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Facts about Standardization of Herbal Medicines
Published in Rohit Dutt, Anil K. Sharma, Raj K. Keservani, Vandana Garg, Promising Drug Molecules of Natural Origin, 2020
Vandana Garg, Ghazala Zia, Mahima Chauhan, Rohit Dutt
Liquid Chromatography-Mass Spectroscopy: (LC-MS) LC-MS is a useful tool in drug development and detection of sensitivity and specificity. Laser mass spectroscopy with 600 MHz is the best instrument for the determination of molecular weight peptides, proteins, and isotopes pattern (Zhang et al., 2009). For separation and structural elucidation of unknown compounds, mixtures, light, and oxygen-sensitive substances, the combination of liquid chromatography with NMR spectroscopy is one of the most powerful and time-saving methods. Supercritical fluid extraction is the most advanced technology in which compressed carbon dioxide gas-liquid is used. The main advantage of using SCFE is less amount of plant material is required but it is very expensive. Supercritical fluid chromatography is a fusion of gas and liquid chromatography. This technique is used for the analysis of nonvolatile and thermolabile compounds where other analytical techniques are not applicable (Pandey et al., 2014).
Supercritical Fluid Chromatography
Published in Steven H. Y. Wong, Iraving Sunshine, Handbook of Analytical Therapeutic Drug Monitoring and Toxicology, 2017
Klesper et al.17 demonstrated the first SFC analysis of porphyrins by using SF freon. From the investigation of the separation modes of SFC and pressure programming, Sie et al.18 proposed the term supercritical fluid chromatography. Giddings et al.19,20 and Gouw and Jentoft21 studied the fundamentals of the SFC processes. Gere et al.13 were credited with the modification of an existing HPLC to perform SFC in the early 1980s, whereas Novotny et al.22 and Lee and Markides23 demonstrated the initial application of capillary SFC.
High-Performance Liquid Chromatography
Published in Joseph Chamberlain, The Analysis of Drugs in Biological Fluids, 2018
Everyday experience with compounds that can exist as gases, liquids, or solids suggests that heating a solid (for example, ice) converts it to a liquid (water) and then to a gas (water-vapor). However, the state of the compound depends not only on the temperature, but also on the pressure; carbon dioxide as dry ice will convert straight to the gaseous form without becoming a liquid because the ambient pressures are below the so-called critical pressure. If the pressure is increased, then carbon dioxide can also exist as a liquid; this is the supercritical fluid state of the compound. The properties of the supercritical fluid, including its ability to dissolve other compounds, can be modified by varying the temperature and pressure. Supercritical fluids have wide application in industry as extractants, one of the great advantages of using supercritical carbon dioxide is that the solvent can be readily removed at room temperature and pressure. This property has also been utilized to prepare blood samples for the trace analysis of flavone,859 with subsequent HPLC analysis. The use of supercritical fluids as chromatographic mobile phases was first described by Klesper et al.,860 but was little developed until 1981, when Novotny et al.861 described the use of supercritical fluids in capillary chromatography. The apparent use of liquid chromatography principles using a piece of equipment that is a mainstay of the more advanced gas chromatography neatly sums up the position of supercritical fluid chromatography between the two types of fluid chromatography. Recent developments in the technique have run in parallel with developments in HPLC and gas chromatography and have made use of improvements in solvent modifiers, equipment design, and linking the technique with diverse detection methods. This ability of supercritical fluid chromatography to borrow from the older types of chromatography was demonstrated by Roberts and Wilson.862Table 7.10 summarizes some recent publications that demonstrate the same point.
The dark side of lipid metabolism in prostate and renal carcinoma: novel insights into molecular diagnostic and biomarker discovery
Published in Expert Review of Molecular Diagnostics, 2023
Nicola Antonio di Meo, Francesco Lasorsa, Monica Rutigliano, Martina Milella, Matteo Ferro, Michele Battaglia, Pasquale Ditonno, Giuseppe Lucarelli
In order to determine whether patients with breast cancer, RCC, and PCa had a different lipidomic profile from healthy controls, Wolrab et al. [198] collected human plasma samples from these patients in 2021. By combining MS with ultrahigh-performance supercritical fluid chromatography (UHPSFC), they carried out a lipidomic analysis of human plasma. Multiple discriminant analyses identified the use of lipidomics as a diagnostic tool for all three cancer types under study. High sensitivity, specificity, and accuracy were hallmarks of classification model performance in cancer prediction. While variations in sphingolipid and glycerophospholipid profiles are more prominent in breast and PCa, nonpolar lipids such cholesteryl esters and triacylglycerols are more significant for kidney cancer. Only a minor reduction in sensitivity, specificity, and accuracy was seen when the amount of measured lipid species utilized for MDA was decreased. Yet, a prospective clinical application may be made easier by the method’s reduced complexity as compared to the whole lipidomic profiling.
New designs for HIV-1 integrase inhibitors: a patent review (2018-present)
Published in Expert Opinion on Therapeutic Patents, 2023
Yoshiyuki Taoda, Shuichi Sugiyama, Takahiro Seki
In 2018, a patent application WO2018102485A1 was published claiming a tetracyclic scaffold (Formula A) in which a five-membered ring was added to the DTG-like tricyclic scaffold (Figure 2) [51]. Enantiomers 1 and 2 were separated using supercritical fluid chromatography (SFC) at an intermediate stage. The anti-HIV-1 (NL4-3 strain) activity of the compounds was determined in MT4-GFP cells and the IP50 values (the values of 50% inhibitory potency) in the absence and presence of 100% normal human serum (NHS). Although the activity at 0% NHS is nearly identical, there is a 100-fold difference in the IP50 values with 100% NHS, suggesting that binding to proteins in human serum differs greatly between the enantiomers. Fragment X is claimed to be a five- or six-membered monocyclic heteroaryl group other than a carbamoyl group, with a thiadiazolyl group being a specific example (3). For compound 1, the patent application WO2022177840A1 in 2022 describes the structure of a prodrug (Formula B) in which the chelate moiety is alkylated [52]. The results of dog pharmacokinetic studies of these compounds were disclosed, in which fasted male beagle dogs were orally dosed with suspensions equivalent to 10 mg/kg and 25 mg/kg of the parent compound, and blood drug levels were monitored up to 168 hours after dosing. Prodrugs 4 and 5 show increase in absorption versus their metabolite, compound 1.
Validated specific HPLC-DAD method for simultaneous estimation of paracetamol and chlorzoxazone in the presence of five of their degradation products and toxic impurities
Published in Drug Development and Industrial Pharmacy, 2020
Amira F. El-Yazbi, Karin M. Guirguis, Mona M. Bedair, Tarek S. Belal
Combination therapy is commonly used for management of different musculoskeletal painful conditions. PAR, non-steroidal anti-inflammatory drugs, opioid analgesics, and skeletal muscle relaxants are the main ingredients used in these combination therapies. The binary combination of PAR and CZ gained lots of attention and focus. Analysis of this mixture was reported using various techniques such as: chemometric spectrophotometry [32–34], RP-HPLC [35–39], LC-MS/MS [40], packed-column supercritical fluid chromatography (SFC) [41], and HPTLC [42]. In addition, few more specific methods were described dealing with the active ingredients together with the impurities. Simultaneous determination of PAR, CZ, and the related impurities AP, CA, and p-chlorophenol were carried out using HPLC [43]. A stability-indicating TLC-densitometric method for simultaneous determination of PAR, CZ, and their toxic impurities AP and ACP was published [44]. Finally, traditional partial least squares (PLS) and advanced artificial neural network (ANN) models were applied for the spectrophotometric determination of both drugs together with their process-related impurities AP, NP, CA, ACP, and 4-chlorophenol [45].