scholarly journals Pharmacokinetics and Pharmacodynamics of a Depolymerized Glycosaminoglycan from Holothuria fuscopunctata, a Novel Anticoagulant Candidate, in Rats by Bioanalytical Methods

Marine Drugs ◽  
2021 ◽  
Vol 19 (4) ◽  
pp. 212
Author(s):  
Shuang Liu ◽  
Taocui Zhang ◽  
Huifang Sun ◽  
Lisha Lin ◽  
Na Gao ◽  
...  
Keyword(s):  
Peak Concentration ◽  
Bioanalytical Methods ◽  
Subcutaneous Administration ◽  
Parent Drug ◽  
Bleeding Risk ◽  
Rat Plasma ◽  
Preclinical Study ◽  
Time To Peak ◽  
Elimination Half ◽  
Plasma And Urine Samples

dHG-5 (Mw 5.3 kD) is a depolymerized glycosaminoglycan from sea cucumber Holothuria fuscopunctata. As a selective inhibitor of intrinsic Xase (iXase), preclinical study showed it was a promising anticoagulant candidate without obvious bleeding risk. In this work, two bioanalytical methods based on the anti-iXase and activated partial thromboplastin time (APTT) prolongation activities were established and validated to determine dHG-5 concentrations in plasma and urine samples. After single subcutaneous administration of dHG-5 at 5, 9, and 16.2 mg/kg to rats, the time to peak concentration (Tmax) was at about 1 h, and the peak concentration (Cmax) was 2.70, 6.50, and 10.11 μg/mL, respectively. The plasma elimination half-life(T1/2β) was also about 1 h and dHG-5 could be almost completely absorbed after s.c. administration. Additionally, the pharmacodynamics of dHG-5 was positively correlated with its pharmacokinetics, as determined by rat plasma APTT and anti-iXase method, respectively. dHG-5 was mainly excreted by urine as the unchanged parent drug and about 60% was excreted within 48 h. The results suggested that dHG-5 could be almost completely absorbed after subcutaneous injection and the pharmacokinetics of dHG-5 are predictable. Studying pharmacokinetics of dHG-5 could provide valuable information for future clinical studies.

scholarly journals Milk and Blood Pharmacokinetics of Tylosin and Tilmicosin following Parenteral Administrations to Cows

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Tulay Avci ◽  
Muammer Elmas
Keyword(s):  
Peak Concentration ◽  
Subcutaneous Administration ◽  
Parenteral Administration ◽  
Intramuscular Administration ◽  
Withdrawal Period ◽  
Holstein Breed ◽  
Elimination Half ◽  
Time Required

The aim of this study is to determine the pharmacokinetics of tylosin and tilmicosin in serum and milk in healthy Holstein breed cows (n=12) and reevaluate the amount of residue in milk. Following the intramuscular administration of tylosin, the maximum concentrations (Cmax) in serum and milk were found to be1.30±0.24and4.55±0.23 µg/mL, the time required to reach the peak concentration (tmax) was found to be 2nd and 4th h, and elimination half-lives (t1/2β) were found to be20.46±2.08and26.36±5.55 h, respectively. Following the subcutaneous administration of tilmicosin, theCmaxin serum and milk were found to be0.86±0.20and20.16±1.13 µg/mL, thetmaxwas found to be 1st and 8th h, and thet1/2βwere found to be29.94±6.65and43.02±5.18 h, respectively.AUCmilk/AUCserumandCmax-milk/Cmax-serumrates, which are indicators for determining the rate of drugs that pass into milk, were, respectively, calculated as5.01±0.72and3.61±0.69for tylosin and23.91±6.38and20.16±1.13for tilmicosin. In conclusion, it may be stated that milk concentration of tylosin after parenteral administration is higher than expected like tilmicosin and needs more withdrawal period for milk than reported.

Simultaneous Determination of Imatinib and N-Desmethyl Imatinib in Rat Plasma and Tissues Using LC-MS/MS

2019 ◽  
Vol 15 (2) ◽  
pp. 121-129
Author(s):  
Zhi Rao ◽  
Bo-xia Li ◽  
Yong-Wen Jin ◽  
Wen-Kou ◽  
Yan-rong Ma ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Oral Administration ◽  
Parent Drug ◽  
Gradient Elution ◽  
Biological Tissues ◽  
Rat Plasma ◽  
Running Water ◽  
Liver And Kidney ◽  
The Brain

Background: Imatinib (IM) is a chemotherapy medication metabolized by CYP3A4 to Ndesmethyl imatinib (NDI), which shows similar pharmacologic activity to the parent drug. Although methods for determination of IM and/or NDI have been developed extensively, only few observations have been addressed to simultaneously determine IM and NDI in biological tissues such as liver, kidney, heart, brain and bone marrow. Methods: A validated LC-MS/MS method was developed for the quantitative determination of imatinib (IM) and N-desmethyl imatinib (NDI) from rat plasma, bone marrow, brain, heart, liver and kidney. The plasma samples were prepared by protein precipitation, and then the separation of the analytes was achieved using an Agilent Zorbax Eclipse Plus C18 column (4.6 × 100 mm, 3.5 µm) with gradient elution running water (A) and methanol (B). Mass spectrometric detection was achieved by a triplequadrupole mass spectrometer equipped with an electrospray source interface in positive ionization mode. Results: This method was used to investigate the pharmacokinetics and the tissue distributions in rats following oral administration of 25 mg/kg of IM. The pharmacokinetic profiles suggested that IM and NDI are disappeared faster in rats than human, and the tissue distribution results showed that IM and NDI had good tissue penetration and distribution, except for the brain. This is the first report about the large penetrations of IM and NDI in rat bone marrow. Conclusion: The method demonstrated good sensitivity, accuracy, precision and recovery in assays of IM and NDI in rats. The described assay was successfully applied for the evaluation of pharmacokinetics and distribution in the brain, heart, liver, kidney and bone marrow of IM and NDI after a single oral administration of IM to rats.

scholarly journals Toxicity and Pharmacokinetic Studies of Lidocaine and Its Active Metabolite, Monoethylglycinexylidide, in Goat Kids

Animals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 142
Author(s):  
Dinakaran Venkatachalam ◽  
Paul Chambers ◽  
Kavitha Kongara ◽  
Preet Singh
Keyword(s):  
Total Dose ◽  
Plasma Concentrations ◽  
Subcutaneous Administration ◽  
Lidocaine Hydrochloride ◽  
Pharmacokinetic Parameters ◽  
Pharmacokinetic Studies ◽  
Liquid Chromatography Mass Spectrometry ◽  
Elimination Half ◽  
The Mean ◽  
Safe Dose

This study determined the convulsant plasma concentrations and pharmacokinetic parameters following cornual nerve block and compared the results to recommend a safe dose of lidocaine hydrochloride for goat kids. The plasma concentrations of lidocaine and monoethylglycinexylidide (MGX) were quantified using liquid chromatography-mass spectrometry. A total dose of 7 mg/kg body weight (BW) was tolerated and should therefore be safe for local and regional anesthesia in goat kids. The mean plasma concentration and mean total dose that produced convulsions in goat kids were 13.59 ± 2.34 µg/mL and 12.31 ± 1.42 mg/kg BW (mean ± S.D.), respectively. The absorption of lidocaine following subcutaneous administration was rapid with Cmax and Tmax of 2.12 ± 0.81 µg/mL and 0.33 ± 0.11 h, respectively. The elimination half-lives (t½λz) of lidocaine hydrochloride and MGX were 1.71 ± 0.51 h and 3.19 ± 1.21 h, respectively. Injection of 1% lidocaine hydrochloride (0.5 mL/site) was safe and effective in blocking the nerves supplying horn buds in goat kids.

Development of a ultra-performance LC–MS/MS method for quantification of GW788388 and its applications in pharmacokinetic study in rats

Bioanalysis ◽  
2020 ◽  
Vol 12 (23) ◽  
pp. 1681-1688
Author(s):  
Lina Fang ◽  
Chunling Zhou ◽  
Meihua Jiang ◽  
Xiaoxin Li ◽  
Tianzhu Liu ◽  
...  
Keyword(s):  
Relative Error ◽  
Peak Concentration ◽  
Renal Fibrosis ◽  
Pharmacokinetic Profile ◽  
Rat Plasma ◽  
Precipitation Method ◽  
Quantification Method ◽  
Orally Active ◽  
Tgf Β1

Aim: GW788388 is a selective and orally active TGF-β1 receptor inhibitor that shows potent activity in renal fibrosis. We aimed to establish and validate a simple and sensitive ultra-performance LC–MS/MS method for the determination of GW788388 in plasma samples. Methodology & results: GW788388 in rat plasma was processed with protein precipitation method and then separated on a C18 column. The calibration curve presented a good linearity in the range of 1.0–1200 ng/ml, with satisfactory accuracy (relative error, [-17.5% < relative error <11.7%) and precision (CV <8.9%) for all quality control samples. After oral administration, GW788388 was absorbed quickly and reached a peak concentration of 595.3 ± 60.2 ng/ml after 20 min. Conclusion: The validated method provides a quantification method of GW788388 in rat plasma in detail, and can be utilized to successfully describe the pharmacokinetic profile of GW788388.

Pharmacokinetic and pharmacodynamic evaluation of the topoisomerase inhibitor irinotecan in cancer patients.

1997 ◽  
Vol 15 (4) ◽  
pp. 1502-1510 ◽  
Author(s):  
E Gupta ◽  
R Mick ◽  
J Ramirez ◽  
X Wang ◽  
T M Lestingi ◽  
...  
Keyword(s):  
Volume Of Distribution ◽  
Transport Systems ◽  
Parameter Estimates ◽  
Urinary Recovery ◽  
Intestinal Toxicity ◽  
Elimination Half ◽  
Black Patients ◽  
Increased Risk ◽  
Plasma And Urine Samples ◽  
Grade 3

PURPOSE We conducted a pharmacokinetic and pharmacodynamic evaluation of irinotecan (CPT-11) and determined the effect of race and sex on disposition and toxicity of CPT-11. We tested the efficacy of acetaminophen (AAP) to phenotype SN-38 glucuronidation. PATIENTS AND METHODS Forty patients received a dose of 145 mg/m2 of CPT-11 as a 90-minute infusion. Total CPT-11, SN-38, and SN-38G were quantitated in plasma and urine samples. Following administration of 1 g AAP, urinary concentrations of AAP and AAP-glucuronide (AAP-G) were assessed. RESULTS CPT-11 exhibited a mean elimination half-life (t1/2) of 8.8 hours, an average clearance (CL) of 14.6 L/h/m2, and a mean volume of distribution at steady-state (Vdss) of 136 L/m2. SN-38 and SN-38G had low plasma availabilities (3% and 10% relative to CPT-11), with mean t1/2 values of 11.6 and 10.5 hours, respectively. Urinary recovery accounted for 15% of the dose. Race and sex had no effect on the plasma availability of CPT-11, SN-38, and SN-38G. The applicability of biliary index (BI) in predicting dose-limiting intestinal toxicity was validated. Patients who developed grade 3 or 4 toxicity had significantly higher index values compared with patients with grade 0 to 2 toxicity (P = .001). There was no difference in the incidence and severity of toxicity based on race and sex. AAP was a poor predictor of SN-38 glucuronidation. CONCLUSION The high degree of interpatient variability in parameter estimates suggests pharmacogenetic variation or differential induction or inhibition of the sequential metabolic pathway of CPT-11, as well as variability in transport systems. The low urinary recovery indicates substantial biliary excretion and supports the significant correlation between intestinal toxicity and BI. Black patients are not at increased risk of toxicity. An assessment of individual differences in SN-38 conjugation remains to be established.

scholarly journals Disposition of Posaconazole following Single-Dose Oral Administration in Healthy Subjects

2004 ◽  
Vol 48 (9) ◽  
pp. 3543-3551 ◽  
Author(s):  
Philip Krieter ◽  
Brian Flannery ◽  
Timothy Musick ◽  
Mark Gohdes ◽  
Monika Martinho ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Fungal Infections ◽  
Phase 1 ◽  
Parent Drug ◽  
Total Radioactivity ◽  
Plasma And Urine Samples ◽  
Dose Oral ◽  
Orally Bioavailable ◽  
A Minor ◽  
Male Subjects

ABSTRACT Posaconazole is a potent, broad-spectrum triazole antifungal agent currently in clinical development for the treatment of refractory invasive fungal infections. Eight healthy male subjects received a single 399-mg (81.7 μCi) oral dose of [14C]posaconazole after consuming a high-fat breakfast. Urine, feces, and blood samples were collected for up to 336 h postdose and assayed for total radioactivity; plasma and urine samples were also assayed for parent drug. Posaconazole was orally bioavailable, with a median maximum posaconazole concentration in plasma achieved by 10 h postdose. Thereafter, posaconazole was slowly eliminated, with a mean half-life of 20 h. The greatest peak in the radioactivity profile of pooled plasma extracts was due to posaconazole, with smaller peaks due to a monoglucuronide, a diglucuronide, and a smaller fragment of the molecule. The mean total amount of radioactivity recovered was 91.1%; the cumulative excretion of radioactivity in feces and in urine was 76.9 and 14.0% of the dose, respectively. Most of the fecal radioactivity was associated with posaconazole, which accounted for 66.3% of the administered dose; however, urine contained only trace amounts of unchanged posaconazole. The radioactivity profile of pooled urine extracts included two monoglucuronide conjugates and a diglucuronide conjugate of posaconazole. These observations suggest that oxidative (phase 1) metabolism by cytochrome P450 isoforms represents only a minor route of elimination for posaconazole, and therefore cytochrome P450-mediated drug interactions should have a limited potential to impact posaconazole pharmacokinetics.

scholarly journals Use of a rapid HPLC assay for determination of pharmacokinetic parameters of ibuprofen in patients with cystic fibrosis

1996 ◽  
Vol 42 (11) ◽  
pp. 1812-1816 ◽  
Author(s):  
N Rifai ◽  
M Sakamoto ◽  
T Law ◽  
V Galpchian ◽  
N Harris ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Adverse Effects ◽  
Peak Concentration ◽  
Therapeutic Monitoring ◽  
Pharmacokinetic Parameters ◽  
Hplc Assay ◽  
Average Recovery ◽  
Time To Peak ◽  
High Doses

Abstract High doses of ibuprofen have been shown to delay the progression of lung disease without serious adverse effects in patients with cystic fibrosis. To be effective, peak ibuprofen concentration of 50 to 100 mg/L has to be achieved. We developed an HPLC assay to rapidly determine plasma ibuprofen concentration. We used this assay to determine the pharmacokinetics of ibuprofen in patients with cystic fibrosis. The assay possessed linearity up to 500 mg/L, sensitivity to 1 mg/L, average recovery of 98%, and run-to-run precision (n = 23) of 3%. Furthermore, the assay proved to be free of interference from 51 medications. Observed time to peak concentration varied significantly between those receiving ibuprofen tablets (mean + SD, 94 +/- 29 min, n = 16) and syrup (30 +/- 0 min, n = 4) (P &lt; 0.0001). We conclude that the method described here is ideal for therapeutic monitoring of ibuprofen.

scholarly journals 81 Bioequivalence of a Manipulation-Resistant Immediate-Release Amphetamine Sulfate Formulation Compared with Reference Standard

CNS Spectrums ◽  
2019 ◽  
Vol 24 (1) ◽  
pp. 216-216
Author(s):  
Steve Caras ◽  
Terrilyn Sharpe
Keyword(s):  
Single Dose ◽  
Healthy Volunteers ◽  
Peak Concentration ◽  
Immediate Release ◽  
Open Label ◽  
Time Curve ◽  
Time To Peak ◽  
Amphetamine Sulfate ◽  
Quantifiable Concentration ◽  
Funding Acknowledgements

AbstractStudy ObjectivesWe compared the bioavailability of racemic amphetamine (d-amphetamine and l-amphetamine) from a manipulation-resistant immediate-release (IR) amphetamine sulfate capsule (AR19) versus amphetamine sulfate IR tablets (reference).MethodIn this open-label, randomized, two-period, two-treatment, two-sequence, crossover study, 36 healthy volunteers aged 18–45 received a single dose (20-mg capsule) of AR19 in one period and a single dose (2 x 10-mg tablets) of reference in another period, after a 10-hour overnight fast. Each drug administration was separated by a washout period of at least 6days. Bioequivalence for d- and l-amphetamine was assessed using time to peak concentration (Tmax), peak concentration in plasma (Cmax), and area under the plasma concentration–time curve from time-zero to the time of the last quantifiable concentration (AUClast) and extrapolated to infinity (AUCinf).ResultsAll 36 volunteers completed both treatment sequences. Mean (standard deviation; SD) Tmax for d- and l-amphetamine was similar for AR19 (2.84[1.05]; 3.05[1.22], respectively) and reference (2.52[0.75]; 2.75[1.00], respectively). The geometric least-squares mean ratios and 90% confidence intervals were within the boundary of 80%–125% for bioequivalence for Cmax (d-amphetamine, 98.35% [96.12–100.64]; l-amphetamine, 98.82% [96.42–101.28]), AUClast (d-amphetamine, 99.45% [96.92–102.05]; l-amphetamine, 99.29% [96.55–102.10]), and AUCinf (d-amphetamine, 99.50%[96.77–102.30]; l-amphetamine, 99.23% [96.06–102.50]). A total of 13 mild adverse events were reported by 7 volunteers (AEs; AR19, n=5; reference, n=8). No serious AEs were reported.ConclusionAR19 was well tolerated and was bioequivalent to reference when administered as a 20-mg dose in healthy volunteers.Funding Acknowledgements: This study was funded by Arbor Pharmaceuticals, LLC.

scholarly journals Pharmacodynamics of Gatifloxacin against Streptococcus pneumoniae in an In Vitro Pharmacokinetic Model: Impact of Area under the Curve/MIC Ratios on Eradication

2002 ◽  
Vol 46 (1) ◽  
pp. 69-74 ◽  
Author(s):  
Philip D. Lister
Keyword(s):  
Streptococcus Pneumoniae ◽  
Peak Concentration ◽  
Pharmacokinetic Model ◽  
Area Under The Curve ◽  
Logarithmic Phase ◽  
Pharmacokinetic Models ◽  
Elimination Half ◽  
The Impact ◽  
Similar Peak

ABSTRACT Previous studies have demonstrated that fluoroquinolone area under the curve (AUC)/MIC ratios of 30 to 50 are sufficient to eradicate pneumococci from in vitro pharmacokinetic models (IVPMs). However, more systematic studies of the impact of AUC/MIC ratios on the antipneumococcal activities of fluoroquinolones are needed. In the present study, a two-compartment IVPM was used to evaluate the impact of AUC/MIC ratios on the pharmacodynamics of gatifloxacin against four strains of Streptococcus pneumoniae. Gatifloxacin MICs were 0.4 to 1 μg/ml, whereas levofloxacin MICs were 1.8 to 3.2 μg/ml. Since both peak concentration/MIC (peak/MIC) and AUC/MIC ratios affect fluoroquinolone pharmacodynamics, logarithmic-phase cultures (5 × 107 CFU/ml) were exposed to gatifloxacin at constant peak/MIC ratios of 2:1 to 3:1 at 0 and 24 h, elimination half-lives were varied to provide a range of AUC/MIC ratios, and changes in viable counts were measured over 30 h. As a comparison, levofloxacin was evaluated at similar peak/MIC ratios and at AUC/MIC ratios of 30 to 38. For each strain, killing rates through 4 to 8 h were similar since peak/MIC ratios were kept constant. However, continued killing and eradication were observed only when gatifloxacin AUC/MIC ratios were 27 to 48. Levofloxacin also provided eradication. In contrast, substantial regrowth was observed in most experiments when gatifloxacin AUC/MIC ratios were 9 to 24. These data provide further support that fluoroquinolone AUC/MIC ratios of approximately 30 or higher can be sufficient for eradication of pneumococci from IVPMs. Furthermore, the overall impact of the AUC/MIC ratio was not influenced by the strain evaluated or its susceptibility to gatifloxacin. Further studies with other fluoroquinolones and pneumococci that exhibit wider ranges of susceptibilities are warranted. In addition, similar studies with higher peak/MIC ratios are needed to better define the impact of AUC/MIC ratios and peak/MIC ratios on the antipneumococcal pharmacodynamics of fluoroquinolones.

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