Oleanolic acid (OA) and ursolic acid (UA) are isomeric triterpenic acids and only one methyl's position is different between them. OA and UA always exist in the same plant, so it is difficult to separate them when determining contents by RP-HPLC. In this study, a very simple mobile phase for HPLC was developed to simultaneously determine UA and OA, and the factors affecting separation were also discussed. The mobile phase is methanol: water (95:5) with flow rate 0.4 mL/min. The retention time for OA and UA was 20.58 and 21.57 min, respectively, the resolution was 1.61. The average contents of OA and UA of three Loquat leaves sets were 1.4 mg/g and 5.6 mg/g, respectively. Regarding the HPLC, we found that changing mobile phase, adjusting the pH value or adding ion-pairing agent could not affect the separation between UA and OA greatly. While adjustment of the flow rate and column temperature could improve the resolution greatly.
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http://dx.doi.org/10.1016/j.jpha.2012.01.006 | DOI Listing |
Sci Rep
January 2025
Pharmaceutical Chemistry Department, Faculty of Pharmacy, Horus University, New Damietta, 34517, Egypt.
RP-HPLC technique was developed and optimized for simultaneous identification and estimation of nirmatrelvir (NIR) and ritonavir (RIT) in their new copackaged tablet. Stability of nirmatrelvir (NIR) was studied after exposure to different five stress conditions; alkali, acid, heat, photo and oxidation degradation. The chromatographic separation was achieved using VDSpher PUR 100 ODS (4.
View Article and Find Full Text PDFJ Dairy Sci
January 2025
Department of Food Science, College of Agriculture and Veterinary Medicine, United Arab Emirates University (UAEU), Al Ain, 15551, United Arab Emirates. Electronic address:
The increased use of dairy fat in various applications is facilitated by its fractionation into hard and liquid fractions. Herein, the fractionation of bovine ghee and buffalo ghee was investigated, and triacylglycerol (TAG) profiles of milk fat fractions and 2 categories of infant formulas fat were quantified by using ultra-performance convergence chromatography quadrupole time-of-flight mass spectrometry (UPC-Q-TOF-MS) using carbon dioxide as the mobile phase. Furthermore, the thermal behavior of the different samples was evaluated, and tocopherols content was also quantified.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
January 2025
School of Pharmacy, Lanzhou University, Lanzhou 730030 China; Department of Pharmacy, The Second Hospital & Clinical Medical School, Lanzhou University, Lanzhou 730030 China. Electronic address:
Objective: To develop a rapid, convenient, accurate, and low-residual-effect ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the determination of polymyxin B sulfate and colistin sulfate in the blood of patients with multidrug-resistant bacterial infections, as well as caspofungin acetate in the blood of patients with fungal infections, thus facilitating the rational use of antibiotics in clinical applications.
Methods: All analytes were diluted with 0.2 % aqueous formic acid, and plasma proteins were precipitated using acetonitrile.
Am J Transl Res
December 2024
Department of Pharmacy, The Fourth Hospital of Hebei Medical University Shijiazhuang 050000, Hebei, China.
Objectives: The aim of this study was to establish an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the detection of osimertinib in rat plasma, lung and brain tissues.
Methods: Forty-eight rats were randomly divided into an experimental group (receiving osimertinib at doses of 5, 8, and 10 mg/kg) and a control group. After continuous intragastric administration for 15 days, samples of blood, lung, and brain tissue were collected.
Anal Methods
January 2025
Analytical Chemistry Department, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt.
Hypertension and dyslipidemia are two of the most frequently co-occurring cardiovascular risk factors. The combined regimen of hydrochlorothiazide (HCTZ), rosuvastatin (ROS), and losartan (LOS) helped in the successful management of both conditions. This work's objective is to develop an eco-friendly, sensitive, simple, and reliable chromatographic method for the simultaneous estimation of HCTZ, ROS, and the LOS ternary mixture in their pure form, and pharmaceutical formulations.
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