes con dichos factores (AU)

Background. Invasive fungal infection (IFI) has increased in recent years due to there being a greater number of risk factors. IFI caused by Candida is the most frequent, and although Candida albicans is the most isolated species, there is currently a decrease of C. albicans and an increase of other species of the genus. Aims. To analyse the epidemiology, risk factors, and antifungal susceptibility of blood culture isolates of non-C.albicans Candida species in our hospital in the last 12years. Methods. A retrospective study was conducted on 107 patients with candidaemia admitted to our hospital. Candida isolates susceptibility to fluconazole, itraconazole, voriconazole, amphotericinB, 5-fluorocytosine, caspofungin, micafungin, and anidulafungin was determined by means of a microdilution technique (Sensititre Yeast One; Izasa, Spain). Results. From a total of 109 strains, 59 belonged to non-C. albicans Candida species: 25 Candida parapsilosis complex, 14 Candida glabrata complex, 13 Candida tropicalis, 4 Candida krusei, 1 Candida lipolytica, 1 Candida membranaefaciens, and 1 Candida pulcherrima. The most common risk factor in adults and children was catheter use. It was observed that 8.5% of those non-C.albicans strains were resistant to fluconazole. Conclusions. The results of this work confirm that it is necessary to know the epidemiology of non-C.albicans Candida species, the in vitro susceptibility of the species involved, and the main risk factors, especially in patients with predisposing conditions (AU)

Identification and determination of chlorinated azoles in sludge using liquid chromatography quadrupole time-of-flight and triple quadrupole mass spectrometry platforms.

Four antimycotic drugs (tioconazole, TCZ; sertaconazole, STZ; fenticonazole, FTZ and itraconazole, ITZ) and the fungicide imazalil (IMZ) are determined in sludge from sewage treatment plants (STPs) following a bottom-up analytical strategy. First, sludge extracts, obtained under different sample preparation conditions, were analyzed by liquid chromatography (LC) quadrupole time-of-flight (QTOF) mass spectrometry (MS). A non-target search strategy, combined with the use of the chlorine mass filter, permitted to detect several chlorinated pollutants including the above referred azoles, which either had not been previously reported (TCZ, STZ, FTZ and ITZ), or scarcely investigated (IMZ), in this environmental compartment. Then, the sample preparation procedure was validated using standards of these compounds and their sensitive and selective determination was performed by LC-MS/MS, based on a QqQ system. Under final working conditions, quantitative extraction yields were attained with negligible changes in ionization efficiencies between sample extracts and standards; therefore, the above compounds were quantified against authentic standard solutions, with absolute recoveries in the range from 75 to 124%, achieving a limit of quantification of 2ngg-1. Analysis of sludge from 10 municipal STPs demonstrated the ubiquity of the identified chlorinated azoles with average concentrations from 31ngg-1, for IMZ, to more than 200ngg-1, for ITZ.

Investigation of Polymer-Surfactant and Polymer-Drug-Surfactant Miscibility for Solid Dispersion.

In a solid dispersion (SD), the drug is generally dispersed either molecularly or in the amorphous state in polymeric carriers, and the addition of a surfactant is often important to ensure drug release from such a system. The objective of this investigation was to screen systematically polymer-surfactant and polymer-drug-surfactant miscibility by using the film casting method. Miscibility of the crystalline solid surfactant, poloxamer 188, with two commonly used amorphous polymeric carriers, Soluplus® and HPMCAS, was first studied. Then, polymer-drug-surfactant miscibility was determined using itraconazole as the model drug, and ternary phase diagrams were constructed. The casted films were examined by DSC, PXRD and polarized light microscopy for any crystallization or phase separation of surfactant, drug or both in freshly prepared films and after exposure to 40°C/75% RH for 7, 14, and 30 days. The miscibility of poloxamer 188 with Soluplus® was <10% w/w, while its miscibility with HPMCAS was at least 30% w/w. Although itraconazole by itself was miscible with Soluplus® up to 40% w/w, the presence of poloxamer drastically reduced its miscibility to <10%. In contrast, poloxamer 188 had minimal impact on HPMCAS-itraconazole miscibility. For example, the phase diagram showed amorphous miscibility of HPMCAS, itraconazole, and poloxamer 188 at 54, 23, and 23% w/w, respectively, even after exposure to 40°C/75% RH for 1 month. Thus, a relatively simple and practical method of screening miscibility of different components and ultimately physical stability of SD is provided. The results also identify the HPMCAS-poloxamer 188 mixture as an optimal surface-active carrier system for SD.

Determination of itraconazole and its photodegradation products with kinetic evaluation by ultra-performance liquid chromatography/tandem mass spectrometry.

A simple and reproducible UPLC-MS/MS method for the determination of itraconazole (ITZ) and its photodegradation products formed during exposure to UV-A radiation was developed. Chromatographic separations were carried out using an Acquity UPLC BEH C18 column (2.1 × 100 mm, 1.7 µm particle size). The column was maintained at 40°C, and eluted under gradient conditions from 100% to 50% of eluent A over 13 min, at a flow rate of 0.3 mL min-1 . Eluent A was 0.1% (v/v) formic acid in water; eluent B was 0.1% (v/v) formic acid in acetonitrile. The linear regression analysis for the calibration curve showed a good linear correlation over the concentration range 0.0066-0.15 mg mL-1 with determination coefficient > 0.99. The activities of some photocatalysts during degradation process of ITZ were compared. It was found that indirect photodegradation of ITZ was more effective than direct photolysis. Under our experimental conditions the photodegradation rate constant depended on the applied catalysts with catalytic activity decreasing in the following pattern: FeCl3 > TiO2 /FeCl3 > TiO2 . The kinetic analysis of the photodegradation data revealed that the degradation of the ITZ follows first-order kinetics. The photodegradation products of ITZ were identified, and their fragmentation pathways, derived from MS/MS data, were proposed. Copyright © 2016 John Wiley & Sons, Ltd.

Simultaneous determination of benznidazole and itraconazole using spectrophotometry applied to the analysis of mixture: A tool for quality control in the development of formulations.

The aim of this work was the development of an analytical procedure using spectrophotometry for simultaneous determination of benznidazole (BNZ) and itraconazole (ITZ) in a medicine used for the treatment of Chagas disease. In order to achieve this goal, the analysis of mixtures was performed applying the Lambert-Beer law through the absorbances of BNZ and ITZ in the wavelengths 259 and 321 nm, respectively. Diverse tests were carried out for development and validation of the method, which proved to be selective, robust, linear, and precise. The lower limits of detection and quantification demonstrate its sensitivity to quantify small amounts of analytes, enabling its application for various analytical purposes, such as dissolution test and routine assays. In short, the quantification of BNZ and ITZ by analysis of mixtures had shown to be efficient and cost-effective alternative for determination of these drugs in a pharmaceutical dosage form.

[Selective determination of itraconazole in the presence of its oxidative degradation product by a new spectrophotometric method].

A simple, specific, accurate and precise spectrophotometric stability indicating method is developed for determination of itraconazole in the presence of its oxidative degradation product and in pharmaceutical formulations. A newly developed spectrophotometric method called ratio difference method by measuring the difference in amplitudes between 230 and 265 nm of ratio spectra. The calibration curve is linear over the concentration range of 5-25 microg x mL(-1) with mean percentage recovery of 99.81 +/- 1.002. Selective quantification of itraconazole, singly in bulk form, pharmaceutical formulations and in the presence of its oxidative degradation product is demonstrated. The results have been statistically compared with a pharmacopeial method.

Rapid liquid chromatographic determination of itraconazole and its production impurities.

A simple, rapid ultra-performance liquid chromatography (UPLC) method was developed for the analysis of itraconazole and its associated production impurities. The optimum chromatographic conditions were achieved using an Agilent Zorbax Eclipse XDB C18 column, 1.8 µm (4.6 × 50 mm) installed in a column oven heater utilizing a gradient mobile phase of 0.08M tetrabutylammonium hydrogen sulfate buffer-acetonitrile (80:20, v/v), with ultraviolet detection at 235 nm. An Agilent 1200 RRLC Series was used for the UPLC analysis. UPLC is a technology that greatly reduces analysis time by utilizing columns packed with sub-2 µm particles. The method was validated according to International Conference on Harmonization guidelines with respect to precision, accuracy, linearity, robustness and limits of detection and quantification. All parameters were found to be well within the stated guidelines. The total analysis time was reduced by two-thirds, from over 30 min (the current European Pharmacopeia method) to under 10 min, and the method is applicable for assay and related substance determination. A method utilizing the sub-2 µm column on a conventional high-performance liquid chromatography system was also developed and validated, resulting in substantial time and solvent savings.

Differential pulse polarographic investigation of the antifungal drugs itraconazole, ketoconazole, fluconazole and voriconazole using a dropping mercury electrode.

The electrochemical reactions of the antifungal drugs itraconazole, ketoconazole, fluconazole and voriconazole have been investigated by differential pulse polarography (DPP) using a dropping mercury electrode (DME). All investigations were carried out in Britton-Robinson buffer solutions and methanol with varying pH values. Ketoconazole and itraconazole both showed a reduction peak with a potential between -1.5V and -1.6 V. Stable and reproducible conditions for the determination of itraconazole (c = 1 x 10(-7) M) were found within the pH range of 6.0 to 8.0 and for the determination of ketoconazole (c = 5 x 10(-8) M) within pH 6.0 to 7.0. Voriconazole showed a reduction peak with a peak potential of -1.7 V (c = 1 x 10(-5) M) within the pH range of 8.0 to 10.0. In the case of fluconazole no electrochemical activity was found.

In vitro/in vivo performance of different complexes of itraconazole used in the treatment of vaginal candidiasis

A large majority of new chemical entities and many existing drug molecules exhibit poor aqueous solubility, which may limit their potential use in developing drug formulations, with optimum bioavailability. One of the approaches to improve the solubility of a poorly water soluble drug and eventually its bioavailability is complexation with agents like humic acid (HA), fulvic acid (FA), β-cyclodextrin (β-CD), 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) and caffeine (Caff). The current work emphasized at employing these agents to prepare different complexes and their in vitro/in vivo assessment. All the complexes evaluated for their complexation efficiency and authenticated by molecular modeling; conformational analysis, differential scanning calorimetry (DSC), X-ray diffraction (XRD), nuclear magnetic resonance (NMR) and mass spectroscopy. Furthermore, the complexes were assessed in an in vivo, rat vaginal model for their efficacy in treatment of vaginal candidiasis. Amongst the five tested complexes, fulvic acid-itraconazole complex yielded better solubility as well as in vivo efficacy and therefore may further be explored for developing a commercial formulation for treating vaginal candidiasis.

A maioria das novas entidades químicas e muitas moléculas de fármacos existentes apresenta fraca solubilidade em água, o que pode limitar seu uso potencial no desenvolvimento de formulações com biodisponibilidade ideal. Uma das abordagens para melhorar a solubilidade de um fármaco pouco solúvel em água e, eventualmente, a sua biodisponibilidade é a complexação com agentes como o ácido húmico (HA), ácido fúlvico (FA), β-ciclodextrina (β-CD), 2-hidroxipropil-β-ciclodextrina (HP-β-CD) e cafeína (Caff). O presente trabalho baseia-se no uso desses agentes para preparar diferentes complexos e suas avaliações in vitro/in vivo. Todos os complexos foram avaliados quanto à eficiência de complexação por modelação molecular, análise conformacional, calorimetria de varredura diferencial (DSC), difração de raios-X (XRD), ressonância magnética nuclear (RMN) e espectroscopia de massas. Além disso, os complexos foram avaliados in vivo, em ratas, no tocante à sua eficácia no tratamento de candidíase vaginal. Entre os cinco complexos testados, o complexo de ácido fúlvico-itraconazol foi o que apresentou melhor solubilidade, bem como melhor eficácia in vivo e, portanto, pode ser explorado para o desenvolvimento de uma formulação comercial para o tratamento de candidíase vaginal.

Comparison of mesoporous silicon and non-ordered mesoporous silica materials as drug carriers for itraconazole.

Mesoporous materials have an ability to enhance dissolution properties of poorly soluble drugs. In this study, different mesoporous silicon (thermally oxidized and thermally carbonized) and non-ordered mesoporous silica (Syloid AL-1 and 244) microparticles were compared as drug carriers for a hydrophobic drug, itraconazole (ITZ). Different surface chemistries pore volumes, surface areas, and particle sizes were selected to evaluate the structural effect of the particles on the drug loading degree and on the dissolution behavior of the drug at pH 1.2. The results showed that the loaded ITZ was apparently in amorphous form, and that the loading process did not change the chemical structure/morphology of the particles' surface. Incorporation of ITZ in both microparticles enhanced the solubility and dissolution rate of the drug, compared to the pure crystalline drug. Importantly, the physicochemical properties of the particles and the loading procedure were shown to have an effect on the drug loading efficiency and drug release kinetics. After storage under stressed conditions (3 months at 40 °C and 70% RH), the loaded silica gel particles showed practically similar dissolution profiles as before the storage. This was not the case with the loaded mesoporous silicon particles due to the almost complete chemical degradation of ITZ after storage.

Cysteine modified small ligament Au nanoporous film: an easy fabricating and highly efficient surface-assisted laser desorption/ionization substrate.

Au nanoporous films (NPFs) with different surface modification and morphology were fabricated and utilized as substrates for the analysis of a series of compounds, including amino acids, drug, cyclodextrins, peptides, and polyethylene glycols, using surface-assisted laser desorption/ionization time-of-flight mass spectrometry (SALDI-TOF MS). It was found that the size and interconnection state of the NPF ligament as well as the surface modification are key parameters that affect the laser desorption/ionization performance. Compared with 2,5-dihydroxybenzoic acid, pristine NPF, and aminobenzenethiol or 3-mercaptopropanoic acid modified Au NPFs, cysteine modified Au NPF generated intense and background-suppressing mass spectra. Regarding the effect of Au NPF morphology, the Au NPF with nanopores in the range of 10-30 nm, ligament size of 5 nm, and electrochemistry surface area of 26.1 m(2)/g exhibited the highest performance as a substrate. This high-performance NPFs can be easily fabricated by capping agent replacement induced self-organization of ultrathin nanowires, followed by self-assembling of a monolayer (SAM) of cysteine. The good thermal/electroconductivity and uniformity of Au NPFs avoided the fragmentation of analytes, eliminated the intrinsic matrix ions interference, and provided good reproducibility (RSD ≤ 10%). Additionally, the fabricated NPFs can be easy divided into microarrays (a ~4 × 4 array from a 1 cm × 1 cm NPF). This work provides a simple and cost-effective route for acquiring an Au nanostructure as a SALDI substrate, which offers a new technique for high-speed analysis of low-molecular weight compounds.