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Traditional Analytical Methods (traditional + analytical_methods)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

Assessing the longitudinal course of depression and economic integration of south-east Asian refugees: an application of latent growth curve analysis

INTERNATIONAL JOURNAL OF METHODS IN PSYCHIATRIC RESEARCH, Issue 4 2002
K.A.S. Wickrama
Abstract This paper has both methodological and substantive application for mental-health researchers. Methodologically, it presents the latent growth curve (LGC) technique within a structural equation modelling (SEM) framework as a powerful tool to analyse change in depressive symptoms and potential correlates of such changes. The rationale for LGC analysis and subsequent elaboration of this statistical approach are presented. The limitations of traditional analytical methods are also addressed. Substantively, the paper considers socio-contextual factors as correlates of change in symptoms, and examines the dynamic systematic relationship with the degree of economic integration of south-east Asian immigrants in Canada over time. Using the LGC technique, this study also investigated how the longitudinal course of sub-clinical depression places individuals at risk for developing full-blown major depression. The LGC results provided strong evidence for the reciprocal influence between economic integration and subclinical depression of immigrants. The initial level of economic integration negatively influenced the rate of change in subclinical depression whereas the initial level of sub-clinical depression negatively influenced the rate of change in economic integration. Both initial level and the rate of change in subclinical depression placed individuals at risk for full-blown major depression. However, traditional auto-regressive models were not capable of revealing these dynamic associations. Thus, an investigation of within-individual change in symptoms and potential correlates of such changes is necessary to understand the process that results in full-blown mental disorder. Copyright © 2002 Whurr Publishers Ltd. [source]

Near infrared spectroscopy in the development of solid dosage forms

JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 2 2007
Eetu Räsänen
The use of near infrared (NIR) spectroscopy has rapidly grown partly due to demands of process analytical applications in the pharmaceutical industry. Furthermore, newest regulatory guidelines have advanced the increase of the use of NIR technologies. The non-destructive and non-invasive nature of measurements makes NIR a powerful tool in characterization of pharmaceutical solids. These benefits among others often make NIR advantageous over traditional analytical methods. However, in addition to NIR, a wide variety of other tools are naturally also available for analysis in pharmaceutical development and manufacturing, and those can often be more suitable for a given application. The versatility and rapidness of NIR will ensure its contribution to increased process understanding, better process control and improved quality of drug products. This review concentrates on the use of NIR spectroscopy from a process research perspective and highlights recent applications in the field. [source]

Rapid detection and characterization of reactive drug metabolites in vitro using several isotope-labeled trapping agents and ultra-performance liquid chromatography/time-of-flight mass spectrometry

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 6 2009
Timo Rousu
Reactive metabolites are believed to be one of the main reasons for unexpected drug-induced toxicity issues, by forming covalent adducts with cell proteins or DNA. Due to their high reactivity and short lifespan they are not directly detected by traditional analytical methods, but are most traditionally analyzed by liquid chromatography/tandem mass spectrometry (LC/MS/MS) after chemical trapping with nucleophilic agents such as glutathione. Here, a simple but very efficient assay was built up for screening reactive drug metabolites, utilizing stable isotope labeled glutathione, potassium cyanide and semicarbazide as trapping agents and highly sensitive ultra-performance liquid chromatography/time-of-flight mass spectrometry (UPLC/TOFMS) as an analytical tool. A group of twelve structurally different compounds was used as a test set, and a large number of trapped metabolites were detected for most of them, including many conjugates not reported previously. Glutathione-trapped metabolites were detected for nine of the twelve test compounds, whereas cyanide-trapped metabolites were found for eight and semicarbazide-trapped for three test compounds. The high mass accuracy of TOFMS provided unambiguous identification of change in molecular formula by formation of a reactive metabolite. In addition, use of a mass defect filter was found to be a usable tool when mining the trapped conjugates from the acquired data. The approach was shown to provide superior detection sensitivity in comparison to traditional methods based on neutral loss or precursor ion scanning with a triple quadrupole mass spectrometer, and clearly more efficient detection and characterization of reactive drug metabolites with a simpler test setup. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Product and contaminant measurement in bioprocess development by SELDI-MS

BIOTECHNOLOGY PROGRESS, Issue 3 2010
Alex Berrill
Abstract Bioprocesses for therapeutic protein production typically require significant resources to be invested in their development. Underlying these efforts are analytical methods, which must be fit for the purpose of monitoring product and contaminants in the process. It is highly desirable, especially in early-phase development when material and established analytical methods are limiting, to be able to determine what happens to the product and impurities at each process step with small sample volumes in a rapid and readily performed manner. This study evaluates the utility of surface-enhanced laser desorption ionization mass spectroscopy (SELDI-MS), known for its rapid analysis and minimal sample volumes, as an analytical process development tool. In-process samples from an E. coli process for apolipoprotein A-IM (ApoA-IM) manufacture were used along with traditional analytical methods such as HPLC to check the SELDI-MS results. ApoA-IM is a naturally occurring variant of ApoA-I that appears to confer protection against cardiovascular disease to those that carry the mutated gene. The results show that, unlike many other analytical methods, SELDI-MS can handle early process samples that contain complex mixtures of biological molecules with limited sample pretreatment and thereby provide meaningful process-relevant information. At present, this technique seems most suited to early-phase development particularly when methods for traditional analytical approaches are still being established. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source]