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DAPB, a new molecule including danshensu, borneol, and a mother nucleus of ACEI (Angiotensin-converting enzyme inhibitors), is being developed as an antihypertensive candidate compound. A rapid, accurate, and sensitive ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method was established and validated for the determination of DAPB in rat plasma. Chromatographic separation was performed on an Agilent SB-C18 column after protein precipitation by acetonitrile with a mobile phase consisting of acetonitrile and deionized water with 0.02% formic acid and 5 mM NH4F (v/v) at a flow rate of 0.2 mL/min. Quantification was performed using electrospray positive ionization mass spectrometry in the multiple reaction monitoring (MRM) mode. The method was linear over the range of 2–1000 ng/mL. The intra- and inter-day precision was within 12%, with accuracies less than 7%. Stability was within the acceptable limits under various storage and processing conditions. No apparent matrix effect was detected. The validated method was applied to the pre-clinical pharmacokinetic study of DAPB after oral administration of 30 mg/kg and intravenous administration of 6 mg/kg in rats. [ABSTRACT FROM AUTHOR]

Leuprolide is a synthetic nonapeptide drug (pyroGlu-His-Trp-Ser-Tyr-d-Leu-Leu-Arg-Pro-NHEt) that acts as a gonadotropin-releasing hormone agonist. The continuous administration of therapeutic doses of leuprolide inhibits gonadotropin secretion, which is used in androgen-deprivation therapy for the treatment of advanced prostate cancer, central precocious puberty, endometriosis, uterine fibroids, and other sex-hormone-related conditions. To improve the pharmacokinetic properties of peptide drugs, a fatty acid was conjugated with leuprolide for long-term action. In this study, we developed a simple ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the simultaneous determination of leuprolide and leuprolide–oleic acid conjugate (LOC) levels. The developed method was validated in terms of linearity, precision, accuracy, recovery, matrix effect, and stability according to the US Food and Drug Administration guidelines, and the parameters were within acceptable limits. Subsequently, the pharmacokinetics of leuprolide and LOCs were evaluated. In vivo rat subcutaneous studies revealed that conjugation with fatty acids significantly altered the pharmacokinetics of leuprolide. After the subcutaneous administration of fatty-acid-conjugated leuprolide, the mean absorption time and half-life were prolonged. To the best of our knowledge, this is the first study showing the effects of fatty acid conjugates on the pharmacokinetics of leuprolide using a newly developed UPLC-MS/MS method for the simultaneous quantification of leuprolide and LOCs. [ABSTRACT FROM AUTHOR]

Traditional Chinese medicine considers Lonicerae japonicae flos to have antibacterial detoxification, liver protection, and gallbladder protection. At present, studies have proven that Lonicerae japonicae flos has a good therapeutic effect on liver injury. Therefore, to confirm the clinical applicability of Lonicerae japonicae flos in the treatment of liver injury, we were the first to compare the pharmacokinetics of an oral ethanol extract of Lonicerae japonicae flos in normal rats and carbon tetrachloride-induced liver injury model rats. A method was developed for the simultaneous determination of 3-caffeoylquinic acid, 4-caffeoylquinic acid, 5-caffeoylquinic acid, 3,5-dicaffeoylquinic acid, 4,5-dicaffeoylquinic acid, protocatechuic acid, Sweroside, and Secoxyloganin in rat plasma by ultra-performance liquid chromatography tandem mass spectrometry. The results show that the method is reliable and reproducible and can be used for quantitative determination of biological samples. The pharmacokinetic parameters showed that the area under the concentration–time curve of eight compounds in the model group was significantly increased. The results showed that the total absorption of the active components of Lonicerae japonicae flos in the blood increased, the clearance rate slowed down, and the bioavailability of Lonicerae japonicae flos increased in liver injury diseases. [ABSTRACT FROM AUTHOR]

Sorafenib (SOR), an inhibitor of multiple kinases, is a classic targeted drug for advanced hepatocellular carcinoma (HCC) which often coexists with type 2 diabetes mellitus (T2DM). Dapagliflozin (DAPA), a sodium–glucose cotransporter-2 inhibitor (SGLT2i), is widely used in patients with T2DM. Notably, co-administration of SOR with DAPA is common in clinical settings. Uridine diphosphate-glucuronosyltransferase family 1 member A9 (UGT1A9) is involved in the metabolism of SOR and dapagliflozin (DAPA), and SOR is the inhibitor of UGT1A1 and UGT1A9 (in vitro). Therefore, changes in UGT1A9 activity caused by SOR may lead to pharmacokinetic interactions between the two drugs. The objective of the current study was to develop an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the simultaneous determination of SOR and DAPA in plasma and to evaluate the effect of the co-administration of SOR and DAPA on their individual pharmacokinetic properties and the mechanism involved. The rats were divided into four groups: SOR (100 mg/kg) alone and co-administered with DAPA (1 mg/kg) for seven days, and DAPA (1 mg/kg) alone and co-administered with SOR (100 mg/kg) for seven days. Liquid–liquid extraction (LLE) was performed for plasma sample preparation, and the chromatographic separation was conducted on Waters XSelect HSS T3 column with a gradient elution of 0.1% formic acid and 5 mM ammonium acetate (Phase A) and acetonitrile (Phase B). The levels of Ugt1a7 messenger RNA (mRNA) were determined in rat liver and intestine using quantitative real-time polymerase chain reaction (qRT-PCR). The method was successfully applied to the study of pharmacokinetic interactions. DAPA caused a significant decrease in the maximum plasma concentrations (Cmax) and the area under the plasma concentration–time curves (AUC0–t) of SOR by 41.6% and 50.5%, respectively, while the apparent volume of distribution (Vz/F) and apparent clearance (CLz/F) significantly increased 2.85- and 1.98-fold, respectively. When co-administering DAPA with SOR, the AUC0–t and the elimination half-life (t1/2Z) of DAPA significantly increased 1.66- and 1.80-fold, respectively, whereas the CLz/F significantly decreased by 40%. Results from qRT-PCR showed that, compared with control, seven days of SOR pretreatment decreased Ugt1a7 expression in both liver and intestine tissue. In contrast, seven days of DAPA pretreatment decreased Ugt1a7 expression only in liver tissue. Therefore, pharmacokinetic interactions exist between long-term use of SOR with DAPA, and UGT1A9 may be the targets mediating the interaction. Active surveillance for the treatment outcomes and adverse reactions are required. [ABSTRACT FROM AUTHOR]

Jin-Gu-Lian (JGL) is traditionally used by Miao for the treatment of rheumatism arthralgia. At the same time, the combination of Sargentodoxa cuneata (Oliv.) Rehd. et W (SC) and Alangium chinense (Lour.) Harms (AC), the core drug pair (CDP) in the formula of JGL, is used at high frequencies in many Miao medicine prescriptions for rheumatic diseases. However, previous research lacks the pharmacokinetic study of JGL, and study on the compatibility of its CDP with other medicinal herbs in the formula is needed. This study aims to establish a simple, rapid, and sensitive Ultra Performance Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS/MS) method for the simultaneous determination of four main bioactive components of JGL in rat plasma, including Salidroside (Sal), Anabasine (Ana), Chlorogenic Acid (CA), and Protocatechuic Acid (PCA), and compare the pharmacokinetic properties of two groups of rats after being orally administrated with JGL and its CDP extracts, respectively. The results showed that area under the plasma concentration-time curve (AUC), mean retention time (MRT), and clearance rate (CL), of Sal, Ana, CA and PCA in the two groups of rats were changed in different degrees. The CDP combined with other drugs could significantly increase the absorption of Sal and Ana, prolong its retention time in vivo, and may accelerate the absorption rate of CA and PCA. This indicated that the combination of CDP and other herbs may affect the pharmacokinetics process of active components in vivo, increase the exposure and bioavailability of compounds in the JGL group, and prolong the retention time, which may be the reason why JGL has a better inhibitory effect on inflammatory cytokines, providing a viable orientation for the compatibility investigation of herb medicines. [ABSTRACT FROM AUTHOR]

Lenvatinib is a multi-targeted tyrosine kinase inhibitor that inhibits tumor angiogenesis, but hypertension is the most common adverse reaction. Telmisartan is an angiotensin receptor blocker used to treat hypertension. In this study, a simple ultra-performance liquid chromatography-tandem mass spectrometry method was developed for the simultaneous determination of lenvatinib and telmisartan, and it was applied to the pharmacokinetic drug interaction study. Plasma samples were treated with acetonitrile to precipitate protein. Water (containing 5 mM of ammonium acetate and 0.1% formic acid) and acetonitrile (0.1% formic acid) were used as the mobile phases to separate the analytes with gradient elution using a column XSelect HSS T3 (2.1 mm × 100 mm, 2.5 μm). Multiple reaction monitoring in the positive ion mode was used for quantification. The method was validated and the precision, accuracy, matrix effect, recovery, and stability of this method were reasonable. The determination of analytes was not interfered with by other substances in the blank plasma, and the calibration curves of lenvatinib and telmisartan were linear within the range of 0.2–1000 ng/mL and 0.1–500 ng/mL, respectively. The results indicate that lenvatinib decreased the systemic exposure of telmisartan. Potential drug interactions were observed between lenvatinib and telmisartan. [ABSTRACT FROM AUTHOR]