scholarly journals Plasma profile of cimicoxib in sheep after oral administration at two different rates

2017 ◽  
Vol 20 (3) ◽  
pp. 535-538
Author(s):  
A. Di Salvo ◽  
M. Giorgi ◽  
H.K. Lee ◽  
C. Vercelli ◽  
F. Rueca ◽  
...  

Abstract Sheep are often subjected to painful procedures and thus they need to be treated with analgesics. Nevertheless, knowledges about pharmacokinetic features of these drugs in this species are poor. The aim of this study was to evaluate plasma behaviour of cimicoxib in sheep after a single oral administration at two different dose rates (4 and 6 mg/kg). Maximum plasma concentrations of cimicoxib were equal to 273.78 (median value; range 189.00-567.32) and 565.01 (range 308.27-822.59) ng/mL after treatment with 4 and 6 mg/kg, respectively. The time of maximum concentration (Tmax) was achieved between 4 and 10 hours following treatment at the lower dose, and between 6 and 10 hours after the administration of the higher dose, with one sheep achieving the concentration peak at 0.75 hours. The slow absorption and the great individual variability in plasma concentration, probably due to ruminal effects, suggest that cimicoxib is not suitable for oral treatment in sheep.

2015 ◽  
Vol 10 (9) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Rosario Russo ◽  
Angelo Mancinelli ◽  
Michele Ciccone ◽  
Fabio Terruzzi ◽  
Claudio Pisano ◽  
...  

Diosmin is a naturally occurring flavonoid present in citrus fruits and other plants belonging to the Rutaceae family. It is used for the treatment of chronic venous insufficiency (CVI) for its pheblotonic and vaso-active properties, safety and tolerability as well. The aim of the current in vivo study was to investigate the pharmacokinetic profile of a branded micronized diosmin (μSMIN Plus™) compared with plain micronized diosmin in male Sprague-Dawley rats. After oral administration by gastric gavage, blood samples were collected via jugular vein catheters at regular time intervals from baseline up to 24 hours. Plasma concentrations were assessed by LC/MS. For each animal, the following pharmacokinetic parameters were calculated using a non-compartmental analysis: maximum plasma drug concentration (Cmax), time to reach Cmax (Tmax), area under the plasma concentration-time curve (AUC0-last), elimination half-life (t1/2), and relative oral bioavailability (%F). The results of the current study clearly showed an improvement in the pharmacokinetic parameters in animals treated with μSMIN Plus™ compared with animals treated with micronized diosmin. In particular, μSMIN Plus™ showed a 4-fold increased bioavailability compared with micronized diosmin. In conclusion, the results from the current study provided a preliminary pharmacokinetic profile for μSMIN Plus™, which may represent a new tool for CVI management.


Blood ◽  
1998 ◽  
Vol 91 (5) ◽  
pp. 1533-1541 ◽  
Author(s):  
Gladys I. Rodriguez ◽  
John G. Kuhn ◽  
Geoffrey R. Weiss ◽  
Susan G. Hilsenbeck ◽  
John R. Eckardt ◽  
...  

Abstract Despite the widespread usage of hydroxyurea in the treatment of both malignant and nonmalignant diseases and a recent expansion in the recognition of its potential therapeutic applications, there have been few detailed studies of hydroxyurea's pharmacokinetic (PK) behavior and oral bioavailability. Parenteral administration schedules have been evaluated because of concerns about the possibility for significant interindividual variability in the PK behavior and bioavailability of hydroxyurea after oral administration. In this PK and bioavailability study, 29 patients with advanced solid malignancies were randomized to treatment with 2,000 mg hydroxyurea administered either orally or as a 30-minute intravenous (IV) infusion accompanied by extensive plasma and urine sampling for PK studies. After 3 weeks of treatment with hydroxyurea (80 mg/kg orally every 3 days followed by a 1-week washout period), patients were crossed over to the alternate route of administration, at which time extensive PK studies were repeated. Three days later, patients continued treatment with 80 mg/kg hydroxyurea orally every 3 days for 3 weeks, followed by a 1-week rest period. Thereafter, 80 mg/kg hydroxyurea was administered orally every 3 days. Twenty-two of 29 patients had extensive plasma and urine sampling performed after treatment with both oral and IV hydroxyurea. Oral bioavailability (F) averaged 108%. Moreover, interindividual variability in F was low, as indicated by 19 of 22 individual F values within a narrow range of 85% to 127% and a modest coefficient of variation of 17%. The time in which maximum plasma concentrations (Cmax) were achieved averaged 1.22 hours with an average lag time of 0.22 hours after oral administration. Except for Cmax, which was 19.5% higher after IV drug administration, the PK profiles of oral and IV hydroxyurea were very similar. The plasma disposition of hydroxyurea was well described by a linear two-compartment model. The initial harmonic mean half-lives for oral and IV hydroxyurea were 1.78 and 0.63 hours, respectively, and the harmonic mean terminal half-lives were 3.32 and 3.39 hours, respectively. For IV hydroxyurea, systemic clearance averaged 76.16 mL/min/m2 and the mean volume of distribution at steady-state was 19.71 L/m2, whereas Cloral/F and Voral/F averaged 73.16 mL/min/m2 and 19.65 L/m2, respectively, after oral administration. The percentage of the administered dose of hydroxyurea that was excreted unchanged into the urine was nearly identical after oral and IV administration—36.84% and 35.82%, respectively. Additionally, the acute toxic effects of hydroxyurea after treatment on both routes were similar. Relationships between pertinent PK parameters and the principal toxicity, neutropenia, were sought, but no pharmacodynamic relationships were evident. From PK, bioavailability, and toxicologic standpoints, these results indicate that there are no clear advantages for administering hydroxyurea by the IV route except in situations when oral administration is not possible and/or in the case of severe gastrointestinal impairment.


Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1816 ◽  
Author(s):  
You Jin Han ◽  
Bitna Kang ◽  
Eun-Ju Yang ◽  
Min-Koo Choi ◽  
Im-Sook Song

Glycyrrhizae Radix is widely used as herbal medicine and is effective against inflammation, various cancers, and digestive disorders. We aimed to develop a sensitive and simultaneous analytical method for detecting glycyrrhizin, isoliquiritigenin, liquiritigenin, and liquiritin, the four marker components of Glycyrrhizae Radix extract (GRE), in rat plasma using liquid chromatography-tandem mass spectrometry and to apply this analytical method to pharmacokinetic studies. Retention times for glycyrrhizin, isoliquiritigenin, liquiritigenin, and liquiritin were 7.8 min, 4.1 min, 3.1 min, and 2.0 min, respectively, suggesting that the four analytes were well separated without any interfering peaks around the peak elution time. The lower limit of quantitation was 2 ng/mL for glycyrrhizin and 0.2 ng/mL for isoliquiritigenin, liquiritigenin, and liquiritin; the inter- and intra-day accuracy, precision, and stability were less than 15%. Plasma concentrations of glycyrrhizin, isoliquiritigenin, liquiritigenin, and liquiritin were quantified for 24 h after a single oral administration of 1 g/kg GRE to four rats. Among the four components, plasma concentration of glycyrrhizin was the highest and exhibited a long half-life (23.1 ± 15.5 h). Interestingly, plasma concentrations of isoliquiritigenin and liquiritigenin were restored to the initial concentration at 4–10 h after the GRE administration, as evidenced by liquiritin biotransformation into isoliquiritigenin and liquiritigenin, catalyzed by fecal lysate and gut wall enzymes. In conclusion, our analytical method developed for detecting glycyrrhizin, isoliquiritigenin, liquiritigenin, and liquiritin could be successfully applied to investigate their pharmacokinetic properties in rats and would be useful for conducting further studies on the efficacy, toxicity, and biopharmaceutics of GREs and their marker components.


Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 71 ◽  
Author(s):  
Yu-Feng Yao ◽  
Chao-Zhan Lin ◽  
Fang-Le Liu ◽  
Run-Jing Zhang ◽  
Qiu-Yu Zhang ◽  
...  

The metabolic and pharmacokinetic studies on complanatuside, a quality marker of a Chinese materia medicatonic, Semen Astragali Complanati, were carried out. The UHPLC-Q-TOF/MS (ultra-high performance liquid chromatography coupled with electrospray ionization tandem quadrupole-time-of-flight mass spectrometry) method was applied to identify the metabolites of complanatuside in rat plasma, bile, stool, and urine after oral administration at the dosage of 72 mg/kg. Up to 34 metabolites (parent, 2 metabolites of the parent drug, and 31 metabolites of the degradation products) were observed, including processes of demethylation, hydroxylation, glucuronidation, sulfonation, and dehydration. The results indicated glucuronidation and sulfonation as major metabolic pathways of complanatuside in vivo. Meanwhile, a HPLC-MS method to quantify complanatuside and its two major metabolites—rhamnocitrin 3-O-β-glc and rhamnocitrin—in rat plasma for the pharmacokinetic analysis was developed and validated. The Tmax (time to reach the maximum drug concentration) of the above three compounds were 1 h, 3 h, and 5.3 h, respectively, while the Cmax (maximum plasma concentrations)were 119.15 ng/mL, 111.64 ng/mL, and 1122.18 ng/mL, and AUC(0-t) (area under the plasma concentration-time curve) was 143.52 µg/L·h, 381.73 µg/L·h, and 6540.14 µg/L·h, accordingly. The pharmacokinetic characteristics of complanatuside and its two metabolites suggested that complanatuside rapidly metabolized in vivo, while its metabolites—rhamnocitrin—was the main existent form in rat plasma after oral administration. The results of intracorporal processes, existing forms, and pharmacokinetic characteristics of complanatuside in rats supported its low bioavailability.


1993 ◽  
Vol 16 (3) ◽  
pp. 377-379 ◽  
Author(s):  
S. M. TAYLOR ◽  
J. KENNY ◽  
A. HOUSTON ◽  
W. G. SMYTH ◽  
D. G. KENNEDY ◽  
...  

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Tae Hwan Kim ◽  
Gi-Young Park ◽  
Soyoung Shin ◽  
Dong Rak Kwon ◽  
Won Sik Seo ◽  
...  

The potential pharmacokinetic (PK) interaction of conventional western drug, baclofen, and oriental medications Oyaksungisan (OY) andAchyranthes bidentata radix(AB) extract for the treatment of spasticity has been evaluated. Rats were pretreated with distilled water (DW), OY, or AB extract by oral administration every day for 7 days. After 10 min of the final dose of DW or each herbal medication, baclofen (1 mg/kg) was given by oral administration and plasma concentrations of baclofen were determined by LC/MS/MS. The plasma baclofen concentration-time profiles were then analyzed by noncompartmental analysis and a population PK model was developed. Baclofen was rapidly absorbed, showed biexponential decline with elimination half-life of 3.42–4.10 hr, and mostly excreted into urine. The PK of baclofen was not affected by AB extract pretreatment. However, significantly lower maximum plasma concentration (Cmax) and longer time to reachCmax(Tmax) were observed in OY pretreated rats without changes in the area under the curve (AUC) and the fraction excreted into urine (Furine). The absorption rate (Ka) of baclofen was significantly decreased in OY pretreated rats. These data suggested that repeated doses of OY might delay the absorption of baclofen without changes in extent of absorption, which needs further evaluation for clinical significance.


Author(s):  
Ye Htut Linn ◽  
Myat Myat Soe ◽  
K Khine Thu ◽  
Thida Tun ◽  
Mi Kun Kaw San ◽  
...  

Background: Tramadol is one of the most commonly used analgesics, thanks to its efficacy and safety. It is widely used in Myanmar for postoperative and cancer pain control. The use of generic drugs has been steadily increasing worldwide, mostly in developing countries. Generic drugs should have efficacy and safety comparable to their innovators or other approved generic products. Objectives: This study aims to compare the bioequivalence of locally producing, Tramadol BPI® capsule (test product) with the Tramazac® capsule (reference product) in healthy Myanmar volunteers. Methods: The bioequivalence was determined in 16 healthy Myanmar volunteers after a single oral administration of 100 mg tramadol (under fasting condition) in a randomized, openlabel, two-period, and two-treatment crossover study with a two-week washout period. Blood samples were collected at specified times, and plasma tramadol concentrations were measured with a validated high-performance liquid chromatography method with a fluorescence detector. Pharmacokinetic parameters were determined using the plasma concentration-time data in a noncompartmental model. Results: The analysis of variance of the logarithmically transformed parameters (maximum plasma concentration (Cmax), Area Under the concentration-time Curve from the time of administration to the last measured concentration (AUC0-t), and to infinity (AUC0-∞) revealed no sequence, period, and formulation effects between the test and reference products. Significant differences were found between the subjects within the sequence for both AUC0-t, and AUC0-∞, indicating a substantial intersubject variation. The geometric mean ratio of test/reference and their 90% confidence intervals were within the ASEAN (Association of Southeast Asian Nations) bioequivalence acceptance interval of 80% to 125%. Conclusion: Tramadol BPI® and Tramazac® capsules, after a single oral administration of 100 mg, were bioequivalent in respect of their rate and extent of absorption under fasting condition.


2021 ◽  
Vol 10 (2) ◽  
pp. 106-111
Author(s):  
V. M. Kosman ◽  
D. V. Demchenko ◽  
E. A. Jain (Korsakova) ◽  
V. G. Makarov ◽  
V. Yu. Balabanyan

Introduction. The study of pharmacokinetics of medicinal substances and evaluation of their pharmacokinetic parameters is a necessary stage of pharmaceutical development of original medicinal agents, allowing to choose the composition and dosage form of the preparation. This is due to obtaining characteristics of all processes that occur in the body of an animal (human), from the absorption of a drug from the place of administration to its excretion from the body.Aim. To conduct a study of the pharmacokinetics of the pharmaceutical substance and the complex compounds based on it to confirm the pharmaceutical development of a drug of 1-[2-(2-benzoylphenoxy)ethyl]-6-methyluracil and to justify the optimal composition of the ready dosage form (GLP).Materials and methods. The study was carried out on male rabbits with a single oral administration of investigated objects in one dose. Plasma concentrations of 1-[2-(2-benzoylphenoxy)ethyl]-6-methyluracil were determined by high performance liquid chromatography (HPLC) with ultraviolet (UV) detection. Pharmacokinetic parameters were calculated by extramodel method of statistical moments.Results and discussion. Assay 1-[2-(2-benzoylphenoxy)ethyl]-6-methyluracil quantification in rabbit blood plasma by HPLC has been developed and validated in the concentration range 10–720 ng/ml in accordance with modern requirements and satisfies them for all indicators. Assay was applicated to analysis of plasma samples obtained from laboratory animals after a single oral administration of a substance and solid dispersion systems of 1-[2-(2-benzoylphenoxy)ethyl]-6-methyluracil in one dose. The main pharmacokinetic parameters of the studied objects were calculated after obtained plasma concentrations of 1-[2-(2-benzoylphenoxy)ethyl]-6-methyluracil. It was found that the solid dispersion system with Kollidon 17PF has the greatest relative bioavailability from the examined objects; its relative bioavailability to the substance by oral administration was 583 %.Conclusion. The solid dispersion system method increased the bioavailability of 1-[2-(2-benzoylphenoxy)ethyl]-6-methyluracil. Obtained results confirmed correctness of solid dispersion system selection drug e composition and technology development.


Author(s):  
Virginia D. Schmith ◽  
Jie (Jessie) Zhou ◽  
Lauren RL Lohmer

AbstractIntroductionCaly, Druce (1) reported that ivermectin inhibited SARS-CoV-2 in vitro for up to 48 h using ivermectin at 5μM. The concentration resulting in 50% inhibition (IC50, 2 µM) was >35x higher than the maximum plasma concentration (Cmax) after oral administration of the approved dose of ivermectin when given fasted.MethodSimulations were conducted using an available population pharmacokinetic model to predict total (bound and unbound) and unbound plasma concentration-time profiles after a single and repeat fasted administration of the approved dose of ivermectin (200 μg/kg), 60 mg, and 120 mg. Plasma total Cmax was determined and then multiplied by the lung:plasma ratio reported in cattle to predict the lung Cmax after administration of each single dose.ResultsPlasma ivermectin concentrations of total (bound and unbound) and unbound concentrations do not reach the IC50, even for a dose level 10x higher than the approved dose. Even with higher exposure in lungs than plasma, ivermectin is unlikely to reach the IC50 in lungs after single oral administration of the approved dose (predicted lung: 0.0857 µM) or at doses 10x higher that the approved dose administered orally (predicted lung: 0.817 µM).ConclusionsThe likelihood of a successful clinical trial using the approved dose of ivermectin is low. Combination therapy should be evaluated in vitro. Re-purposing drugs for use in COVID-19 treatment is an ideal strategy but is only feasible when product safety has been established and experiments of re-purposed drugs are conducted at clinically relevant concentrations.


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