The goal of this study was the methodological development of Raman microscopy application for advanced and reliable monitoring of pharmaceutical tablets disintegration in aqueous media. First step of the development involved new design and testing of static, flow cell and tablet holders. On-line Raman mapping method enables observation of the tested tablet interphase changes, particularly the changes of tablet composition during interaction of the solid-state drug form with disintegration medium. Furthermore, the quantitative information of tablet components (% w/w) from Raman maps was calculated. Second part of this study performs off-line Raman mapping, which was focused on the mapping of disintegrated tablet residua. Time-dependent Raman chemical maps provide an understanding of the role of several synergic processes, e.g. solvation, solvent penetration, both active pharmaceutical ingredient and excipient dissolution etc., which occur simultaneously on the surface of dissolving tablet. Raman data of disintegration process were evaluated by a chemometric method - Principal Component Analysis (PCA).

• Klíčová slova
• Disintegration cells, Dissolution studies, Ibuprofen, Lactose, Principal component analysis, Raman mapping,
• MeSH
• analýza hlavních komponent MeSH
• časové faktory MeSH
• chemie farmaceutická metody   MeSH
• farmaceutická technologie metody   MeSH
• léčivé přípravky chemie   MeSH
• pomocné látky chemie   MeSH
• Ramanova spektroskopie metody   MeSH
• rozpouštědla chemie   MeSH
• tablety MeSH
• uvolňování léčiv MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• léčivé přípravky MeSH
• pomocné látky MeSH
• rozpouštědla MeSH
• tablety MeSH

Raman micro-spectroscopy technique offers a combination of relatively high spatial resolution with identification of components or mixtures of components in different sample areas, e.g. on the surface or the cross-section of a sample. This study is focused on the analysis of the tablets from pharmaceutical development with different technological parameters: (1) the manufacturing technology, (2) the particle size of the input API (active pharmaceutical ingredient) and (3) the quantitative composition of the individual excipients. These three mentioned parameters represent the most frequently solved problems in the field of reverse engineering in pharmacy. The investigation aims to distinguish tablets with the above-described technological parameters with limited subjective steps by Raman microscopy. Furthermore, non-subjective methods of Raman data analysis using advanced statistical analysis have been proposed, namely Principal Component Analysis, Soft Independent Modelling of Class Analogy and Linear Discriminant Analysis. The methods successfully distinguished and identified even very small differences in the analysed tablets within our study and provided objective statistic evaluation of Raman maps. The information on component and particle size distribution including their small differences, which is the critical parameter in the development of the original and generic products, was obtained due to combination of these methods. Even though each of these chemometric methods evaluates the data set from a different perspective, their mutual application on the problem of Raman maps evaluation confirmed and specified results on level that would be unattainable with the use of only one them.

• Klíčová slova
• Linear Discriminant Analysis, Multivariate analysis, Principal Component Analysis, Raman mapping, Soft Independent Modelling of Class Analogy, Tablets,
• MeSH
• chemometrika MeSH
• farmacie * MeSH
• léčivé přípravky * MeSH
• pomocné látky MeSH
• Ramanova spektroskopie MeSH
• tablety MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• léčivé přípravky * MeSH
• pomocné látky MeSH
• tablety MeSH

Raman mapping microspectroscopy was used as an advantageous high spatial resolution method for detailed assessment of the structure of radiation-induced halos in bituminous coal (Upper Paleozoic) with numerous inclusions of uraninite and coffinite. The uranium content in inclusions in the samples studied ranged from 40 to 50 wt%. Raman structural parameters such as full width at half maximum, the positions of the D-band and G-band peaks and their area ratios were calculated, and these correlated well with vitrinite reflectance. Using linear profiles across the entire halos, changes in the degree of radiolytic alteration of coal matter caused by ionising radiation resulting from the decay of uranium and its daughter products, were described. Using micro-ATR-FTIR, oxidative radiolytic alteration of coal was identified in halos, with oxidisation to alcohols, ketones and carboxyl groups, which were then converted to COO- ions bound to the cations present, including UO22+. From our data, we conclude that the conversion of the original coal to a type of anthracite occurred during the process of CH and CC cleavage, dehydroaromatisation of naphthenic rings and oxidation resulting in the transformation of aliphatic structures into aromatic clusters. Generally, radiolytic alteration increased the structural organisation of coal. Monte Carlo simulations of the observed radiation alteration by the ionising energy loss and non-ionising energy loss were performed.

• Klíčová slova
• Coal, Halos, Micro-ATR-FTIR, Radiolytic alteration, Raman mapping, Uranium,
• Publikační typ
• časopisecké články MeSH

The properties of dry-coated paracetamol particles (fast-dissolving model drug) with carnauba wax particles as the coating agent (dissolution retardant) were investigated. Raman mapping technique was used to non-destructively examine the thickness and homogeneity of coated particles. The results showed that the wax existed in two forms on the surface of the paracetamol particles, forming a porous coating layer: i) whole wax particles on the surface of paracetamol and glued together with other wax surface particles, and ii) deformed wax particles spread on the surface. Regardless of the final particle size fraction (between 100 and 800 μm), the coating thickness had high variability, with average thickness of 5.9 ± 4.2 μm. The ability of carnauba wax to decrease the dissolution rate of paracetamol was confirmed by dissolution of powder and tablet formulations. The dissolution was slower for larger coated particles. Tableting further reduced the dissolution rate, clearly indicating the impact of subsequent formulation processes on the final quality of the product.

• Klíčová slova
• Dissolution, Dry-coating, Particle coating thickness, Polymers, Raman mapping,
• Publikační typ
• časopisecké články MeSH

GO is a 2D nanomaterial that has attracted attention in many industries in recent years, such as the chemical industry, electronics or medicine. Due to its unique properties such as strength, hydrophilicity and large specific surface area with the possibility of functionalization, GO is a particularly attractive material in biomedicine as a candidate for use in targeted drug delivery. In such a case, we need information on whether graphene oxide penetrates into cells and whether we are able to detect and monitor GO in these cells during and also after the treatment to evaluate possible degradation process of GO and its interaction within the cell compartements. This work introduces the Raman spectroscopy as label-free detection method showing the advantages of combining Raman spectroscopy with MCR (Multivariate Curve Resolution) analysis for advanced detection of GO in cervical cancer (HeLa) cells. Our synthesized GO is characterized firstly by AFM, SEM and Raman spectroscopy and then MCR-Raman spectroscopy is used to detect internalized GO in individual HeLa cells. Moreover, by using our methodology, distribution of GO as well as its chemical stability inside the cell for up to six months is investigated without using any additional labeling or tracing the GO. Thus, MCR-Raman spectroscopy may become a new analytical tool in preclinical and clinical applications of graphene-based nanotheranostics.

• MeSH
• chemický průmysl MeSH
• grafit * MeSH
• HeLa buňky MeSH
• lidé MeSH
• Ramanova spektroskopie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• grafit * MeSH
• graphene oxide MeSH Prohlížeč

Surface-enhanced Raman spectrometry (SERS) is a universal detection tool identifying molecules via vibrations of their chemical bonds. Its function requires the close localization of metal nanostructures and the analyte. In this work, we present a lab-made instrumentation for the deposition of silver nanoparticles on a strongly hydrophilic nanofibrous composite via a nanospray for SERS mapping of an incorporated peptide. The nanospray-sample distance was revealed as the most crucial parameter since it directly influences the moisture of the deposited colloid. Residual water was recognized as a sensitivity enhancer. Additionally, we continuously introduced a solution of sodium chloride to the colloid increasing its ionic strength, which formed a more homogeneous profile of the deposit. After the deposition process, the treated sample was scanned via a SERS laser and the collected Raman spectra were transformed into a distribution map of the peptide at a concentration of 5 μg/g.

• Klíčová slova
• Colloid, Mapping, Nanofibers, Nanoparticles, Nanospray, Surface-enhanced Raman spectrometry,
• Publikační typ
• časopisecké články MeSH

Raman imaging allows one to obtain spatially resolved chemical information in a nondestructive manner. Herein, we present analytical aspects of effective in situ and in vivo Raman imaging of algae and cyanobacteria from within their native rock habitats. Specifically, gypsum and halite inhabited by endolithic communities from the hyperarid Atacama Desert were analyzed. Raman imaging of these phototrophic colonization reveals a pigment composition within the aggregates that helps in understanding some of their adaptation strategies to survive in this harsh polyextreme environment. The study is focused on methodical aspects of Raman imaging acquisition and subsequent data processing. Point imaging is compared with line imaging in terms of their image quality, spatial resolution, spectral signal-to-noise ratio, time requirements, and risk of laser-induced sample alteration. The roles of excitation wavelength, exposure time, and step size of the imaging grid on successful Raman imaging results are also discussed. Graphical abstract.

• Klíčová slova
• Astrobiology, Bioimage, Geobiology, Image analysis, Raman mapping, Scytonemin,
• MeSH
• biologické pigmenty analýza   MeSH
• ekosystém MeSH
• pouštní klima MeSH
• půdní mikrobiologie * MeSH
• Ramanova spektroskopie * metody   MeSH
• sinice chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• biologické pigmenty MeSH

The aim of this study was to investigate the molecular structures of tadalafil solid dispersions prepared by different techniques and further to relate them to surface free energy information indicating the final amorphousness of the product. Thus, we tried to complement the existing knowledge of solid dispersion formation. Poorly water-soluble tadalafil was combined with different polymers, i.e. Kollidon® 12 PF, Kollidon® VA 64 and Soluplus®, to form model systems. To assess the extent of drug-polymer miscibility, we studied model solid dispersion surface energy using inverse gas chromatography and phase micro-structure using confocal Raman microscopy. The selection of the preparation method was found to play a crucial role in the molecular arrangement of the incorporated drug and the polymer in resulting solid dispersion. Our results showed that a lower surface free energy indicated the formation of a more homogeneous solid dispersion. Conversely, a higher surface free energy corresponded to the heterogeneous systems containing tadalafil amorphous clusters that were captured by Raman mapping. Thus, we successfully introduced a novel evaluation approach of the drug molecular arrangement in solid dispersions that is especially useful for examining the miscibility of the components when the conventional characterizing techniques are inconclusive or yield variable results.

• Klíčová slova
• Drug-polymer interaction, Inverse gas chromatography, Molecular dispersion, Raman mapping, Structure of solid dispersions, Surface free energy,
• MeSH
• chromatografie plynová MeSH
• polymery * chemie   MeSH
• povidon * chemie   MeSH
• rozpustnost MeSH
• tadalafil chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• polymery * MeSH
• povidon * MeSH
• tadalafil MeSH

The effects of herbicides from three mode-of-action groups - inhibitors of protoporphyrinogen oxidase (carfentrazone-ethyl), inhibitors of carotenoid biosynthesis (mesotrione, clomazone, and diflufenican), and inhibitors of acetolactate synthase (amidosulfuron) - were studied in sunflower plants (Helianthus annuus). Raman spectroscopy, chlorophyll fluorescence (ChlF) imaging, and UV screening of ChlF were combined to evaluate changes in pigment composition, photosystem II (PSII) photochemistry, and non-photochemical quenching in plant leaves 6d after herbicide application. The Raman signals of phenolic compounds, carotenoids, and chlorophyll were evaluated and differences in their intensity ratios were observed. Strongly augmented relative content of phenolic compounds was observed in the case of amidosulfuron-treated plants, with a simultaneous decrease in the chlorophyll/carotenoid intensity ratio. The results were confirmed by in vivo measurement of flavonols using UV screening of ChlF. Herbicides from the group of carotenoid biosynthesis inhibitors significantly decreased both the maximum quantum efficiency of PSII and non-photochemical quenching as determined by ChlF. Resonance Raman imaging (mapping) data with high resolution (150,000-200,000 spectra) are presented, showing the distribution of carotenoids in H. annuus leaves treated by two of the herbicides acting as inhibitors of carotenoid biosynthesis (clomazone or diflufenican). Clear signs were observed that the treatment induced carotenoid depletion within sunflower leaves. The depletion spatial pattern registered differed depending on the type of herbicide applied.

• Klíčová slova
• Carotenoids, Chlorophyll fluorescence, Flavonoids, Photosynthesis, Raman mapping, Secondary metabolites,
• MeSH
• chlorofyl a MeSH
• chlorofyl metabolismus   MeSH
• epidermis rostlin metabolismus   MeSH
• flavonoly analýza   MeSH
• fluorescence MeSH
• fotosystém II - proteinový komplex chemie   MeSH
• Helianthus chemie   účinky léků   MeSH
• herbicidy toxicita   MeSH
• listy rostlin chemie   MeSH
• Ramanova spektroskopie * MeSH
• referenční standardy MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chlorofyl a MeSH
• chlorofyl MeSH
• flavonoly MeSH
• fotosystém II - proteinový komplex MeSH
• herbicidy MeSH

Drop coating deposition Raman (DCDR) spectroscopy was used to study liposomes (DPPC and asolectin) with growing proportion of cholesterol. Deposited samples of both liposomes on special hydrophobic surface formed a dried drop with a circular shape with a ring of concentrated liposomes at the outer edge. The presence of cholesterol in liposome causes a diminishing of the drop size and an increasing in diameter of the ring, but DPPC with 20% of cholesterol forms the compact drop without the ring. Raman spectra contain characteristics of both lipids and cholesterol, liposomes do not change their initial phase state after drying. Spectral mapping shows that maximum Raman intensity originated from the inner part of the ring. Our results suggest that DCDR spectroscopy can be used for studying lipids containing cholesterol in situ.

• Klíčová slova
• Asolectin, Cholesterol, DPPC, Drop coating deposition Raman spectroscopy, Liposome,
• MeSH
• 1,2-dipalmitoylfosfatidylcholin chemie   MeSH
• cholesterol chemie   MeSH
• fosfatidylcholiny chemie   MeSH
• hydrofobní a hydrofilní interakce MeSH
• liposomy chemie   MeSH
• Ramanova spektroskopie * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 1,2-dipalmitoylfosfatidylcholin MeSH
• asolectin MeSH Prohlížeč
• cholesterol MeSH
• fosfatidylcholiny MeSH
• liposomy MeSH