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A nanotechnology-based approach to drug delivery presents one of the biggest trends in biomedical science that can provide increased active concentration, bioavailability, and safety compared to conventional drug-delivery systems. Nanoemulsions stand out amongst other nanocarriers for being biodegradable, biocompatible, and relatively easy to manufacture. For improved drug-delivery properties, longer circulation for the nanoemulsion droplets should be provided, to allow the active to reach the target site. One of the strategies used for this purpose is PEGylation. The aim of this research was assessing the impact of the oil phase selection, soybean or fish oil mixtures with medium chain triglycerides, on the physicochemical characteristics and injectability of curcumin-loaded PEGylated nanoemulsions. Electron paramagnetic resonance spectroscopy demonstrated the structural impact of the oil phase on the stabilizing layer of nanoemulsions, with a more pronounced stabilizing effect of curcumin observed in the fish oil nanoemulsion compared to the soybean oil one. The design of the experiment study, employed to simultaneously assess the impact of the oil phase, different PEGylated phospholipids and their concentrations, as well as the presence of curcumin, showed that not only the investigated factors alone, but also their interactions, had a significant influence on the critical quality attributes of the PEGylated nanoemulsions. Detailed physicochemical characterization of the NEs found all formulations were appropriate for parenteral administration and remained stable during two years of storage, with the preserved antioxidant activity demonstrated by DPPH and FRAP assays. In vitro release studies showed a more pronounced release of curcumin from the fish oil NEs compared to that from the soybean oil ones. The innovative in vitro injectability assessment, designed to mimic intravenous application, proved that all formulations tested in selected experimental setting co

The current study describes the experimental design guided development of PEGylated nanoemulsions as parenteral delivery systems for curcumin, a powerful antioxidant, as well as the evaluation of their physicochemical characteristics and antioxidant activity during the two years of storage. Experimental design setup helped development of nanoemulsion templates with critical quality attributes in line with parenteral application route. Curcumin-loaded nanoemulsions showed mean droplet size about 105 nm, polydispersity index <0.15, zeta potential of −40 mV, and acceptable osmolality of about 550 mOsm/kg. After two years of storage at room temperature, all formulations remained stable. Moreover, antioxidant activity remained intact, as demonstrated by DPPH (IC50 values 0.078–0.075 mg/mL after two years) and FRAPS assays. In vitro release testing proved that PEGylated phospholipids slowed down the curcumin release from nanoemulsions. The nanoemulsion carrier has been proven safe by the MTT test conducted with MRC-5 cell line, and effective on LS cell line. Results from the pharmacokinetic pilot study implied the PEGylated nanoemulsions improved plasma residence of curcumin 20 min after intravenous administration, compared to the non-PEGylated nanoemulsion (two-fold higher) or curcumin solution (three-fold higher). Overall, conclusion suggests that developed PEGylated nanoemulsions present an acceptable delivery system for parenteral administration of curcumin, being effective in preserving its stability and antioxidant capacity at the level highly comparable to the initial findings.

The objective of this work was to develop low-energy nanoemulsions for enhanced dermal delivery of curcumin, using monoterpene compounds eucalyptol (EUC) and pinene (PIN) as chemical penetration enhancers. Spontaneous emulsification was the preparation method. All formulations contained 10% of the oil phase (medium-chain triglycerides (MCT), or their mixture with EUC or PIN). Formulations were stabilized by the combination of polysorbate 80 and soybean lecithin (surfactant-to-oil-ratio=1). Concentration of curcumin was set to 3 mg/ml. Average droplet diameter of all tested formulations ranged from 102 nm to 132 nm, but the ones containing monoterpenes had significantly smaller size compared to the MCT formulation. Such finding was profoundly studied through electron paramagnetic resonance spectroscopy, which proved that the presence of monoterpenes modified the nanoemulsions’ interfacial environment, resulting in droplet size reduction. The release study of curcumin (using Franz cells) demonstrated that the cumulative amount released after 6 h of the experiment was 10.1 ± 0.2% for the MCT nanoemulsions, 13.9 ± 0.1% and 14.0 ± 0.2% for PIN and EUC formulations, respectively. In vivo tape stripping revealed their performances in delivering curcumin into the skin, indicating the following order: EUC>MCT>PIN. The formulation with EUC was clearly the most successful, giving the highest cumulative amount of curcumin that penetrated per surface unit: 34.24±5.68 µg/cm2. The MCT formulation followed (30.62±2.61 µg/cm2) and, finally, the one with PIN (21.61±0.11 µg/cm2). These results corelated with curcumin's solubility in the chosen oils: 4.18±0.02 mg/ml for EUC, 1.67±0.04 mg/ml for MCT and 0.21±0.01 mg/ml for PIN. Probably, higher solubility in the oil phase of the nanoemulsion promoted curcumin's solubility in the superficial skin layers, providing enhanced penetration.

As the number of poorly soluble drugs is increasing, nanocrystals have become very interesting due to wide range of application possibilities. Curcuminwas used as a model active ingredient in this work. Even though it has many proven positive effects, due to its physicochemical issues, its possibilities have not been fully exploited. The goal of this work was to select optimal conditions for a top-down method for curcumin nanosuspension production, and to perform their comprehensive characterization applying complementary methodologies: dynamic light scattering, polarization and atomic force microscopy, thermal analysis, X-ray powder diffraction, antioxidant activity evaluation, release kinetics assessment, and screening of potential biological effects applying cell viability assays on normal human lung fibroblasts, human melanoma and human adenomacarcinoma cells. After 30 min of milling, nanosuspensions stabilized by polysorbate 80 and by its combinations with sucrose palmitate showed good stability, while curcumin crystal structure was unaltered. Obtained nanocrystals were well defined, with average diameter 120-170 nm and PDI of about 0.25, zeta potential was below -30 mV and pH~5 for all formulations. Nanodispersions exhibited high antioxidant potential and improved dissolution rate compared to the corresponding coarse dispersions. Although curcumin nanodispersions exhibited significant antiproliferative effect to each cancer cell line, the highest effect was towards adenocarcinoma cells.

Passive gastrointestinal absorption and membrane retention of twelve esters of (S,S)-ethylenediamine-N,N'-di-2-(3-cyclohexyl)propanoic acid (EDCP) and (S,S)-1,3-propanediamine-N,N'-di-2-(3-cyclohexyl)propanoic acid (PDCP), as well as of these two non-esterified acids were estimated using PAMPA test. Artificial PAMPA membrane used in this study for the simulation of gastrointestinal barrier was solution of egg lecithin in dodecane (1 % w/v). All tested compounds belong to class III (high membrane retention and low permeation), whereas EDCP, dipentyl ester of PDCP (DPE-PDCP) and diisopentyl ester of PDCP (DIPE-PDCP) belong to class I (negligible membrane retention and low permeation). Finally, quantitative structure – permeability and structure – retention relationships models were created in order to find quantitative relationships between physico-chemical properties of tested compounds and PAMPA membrane permeability/membrane retention parameters. Statistically the most reliable models were analysed and used for the design of new compounds for which favourable membrane permeability and retention can be expected.

In previously in vitro studies on different cell lines and in vivo on melanoma and 4T1 murine breast cancer and metastasis it was shown antiproliferative activity for ester derivatives of (S,S)-ethylenediamine-N,N′-di-2-(3-cyclohexyl)propanoic acid, and (S,S)-1,3-propanediamine-N,N′-di-2-(3-cyclohexyl)propanoic acid. The aim of this study was to predict membrane permeability by parallel artificial membrane permeability assay (PAMPA), molecular mechanism of action, metabolites and absorption, distribution, metabolism, toxicity—ADMET properties for observed substances using in vitro and in silico methods. Obtained results of PAMPA show the best membrane permeability of ethyl esters analogs (DE-EDCP and DE-PDCP) and refer to the hypothesis that the retention in cell membrane is important for cytotoxic activity of investigated substances. Prediction of main metabolic pathways was performed by the Metabolizer software and it was obtained that the major metabolic reactions were the hydrolyses of ester and subsequently intramolecular cyclization. Toxicity of investigated substances and their potential metabolites are lower than toxicity of observed official cytotoxic drugs. Based on the results obtained by the Molecular docking, it can be assumed that the antiproliferative effects of the investigated substances were realized through the multiple mechanisms by potential metabolites: acids, lactam carboxylate and lactam alkyl esters, while the esters are probably a prodrug substance with favorable properties to provide sufficient bioavailability at the target of action. Based on obtained results it can be proposed there to be investigated the existence of the metabolites: lactam carboxylate and lactam alkyl esters in biological materials.

BACKGROUND: Fruit wines are well known for their profound health-promoting properties including both enzyme activations and inhibitions. They may act preventive in regard to diabetes melitus and other chronic diseases. OBJECTIVES: Potential α-glucosidase inhibitory activity of fruit wines made from blueberry, black chokeberry, blackberry, raspberry and sour cherry was the subject of this study. METHOD: In order to increase the alcohol content due to enriched extraction of total phenolics, sugar was added in the fruit pomace of the half of the examined fruit wine samples. RESULTS: Compared with acarbose used as a positive control (IC50 = 73.78 µg/mL), all fruit wine samples exhibited higher α-glucosidase inhibitory activity. Indeed, blueberry wine samples stood out, both prepared with IC50 = 24.14 µg/mL, lyophilised extract yield 3.23% and without IC50 = 46.39 µg/mL, lyophilised extract yield 2.89% and with addition of sugar before fermentation. Chlorogenic acid predominantly contributed to α-glucosidase inhibitory activity of the blueberry, black chokeberry and sour cherry wine samples. However, ellagic acid, a potent α-glucosidase inhibitor possessing a planar structure, only slightly affected the activity of the blueberry wine samples, due to the lower concentration. In addition to this, molecular docking study of chlorogenic acid pointed out the importance of binding energy (-8.5 kcal/mol) for the inhibition of the enzyme. CONCLUSION: In summary, fruit wines made from blueberry should be primarily taken into consideration as a medicinal food targeting diabetes mellitus type 2 in the early stage, if additional studies would confirm their therapeutic potential for the control of postprandial hyperglycemia. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

The objective of this work was to investigate and profoundly characterize low-energy nanoemulsions as multifunctional carriers, with slight reference to dermal administration. An evidence-based approach was offered for deepening the knowledge on their formation via spontaneous emulsification. Curcumin, a compound of natural origin, potentially powerful therapeutic, was chosen as a model API. Due to curcumin's demanding properties (instability, poor solubility, low permeability), its potentials remain unreached. Low-energy nanoemulsions were considered carriers capable of overcoming imposed obstacles. Formulation consisting of Polysorbate 80 and soybean lecithin as stabilizers (9:1, 10%), medium-chain triglycerides as the oil phase (10%) and ultrapure water was selected for curcumin incorporation in 3 different concentrations (1, 2 and 3 mg/mL). Physicochemical stability was demonstrated during 3 months of monitoring (mean droplet size: 111.3-146.8 nm; PDI LT 0.2; pH: 4.73-5.73). Curcumin's release from developed vehicles followed Higuchi's kinetics. DPPH (IC50 = 0.1187 mg/ mL) and FRAP (1.19 +/- 0.02 mmol/g) assays confirmed that curcumin acts as a potent antioxidant through different mechanisms, with no alterations after incorporation in the formulation. High biocompatibility in line with antigenotoxic activity of curcumin-loaded formulations (protective and reparative) was estimated through Comet assay. A multidisciplinary approach is needed to fully characterize developed systems, directing them to more concrete application possibilities.

O,O'-diethyl-(S, S)-ethylenediamine-N, N'-di-2-(3-cyclohexyl) propanoate (DE-EDCP) is novel substance with cytotoxic activity in human leukemic cells. The aim of this study has been to predict in vivo bioavailability of the DE-EDCP and its potential metabolite (S, S)-ethylenediamine-N, N'-di-2-(3-cyclohexyl) propanoic acid (EDCP) by in vitro characterization which includes determination of lipophilicity and passive membrane permeability. There has also been evaluated inter-laboratory reproducibility of the bio-analytical method which was previously developed and validated for non-clinical study of the DE-EDCP and EDCP. Distribution coefficient n-octanol/water was 1.68 and 0.03, and apparent permeability coefficient was 4 x 10(-4) cm/s and 20 x 10(-4) cm/s, for the DE-EDCP and EDCP, respectively. Observed results have shown that the DE-EDCP is more lipophilic with better membrane retention, but the EDCP has better pass through the membrane. Also, there has been demonstrated a reproducibility and robustness of the proposed bio-analytical method.

Fourteen compounds representing ester derivatives of (S,S)-1,2-ethanediamine-N,N'-di-2-(3-cyclohexyl) propanoic and (S,S)-1,3-propanediamine-N,N'-di-2-(3-cyclohexyl)propanoic acids, expressing antiproliferative activity in vitro were examined. The objective of this study was to determinate their lipophilicity data, and also to ensure a mathematical model for prediction lipophilicity data of potential in vivo metabolites and new derivatives of (S,S)-1,2-ethanediannine-N,N'-di-2-(3-cyclohexyl)propanoic acid, based on chromatographic parameters. Experimentally, lipophilicity data were obtained by a traditional shake flask procedure and an ultra-high performance liquid chromatographic tandem mass spectrometry (UHPLC-MS) method. A correlation between the partition coefficient n-octanol/water (logD(7,4)) and chromatographic data (CHI, phi(0)), and also, between logD(7,4) and retention time was investigated. A very good correlation (r(2)=0.8969) was found between lipophilicity parameters phi(0) and logD(7,4) obtained using UHPLC-MS and shake flask methods: logD(7,4) = (0.11 +/- 0.01)x phi(0) + (1.25 +/- 0.20)xN(c) - (9.19 +/- 1.18); statistical parameter F=47.84; significance of F = 3.74x10(-6), N-c=number of C atoms between two amino groups (N-c=2 for 1,2-ethanediamine derivatives and N-c=3 for 1,3-propanediamine derivatives).The model predictivity power was determined by cross validation leave one out (LOO) technique, and expressed by the term Q(2), was 0.89. The developed model has good predictivity power for prediction lipophilicity data of potential in vivo metabolites of the investigated compounds, such as novel 1,2-ethanediamine and 1,3-propanediamine N,N'-di-2-(3-cyclohexyl)propanoic acid derivatives. Also, the lipophilicity data obtained in the present study correlated with the antiproliferative activity of the investigated substances shown previously in in vitro studies.

A series of new (S,S)-ethylenediamine-N,N'-di-2-(3-cyclohexyl)propanoate esters has shown cytotoxic activity towards human leukemic cell lines. The aim of this study was to develop and validate a bioanalytical method for quantification of (S,S)-O,O-diethyl-ethylenediamine-N,N'-di-2-(3-cyclohexyl)propanoate dihydrochlorides (DE-EDCP) and its metabolite, substituted propanoic acid (EDCP), in mouse serum by ultra high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Structural analog, derivative of 1,3-propanediamine, was used as an internal standard (IS). Sample preparation employed protein precipitation by acetonitrile and subsequent centrifugation. Optimal UHPLC separation conditions were set to achieve simultaneous determination of both compounds in a short run time of 6 min. Additionally, the selected reaction monitoring (SRM) mode developed in this method allowed a highly sensitive, accurate, and precise identification of compounds of interest. The lower limit of quantitation (LOQ) was 1.3 ng mL(-1) for DE-EDCP and 0.3 mu g mL(-1) for EDCP. The calibration curves were linear over the concentration range of 1.3-26.7 ng mL(-1) and 0.3-6.7 mu g mL(-1) for DE-EDCP and EDCP, respectively. Precision (%CV) and accuracy (% RE) for DE-EDCP and EDCP ranged from 3.5% to 16.0% and from 1.8% to 14.4%, respectively. The validation process was performed in accordance with the regulatory guidance/guideline, and all of the obtained results met the established acceptance criteria. The newly developed and validated UHPLC-MS/MS method is rapid, sensitive, and selective, and it can be successfully applied to drug monitoring in nonclinical studies.

During the early stages of drug discovery, it is very important to determine lipophilicity and to investigate and predict processes of drug distribution and resorption in human body, i.e. their bioavailability. Novel fourteen compounds representing ester derivatives of (S,S')-1,2- ethanediamme-N,N'-di-2-(3-cyclohexyl)propanoic and (S,S)- 1,3-propanediamine-N,N'-di-2-(3-cyclohexyl)propanoic acids, expressing antiproliferative activity in vitro were examined. The objective of this study was to estimation a lipophilicity data of observed fourteen compounds by ultra-high performance liquid chromatographic tandem mass spectrometry (UHPLC-MS) method. It was used gradient and isocratic method to obtain chromatographic parameters of lipophilicity/ hydrophobicity, which are needed for calculated logP values. Results of lipophilicity data for observed 14 compounds, which were obtained by UHPLC-MS method and presented in this paper, are showed that the derivatives of 1,2 ethandiamine-N,N'-di-2-(3-cyclohexyl) propanoic acid have higer values of logP, than derivatives of 1,3-propanediamine- N,N'-di-2-(3-cyclohexyl) propanoic acid. Also, value of lipophilicity data for each of investigated compounds depends on the length of the alkyl chain on the esters bounds. Branching of the alkyl chain on the esters bounds has insignificant influence on the values of lipophilicity/ hydrophobicity.

Chronic stress conditions can lead to considerable and extensible changes in physiological and psychological performances, and in emergence of risk for various somatic diseases. On the other hand, the neuropeptide oxytocin is reported to increase the resistance of the organism to stress and modulate activity of autonomic nervous system. Chronic corticosterone administration is used as a rat model for a state observed in terms of chronic stress exposure, when negative feedback mechanism of hypothalamus-pituitary-adrenal axis activity is disrupted. In our study, we aimed to investigate whether chronic administration of oxytocin (10114400 pI/day for 14 days, s.c.) influenced adrenal gland morphology and activity in adult male Wistar rats during long-term corticosterone administration via drinking water (100 mg/L for 21 days). We examined the influence of treatments on the levels of adrenal gland hormones, corticosterone, adrenaline and noradrenaline, as well as their response to an acute stress challenge evoked by 15-min forced swimming. In addition, the expression of two main monoamine transporters, the noradrenaline transporter (NAT) and vesicular monoamine transporter 2 (VMAT2) in adrenal medulla was measured in the rats exposed to acute stress. Our results showed that oxytocin treatment prevented corticosterone-induced decrease in body weight gain, attenuated adrenal gland atrophy by increasing glandular weight, and the area of the zona fasciculate and reticularis. Chronic corticosterone intake blunted the response of all measured hormones to acute stress, whereas concomitant oxytocin treatment reversed adrenaline and noradrenaline response to acute stress. Furthermore, in adrenal medulla, oxytocin produced significant vasodilatation and stimulated expression of both catecholamine transporters detected both on mRNA and protein level. Our data suggest that oxytocin, by reducing atrophy of adrenal gland, and by increasing catecholamine storage capacity, may be benefi

We aimed to develop lecithin-based nanoemulsions intended for effective aceclofenac (ACF) skin delivery utilizing sucrose esters [sucrose palmitate (SP) and sucrose stearate (SS)] as additional stabilizers and penetration enhancers. To find the suitable surfactant mixtures and levels of process variables (homogenization pressure and number of cycles-high pressure homogenization manufacturing method) that result in drug-loaded nanoemulsions with minimal droplet size and narrow size distribution, a combined mixture-process experimental design was employed. Based on optimization data, selected nanoemulsions were evaluated regarding morphology, surface charge, drug-excipient interactions, physical stability, and in vivo skin performances (skin penetration and irritation potential). The predicted physicochemical properties and storage stability were proved satisfying for ACF-loaded nanoemulsions containing 2% of SP in the blend with 0%-1% of SS and 1%-2% of egg lecithin (produced at 50 degrees C/20 cycles/800 bar). Additionally, the in vivo tape stripping demonstrated superior ACF skin absorption from these nanoemulsions, particularly from those containing 2% of SP, 0.5% of SS, and 1.5% of egg lecithin, when comparing with the sample costabilized by conventional surfactant-polysorbate 80. In summary, the combined mixture-process experimental design was shown as a feasible tool for formulation development of multisurfactant-based nanosized delivery systems with potentially improved overall product performances.

A simple and sensitive liquid chromatography-tandem mass spectrometry method was developed for the quantification of atorvastatin, ortho-hydroxyatorvastatin, para-hydroxyatorvastatin, and atorvastatin lactone in rat plasma. Solid-phase extraction was used for preparation of samples. Rosuvastatin was chosen as an internal standard. Chromatographic separation was achieved on ZORBAX Eclipse C-18 Analytical, 4.6 x 100 mm (3.5 mu m) column with a gradient mobile phase composed of acetonitrile and 0.1% acetic acid, at a flow rate of 400 mu L min(-1). The column was kept at constant temperature (25 degrees C), and autosampler tray temperature was set at 4 degrees C. The following selected reaction monitoring (SRM) transitions were selected: (m/z, Q1 - gt Q3, collision energy) atorvastatin (559.47 - gt 440.03, 22 eV), atorvastatin lactone (541.36 - gt 448.02, 19 eV), orthohydroxyatorvastatin (575.20 - gt 440.18, 20 eV), para-hydroxyatorvastatin (575.54 - gt 440.18, 20 eV), and rosuvastatin (482.25 with selected combination of two fragments 257.77, 31 eV, and 299.81, 35 eV) in positive ion mode. The method was validated over a concentration range of 0.5-20 ng mL(-1) for ortho-hydroxyatorvastatin and para-hydroxyatorvastatin and 0.1-20 ng mL(-1) for atorvastatin and atorvastatin lactone with excellent linearity (r(2) gt = 0.99). This method demonstrated acceptable precision and accuracy at four quality control concentration levels. The detection limits were 0.1 and 0.13 ng mL(-1) for orthohydroxyatorvastatin and para-hydroxyatorvastatin, respectively, and 0.05 ng mL(-1) for atorvastatin and atorvastatin lactone. All analytes were found to be stable at examined conditions. Validated method was applied for determination of atorvastatin and its metabolites in plasma of experimental animals.

This paper describes design and evaluation of parenteral lecithin-based nanoemulsions intended for brain delivery of risperidone, a poorly water-soluble psychopharmacological drug. The nanoemulsions were prepared through cold/hot high pressure homogenization and characterized regarding droplet size, polydispersity, surface charge, morphology, drug-vehicle interactions, and physical stability. To estimate the simultaneous influence of nanoemulsion formulation and preparation parameters-co-emulsifier type, aqueous phase type, homogenization temperature-on the critical quality attributes of developed nanoemulsions, a general factorial experimental design was applied. From the established design space and stability data, promising risperidone-loaded nanoemulsions (mean size about 160 nm, size distribution LT 0.15, zeta potential around -50 mV), containing sodium oleate in the aqueous phase and polysorbate 80, poloxamer 188 or Solutol (R) HS15 as co-emulsifier, were produced by hot homogenization and their ability to improve risperidone delivery to the brain was assessed in rats. Pharmacokinetic study demonstrated erratic brain profiles of risperidone following intraperitoneal administration in selected nanoemulsions, most probably due to their different droplet surface properties (different composition of the stabilizing layer). Namely, polysorbate 80-costabilized nanoemulsion showed increased (1.4-7.4-fold higher) risperidone brain availability compared to other nanoemulsions and drug solution, suggesting this nanoemulsion as a promising carrier worth exploring further for brain targeting.

To elaborate the decisive role of surfactants in promotion of aceclofenac' skin absorption, potentially avoiding irritation, we developed non-ionic microemulsions varying natural or synthetic surfactants: sucrose esters (laurate or myristate) vs. polysorbate 80. A comprehensive physicochemical characterization indicated no significant influence of the solubilized nonsteroidal anti-inflammatory drug on the bicontinuous structure of blank formulations. To evaluate skin tolerability of isopropyl alcohol, a sucrose ester-based microemulsion containing transcutol P as a cosurfactant was also developed. The measured skin parameters strongly depended on the (co)surfactant type, showing higher compatibility of the microemulsions containing sucrose ester and isopropyl alcohol. In vitro release results, in vivo tape stripping and pharmacokinetics in rats confirmed superiority of the sucrose ester-over polysorbate-based microemulsions (total amounts of aceclofenac penetrated 60.81 +/- 5.97 and 60.86 +/- 3.67 vs. 27.00 +/- 5.09 mu g/cm(2), and its maximum plasma concentrations 275.57 +/- 109.49 and 281.31 +/- 76.76 vs. 150.23 +/- 69.74 ng/ml for sucrose laurate- and myristate- vs. polysorbate 80-based microemulsions, respectively). Hence, sugar-based excipients increased delivery of aceclofenac through stratum corneum by increasing its fluidity, showing overall more satisfying safety profiles. In conclusion, sucrose ester-based microemulsions proved to be promising carriers for dermal/transdermal aceclofenac delivery.

The objects of this investigation were the comparative kinetic analysis of the NiO and NiCl2 reduction by hydrogen during an induction period and elimination of the calcination during the synthesis of Ni/Al2O3 catalysts. The effect of temperature and time on NiO and NiCl2 reduction degrees was studied. Avrami I equation was selected as the most favorable kinetic model and used to determine activation energy of the NiO and NiCl2 reduction for the investigated temperature range (623-923 K) and time intervals (1-5 minutes). The investigation enabled reaching conclusions about the reaction ability and rate of the reduction processes. Afterward, Ni/Al2O3 catalysts were obtained by using oxide and chloride precursor for Ni. The catalysts were supported on alumina-based foam and prepared via aerosol route. Properties of the samples before and after low-temperature hydrogen reduction (633 K) were compared. Obtained results indicated that the synthesis of Ni/Al2O3 catalysts can be more efficient if chloride precursor for Ni is directly reduced by hydrogen during the synthesis process, without the calcination step. In addition, Ni-Pd/Al2O3 catalysts with different metal content were prepared by using chloride precursors. Lower reduction temperature was utilized and the chlorides were almost completely reduced at 533 K. © 2015 Miroslav Sokić et al.

The partition coefficients (log P) of theoretically possible alkyliodinated iminodiacetic acid (IDA) derivatives and commercial IDA derivatives were calculated using two computer programs: ChemSketch Log P and ChemOffice Ultra. Newly synthesized ligands (DIETHYLIODIDA and DIISOPROPYLIODIDA) with the highest calculated log P were labeled with technetium-99m. The biodistribution and the influence of bilirubin on their biokinetics were investigated in rats and compared to corresponding results for commercial Tc-99m-BROMIDA. Log P of Tc-99m-complexes of synthesized ligands were determined experimentally as well as the protein binding. In comparison to Tc-99m-BROMIDA, Tc-99m-DIETHYLIODIDA has: (a) better biliary excretion (2.76 +/- 0.15%ID/g versus 1.83 +/- 0.10%ID/g); (b) faster hepatic clearance (2.90 +/- 0.21%ID/g versus 7.47 +/- 0.70%ID/g) and decreased biliary excretion (for 14% versus 22%) in conditions of hyperbilirubinemia after 15 min. It is proved that Tc-99m-DIISOPROPYLIODIDA has a prolonged hepatic transit time and decreased biliary excretion. (c) 2012 Elsevier Ltd. All rights reserved.