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Herbal slimming products (HSPs) contain multiple herbs used in weight loss. Phytoconstituents of several plant extracts show the inhibitory effects on the drug-metabolizing enzymes causing interaction when taken with other drugs. Atorvastatin (ATS) is used in the treatment of hyperlipidemia. This study aimed to investigate the effect of HSPs on the pharmacokinetics and pharmacodynamics of ATS. ATS (10 mg/Kg) was administered alone or in combination with HSP1 (200 mg/Kg)/HSP2 (165 mg/Kg) orally in the SD rats for pharmacokinetics study. Hyperlipidemia was induced in Golden Syrian Hamster by feeding HFD (60% kcal). Furthermore, biochemical levels in serum, ROS, gene expression and lipid accumulation levels were examined in hamster liver tissue. HSPs have significantly enhanced the permeability and inhibited the metabolism of ATS by inhibiting the CYP3A4 isoenzyme confirmed by in vitro assay. Co-administration of HSPs with ATS enhanced the relative bioavailability of ATS.Concomitant administration of HSPs with ATS has significantly reduced the fat content, inflammatory cytokines, TG, VLDL, LDL levels, tissue MDA level, HMGCR and SREBP1c mRNA expression levels, lipid accumulation as well as collagen content and has increased the serum HDL level as well as tissue SOD, CAT, GHS and mRNA expression levels of LXRa and CYP7A1. The aforementioned outcomes indicated that coadministration of HSPs with ATS may lead to herb-drug interaction. Therefore, precaution should be taken and dose adjustment is required when administered simultaneously. [ABSTRACT FROM AUTHOR]

Cissus quadrangularis is a nutrient-rich plant with a history of use in traditional medicine. It boasts a diverse range of polyphenols, including quercetin, resveratrol, β-sitosterol, myricetin, and other compounds. We developed and validated a sensitive LC-MS/MS method to quantify quercetin and t-res biomarkers in rat serum and applied this method to pharmacokinetic and stability studies. The mass spectrometer was set to negative ionization mode for the quantification of quercetin and t-res. Phenomenex Luna (C18(2), 100 A, 75 × 4.6 mm, 3 µ) column was utilized to separate the analytes using an isocratic mobile phase consisting of methanol and 0.1% formic acid in water (82:18). Validation of the method was performed using various parameters, including linearity, specificity, accuracy, stability, intra-day, inter-day precision, and the matrix effect. There was no observed significant endogenous interference from the blank serum. The analysis was completed within 5.0 min for each run, and the lower limit of quantification was 5 ng/mL. The calibration curves showed a linear range with a high correlation coefficient (r2 > 0.99). The precision for intra- and inter-day assays showed relative standard deviations from 3.32% to 8.86% and 4.35% to 9.61%, respectively. The analytes in rat serum were stable during bench-top, freeze-thaw, and autosampler (−4 °C) stability studies. After oral administration, the analytes showed rapid absorption but underwent metabolism in rat liver microsomes despite being stable in simulated gastric and intestinal fluids. Intragastric administration resulted in higher absorption of quercetin and t-res, with greater Cmax, shorter half-life, and improved elimination. No prior research has been conducted on the oral pharmacokinetics and stability of anti-diabetic compounds in the Ethanolic extract of Cissus quadrangularis EECQ, making this the first report. Our findings can provide the knowledge of EECQ's bioanalysis and pharmacokinetic properties which is useful for future clinical trials. [ABSTRACT FROM AUTHOR]

Raloxifene is a well-known modulator of estrogen receptors which is structurally similar to tamoxifen. As flavonoids can interact with the estrogen modulator raloxifene in vitro, we performed an in vitro stability study and in situ permeability assay of raloxifene and cladrin in female Sprague-Dawley rats when administered alone and when co-administered. The in vitro study samples were analyzed by HPLC; raloxifene administered individually and in combination with cladrin was compared. In this study, we investigated the absorption, metabolic stability, plasma stability, determination of permeability and plasma protein binding of both drugs in SD rats using an established in situ single pass intestinal perfusion model. Increase in the bioavailability of raloxifene and cladrin alone or in co-administration also could be because of the activation of P-glycoprotein in the rat intestine. Further the present report concludes on the basis of ATPase assay of both raloxifene and cladrin alone and in combination showed that both drugs are P-gp substrate. In in situ permeability assay showed that the both drugs competitively lower the permeability of each other but still the predicted human permeability value lied in the range of high permeability drug. [ABSTRACT FROM AUTHOR]

Trans-Resveratrol (T-RES) is a compound with wide therapeutic applications that shows low bioavailability and distribution across blood-brain barrier. The purpose of our study was to develop T-RES loaded mixed micelle (T-RES-MM) for its enhanced systemic availability and targeting to the brain. T-RES-MMs were formulated using Pluronic F-127 (PF-127) and d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) by using film hydration process. Formulations were characterized for size of particles, zeta potential, drug efficiency of entrapment, drug loading, and hemolytic study. Further in vivo pharmacokinetic and brain distribution study carried out in Sprague Dawley rats. The nano ranged size for drug-loaded mixed micelles was 21.55 ± 2.15 nm for optimized formulation with PF-127:TPGS (4:1). Formulation with maximum drug loading and entrapment efficiency of 8.4 ± 0.37% and 94.37 ± 1.01% respectively were further used for in vivo study. Percent hemolysis by micelles at all concentrations indicates the biocompatibility and safety for administration by i.v. route. The AUC0-t for T-RES-MM was 460.98 ± 158.99 h*ng/ml while for T-RES it was 276.27 ± 174.05 h*ng/ml. Drug targeting index suggests successful targeting of T-RES to the brain. Overall findings conclude in prepared T-RES-MM exhibit superiority of formulation as compared to T-RES solution. [ABSTRACT FROM AUTHOR]

PSTi8 is a pancreastatin inhibitory peptide that is effective in the treatment of diabetic models. This study investigates the pharmacokinetic (PK) properties of PSTi8 in Sprague Dawley rats, for the first time. In vitro and in vivo PK studies were performed to evaluate the solubility, stability in plasma and liver microsomes, plasma protein binding, blood–plasma partitioning, bioavailability, dose proportionality, and gender difference in PK. Samples were analyzed using the validated LC-MS/MS method. The solubility of PSTi8 was found to be 9.30 and 25.75 mg/mL in simulated gastric and intestinal fluids, respectively. The protein binding of PSTi8 was estimated as >69% in rat plasma. PSTi8 showed high stability in rat plasma and liver microsomes and the blood–plasma partitioning was >2. The bioavailability of PSTi8 after intraperitoneal and subcutaneous administration was found to be 95.00 ± 12.15 and 78.47 ± 17.72%, respectively, in rats. PSTi8 showed non-linear PK in dose proportionality studies, and has no gender difference in the PK behavior in rats. The high bioavailability of PSTi8 can be due to high water solubility and plasma protein binding, low clearance and volume of distribution. Our in vitro and in vivo findings support the development of PSTi8 as an antidiabetic agent. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • LC-MS/MS method has been developed and validated for the first time for S012-1332. • Absolute oral bioavailability of S012-1332 was 7.04% in rats. • In vitro findings show low solubility, high metabolism, moderate protein binding. • Stable in plasma and biorelevant media and highly permeable. Abstract S012-1332 is the first DNA ligase I inhibitor that demonstrated in vivo anti-breast cancer activity. The present study aimed to assess the in vivo pharmacokinetics of S012-1332 in rats and interpret them with in vitro findings. A sensitive and selective liquid chromatography-tandem mass spectrometry bioanalytical method was developed and validated to determine S012-1332. Following oral administration, the absolute bioavailability was 7.04%. The absorption was prolonged which can be explained by low solubility in simulated gastric fluid and several folds higher solubility in simulated intestinal fluid. The effective permeability across the intestinal membrane in in situ single pass perfusion study for S012-1332 was 5.58 ± 1.83 * 10−5 cm/sec compared to 5.99 ± 0.65 * 10−5 cm/sec for carbamazepine, with no significant difference, indicating S012-1332 has high permeability. It was rapidly partitioning into plasma in blood, where it was stable. Plasma protein binding was moderate which may have attributed to the rapid distribution out of the vascular compartment. The pharmacokinetics of S012-1332 was characterized by extensive clearance as seen with rat liver and intestinal microsomes. In vitro results elucidate the in vivo pharmacokinetic data. These findings provide crucial information for further development of S012-1332 as anti-breast cancer agent. [ABSTRACT FROM AUTHOR]

• LC-MS/MS technique has been developed and validated for analyte quantification. • LLOQ of all analytes was 2 ng/mL and this is in linear range at r2 > 0.999. • Method was successfully applied to in vitro and in vivo pharmacokinetic studies. • Five marker compounds are estimated simultaneously. • One-compartment pharmacokinetic model is used in the oral pharmacokinetic profile. Withania Somnifera (WS) is a popular nutritional supplement in the USA, Europe, and Asia, known for its pharmacological effects on neurological disorders. However, the bioanalytical method development, validation, and pharmacokinetics of WS NMITLI-118R AF1 biomarkers Withanolide A (WLD A), Withanone (WNONE), Withanolide B (WLD B), Withaferin A (WF A), and 12 Deoxywithastramonolide (12 DEOXY) in rats have not been comprehensively explored. This study aimed to develop and validate a sensitive and selective LC-ESI-MS/MS method for these biomarkers in male Sprague Dawley rats plasma and brain matrix. Rats were divided into eight groups, each containing five rats. A plant extract of NMITLI-118R AF1 at 50 mg/kg was orally administered to the rats for in-vivo pharmacokinetic investigation. All the analytes had a linear calibration curve (r2 > 0.999), and intra-day and inter-day precision (%) were found in the range of 2.46 – 13.71% and accuracy were within the acceptable range (±15%). The biomarkers of NMITLI-118R AF1 were found stable in in-vitro plasma and simulated gastro-intestinal fluids. The observed (C max) and (T max) values for the biomarkers in the systemic circulation were WLD A (5.59 ± 0.34 ng/mL, T max 1.00 ± 0.00 h), WNONE (6.28 ± 0.41 ng/mL, T max 0.95 ± 0.11 h), WLD B (6.45 ± 2.87 ng/mL, T max 0.95 ± 0.11 h), WF A (6.50 ± 0.27 ng/mL, T max 1.00 ± 0.00 h), and 12 DEOXY (5.68 ± 0.39 ng/mL, T max 1.00 ± 0.00 h). In contrast to the old method, our approach exhibits a lower limit of quantification (LLOQ), shorter run time (less than10 min), and enables the detection of WF A and WNONE in fresh rat plasma by other quantitative analysis of mass spectrometry (m / z) [M]+. Shows high sample volumes for both, larger plasma volumes, costlier sample collection techniques dried blood spot (DBS), more expensive solid phase extraction techniques (SPE) and longer analysis time 14 min. Moreover, our method requires a smaller sample volume 10 µL, offers faster analysis time 4 min, and achieves a higher sensitivity 1 ng/mL. This is the first report of a comprehensive study on in-vitro and in-vivo pharmacokinetics of NMITLI-118R AF1 biomarkers, which may aid in further pre-clinical and clinical trial investigations. [ABSTRACT FROM AUTHOR]

Miltefosine (MFS) is the first effective oral drug for treatment of visceral, mucosal and cutaneous leishmaniasis. In this study, liquid chromatography coupled mass spectrometry (LC–MS/MS) method of MFS was validated in rat plasma and its practical utilization to pharmacokinetic studies in rats for the first time. A rapid, selective and sensitive LC–MS/MS method for MFS in rat plasma was linear over the calibration range of 1–500 ng/mL. MFS and Phenacetin (internal standard) were separated on Phenomenex Luna 3 μ HILIC 200A (150 × 4.6 mm) column under isocratic condition using methanol: 0.1% formic acid in triple distilled water, 90:10 (v/v) mobile phase at a flow rate of 0.8 mL/min. The total chromatographic run time was 4.0 min. The intra- and inter-day assay accuracy was observed between 99.45-102.88% and 99.92-101.58%, respectively. The intra- and inter-day assay precision was observed between 2.68-5.54% and 2.35-5.94%, respectively. The validated assay was practically applied to determine the plasma concentrations after oral and intravenous administration of MFS to rats. After oral administration, MFS showed C max (3200.00 ± 95.39 ng/mL) was observed at 12.00 h (t max ) and t 1/2 was 102.36 ± 16.65 h. The absolute bioavailability of MFS was 60.33 ± 2.32%. [ABSTRACT FROM AUTHOR]

• Analysis of PSTi8 peptide in mice plasma using SPE followed by LC–MS/MS has been developed for the first time. • Validation studies, including stability test of the developed method were performed. • The LLOQ was 5 ng/mL. • SPE has provided good recovery, cleaner samples and no matrix effect for PSTi8. • The absolute bioavailability of PSTi8 peptide was 52.74 ± 13.50 %. PSTi8 is a 21 amino acid pancreastatin inhibitory peptide that demonstrated potent antidiabetic activity in insulin resistant rodent models. The goal of the current work is to establish and validate the LC–ESI–MS/MS bioanalytical assay of PSTi8 in mice plasma in order to unveil its pharmacokinetic (PK) behaviour for the first time. The MS detection of PSTi8 and diprotin A (internal standard, IS) was conducted with Q1/Q3 SRM transitions at 607.80 ([M+4 H]4+)/771.20 and 342.20/229.10, respectively using positive ESI. Phenomenex Aqua 5μ 125A (250 × 4.6 mm) column was utilized to separate PSTi8 and IS with a mobile phase consists of MeOH-0.1 % formic acid (1:1, v/v) using 0.4 mL/min flow rate. SPE using medium anion exchange cartridge (Oasis MAX) was used for the extraction of analyte and IS from the mice plasma and the extraction recovery was found to be >55 %. PSTi8 displayed good linearity across the 5−1000 ng/mL concentrations range. The intra- and inter- day accuracy was observed between 99.44–110.20 % and 99.66–110.93 %, respectively. The intra- and inter- day precision was observed between 2.61–4.03 % and 2.90–7.16 %, respectively. The intra-day and inter-day accuracy and precision data was within the 100 ± 15 % nominal values recommended by the United States Food and Drug Administration bioanalytical guidance. The LC–MS/MS assay was validated effectively to investigate the PSTi8 plasma concentrations following intravenous and intraperitoneal PK studies in mice. The absolute bioavailability of PSTi8 was 52.74 ± 13.50 %. [ABSTRACT FROM AUTHOR]