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1.
PLoS One ; 16(11): e0258591, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34762660

RESUMEN

Business interaction is important for innovation performance but may be challenging in cross-border regions. The objective of this research was to investigate the relation between factors that define cross-border business interaction and innovativeness. From the cross-border regional innovation systems literature, we operationalized thirty-five factors which potentially influence cross-border business interaction; these factors concern availability of science and knowledge bases, socio-cultural proximity, accessibility, institutional set-up, and governance. We conducted a survey focusing on these factors and analyzed the data using Cronbach's alpha and linear regression. The cross-border interaction factors identified in the survey results served as independent variables and the differences in innovativeness levels in different European cross-border regions served as our dependent variable. This study confirmed that differences in innovativeness levels between countries can be related to factors hindering cross-border business interaction.


Asunto(s)
Comercio , Creatividad , Cultura , Europa (Continente) , Geografía , Humanos , Estándares de Referencia , Análisis de Regresión , Encuestas y Cuestionarios
2.
J Pharm Biomed Anal ; 134: 122-129, 2017 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-27907854

RESUMEN

In order to ensure the stability of pharmaceutical products appropriate manufacturing and storage conditions are required. In general, the degradation of active pharmaceutical ingredients (APIs) and subsequent formation of degradation products affect the pharmaceutical quality. Thus, a fast and effective detection and characterization of these substances is mandatory. Here, the applicability of Raman spectroscopy and CZE for the characterization of the degradation of effervescent tablets containing acetylsalicylic acid (ASA) and ascorbic acid (AA) was evaluated. Therefore, a degradation study was performed analyzing tablets from two different manufacturers at varying conditions (relative humidity (RH) 33%, 52% and 75% at 30°C). Raman spectroscopy combined with principal component analysis could be successfully applied for the fast and easy discrimination of non-degraded and degraded effervescent tablets after a storage period of approximately 24h (RH 52%). Nevertheless, a clear identification or quantification of APIs and degradation products within the analyzed tablets was not possible, i.a. due to missing reference materials. CZE-UV enabled the quantification of the APIs (ASA, AA) and related degradation products (salicylic acid (SA); semi-quantitative also mono- and diacetylated AA) within the complex tablet mixtures. The higher the RH, the faster the degradation of ASA and AA as well as the formation of the degradation products. Mono- and diacetylated AA are major primary degradation products of AA for the applied effervescent tablets. A significant degradation of the APIs was detected earlier by CZE (6-12h, RH 52%) than by Raman spectroscopy. Summarized, Raman spectroscopy is well-suited as quick test to detect degradation of these tablets and CZE can be utilized for further detailed characterization and quantification of specific APIs and related degradation products.


Asunto(s)
Ácido Ascórbico/análisis , Aspirina/análisis , Espectrometría Raman/métodos , Ácido Ascórbico/química , Aspirina/química , Electroforesis Capilar/métodos , Electroforesis Capilar/normas , Excipientes/análisis , Excipientes/química , Espectrometría Raman/normas , Comprimidos
3.
Anal Bioanal Chem ; 408(30): 8701-8712, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27405873

RESUMEN

Capillary electrophoresis is commonly applied for the analysis of pharmaceutical products due to its high separation efficiency and selectivity. For this purpose, electrospray-ionization-(ESI)-interfering additives or electrolytes are often required, which complicates the identification of impurities and degradation products by mass spectrometry (MS). Here, a capillary zone electrophoresis (CZE) method with ultraviolet (UV) absorption detection for the simultaneous determination and quantification of ascorbic acid and acetylsalicylic acid in effervescent tablets was developed. Related degradation products were identified via CZE-CZE-MS. Systematic optimization yielded 100 mM tricine (pH = 8.8) as appropriate background electrolyte, resulting in baseline separation of ascorbic acid, acetylsalicylic acid, and related anionic UV-active degradation products. The CZE-UV method was successfully validated regarding the guidelines of the Food and Drug Administration. The validated method was applied to trace the degradation rate of the active pharmaceutical ingredients at defined ambient conditions. A heart-cut CZE-CZE-MS approach, including a 4-port-nL-valve, was performed for the identification of the observed degradation products. This 2D setup enables a precise cutting of accurate sample volumes (20 nL) and the independent operation of two physically separated CZE dimensions, which is especially beneficial regarding MS detection. Hence, the ESI-interfering tricine electrolyte components were separated from the analytes in a second electrophoretic dimension prior to ESI-MS detection. The degradation products were identified as salicylic acid and mono- and diacetylated ascorbic acid. This setup is expected to be generally applicable for the mass spectrometric characterization of CZE separated analytes in highly ESI-interfering electrolyte systems. Graphical Abstract A CZE-UV method for the quantification of effervescent tablet ingredients and degradation products was developed and validated. In order to identify unknown degradation products separated in the CZE-UV, a 2D heart-cut approach was performed applying a mechanical 4-port-valve. The unknown substances were transferred from the 1st to the 2nd dimension followed by the separation of ESI-interfering tricine from the analytes prior to mass spectrometric detection.


Asunto(s)
Ácido Ascórbico/aislamiento & purificación , Aspirina/aislamiento & purificación , Electroforesis Capilar/métodos , Espectrometría de Masa por Ionización de Electrospray/métodos , Espectrofotometría Ultravioleta/métodos , Ácido Ascórbico/química , Aspirina/química , Tampones (Química) , Glicina/análogos & derivados , Glicina/química , Guías como Asunto , Comprimidos , Estados Unidos , United States Food and Drug Administration
4.
Methods Mol Biol ; 1466: 43-56, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27473480

RESUMEN

Capillary electrophoresis (CE) has been shown to be a suitable separation technique for complex samples. Combined with electrospray ionization-mass spectrometry (ESI-MS), it is a powerful tool offering the opportunity of high selectivity and sensitivity combined with the possibility to identify and characterize intact proteins. In this protocol, we demonstrate a screening method for intact proteins based on capillary zone electrophoresis (CZE) separation coupled with online mass spectrometric detection. In order to avoid protein-wall interactions, a neutral coated capillary is used to create a universal method for proteins with both low and high electrophoretic mobilities. In addition, we show the successful validation and application of this screening method for a set of eight standard proteins and the glycoprotein erythropoietin.


Asunto(s)
Electroforesis Capilar/métodos , Eritropoyetina/aislamiento & purificación , Espectrometría de Masa por Ionización de Electrospray/métodos , Materiales Biocompatibles Revestidos , Humanos , Proteínas Recombinantes/aislamiento & purificación
5.
J Pharm Biomed Anal ; 112: 70-8, 2015 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-25956227

RESUMEN

In the last decade, counterfeit pharmaceutical products have become a widespread issue for public health. Raman spectroscopy which is easy, non-destructive and information-rich is particularly suitable as screening method for fast characterization of chemicals and pharmaceuticals. Combined with chemometric techniques, it provides a powerful tool for the analysis and determination of counterfeit medicines. Here, for the first time, a systematic study of the benefits and limitations of Raman spectroscopy for the analysis of pharmaceutical samples on a large set of model tablets, varying with respect to chemical and physical properties, was performed. To discriminate between the different mixtures, a combination of dispersive Raman spectroscopy performing in backscattering mode and principal component analysis was used. The discrimination between samples with different coatings, a varying amount of active pharmaceutical ingredients and a diversity of excipients were possible. However, it was not possible to distinguish between variations of the press power, mixing quality and granulation. As a showcase, the change in Raman signals of commercial acetylsalicylic acid effervescent tablets due to five different storage conditions was monitored. It was possible to detect early small chemical changes caused by inappropriate storage conditions. These results demonstrate that Raman spectroscopy combined with multivariate data analysis provides a powerful methodology for the fast and easy characterization of genuine and counterfeit medicines.


Asunto(s)
Medicamentos Falsificados/análisis , Medicamentos Falsificados/química , Comprimidos/análisis , Comprimidos/química , Aspirina/química , Excipientes/química , Análisis Multivariante , Análisis de Componente Principal/métodos , Espectrometría Raman/métodos
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