September 30th 2024
Universidad Católica del Maul scientists reviewed advancements made in using machine learning and MALDI-TOF-MS for predicting antimicrobial resistance in different materials.
Approaches to Singleton Achiral Purification of Difficult Samples for Discovery Research Support
April 1st 2009Several approaches for purifying difficult samples more efficiently for discovery research support are mentioned in this paper. These approaches use mass triggered HPLC on various specialty columns.
A Quality-by-Design Methodology for Rapid LC Method Development, Part II
January 1st 2009This second part of the series describes the data loss inherent in most early method development experiments due to coelution, peak exchange, and the general difficulty of accurately identifying peaks across the experiment trial chromatograms.
A Quality-by-Design Methodology for Rapid LC Method Development, Part I
December 1st 2008This installation of "Validation Viewpoint" describes how statistically rigorous quality-by-design (QbD) principles can be put into practice to accelerate each phase of liquid chromatography (LC) instrument method development.
Analytical Method Validation in Proteomics and Peptidomics Studies
November 1st 2008While the "Validation Viewpoint" column has focused on conventional and recombinant pharmaceutical products, and at times, bioanalytical methods, we have just begun to think about method validation as it relates to -omics type studies.
The Role of Polymers in Solid-Phase Extraction and Sample Preparation
November 1st 2008This installment of SPP will compare and contrast the various types of polymeric and non-polymeric sorbents. The major advantages or polymeric sorbents will be discussed, and some applications will illustrate the versatility of polymeric SPE.
Ultra-Fast Separations of Pharmaceutical Compounds with 10 mm Columns Packed with Sub-2 µm Particles
October 1st 2008Very short columns filled with 1.9 µm particles were evaluated for the ultra-fast analysis of pharmaceutical formulations. Local anæsthetic, mydriatic and anti-hypertensive agents were chosen as analytes and a method was developed and validated for each of these substances, according to ICH guidelines. Excellent quantitative performance was obtained using an optimized chromatographic system that reduces the importance of extra-column effects and cuts the analysis time to less than 15 s.
Synthesis and Structural Elucidation of Impurities in Ramipril Tablets
July 1st 2008Ramipril impurities D and E are well-known degradation products of ramipril in the finished dosage form. A significant amount of an additional impurity was detected in ramipril tablets by an isocratic reversed-phase high performance liquid chromatography (HPLC) method on a short column. The structure of this impurity was proposed based on liquid chromatography–mass spectrometry (LC–MS) data using an electron spray ionization source. Structural elucidation using nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy was facilitated by a newly developed preparative isolation method. This impurity was characterized as (2R,3aR,6aR)-1-[(R)-2-[[(R)-1-(ethoxycarbonyl)-3-phenylpropyl]amino]propanoyl]octahydrocyclopenta[b]pyrrole-2-carboxylic acid (impurity L). Its identification, synthesis and characterization are discussed.
A Hydrophilic Interaction Chromatography Method for the Purity Analysis of Cytosine
July 1st 2008The authors meet the need for a method for the determination of cytosine purity by developing a hydrophilic interaction chromatography (HILIC) method with demonstrated advantages in comparison to other separation techniques.
Inside the Personalized Medicine Toolbox: GCxGC-Mass Spectrometry for High-Throughput Profiling...
The authors present results that suggest that high-throughput, high-coverage profiling capabilities, such as those afforded by GCxGC-TOF-MS, can impact the development of personalized medicine.
Analysis of Pharmaceutical Residual Solvents Using Comprehensive Two-Dimensional Gas Chromatograhy
January 1st 2008Comprehensive GCxGC was employed for the separation of ICH and USP 1, 2, and 3 pharmaceutical solvents. The significantly improved peak capacity in GCxGC allows a single method for any combination of solvents and mitigates interference due to impurities in the solvents, diluents, analyte matrices, and from column or septum bleed, through the increased separation space.
Impurity Determinations for Biotechnology-Derived Biopharmaceuticals and Related Products
December 1st 2007This installment of "Validation Viewpoint" column addresses, in the hopes of clarifying what the biopharmaceutical industry is required to do today to identify and quantify impurities in their biotech, proteinaceous products.
Immunosorbents for Selective Sample Preparation of Complex Mixtures
December 1st 2007In this month?s installment, columnist Ron Majors covers the field of immunoextraction, a technique that employs immobilized antibodies to selectively capture specific analytes using molecular recognition via antibody?antigen interactions. Recently, the introduction of commercial products for specific high-volume environmental and food safety applications has spurred further applications of this technique.
A Strategy for Developing HPLC Methods for Chiral Drugs
November 1st 2007Basic information on stereochemistry is provided in this article to help readers develop a better understanding of the separation mechanisms that come into play in various separation methods used for chiral compounds. This knowledge can allow readers to select a desirable chiral separation method, based upon the molecular structure of the chiral compound of interest. Logical reasons for the selection process are discussed later in this article.
Development and Validation of a UHPLC Method for Paroxetine Hydrochloride
October 1st 2007An ultrahigh-pressure liquid chromatography (UHPLC) method was developed to separate paroxetine from several of its related compounds using a systematic screening protocol that monitors combinations of selectivity factors including column chemistry, organic modifier, and pH. When the best combination of these factors was selected, the method was optimized by varying gradient slope and temperature.