Methotrexate and cytarabine - loaded nanocarriers for multidrug cancer therapy : spectroscopic study

Determining the properties of nanoparticles obtained by novel methods and defining the scope of their application as drug carriers has important practical significance. This article presents the pioneering studies concerning high degree incorporation of cytarabine (AraC) and methotrexate (MTX) into liposome vesicles. The main focus of this study were cytarabine-methotrexate-dipalmitoylphosphatidylcholine (DPPC) interactions observed in the gel and fluid phases of DPPC bilayers. The proposed new method of use the Transmittance2919/2850 ratio presented in our research is sensitive to subtle changes in conformational order resulting from rotations, kinks and bends of the lipid chains. The transition temperatures characterized by Fourier Transform Infrared Spectroscopy (FT-IR) were consistent with the results obtained by Differential Scanning Calorimetry (DSC). Transmission Electron Microscopy (TEM) was used in order to determine the size and shape of the liposomes obtained. The mutual interactions occurring between the drugs studied and the phospholipids were analyzed using the Nuclear Magnetic Resonance (NMR)

Rapid Screening of Mupirocin Skin Permeation Modification by Micronized and Nanonized Alaptide

The investigation deals with the affection of permeation of mupirocin from the Bactroban® Leciva ointment through full-thickness pig ear skin by alaptide that was applied in micronized or nanonized form as a potential excipient. Alaptide, (S)-8-methyl-6,9-diazaspiro[4.5]decan-7,10-dione, was the original Czech compound. It was discovered that micronized alaptide significantly enhanced the permeation of mupirocin within 1 h after administration (approx. 5-fold). On the other hand, nanonized alaptide almost completely inhibited permeation of mupirocin from Bactroban® Leciva through the skin. Rapid primary screening showed that the two forms of alaptide differently influenced the depth and the rate of permeation/penetration of mupirocin into/through the skin, i.e., affect curative effect of mupirocin on/in skin immediately after application of drug formulation

Investigation of hydro-lipophilic properties of n-alkoxyphenylhydroxynaphthalenecarboxamides

The evaluation of the lipophilic characteristics of biologically active agents is indispensable for the rational design of ADMET-tailored structure–activity models. N-Alkoxy-3-hydroxynaphthalene-2-carboxanilides, N-alkoxy-1-hydroxynaphthalene-2-carboxanilides, and N-alkoxy-2-hydroxynaphthalene-1-carboxanilides were recently reported as a series of compounds with antimycobacterial, antibacterial, and herbicidal activity. As it was found that the lipophilicity of these biologically active agents determines their activity, the hydro-lipophilic properties of all three series were investigated in this study. All 57 anilides were analyzed using the reversed-phase high-performance liquid chromatography method for the measurement of lipophilicity. The procedure was performed under isocratic conditions with methanol as an organic modifier in the mobile phase using an end-capped non-polar C18 stationary reversed-phase column. In the present study, a range of software lipophilicity predictors for the estimation of clogP values of a set of N-alkoxyphenylhydroxynaphthalenecarboxamides was employed and subsequently cross-compared with experimental parameters. Thus, the empirical values of lipophilicity (logk) and the distributive parameters (π) were compared with the corresponding in silico characteristics that were calculated using alternative methods for deducing the lipophilic features. To scrutinize (dis)similarities between the derivatives, a PCA procedure was applied to visualize the major differences in the performance of molecules with respect to their lipophilic profile, molecular weight, and violations of Lipinski’s Rule of Five

Sulfolane: Magic Extractor or Bad Actor? Pilot-Scale Study on Solvent Corrosion Potential

The sulfur-containing derivatives and their metabolites, regarded as ‘old devils of green’ chemistry, constitute a relevant class of air/water/soil contaminants in over-polluted world. In fact, some industrially-engineered solvents have become environmentally unfavorable. An attractive alternative to commonly used industrial liquids is sulfolane (C4H8SO2), an anthropogenic medium. The main objective of this paper is the comprehensive review focusing mainly on the state-of-the-art aspects of the sulfolane synthesis, application of sulfolane as an extractive solvent due to its ‘unique’ physicochemical properties as well as the potential of sulfolane to cause equipment corrosion and subsequent spills. The potential risk for groundwater contamination, danger for human health and ways of sulfolane biodegradation were briefly reviewed as well. Interestingly, the analysis performed on data stored in the Reaxys database revealed an alternating tendency of waxing and waning interest in sulfolane during the space of the last fifty years. Moreover, the primary goal of the presented case study was to verify applicability of industrial, multi-electrochemical technique for reliable detection of corrosion in low conductive process fluids. Several aspects of corrosion measurement including the impact of process parameters (temperature) and impurities (oxygen and chlorides) on stainless steel corrosion in pure sulfolane were investigated briefly

Rapid and simple TLC-densitometric method for assay of clobetasol propionate in topical solution

A rapid, simple to use and low-cost thin-layer chromatographic procedure in normal phase system with densitometric detection at 246 nm was carefully validated according to the International Conference on Harmonisation (ICH) guidelines for assay of clobetasol propionate in topical solution containing clobetasol propionate in quantity 0.50 mg/mL. The adopted thin-layer chromatographic (TLC)-densitometric procedure could effectively separate clobetasol propionate from its related compound, namely clobetasol. It is linear for clobetasol propionate in the range of 0.188 5 g/spot. The limit of detection (LOD) and limit of quantification (LOQ) value is 0.061 and 0.186 g/spot, respectively. Accuracy of proposed procedure was evaluated by recovery test. The mean recovery of studied clobetasol propionate ranges from 98.7 to 101.0%. The coefficient of variation (CV, %) obtained during intra-day and inter-day studies, which was less than 2% (0.40 1.17%), confirms the precision of described method. The assay value of clobetasol propionate is consistent with the pharmacopoeial requirements. In conclusion, it can be suitable as a simple and economic procedure for routine quality control laboratories of clobetasol propionate in topical solution

Permeation of Indomethacin through Skin Using Nanonized Alaptide

Alaptide, (S)-8-methyl-6,9-diazaspiro[4.5]decan-7,10-dione, is an original Czech compound; in this paper it is used as an excipient. The investigation deals with the affection of the permeation of indomethacin through full-thickness pig ear skin using a Franz diffusion cell from the donor vehicle of propylene glycol/water (1:1) using nanonized alaptide as a potential transdermal permeation enhancer. Alaptide was applied in ratio 1:10 (w/w) related to the amount of indomethacin. Nanonized alaptide showed an excellent rapid onset of enhancement effect, already at the 30th minute after application, when the permeated amount of indomethacin was 5-fold more than in the formulation without alaptide. The enhancement ratio of nanonized alaptide was 5.6, which indicates that alaptide modifies skin structure, which results in significantly enhanced permeation at long-term application

Towards intelligent drug design system: Application of artificial dipeptide receptor library in QSAR-oriented studies

The pharmacophore properties of a new series of potential purinoreceptor (P2X) inhibitors determined using a coupled neural network and the partial least squares method with iterative variable elimination (IVE-PLS) are presented in a ligand-based comparative study of the molecular surface by comparative molecular surface analysis (CoMSA). Moreover, we focused on the interpretation of noticeable variations in the potential selectiveness of interactions of individual inhibitor-receptors due to their physicochemical properties; therefore, the library of artificial dipeptide receptors (ADP) was designed and examined. The resulting library response to individual inhibitors was arranged in the array, preprocessed and transformed by the principal component analysis (PCA) and PLS procedures. A dominant absolute contribution to PC1 of the Glu attached to heptanoic gating acid and Phe bonded to the linker m-phenylenediamine/triazine scaffold was revealed by the PCA. The IVE-PLS procedure indicated the receptor systems with predominant Pro bonded to the linker and Glu, Gln, Cys and Val directly attached to the gating acid. The proposed comprehensive ligand-based and simplified structure-based methodology allows the in-depth study of the performance of peptide receptors against the tested set of compounds.NC

2-Methyl-3-(n-octylsulfan­yl)quinoxaline

All the non-H atoms of the title compound, C17H24N2S, lie almost in a common plane (r.m.s. deviation = 0.049 Å). The octyl chain adopts an all-trans conformation

1-Benzyl-3-methyl­quinoxalin-2(1H)-one

The asymmetric unit of the title compound, C16H14N2O, contains three independent mol­ecules. The dihedral angles between the quinoxaline and phenyl planes in the three mol­ecules are 82.58 (8), 85.66 (9) and 85.36 (9)°. The crystal packing is stabilized by C—H⋯O and C—H⋯N hydrogen bonds

Photosynthesis-inhibiting activity of N-(Disubstitutedphenyl)-3- hydroxynaphthalene-2-carboxamides

A set of twenty-four 3-hydroxynaphthalene-2-carboxanilides, disubstituted on the anilide ring by combinations of methoxy/methyl/fluoro/chloro/bromo and ditrifluoromethyl groups at different positions, was prepared. The compounds were tested for their ability to inhibit photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. N-(3,5-Difluorophenyl)-, N-(3,5-dimethylphenyl)-, N-(2,5-difluorophenyl)- and N-(2,5-dimethylphenyl)-3-hydroxynaphthalene-2-carboxamides showed the highest PET-inhibiting activity (IC50 ~ 10 M) within the series. These compounds were able to inhibit PET in photosystem II. It has been found that PET-inhibiting activity strongly depends on the position of the individual substituents on the anilide ring and on the lipophilicity of the compounds. The electron-withdrawing properties of the substituents contribute towards the PET activity of these compounds