Supeecha Wittayalertpanya

The bioactive flavonoids pinostrobin (PN) and panduratin A (PA) from Boesenbergia rotunda are essential for research and therapeutic applications. This study introduces an innovative method utilizing ultrasound-assisted extraction with n-hexane pre-treatment, followed by one-step centrifugal partition chromatography (CPC) purification. Extraction efficiency was evaluated using ultra high-performance liquid chromatography (UHPLC), and the isolated compounds were characterized through ¹H-NMR and liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS), adhering to AOAC validation guidelines. Optimal extraction conditions comprised a particle size of 125 μm, a solid-to-liquid ratio of 1:30 g/mL, and a 10 min extraction time, yielding a crude extract of 6.96 ± 0.07%. Using an n-hexane/MeOH/water (5/3.4/1.6, v/v) solvent system in ascending mode, PN (2.16 mg, 98.78% purity) and PA (0.4 mg, 99.69% purity) were isolated from 67 mg of crude extract within 30 min. This streamlined approach enhances purification efficiency, allowing for faster extraction and higher purity, making it a suitable method for commercial applications.

Sofosbuvir/Velpatasvir (SOF/VEL) is a combination drug used for chronic hepatitis C (HCV) infection. However, limited information exists regarding the pharmacokinetics of SOF/VEL and its metabolites in hemodialysis patients. We conducted a prospective investigation of the pharmacokinetic parameters of SOF/VEL after a single dose of SOF/VEL (400/100 mg) on days with and without dialysis in 12 Thai hemodialysis patients with chronic HCV infection, who had been undergoing hemodialysis for a duration of 0.5–20 years. Blood samples were collected before dose (0) and 0.5, 1.0, 2.0, 2.5, 3.0, 3.5, 4.0, 5.0, 6.0, 8.0, and 12.0 h after dose. Dialysate samples were also collected before dose (0) and 1.0, 2.0, 3.0, and 4.0 h after dose. Plasma and dialysate samples were quantified for SOF and its metabolite, GS‐331007, and VEL concentrations using a fully validated LCMS technique. In addition, a preliminary efficacy study was conducted using the proposed SOF/VEL dose reduction regimen in all patients. No differences in SOF/VEL PK parameters between on‐ and off‐dialysis studies. On the contrary, GS‐331007 exhibited a 30% reduction in the area under the plasma concentration–time curve from time 0 to 24 h (AUC_0‐24h) on dialysis days compared with non‐dialysis days (AUC_0‐24h ratio 0.68 vs. 1.04, respectively). The dialysis clearance of SOF and GS‐331007 was 9.35 (8.72–15.11) and 8.89 (8.52–14.07) mL/min, respectively. Subsequently, an alternate‐day regimen of SOF/VEL (400/100 mg) was administered for 12 weeks, resulting in an undetectable plasma HCV viral load without side effects. Further clinical studies are warranted to validate the efficacy and safety of our proposed dose reduction regimen.

Background and purpose: The study was aimed at validating a simple, rapid, and low-cost LC-MS/MS method for carvedilol and 4^/-hydroxyphenyl carvedilol assay in human plasma. The validated method was applied to investigate the pharmacokinetics after a low dose of 6.25 mg. carvedilol. Experimental approach: In this study, the plasma was extracted by liquid-liquid extraction and evaporated the organic layer to dryness, then both analytes in the residue were reconstituted and detected by LC- MS/MS. The method was validated following the guideline on bioanalytical method validation. Thirty-one healthy volunteers participated in the pharmacokinetic study. After 10 h of fasting, each volunteer received one tablet of 6.25 mg carvedilol orally. Blood samples were collected at 16 prescheduled time points. The plasma samples were analyzed for pharmacokinetics. Findings/Results: The method was linear over a range of 0.050-50.049 ng/mL for carvedilol and 0.050- 10.017 ng/mL for 4^/-hydroxyphenyl carvedilol. Crucial validated results reached the requirements of selectivity, accuracy, precision, and stability. Pharmacokinetics of carvedilol and 4^/-hydroxyphenyl carvedilol were evaluated which showed C_max at 21.26 ± 9.23 and 2.42 ± 2.07 ng/mL; AUC0-t 66.95 ± 29.45 and 5.93 ± 3.51 ng.h/mL; AUC_0-inf 68.54 ± 30.11 and 6.78 ± 3.49 ng.h/mL; and T1/2 6.30 ± 1.95 and 6.31 ± 6.45 h, respectively. Conclusion and implications: The validated method was able to detect and quantify both analytes in plasma samples and can be applied to the pharmacokinetic study of carvedilol and 4^/-hydroxyphenyl carvedilol after receiving carvedilol at 6.25 mg orally.

The method for the determination of primaquine (PQ) and 5,6-orthoquinone primaquine (5,6-PQ), the representative marker for PQ active metabolites, via CYP2D6 in human plasma and urine has been validated. All samples were extracted using acetonitrile for protein precipitation and analyzed using the ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS) system. Chromatography separation was carried out using a Hypersil GOLD^TM aQ C₁₈ column (100 × 2.1 mm, particle size 1.9 μm) with a C₁₈ guard column (4 × 3 mm) flowed with an isocratic mode of methanol, water, and acetonitrile in an optimal ratio at 0.4 mL/min. The retention times of 5,6-PQ and PQ in plasma and urine were 0.8 and 1.6 min, respectively. The method was validated according to the guideline. The linearity of the analytes was in the range of 25–1500 ng/mL. The matrix effect of PQ and 5,6-PQ ranged from 100% to 116% and from 87% to 104% for plasma, and from 87% to 89% and from 86% to 87% for urine, respectively. The recovery of PQ and 5,6-PQ ranged from 78% to 95% and form 80% to 98% for plasma, and from 102% to from 112% to 97% to 109% for urine, respectively. The accuracy and precision of PQ and 5,6-PQ in plasma and urine were within the acceptance criteria. The samples should be kept in the freezer (−80 °C) and analyzed within 7 days due to the metabolite stability. This validated UHPLC-MS/MS method was beneficial for a pharmacokinetic study in subjects receiving PQ.

A reliable method has been validated using ultra-performance liquid chromatography mass spectrometry (MS)/MS for simultaneous evaluation of human plasma concentration of mycophenolic acid (MPA) and its major metabolites both total and free form. All analytes were extracted from plasma by simple protein precipitation procedure with methanol. Samples for determination of their free form concentration require a preanalytic spin through an ultrafiltration system. The chromatographic separation was completed using C₁₈column at 0.3 ml/min with a gradient condition. Method validation was performed as the United State Food and Drug Administration guidelines for bio-analytical methods concerning precision, accuracy, linearity, selectivity, recovery, and matrix effect. Linearity was obtained over concentration of 0.05–4, 0.5–60, and 0.025–3 μg/ml for total MPA, mycophenolic acid glucuronide (MPAG) and mycophenolic acid acyl-glucuronide (AcMPAG), respectively. The linearity of the method for free form of analytes was confirmed in the range of 10–500, 125–10,000, and 0.5–300 ng/ml for MPA, MPAG, and AcMPAG, respectively. The intra- and interday accuracy ranged from 85.73%–102.01% for total form, and 87.23%–111.89% for free form, and the precisions of all analytes were lower than 15%. The mean recoveries of the analytes ranged from 85.54% to 94.76% and the matrix factor ranged from 0.88–1.06. The developed method is rapid, sensitive and convenient for pharmacokinetic study or therapeutic drug monitoring in patients after oral administration of enteric-coated mycophenolate sodium or mycophenolate mofetil.

Background: Food-drug interaction can decrease drug effectiveness or increase risk of drug toxicity. Simvastatin is widely used for treatment of hypercholesterolemia and hypertriglyceridemia. Therefore, this study aimed to investigate the effects of pomelo juice on the pharmacokinetics of simvastatin, CYP3a2 activity and Mdr1a, Mdr1b and Slc21a5 expressions in rats. Methods: Rats were divided into 4 groups including (i) control, (ii) pomelo that received pomelo juice orally twice daily for 7 days, (iii) simvastatin that received simvastatin on day 8, and (iv) simvastatin + pomelo juice. Plasma concentrations of simvastatin and simvastatin acid were analyzed using LC-MS/MS. Hepatic CYP3a2 activity was evaluated using midazolam hydroxylation assay. The expressions of hepatic and intestinal Mdr1a, Mdr1b and Slc21a5 were measured using the real-time RT-PCR. Results: Oral administration of pomelo juice for 7 days altered pharmacokinetic profiles of simvastatin and its primary active metabolite, simvastatin acid, in rats. Real-time RT-PCR analysis revealed that pomelo juice significantly suppressed the expression of intestinal Mdr1a and Mdr1b and hepatic Slc21a5. Rat hepatic CYP3a2 catalytic activity was also inhibited following pomelo juice administration. Conclusion: The results of this study suggested that there was a risk of potential drug interaction associated with inhibition of drug transporters and CYP3A caused by pomelo juice.

Clopidogrel is an antiplatelet drug, selectively binding to the platelet P2Y12 receptor of adenosine diphosphate. Clopidogrel is a prodrug modified through active metabolite in the liver by two steps of CYP enzyme. The active metabolite is responsible for inhibiting platelet aggregation.

The purpose of the study was to evaluate the pharmacokinetics and bioequivalence of pregabalin following administration of a 150-mg capsule of test and reference products.