China
Africa
Explore chapters and articles related to this topic
Conjugation and Other Methods in Polymeric Vaccines
Published in Mesut Karahan, Synthetic Peptide Vaccine Models, 2021
Chromatography is the general name of the methods for separating components in complex solutions. Amino acid analysis is used for differentiation of amino acids and peptides, determination of amino acid composition of proteins, analysis of peptide sequences, and diagnosis of diseases belonging to amino acid metabolism. According to this information high performance liquid chromatography (HPLC) is a chromatographic technique that is used to separate, identify, and quantify components of a mixture, for example the separation of chemical compounds or identification of constituents of a biological sample; a typical HPLC system contains a stationary phase, a mobile phase of varying polarity, and an ultraviolet detector (Blum 2014). This technique is commonly used because it is sensitive, easily adaptable to quantitative determinations, non-volatile (suitable for decomposition of heat-degradable compounds), and has applicability with the most commonly used substances (amino acids, peptides, drugs, pesticides) (Mauldin et al. 2006; Fornaguera and Solans 2018) (Figure 7.1).
Marine Natural Products for Human Health Care
Published in Hafiz Ansar Rasul Suleria, Megh R. Goyal, Health Benefits of Secondary Phytocompounds from Plant and Marine Sources, 2021
A wide range of preparative HPLC columns are available. The surface modification of the column packing material determines the kind of interactions between the sample analytes and the stationary phase. For the isolation of secondary metabolites, RP columns are most frequently utilized, because most drug-like compounds can be purified using RP-HPLC [36]. Among the available RP column packing material surface modifications, octadecyl (C18), bonded silica is most widely used. In addition, a wide range of other RP column packing material surface modifications exists like phenyl-hexyl, fluorophenyl, and dihydroxypropane [35]. The isolation process is often initiated by trial and error, where various HPLC columns and elution gradients are tested for their ability to separate the desired compound from the rest of the sample matrix.
Analysis of Essential Oils
Published in K. Hüsnü Can Başer, Gerhard Buchbauer, Handbook of Essential Oils, 2020
Adriana Arigò, Mariosimone Zoccali, Danilo Sciarrone, Peter Q. Tranchida, Paola Dugo, Luigi Mondello
Essential oils generally contain only volatile components, since their preparation is performed by steam distillation. Citrus oils, extracted by cold-pressing machines, are an exception, containing more than 200 volatile and non-volatile components. The non-volatile fraction, constituting 1%–10% of the oil, is represented mainly by hydrocarbons, fatty acids, sterols, carotenoids, waxes, and oxygen heterocyclic compounds (coumarins, psoralens, and polymethoxylated flavones) (Di Giacomo and Mincione, 1994). The latter can have an important role in the identification of a cold-pressed oil and in the control of both quality and authenticity (Di Giacomo and Mincione, 1994; Dugo et al., 1996; Mc Hale and Sheridan, 1989; Mc Hale and Sheridan, 1988), when the information attained by means of GC is not sufficient. The analysis of these compounds is usually performed by means of liquid chromatography (LC), also referred to as high performance liquid chromatography (HPLC), in normal-phase (NP-HPLC) or reversed-phase (RP-HPLC) applications (Dugo and Di Giacomo, 2002).
The Ethanolic Extract of Trichosanthes Kirilowii Root Exerts anti-Cancer Effects in Human Non-Small Cell Lung Cancer Cells Resistant to EGFR TKI
Published in Nutrition and Cancer, 2022
HPLC was performed using an Agilent 1200 series HPLC system (Agilent Technologies, Santa Clara, CA, USA). Cucurbitacin B (ChemFaces, Wuhan, China) and ETK powder were dissolved in methanol at concentrations of 1 mg/mL and 100 μg/mL, respectively, and diluted with acetonitrile at final concentrations of 100 μg/mL and 100 ng/mL, respectively. The solutions were separated using an InfinityLab Poroshell 120 EC C18 column (100 × 2.1 mm, 2.7 μm) with solvent A (0.1% formic acid, 5 mM ammonium formate in distilled water) and solvent B (0.1% formic acid, 5 mM ammonium formate in methanol). The mobile phases for HPLC were as follows: 90% solvent A and 10% solvent B for 3 min initially, followed by 5% solvent A and 95% solvent B for 4.5 min, and 90% solvent A and 10% solvent B for 2.5 min. The column temperature was 25 °C, and the flow rate was 0.3 mL/min. Electrospray ionization (ESI) mass spectra were recorded in the positive ion mode using Agilent 6410 Triple Quad LC/MS system (Agilent Technologies).
Assessment of vaping devices as an alternative respiratory drug delivery system
Published in Drug Development and Industrial Pharmacy, 2022
Zaid Khaled, Eman Zmaily Dahmash, Jasdip Koner, Raad Al Ani, Hamad Alyami, Abdallah Y. Naser
Fluticasone propionate stock solution was made from 10 mg of FP in 100 ml of acetonitrile (100 µg/ml). The HPLC method was employed for the quantitative analysis of fluticasone propanoate in the solution. The Dionex soften HPLC system from Thermo Fisher Scientific Inc. (Waltham, MA), with a gradient pump UV detector set at 256 nm using 5 μm Fortis C-18 analysis column (250 × 4.6 mm) was used. The method was developed using a mobile phase consisting of 60% acetonitrile and 40% DW. The pump flow rate was 1 ml/min with a sample injection volume of 10 μl and run time of 10 min. Validation of the two methods was done according to ICH guidelines in terms of specificity, accuracy, precision, linearity and limits of detection and LOQ [19]. To investigate the specificity of the HPLC method, 50 µl each of the stock solution (FP 100 µg/ml), and mobile phase as a blank were separately injected to the HPLC and chromatograms developed.
Individualized precision dosing approaches to optimize antimicrobial therapy in pediatric populations
Published in Expert Review of Clinical Pharmacology, 2021
Quyen Tu, Menino Cotta, Sainath Raman, Nicolette Graham, Luregn Schlapbach, Jason A Roberts
In principle, the steps involved in dosing optimization for any medicine include (1) developing a population PK model for the medicine of interest (2), incorporating the model into a Bayesian forecasting software (3), defining the PK-PD targets correlating with clinical outcomes (4), validating the model externally, and finally (5) implementing the MIPD software in the clinical setting. There are, however, barriers to streamlining this process. For example, routine measurement of plasma drug concentrations is not widely accessible for many medicines. Consequently, quantifying drug exposure remains challenging. Technological advancements in high performance liquid chromatography (HPLC) and other analytic techniques may help circumvent accessibility issues, particularly in those facilities with limited resources. Yet, aligning drug exposure with patient outcomes so as to define clinical PK-PD targets represents a great hurdle. Continued collaboration between researchers and clinicians will be essential to overcome these obstacles.