Comparison of α -tocopherol acetate preparations given as single intraperitoneal or subcutaneous doses for increasing plasma and liver α -tocopherol in sheep fed a low vitamin E diet

1996 ◽  
Vol 36 (4) ◽  
pp. 421 ◽  
Author(s):  
GM Smith ◽  
JM Fry ◽  
KF Ilett

This experiment examined the efficacy of a single dose of �-tocopherol acetate (2000 IU) in either an aqueous or oily formulation, given as an intraperitoneal (i.p.) or subcutaneous (s.c.) injection or orally as an aqueous formulation, at raising a-tocopherol concentrations in blood plasma and liver of young sheep with low vitamin E. Maximum plasma concentrations (Cmax) were greatest in sheep supplemented by the s.c.-aqueous method or orally (4.83 and 3.49 mg/L respectively). These values were 3.0-5.7 times the C, values of the other treatment groups. Also, the time taken to reach Cmax (Tmax) was far shorter in these 2 treatments than in the other treatments (Tmax values were 0.70 and 0.65 days respectively). Tmax values were greatest for the oily formulation (42 and 73 days for the i.p. and S.C. injections, respectively). The area under the plasma a-tocopherol concentration-time curve (AUC(0-85d)), was greatest for the s.c.-aqueous group (median of 2066 mg.h/L). Six of the sheep in the i.p.-aqueous group had AUC(0-85d) values similar to the controls whereas the rest were similar to the s.c.-aqueous group. Plasma �-tocopherol acetate was only consistently detected in sheep in the s.c.-aqueous group (Cmax of 25.25 � 3.14 mg/L and Tmax of 0.24 � 0.03 days). Pharmacokinetic modelling of the plasma data obtained from sheep in the s.c.-aqueous group was helpful in understanding the factors which controlled the appearance and disappearance rates of plasma �-tocopherol in this group. In contrast to plasma data, liver concentrations of �-tocopherol at days 24 and 57 were greatest in sheep supplemented by the i.p.-oily method. The s.c.-aqueous was the second most effective method at raising concentrations in the liver. The results suggest that supplementation by s.c. injection of an aqueous formulation may be an effective means of administering vitamin E to 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.


2006 ◽  
Vol 50 (1) ◽  
pp. 279-285 ◽  
Author(s):  
Anne Schmitt-Hoffmann ◽  
Brigitte Roos ◽  
Markus Heep ◽  
Michael Schleimer ◽  
Erhard Weidekamm ◽  
...  

ABSTRACT BAL8557 is the water-soluble prodrug of a novel antifungal triazole, BAL4815. BAL4815 is active against a broad spectrum of major opportunistic and pathogenic fungi, including strains that are resistant to other azoles. Cohorts of healthy male subjects received single-ascending oral (p.o.) doses of BAL8557 that were equivalent to 100, 200, or 400 mg of BAL4815 or single-ascending, 1-h constant-rate intravenous (i.v.) infusions of BAL8557 which were equivalent to 50, 100, or 200 mg of BAL4815. In each cohort, six subjects were randomly assigned to receive active drug and two subjects were assigned to receive the placebo. All doses were well tolerated, and no severe or serious adverse events occurred. Maximum plasma concentrations of BAL4815 were observed 1.5 to 3 h after p.o. drug intake or at the end of the 1-h infusion. After both routes of administration, values for maximum drug concentration observed in plasma and area under the concentration-time curve increased slightly more than proportionally to the administered dose. Mean elimination half-lives were particularly long (56 to 77 h after p.o. administration and 76 to 104 h after i.v. administration). The volume of distribution was large (155 to 292 liters after p.o. administration and 304 to 494 liters after i.v. administration) and systemic clearance was low (1.9 to 2.8 liter/h after p.o. administration and 2.8 to 5.0 liter/h after i.v. administration). Urinary recovery of BAL4815 was less than 0.4% of the infused dose. Based on the exposure data, oral bioavailability of BAL4815 is assumed to be very high. The pharmacokinetics of BAL4815 are well suited to maintaining concentrations of BAL4815 for a long period of time in the body and to enabling an effective treatment of systemic mycoses.


2006 ◽  
Vol 73 (2) ◽  
pp. 227-234 ◽  
Author(s):  
Guillermo E Meglia ◽  
Søren K Jensen ◽  
Charlotte Lauridsen ◽  
Karin Persson Waller

The aim of this study was to compare the effects of supplementing dairy cows with 1000 IU/day of all-rac-α-tocopheryl acetate (SynAc), RRR-α-tocopheryl acetate (NatAc), or RRR-α-tocopherol (NatAlc), from approximately 3 weeks before estimated calving until 2 weeks after calving, on the concentration of α-tocopherol and its stereoisomers (RRR-, RSS-, RRS-, RSR- and the four 2S-forms of α-tocopherol) in blood and milk. An unsupplemented group was included as control. Blood samples were collected at 3, 2 and 1 weeks before estimated calving, at calving, and 3, 7 and 14 days after calving, while milk samples were taken twice within 24 h after calving and at 7 and 14 days in milk. Overall, time and treatment had significant effects on plasma α-tocopherol with higher concentrations in NatAc than in the other groups. In addition, SynAc had higher concentrations than Control, and NatAlc tended to be higher than Control. The lowest plasma concentrations were observed at calving and 3 days after calving. Independent of treatment, the concentration was higher in colostrum than in milk day 7 and 14 after calving. Analyses of the stereoisomer distribution in plasma and milk showed that, irrespective of dietary treatment, RRR-α-tocopherol was the most predominant form, constituting more than 86%, whereas the remaining part of α-tocopherol was made up by the three synthetic 2R isomers, while the 2S isomers only contributed less than 1% of the total α-tocopherol. In control cows and cows supplemented with natural vitamin E, the proportion of RRR-α-tocopherol in plasma and milk constituted more than 98% of the total α-tocopherol. In conclusion, the results indicate that daily oral supplementation of dairy cows with RRR-α-tocopheryl acetate gives the highest blood concentrations of α-tocopherol in the periparturient period. Analyses of the distribution of the individual stereoisomers of α-tocopherol further indicate that the bioavailability of RRR-α-tocopherol relative to synthetic stereoisomers in cattle is considerably higher than officially accepted until now.


2013 ◽  
Vol 61 (3) ◽  
pp. 376-382
Author(s):  
Jelena Šuran ◽  
Dubravka Flajs ◽  
Maja Peraica ◽  
Andreja Prevendar Crnić ◽  
Marcela Šperanda ◽  
...  

Levamisole has been shown to stimulate the immune response in immunocompromised humans and animals. However, its use as an adjuvant in immunocompromised weaned pigs prone to colibacillosis has only been experimentally tested but not yet officially approved. Therefore, the aim of these studies was to study the pharmacokinetics (PK) of an immunomodulating dose of levamisole in weaned pigs. For that purpose, 20 weaned crossbred pigs were divided into two treatment groups. In this parallel-design study, a single dose of levamisole (2.5 mg/kg body weight) was administered by the intramuscular (i.m.) or oral (p.o.) route. Statistically significant differences between the i.m. and p.o. routes in terminal beta rate constant (β), maximum plasma concentration (Cmax), area under the curve (AUC) for plasma concentration-time curve from time zero to infinity (AUC0-inf), area under the plasma concentration-time curve from time 0 to the last quantifiable time point (AUC0-t) were determined. Further research is needed to establish a relationship between the PK and the immunomodulating effect of levamisole in pigs.


2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e13512-e13512 ◽  
Author(s):  
Arthur P. Staddon ◽  
Trilok V. Parekh ◽  
Roland Elmar Knoblauch ◽  
Chi Keung ◽  
Apexa Bernard ◽  
...  

e13512 Background: Trabectedin (Yondelis; T) is a tetrahydroisoquinoline compound initially isolated from the marine tunicate, Ecteinascidia turbinata, and currently produced synthetically. It is primarily metabolized by the cytochrome P450 (CYP)3A4 enzyme. Thus, potent inducers or inhibitors of this enzyme may alter the plasma concentrations of T. This study assessed the effects of rifampin (R), a strong CYP3A4 inducer, on the pharmacokinetics (PK) and safety of T. Methods: In this 2-way crossover study, patients (≥18 years of age) with locally advanced or metastatic disease were randomized (1:1) to receive one of the 2 treatment sequences: sequence 1: R plus T followed 28 days later by T; sequence 2: T followed 28 days later by R plus T. During each sequence, R (600 mg/day) was administered for 6 consecutive days and T (1.3 mg/m2, IV) was administered over a 3 hour infusion. Dexamethasone (20 mg, IV) was administered before T administration. PK and safety of T were evaluated with and without coadministration of R. Results: Of the 11 enrolled patients, 8 were PK evaluable. Coadministration of R with T decreased mean maximum plasma concentration (Cmax) by approximately 22% and mean area under the plasma concentration-time curve from time 0 to the last quantifiable concentration (AUClast) by approximately 31% (Table 1). Coadministration of R with T also resulted in 23% shorter elimination half-life. Overall, the safety profile of T was comparable when administered alone or with R. Conclusions: In comparison with T alone, coadministration of R resulted in reduced systemic exposure of T in these 8 patients, as measured by Cmax and AUClast. The coadministration of potent inducers of CYP3A4 with T may increase the metabolic clearance of T. Clinical trial information: NCT01273480. [Table: see text]


2017 ◽  
Vol 61 (9) ◽  
Author(s):  
Keith A. Rodvold ◽  
Mark H. Gotfried ◽  
Rakesh Chugh ◽  
Mugdha Gupta ◽  
H. David Friedland ◽  
...  

ABSTRACT The nafithromycin concentrations in the plasma, epithelial lining fluid (ELF), and alveolar macrophages (AM) of 37 healthy adult subjects were measured following repeated dosing of oral nafithromycin at 800 mg once daily for 3 days. The values of noncompartmental pharmacokinetic (PK) parameters were determined from serial plasma samples collected over a 24-h interval following the first and third oral doses. Each subject underwent one standardized bronchoscopy with bronchoalveolar lavage (BAL) at 3, 6, 9, 12, 24, or 48 h after the third dose of nafithromycin. The mean ± standard deviation values of the plasma PK parameters after the first and third doses included maximum plasma concentrations (C max) of 1.02 ± 0.31 μg/ml and 1.39 ± 0.36 μg/ml, respectively; times to C max of 3.97 ± 1.30 h and 3.69 ± 1.28 h, respectively; clearances of 67.3 ± 21.3 liters/h and 52.4 ± 18.5 liters/h, respectively, and elimination half-lives of 7.7 ± 1.1 h and 9.1 ± 1.7 h, respectively. The values of the area under the plasma concentration-time curve (AUC) from time zero to 24 h postdosing (AUC0–24) for nafithromycin based on the mean or median total plasma concentrations at BAL fluid sampling times were 16.2 μg · h/ml. For ELF, the respective AUC0–24 values based on the mean and median concentrations were 224.1 and 176.3 μg · h/ml, whereas for AM, the respective AUC0–24 values were 8,538 and 5,894 μg · h/ml. Penetration ratios based on ELF and total plasma AUC0–24 values based on the mean and median concentrations were 13.8 and 10.9, respectively, whereas the ratios of the AM to total plasma concentrations based on the mean and median concentrations were 527 and 364, respectively. The sustained ELF and AM concentrations for 48 h after the third dose suggest that nafithromycin has the potential to be a useful agent for the treatment of lower respiratory tract infections. (This study has been registered at ClinicalTrials.gov under registration no. NCT02453529.)


2009 ◽  
Vol 43 (5) ◽  
pp. 944-949 ◽  
Author(s):  
Lan Fan ◽  
Gong-You Tao ◽  
Guo Wang ◽  
Yao Chen ◽  
Wei Zhang ◽  
...  

Background Ginkgo biloba extract (GBE), the best selling herbal medicine in the world, has been reported to inhibit P-glycoprotein in vitro. However, the effects of GBE on P-glycoprotein activity in humans have not been clarified. Objective To investigate the effects of single and repeated GBE ingestion on the oral pharmacokinetics of talinolol, a substrate drug for P-glycoprotein in humans. Methods Ten unrelated healthy male volunteers were selected to participate in a 3-stage sequential study. Plasma concentrations of talinolol from 0 to 24 hours were measured by high-performance liquid chromatography after talinolol 100 mg was administrated alone, with a single oral dose of GBE (120 mg), and after 14 days of repeated GBE ingestion (360 mg/day). Results A single oral dose of GBE did not affect the pharmacokinetics of talinolol. Repeated ingestion of GBE increased the talinolol maximum plasma concentration (Cmax) by 36% (90% CI 10 to 68; p = 0.025), the area under the concentration-time curve (AUC)0-24 by 26% (90% CI 11 to 43; p = 0.008) and AUC0-∞ by 22% (90% CI 8 to 37; p = 0.014), respectively, without significant changes in elimination half-life and the time to Cmax. Conclusions Our results suggest that long-term use of GBE significantly influenced talinolol disposition in humans, likely by affecting the activity of P-glycoprotein and/or other drug transporters.


2021 ◽  
Vol 7 ◽  
Author(s):  
Salah Uddin Ahmad ◽  
Jichao Sun ◽  
Fusheng Cheng ◽  
Bing Li ◽  
Safia Arbab ◽  
...  

A comparative study on pharmacokinetics of four long-acting enrofloxacin injectable formulations was investigated in 36 healthy pigs after intramuscular injection according to the recommended single dose @ 2.5 mg/kg body weight. The drug concentrations in the plasma were computed using high-performance liquid chromatography (HPLC) with fluorescence detection. WinNonLin5.2.1 software was used to analyze the experimental data and compared it under one-way ANOVA using SPSS software with a 95% confidence interval (CI). The main pharmacokinetic parameters, that is, the maximum plasma concentrations (Cmax), the time to maximum concentration (Tmax), area under the time curve concentration (AUCall) and Terminal half-life (T1/2) were 733.84 ± 129.87, 917.00 ± 240.13, 694.84 ± 163.49, 621.98 ± 227.25 ng/ml, 2.19 ± 0.0.66, 1.50 ± 0.37, 2.89 ± 0.24, 0.34 ± 0.13 h, 7754.43 ± 2887.16, 8084.11 ± 1543.98, 7369.42 ± 2334.99, 4194.10 ± 1186.62 ng h/ml, 10.48 ± 2.72, 10.37 ± 2.38, 10.20 ± 2.81, and 10.61 ± 0.86 h for 10% enrofloxacin (Alkali), 20% enrofloxacin (Acidic), Yangkang and control drug Nuokang® respectively. There were significant differences among Cmax, Tmax, and AUCall of three formulations compare with that of the reference formulation. No significant differences were observed among the T1/2 for tested formulations compare with the reference formulation. The pharmacokinetic parameters showed that the tested formulations were somewhat better compared to the reference one. The calculated PK/PD indices were effective for bacteria such as Actinobacillus pleuropneumoniae and Pasteurella multocida with values higher than the cut-off points (Cmax/MIC90≥10–12 and AUC/MIC90 ≥ 125). However, they were not effective against bacteria like Haemophilus parasuis, Streptococcus suis, E. coli, and Bordetella bronchiseptica where lower values were obtained.


1991 ◽  
Vol 31 (1) ◽  
pp. 45 ◽  
Author(s):  
GJ Judson ◽  
PJ Babidge ◽  
WJ Babidge

Alpha-tocopherol concentrations were measured in plasma, liver and adipose tissue of young sheep given dl-alpha-tocopherol acetate, orally or subcutaneously, at dosages of 0, 15, 30, 60 or 120 mg/kg liveweight while the sheep consumed a pelleted diet containing less than 10 mg/kg dry matter alpha-tocopherol. Significant responses in plasma alpha-tocopherol concentrations were observed after 1 and 4 days in sheep given oral doses of the vitamin but not in those given subcutaneous injections. Variation between animals within treatment groups was not reduced by expressing plasma alpha-tocopherol as a ratio of various plasma lipid fractions. Oral doses of 30 and 120 mg/kg liveweight of alpha-tocopherol increased the mean liver alpha-tocopherol concentrations at 7 days, but only the highest dose significantly increased liver concentrations above that of untreated sheep at 1 and 2 months. Increases in mean liver alpha-tocopherol concentrations were observed 1 month after subcutaneous injections, at dosages above 15 mg/kg liveweight, suggesting a slow mobilisation of the vitamin from the injection site. Concentrations of alpha-tocopherol in adipose tissue were not altered by alpha-tocopherol treatment. Plasma and liver alpha-tocopherol concentrations were positively correlated, although vitamin E treatments and time from treatment had small but significant effects on this relationship. The results suggest that oral dosage is preferable to subcutaneous injection when administering alpha-tocopherol acetate to sheep. An oral dose of 120 mg/kg liveweight will probably maintain adequate liver alpha-tocopherol concentrations for a period of about 2 months in sheep consuming diets of low vitamin E content.


2006 ◽  
Vol 51 (2) ◽  
pp. 560-565 ◽  
Author(s):  
Peter J. Ruane ◽  
Andrew D. Luber ◽  
Mary Beth Wire ◽  
Yu Lou ◽  
Mark J. Shelton ◽  
...  

ABSTRACT Once-daily (QD) fosamprenavir (FPV) at 1,400 mg boosted with low-dose ritonavir (RTV) at 200 mg is effective when it is used in combination regimens for the initial treatment of human immunodeficiency virus infection. Whether a lower RTV boosting dose (i.e., 100 mg QD) could ensure sufficient amprenavir (APV) concentrations with improved safety/tolerability is unknown. This randomized, two 14-day-period, crossover pharmacokinetic study compared the steady-state plasma APV concentrations, safety, and tolerability of FPV at 1,400 mg QD boosted with either 100 mg or 200 mg of RTV QD in 36 healthy volunteers. Geometric least-square (GLS) mean ratios and the associated 90% confidence intervals (CIs) were estimated for plasma APV maximum plasma concentrations (C max), the area under the plasma concentration-time curve over the dosing period (AUC0-τ), and trough concentrations (C τ) during each dosing period. Equivalence between regimens (90% CIs of GLS mean ratios, 0.80 to 1.25) was observed for the plasma APV AUC0-τ (GLS mean ratio, 0.90 [90% CI, 0.84 to 0.96]) and C max (0.97 [90% CI, 0.91 to 1.04]). The APV C τ was 38% lower with RTV at 100 mg QD than with RTV at 200 mg QD (GLS mean ratio, 0.62 [90% CI, 0.55 to 0.69]) but remained sixfold higher than the protein-corrected 50% inhibitory concentration for wild-type virus, with the lowest APV C τ observed during the 100-mg QD period being nearly threefold higher. The GLS mean APV C τ was 2.5 times higher than the historical C τ for unboosted FPV at 1,400 mg twice daily. Fewer clinical adverse drug events and smaller increases in triglyceride levels were observed with the RTV 100-mg QD regimen. Clinical trials evaluating the efficacy and safety of FPV at 1,400 mg QD boosted by RTV at 100 mg QD are now under way with antiretroviral therapy-naïve patients.


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