Vibrational spectroscopic techniques (Raman, FT-IR and FT-NIR spectroscopy) as a means for the solid-state structural analysis of pharmaceuticals

The aim of this work was to assess the suitability of vibrational spectroscopic techniques (Raman, FT-IR and FT-NIR spectroscopy) as a means for the solid-state structural analysis of pharmaceuticals. Budesonide, fluticasone propionate, salbutamol hemisulfate, terbutaline hemisulfate, ipratropium bromide, polymorphic forms of salmeterol xinafoate and two polymorphic forms of sulfathiazole were selected since they are used in the management of certain respiratory disorders and from different chemical and pharmacological entities along with some pharmaceutical excipients. Conventional visual examination is not sufficient to identify and differentiate spectra between different pharmaceuticals. To confirm the assignment of key molecular vibrational band signatures, quantum chemical calculations of the vibrational spectra were employed for better understanding of the first five selected drugs. The nondestructive nature of the vibrational spectroscopic techniques and the success of quantum chemical calculations demonstrated in this work have indeed offered a new dimension for the rapid identification and characterisation of pharmaceuticals and essentially warrant further research. The application of simultaneous in situ Raman spectroscopy and differential scanning calorimetry for the preliminary investigation of the polymorphic transformation of salmeterol xinafoate polymorphs and two polymorphic forms of sulfathiazole has also been explored in this work leading to the development of a new method for the solid-state estimation of the transition temperature of entantiotropically related pharmaceutical polymorphs which represents the first analytical record of the use of this approach for pharmaceutical polymorphs

Effect of curing conditions and harvesting stage of maturity on Ethiopian onion bulb drying properties

The study was conducted to investigate the impact of curing conditions and harvesting stageson the drying quality of onion bulbs. The onion bulbs (Bombay Red cultivar) were harvested at three harvesting stages (early, optimum, and late maturity) and cured at three different temperatures (30, 40 and 50 oC) and relative humidity (30, 50 and 70%). The results revealed that curing temperature, RH, and maturity stage had significant effects on all measuredattributesexcept total soluble solids

Imagiologia de Raman para a avaliação da qualidade de comprimidos de paracetamol

Atualmente, a aplicabilidade da espectroscopia de Raman acoplada à microscopia confocal na indústria farmacêutica vai desde a caracterização das formulações farmacêuticas para a elucidação dos processos cinéticos na entrega da droga à deteção rápida e identificação de medicamentos falsificados. O Paracetamol é um fármaco de propriedades analgésica e antitérmica, considerado dentre os medicamentos mais consumidos. O 4-aminofenol (4-AF) é o produto hidrolítico do Paracetamol e é relatado como tendo nefrotoxicidade e efeitos teratogénicos. Este trabalho teve como objetivo a utilização da espectroscopia de Raman acoplada à microscopia confocal para a caracterização do Paracetamol e a identificação de 4-AF em comprimidos de Ben-U-ron. Posteriormente, os comprimidos preparados foram submetidos à estímulos externos tais como temperatura, humidade e exposição solar, a fim de avaliar a presença de impurezas e algumas alterações físicas ou químicas que possam ocorrer durante o estímulo. Concluiu-se no presente trabalho que a imagiologia de Raman é uma técnica que pode ser útil para a deteção de pequenas quantidades do contaminante 4- AF, em comprimidos de Paracetamol comercializados, apesar de não detetar os teores mínimos estabelecidos pelas Farmacopeias. Avaliou-se em detalhe as variações físicas e químicas dos comprimidos, tais como a sua dureza e a oxidação/degradação dos seus componentes, recorrendo às técnicas de Raman e medidas de compressão, aquando expostos a diversas condições ambientais como, temperatura, humidade e exposição solar.Currently, the applicability of the Raman spectroscopy coupled to confocal microscopy in the pharmaceutical industry, ranges from the characterization of pharmaceutical formulations to elucidate kinetic processes in drug delivery to the rapid detection and identification of counterfeit drugs. Paracetamol is a drug with analgesic and antipyretic properties, considered one of the most consumed drugs. The 4-aminophenol (4-AF) is the hydrolytic product of Paracetamol and, is reported to have nephrotoxicity and teratogenic effects. The main goal of this work was the use of Raman spectroscopy coupled with confocal microscopy to characterize Paracetamol and the identification of 4-AF in Ben-U-ron tablets. Then the as prepared tablets were subjected to external stimuli such as temperature, humidity and sun exposure to assess the presence of impurities and any physical or chemical changes that may have occurred during the stimuli. In the present work, we demonstrate that Raman imaging is a great technique that can be useful for the detection of small amounts of the 4-AF contaminant, or as a residue of chemical synthesis in commercially available Paracetamol tablets, although it does not detect the minimum levels established by the Pharmacopoeias. Then, we have evaluated, in more detail, the physical and chemical variations that can occur on the tablets when they are exposed to various environmental conditions such as temperature, humidity and sun exposure.Mestrado em Químic

Espetroscopia de Raman para aplicações biomédicas

A técnica de Espetroscopia de Raman testemunhou um avanço rápido nos últimos anos, e os interesses crescentes da investigação e da indústria fortaleceram ainda mais a sua aplicação. Nos últimos anos, este rápido desenvolvimento promoveu o uso da Espetroscopia de Raman numa ampla variedade de novas aplicações, incluindo áreas de segurança alimentar, deteção de qualidade, controle de qualidade farmacêutica, análises forenses e biomédicas. A Espetroscopia de Raman é uma técnica ótica de alta resolução, sendo uma poderosa técnica espetroscópica vibracional que permite num curto espaço de tempo diferenciar estruturas moleculares baseadas no espalhamento inelástico da luz monocromática, como a luz laser. A Espetroscopia de Raman mede os modos vibracionais de uma amostra. Um espetro consiste numa distribuição de comprimento de onda de picos correspondentes às vibrações moleculares específicas da amostra que está a ser analisada. Trata-se de uma técnica de análise que se realiza diretamente sobre o material a ser estudado, sendo uma análise não-invasiva e não-destrutiva, com vantagens como utilização de pequenas quantidades amostrais, não necessita de preparação prévia da amostra a analisar, não origina alteração da superfície nem a sua destruição, e é célere na realização da análise. O estudo prático consiste na análise de amostras de duas naturezas distintas, farmacêutica e orgânica animal. As farmacêuticas têm como objetivo o estudo da sensibilidade do equipamento, através da análise de aspirinas e paracetamol no estado sólido e líquido. Por outro lado, as amostras orgânicas surgem numa vertente mais complexa, sendo o foco um estudo às cegas (blind tests) de tecido mamário de fêmeas, Felis catus domesticus, onde se pretende verificar através dos resultados se há alterações no padrão morfológico que sejam potenciais indicadores de patologia.The Raman spectroscopy technique has witnessed a rapid advancement in recent years, and the growing interests of research and industry have further strengthened its application. In recent years, this rapid development has promoted the use of Raman spectroscopy in a wide variety of new applications, including food safety areas, quality detection, pharmaceutical quality control, forensic and biomedical analysis. Raman spectroscopy is a high-resolution photonics technique, being a powerful vibrational spectroscopic technique that allows in a short time to differentiate molecular structures based on the inelastic scattering of monochrome light, such as Laser light. Raman spectroscopy measures the vibrational modes of a sample. A spectrum consists of a wavelength distribution of peaks corresponding to the specific molecular vibrations of the sample being analyzed. It is an analysis technique that is performed directly on the material to be studied, being a non-invasive and non-destructive analysis, with advantages such as the need for small sample quantities, practically no preparation of the specimen, no sample destruction, which does not lead to any alteration of the surface and little time to perform the analysis. The practical study consists of the analysis of samples of two distinct natures, pharmaceutical and organic animal. The pharmaceutical companies aim to study the sensitivity of the equipment through the analysis of aspirins, paracetamol in the solid and liquid state. On the other hand, organic samples emerge in a more complex strand, with the focus being a blind tests of breast tissue of females, Felis catus domesticus, where it is intended to verify through the results if there are alterations in the morphological pattern that are potential indicators of pathology

The surface characterisation of pharmaceutical mini-tablets using thermal probe techniques

This thesis assesses the ability of a range of novel thermo-analytical techniques to determine the spatial distribution of components across the surface of pharmaceutical mini-tablets. Such information is of use in formulation development, as the surface is the point at which a solid dosage form comes into contact with the environment, and where drug stability and excipient functionality are critical. Mini-tablets provide a good model system for surface characterisation, as they have much higher surface area to volume ratios than conventionally sized tablets. Five excipients and two drugs, as powders and after compaction, were individually characterised by the following techniques: scanning electron microscopy (SEM), variable temperature infrared spectroscopy (VT-IR), differential scanning calorimetry (DSC), atomic force microscopy (AFM), micro-thermal analysis (micro-TA), nano-thermal analysis (nano-TA) and transition temperature microscopy (TTM). Compacts of mixed systems were tested using AFM, micro-TA, nano-TA and TTM, building up the complexity to 4-component systems for excipient-only mixtures and 5-component systems for drug-loaded mixtures. Micro-TA, nano-TA and TTM were able to detect each component in all of the multi-component compacts, but AFM could not differentiate between them in complex systems. The study was then repeated on realistic mini-tablet formulations, confirming these initial results. Additionally, Raman microspectroscopy was performed on the mini-tablets as a corroborative technique, this method being based on a different physical phenomenon. In conclusion, the thermal probe techniques (micro-TA, nano-TA and TTM) were shown to be sufficiently discriminating to allow the spatial mapping of components across the surface of realistic mini-tablet formulations. Hence, these techniques could be used alongside spectroscopic techniques in the analysis of complex surfaces. However, some serious issues with the automated analysis and data display functions in the TTM software were identified, which could lead to misinterpretation of the results. Potential corrective measures were suggested to alleviate these concerns and improve experimental reliability

TECHNART 2017. Non-destructive and microanalytical techniques in art and cultural heritage. Book of abstracts

440 p.TECHNART2017 is the international biannual congress on the application of Analytical Techniques in Art and Cultural Heritage. The aim of this European conference is to provide a scientific forum to present and promote the use of analytical spectroscopic techniques in cultural heritage on a worldwide scale to stimulate contacts and exchange experiences, making a bridge between science and art. This conference builds on the momentum of the previous TECHNART editions of Lisbon, Athens, Berlin, Amsterdam and Catania, offering an outstanding and unique opportunity for exchanging knowledge on leading edge developments. Cultural heritage studies are interpreted in a broad sense, including pigments, stones, metal, glass, ceramics, chemometrics on artwork studies, resins, fibers, forensic applications in art, history, archaeology and conservation science. The meeting is focused in different aspects: - X-ray analysis (XRF, PIXE, XRD, SEM-EDX). - Confocal X-ray microscopy (3D Micro-XRF, 3D Micro-PIXE). - Synchrotron, ion beam and neutron based techniques/instrumentation. - FT-IR and Raman spectroscopy. - UV-Vis and NIR absorption/reflectance and fluorescence. - Laser-based analytical techniques (LIBS, etc.). - Magnetic resonance techniques. - Chromatography (GC, HPLC) and mass spectrometry. - Optical imaging and coherence techniques. - Mobile spectrometry and remote sensing

Smart and Safe packaging

In line with the latest innovations in the packaging field, this joint project aims at implementing new and innovative micro- and nanoparticles for the development of active and intelligent packaging solutions dedicated to food and medical packaging applications. More specifically, the project combines two major developments which both falls within the scope of active and intelligent packaging. In this work, a specific focus was given to the development of an antibacterial packaging solution and to the development of smart gas sensors. The antibacterial strategy developed was based on the combination of two active materials - silver nanowires and cellulose nanofibrils - to prepare antibacterial surfaces. The formulation as an ink and the deposition processing has been deeply studied for different surface deposition processes that include coatings or screen-printing. Results showed surfaces that display strong antibacterial activity both against Gram-positive and Gram-negative bacteria, but also interesting properties for active packaging applications such as a highly retained transparency or enhanced barrier properties. Regarding the second strategy, gas sensors have been prepared using a combination of Copper benzene-1,3,5-tricarboxylate Metal Organic Framework and carbon-graphene materials, deposited on flexible screen-printed electrodes. The easy-to-produce and optimized sensors exhibit good performances toward ammonia and toward humidity sensing, proving the versatility and the great potential of such solution to be adapted for different target applications. The results of this project lead to innovative solutions that can meet the challenges raised by the packaging industry