6 research outputs found
Notas sobre a Carta de Veneza
This paper presents a critical reading of the Venice Charter, an Icomos key document, fruit of a conference held in 1964. The Charter is often quoted in Brazil but is not always properly understood. The conservation and restoration charters - especially those produced by international institutions - are documents that have an indicatory or, at the most, prescriptive character. They constitute the deontological foundation of many professionals involved in preservation, but they are not recipes for immediate use. In order to elaborate a well-founded reading of the document, its ideas must be understood in connection to the theoretical postulates of the time they were engendered and to the developments of the field. Thus this paper will examine these subjects, commenting and enlightening the Charter's articles and pointing out the origins of specific ideas. It also discusses how the Charter relates to previous documents and their theoretical foundations. This approach, based in a critical analysis, is necessary in order to reach a fuller interpretation of the Charter's indications so that they can be used in the present
Raman Hyperspectral Imaging: An essential tool in the pharmaceutical field
Resulting from the combination of Raman spectroscopy and optical microscopy, Raman hyperspectral imaging
has proven to be an indispensable tool in the pharmaceutical field. This article will broach a number of Raman
hyperspectral imaging applications that were developed in our laboratory, in order to demonstrate the significance
of the technique
Critical review of surface-enhanced Raman spectroscopy applications in the pharmaceutical field
Surface-enhanced Raman spectroscopy (SERS) is a sensitive analytical tool used in the pharmaceutical field in recent years. SERS keeps all the advantages of classical Raman spectroscopy while being is more sensitive allowing its use for the detection and the quantification of low-dose substances contained in pharmaceutical samples. However, the analytical performance of SERS is limited due to the difficulty to implement a quantitative methodology correctly validated. Nevertheless, some studies reported the development of SERS quantitative methods especially in pharmaceutical approaches.
In this context, this review presents the main concepts of the SERS technique. The different steps that need to be applied to develop a SERS quantitative method are also deeply described. The last part of the present manuscript gives a critical overview of the different SERS pharmaceutical applications that were developed for a non-exhaustive list of pharmaceutical compounds with the aim to highlights the validation criteria for each application
Development of an analytical method for crystalline content determination in amorphous solid dispersions produced by Hot-Melt Extrusion using transmission Raman spectroscopy: A feasibility study.
The development of a quantitative method determining the crystalline percentage in an amorphous solid dispersion is of great interest in the pharmaceutical field. Indeed, the crystalline Active Pharmaceutical Ingredient transformation into its amorphous state is increasingly used as it enhances the solubility and bioavailability of Biopharmaceutical Classification System class II drugs. One way to produce amorphous solid dispersions is the Hot-Melt Extrusion (HME) process. This study reported the development and the comparison of the analytical performances of two techniques, based on backscattering and transmission Raman spectroscopy, determining the crystalline remaining content in amorphous solid dispersions produced by HME.
Principal Component Analysis (PCA) and Partial Least Squares (PLS) regression were performed on preprocessed data and tended towards the same conclusions: for the backscattering Raman results, the use of the DuoScan™ mode improved the PCA and PLS results, due to a larger analyzed sampling volume. For the transmission Raman results, the determination of low crystalline percentages was possible and the best regression model was obtained using this technique. Indeed, the latter acquired spectra through the whole sample volume, in contrast with the previous surface analyses performed using the backscattering mode. This study consequently highlighted the importance of the analyzed sampling volume.Mycomel
Dosages quantitaifs de principes actifs dans les formes solides par spectroscopie proche infrarouge: Application pratique au test d'uniformité de teneur des comprimés
L'augmentation du nombre de dosages à réaliser dans l'industrie pharmaceutique conduit à rechercher des méthodes alternatives. La spectroscopie proche infrarouge répond précisément à cette demande en permettant des dosages rapides, non destructifs et respectueux de l'environnement. Le texte publié dans SFSTP Pharma Pratiques en 2010 énonçait la méthodologie à suivre pour développer une technique de dosage de substance active dans une formulation solide de type comprimé par spectroscopie proche infrarouge. Il est apparu intéressant d'illustrer et de compléter les différentes étapes de cette méthodologies au travers d'exemples
Measurement of imatinib uptake by flow cytometry.
International audienceOne of the essential parameters of targeted therapy efficiency in cancer treatment is the amount of drug reaching the therapeutic target area. Imatinib (IM) was the first specifically targeted drug to be developed and has revolutionized the treatment of patients with chronic myeloid leukemia (CML). To evaluate cellular uptake of IM, we developed a method based on the chemical structure of the molecule and using the natural UV fluorescence that we quantified by flow cytometry. In two CML cell lines, we obtained a satisfactory relationship between intracellular IM (ICIM) levels and media concentrations, and we found a strong correlation between ICIM at 1 h and IM efficacy at 24 h, demonstrating that ICIM at 1 h might be a relevant predictive parameter of cell sensitivity. Our method was more sensitive than the standard physicochemical method. We applied our method to primary cells and found cell morphology-dependent IM accumulation. Moreover, in CML cells from patients at diagnosis, IM accumulation was heterogeneous. In all cases, ICIM at the single-cell level was much higher than in culture media arguing in favor of a predominantly active uptake process. We developed a simple method directly applicable to primary cells that has shown two major advantages: only a small number of cells are required, and cell subsets can be identified according to morphological criteria and/or the presence of particular antigenic sites. This method provides a new tool to assess CML cell sensitivity to IM, and ICIM levels in native CML cells could be used to monitor therapeutic response