scholarly journals Plasma appearance and disappearance of an oral dose of 25-hydroxyvitamin D2in healthy adults

2011 ◽  
Vol 107 (8) ◽  
pp. 1128-1137 ◽  
Author(s):  
Kerry S. Jones ◽  
Inez Schoenmakers ◽  
Les J. C. Bluck ◽  
Shujing Ding ◽  
Ann Prentice
Keyword(s):  
Vitamin D ◽  
Plasma Concentration ◽  
Oral Dose ◽  
Half Life ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Post Dose ◽  
Vitamin D Metabolism ◽  
Blood Samples ◽  
Potential Biomarker

25-Hydroxyvitamin D (25(OH)D) half-life is a potential biomarker for investigating vitamin D metabolism and requirements. We performed a pilot study to assess the approach and practical feasibility of measuring 25(OH)D half-life after an oral dose. A total of twelve healthy Gambian men aged 18–23 years were divided into two groups to investigate the rate and timing of (1) absorption and (2) plasma disappearance after an 80 nmol oral dose of 25(OH)D2. Fasting blood samples were collected at baseline and, in the first group, every 2 h post-dose for 12 h, at 24 h, 48 h and on day 15. In the second group, fasting blood samples were collected on days 3, 4, 5, 6, 9, 12, 15, 18 and 21. Urine was collected for 2 h after the first morning void at baseline and on day 15. 25(OH)D2plasma concentration was measured by ultra-performance liquid chromatography-tandem MS/MS and corrected for baseline. Biomarkers of vitamin D, Ca and P metabolism were measured at baseline and on day 15. The peak plasma concentration of 25(OH)D2was 9·6 (sd0·9) nmol/l at 4·4 (sd1·8) h. The terminal slope of 25(OH)D2disappearance was identified to commence from day 6. The terminal half-life of plasma 25(OH)D2was 13·4 (sd2·7) d. There were no significant differences in plasma 25(OH)D3, total 1,25(OH)2D, parathyroid hormone, P, Ca and ionised Ca and urinary Ca and P between baseline and day 15 and between the two groups. The present study provides data on the plasma response to oral 25(OH)D2that will underpin and contribute to the further development of studies to investigate 25(OH)D half-life.

scholarly journals The Effect of Pre-Postnatal Nicotine Exposure on Types and Levels of Plasma Sialic Acids in Rats

Proceedings ◽  
2018 ◽  
Vol 2 (25) ◽  
pp. 1546
Author(s):  
Soycan Mizrak ◽  
Umut Sahar ◽  
Afrooz Rashnonejad ◽  
Remziye Deveci ◽  
Gulinnaz Ercan
Keyword(s):  
Sialic Acid ◽  
Plasma Concentration ◽  
Half Life ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Albino Rats ◽  
Nicotine Administration ◽  
Wide Range ◽  
Concentration Changes ◽  
Per Oral

Nicotine, is an alkaloid compound consisting of pyridine and pyrolidine ring. Its closed formula is C10H4N2. During smoking peak plasma concentration changes from 25 to 50 ng/mL. Its half-life is 1–2 h. Nicotine is metabolized primarily in the liver and excreted by the kidneys. The plasma concentration of the nicotine metabolite cotinine is 10 times more than nicotine and its half-life is longer around 15 to 20 h. Cotinine can be found in both amniotic fluid and umbilical cord blood given that it passes across the placental barrier. Adverse effects of nicotine and its metabolites on the fetus are suggested but have not been proven by scientific explanations till now. Sialic acid (Sia) is a modified nine-carbon sugar. They are located on the last end of the glycan chains located in the glycoconjugate structures. They organize a wide range of relationships between cells and their environment such as cellular recognition, adhesion, transmission, differentiation and aging. The aim of this study is to determine the possible changes in the sialic acid levels and types in the plasma after different levels of nicotine applied to Swiss Albino rats in order to assess the effect of long-term per oral nicotine administration.

scholarly journals Pharmacokinetics of Tinidazole in Chinese subjects: Comparison of Mongolian, Korean, Hui, Uighur and Han nationalities

2009 ◽  
Vol 12 (2) ◽  
pp. 175 ◽  
Author(s):  
Xin-Yu Chang ◽  
Tao Guo ◽  
Dong-Ya Xia
Keyword(s):  
Oral Dose ◽  
Single Oral Dose ◽  
Half Life ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Elimination Rate ◽  
Area Under The Curve ◽  
Elimination Half ◽  
Pharmacokinetic Properties ◽  
Chinese Subjects

ABSTRACT - Purpose. This study investigated the pharmacokinetics of tinidazole in subjects of five different Chinese nationalities (Han, Mongolian, Korean, Hui, and Uighur). Methods. Fifty healthy subjects (five male and five female of each nationality) were recruited for the study, and each received 1 g tinidazole. A total of 14 blood samples were collected over a 72-hour period after administration. Results. Pharmacokinetic profiles, including area under the curve from time zero to infinity (AUC0-inf), peak plasma concentration (Cmax), time to reach Cmax (tmax), oral clearance (CL/F), elimination rate constant (Ke), and elimination half-life (t1/2), were determined following a single oral dose of tinidazole. The respective pharmacokinetic properties of Han, Mongolian, Korean, Hui, and Uighur nationalities were: half-life (h): 16.94±2.40, 16.40±1.79, 16.63±1.82, 16.81±1.56, 14.34±1.92; Cmax (μg/mL): 19.04±2.42, 19.22±4.93, 20.83±3.33, 20.25±4.05, 18.81±3.10; AUC0-inf (h•μg/mL): 483.13±65.65, 479.70±99.74, 511.07±53.47, 514.25±130.78, 388.58±37.37. The t1/2 and AUC0-inf of Uighur subjects were significantly lower (p =0.023, 0.011) and the CL/F and Ke were significantly higher (p = 0.003, 0.013) than those of other nationalities. After normalization by weight, the differences in AUC0-inf and CL/F between Uigur subjects and those of other races were still significant. Conclusions. The results indicate that ethnicity had significant impact on the pharmacokinetics of tinidazole after a single oral dose in healthy volunteers of different nationalities in China.

scholarly journals Evaluation of the impact of renal impairment on the pharmacokinetics of glasdegib in otherwise healthy volunteers

2021 ◽  
Author(s):  
Naveed Shaik ◽  
Robert R. LaBadie ◽  
Brian Hee ◽  
Geoffrey Chan
Keyword(s):  
Plasma Concentration ◽  
Renal Impairment ◽  
Peak Plasma ◽  
Severe Renal Impairment ◽  
Peak Plasma Concentration ◽  
Safety Data ◽  
Normal Group ◽  
Open Label ◽  
Post Dose ◽  
The Impact

Abstract Purpose Glasdegib is being developed for indications in myeloid malignancies. The effect of renal impairment on the pharmacokinetics (PK) of a single, oral, 100-mg glasdegib dose under fasted conditions was assessed. Methods Open-label, parallel-group study (NCT03596567). Participants of good general health were selected and categorized, based on their estimated glomerular filtration rate, into normal (≥ 90 mL/min), moderate (≥ 30 to < 60 mL/min), or severe (< 30 mL/min) renal impairment groups. Blood samples were collected up to 120 h post-dose. PK exposure parameters were calculated using non-compartmental analysis. Results All 18 participants completed the study. Respectively, ratios of adjusted geometric means (90% confidence interval) for glasdegib area under the curve from time 0 to infinity and peak plasma concentration versus normal participants were 205% (142–295%) and 137% (97–193%) in the moderate group, and 202% (146–281%) and 120% (77–188%) in the severe group. Glasdegib median time to peak plasma concentration was 2.0 h in both impairment groups and 1.5 h in the normal group. Mean oral clearance was decreased by approximately 50% in both renal impairment groups compared with the normal group. The plasma-free fraction of glasdegib was not altered by renal impairment. Five all-causality adverse events were reported in three participants; two were considered treatment-related. Conclusion The similar changes in exposure observed for participants with renal impairment, coupled with the known safety data from clinical experience, suggest that a lower starting dose of glasdegib may not be required for moderate or severe renal impairment. Trial registration: ClinicalTrials.gov: NCT03596567 (started May 17, 2018).

Pharmacokinetics of sternal intraossesous atropine administration in normovolemic and hypovolemic swine

2016 ◽  
Vol 11 (4) ◽  
pp. 233-236
Author(s):  
Mark Cornell, MSN, CRNA ◽  
Jaime Kelbaugh, MSN, CRNA ◽  
Brian Todd, MSN, CRNA ◽  
Krista Christianson, MSN, CRNA ◽  
Kevin Grayson, DVM, PhD ◽  
...  
Keyword(s):  
Experimental Study ◽  
Plasma Concentration ◽  
Maximum Concentration ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Pharmacokinetic Parameters ◽  
Blood Samples ◽  
Absorption Phase ◽  
Distribution Phase ◽  
Study Setting

Objective: Characterize and compare the pharmacokinetics of atropine administered via the sternal intraosseous (IO) route in a normovolemic and hypovolemic swine model.Design: Prospective, experimental study. Setting: Vivarium.Subjects: Yorkshire-cross swine (N = 12).Intervention: Atropine was administered via the sternal IO route to normovolemic and hypovolemic swine. Blood samples were drawn at regular intervals after atropine administration and analyzed for plasma atropine concentration. Pharmacokinetic parameters were obtained from modeling the plasma concentrations.Main Outcome Measurements: Pharmacokinetic parameters, maximum concentration (Cmax), and time to maximum concentration (Tmax).Results: The normovolemic and hypovolemic models reached peak plasma concentration immediately and had a very rapid distribution phase with no apparent absorption phase for the IO groups. The hypovolemic group had slower clearance and longer half-life compared to the normovolemic group.Conclusion: The sternal IO route is an effective method of administering atropine and is comparable to the previously reported tibial IO and intravenous data even under conditions of significant hemorrhage.

Buccal Absorption of Fentanyl Is pH-Dependent in Dogs 

1995 ◽  
Vol 82 (3) ◽  
pp. 759-764 ◽  
Author(s):  
James B Streisand ◽  
Jie Zhang ◽  
Suyi Niu ◽  
Scott McJames ◽  
Remco Natte ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Buccal Mucosa ◽  
Half Life ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Elimination Half Life ◽  
Arterial Blood ◽  
Buccal Absorption ◽  
Elimination Half ◽  
Fentanyl Administration

Background Analgesia and sedation have been achieved noninvasively by fentanyl administration through the oral and nasal mucosa. In theory, the transmucosal bioavailability and absorption of fentanyl could be improved by converting more fentanyl to the unionized form by adjusting the surrounding pH. The authors tested this hypothesis in dogs. Methods Under general anesthesia, each of six mongrel dogs was given fentanyl on repeated occasions, first intravenously (once), then by application to the buccal mucosa (six times). Buccal fentanyl administration was accomplished by placement of a pH-buffered solution of fentanyl into a specially constructed cell, which was clamped to the dog's buccal mucosa for 60 min. Fentanyl solutions with pHs of 6.6, 7.2, and 7.7 were studied to span a tenfold difference in the unionized fraction of fentanyl. Femoral arterial blood samples were sampled frequently and analyzed for fentanyl using a radioimmunoassay. Peak plasma concentration and the time of its occurrence for each buccal study were noted from the plasma concentration verses time profile. Terminal elimination half-life, bioavailability, and permeability coefficients were calculated using standard pharmacokinetic techniques. Results The variables peak plasma concentration, bioavailability, and permeability coefficient increased three- to fivefold as the pH of the fentanyl buccal solution increased and more fentanyl molecules became unionized. There was no difference in terminal elimination half-life after intravenous fentanyl (244 +/- 68 min) or buccal fentanyl administration (pH 7.7, 205 +/- 89 min; pH 7.2, 205 +/- 65 min; pH 6.6, 196 +/- 48 min). In all buccal studies regardless of pH, time to peak plasma concentration occurred within 10 min of removal of the fentanyl solutions from the buccal mucosa. Conclusions The buccal absorption, bioavailability, and permeability of fentanyl are markedly increased as the pH of the fentanyl solution becomes more basic. Most likely, this is because of an increase in the fraction of unionized fentanyl.

scholarly journals Pharmacokinetics of Lornoxicam in rabbits after single intravenous bolus and intramuscular administrations

2016 ◽  
Vol 4 (1) ◽  
pp. 66
Author(s):  
Abubakr El-Mahmoudy
Keyword(s):  
Plasma Concentration ◽  
Half Life ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Plasma Concentrations ◽  
Pharmacokinetic Profile ◽  
Volume Of Distribution ◽  
Bolus Administration ◽  
Systemic Bioavailability ◽  
Total Body

The pharmacokinetics of lornoxicam (a non-steroidal anti-inflammatory drug) at a dose of 0.4 mg/Kg body weight was evaluated after single intravenous (i.v.) and intramuscular (i.m.) bolus administrations in rabbits. An HPLC assay using pure lornoxicam base as a standard was used to measure its concentrations in plasma at prefixed time points up to 12 hours post administration. Following an i.v. bolus injection, the plasma concentration-time curves of lornoxicam were best represented by two-compartment open model. The drug was rapidly distributed and moderately eliminated with half-lives of distribution (t1/2α) and elimination (t1/2β) of 0.238 and 2.611 h, respectively. The volume of distribution was large with (Vdss) value of 1.499 L. The total body clearance (ClB) was 0.413 L/h. After i.m. bolus administration of the same dose, lornoxicam was moderately and completely absorbed in rabbits with an absorption half-life (t½ab) of 1.228 h with peak plasma concentration (Cmax) of 0.463 μg/mL attained at 1.512 h (Tmax) and systemic bioavailability of 99.79%. The elimination half-life following i.m. administration was 2.283 h. The extent of plasma protein binding percent was 98.9%. The study recommends the use of lornoxicam in rabbits because of its good pharmacokinetic profile indicated by good absorption, bioavailability and plasma concentrations.

scholarly journals Pharmacokinetics of clarithromycin after single intravenous and intracrop bolus administrations to broiler chickens

2016 ◽  
Vol 4 (1) ◽  
pp. 12 ◽  
Author(s):  
Hanady AwadAllah ◽  
Shaban Awidat ◽  
Abubakr El-Mahmoudy
Keyword(s):  
Plasma Concentration ◽  
Half Life ◽  
Broiler Chickens ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Plasma Concentrations ◽  
Pharmacokinetic Profile ◽  
Volume Of Distribution ◽  
Bolus Administration ◽  
Systemic Bioavailability

<p>The pharmacokinetics of clarithromycin at a dose of 7.5 mg/kg body weight was evaluated after single intravenous (i.v.) and intracrop (i.c.) bolus administrations in broilers. An HPLC assay using pure clarithromycin base as a standard was used to measure its concentrations in plasma. Following an i.v. bolus injection, the plasma concentration-time curves of clarithromycin were best represented by two-compartment open models. The drug was rapidly distributed and moderately eliminated with half-lives of distribution (<em>t</em><sub>1/2α</sub>) and elimination (<em>t</em><sub>1/2β</sub>) of 0.38 and 4.58 h, respectively. The volume of distribution was large with (V<sub>dss</sub>) value of 6.89 L. The total body clearance (<em>Cl</em><sub>B</sub>) was 1.2 L/h. After i.c. bolus administration of the same dose, clarithromycin was moderately absorbed in broilers with an intermediate absorption half-life (<em>T</em><sub>½ab</sub>) of 0.72 h with peak plasma concentration (<em>C</em><sub>max</sub>) of 1.69 μg/ml attained at 1.7 h (<em>T</em><sub>max</sub>) and systemic bioavailability of 66.54%. The elimination half-life following i.c. administration was 2.11 h. The extent of plasma protein binding percent was 52%. The study recommends the use of clarithromycin in broilers because of its good pharmacokinetic profile indicated by good absorption, bioavailability and plasma concentrations ≥ MICs of many sensitive microorganisms.</p>

Pharmacokinetics of Rapacuronium in Infants and Children with Intravenous and Intramuscular Administration

2000 ◽  
Vol 92 (2) ◽  
pp. 376-376 ◽  
Author(s):  
Lynne M. Reynolds ◽  
Andrew Infosino ◽  
Ronald Brown ◽  
Jim Hsu ◽  
Dennis M. Fisher
Keyword(s):  
Plasma Concentration ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Pediatric Anesthesia ◽  
Infants And Children ◽  
Intramuscular Administration ◽  
Pharmacokinetic Analysis ◽  
Intravenous Route ◽  
Population Pharmacokinetic ◽  
In Infants And Children

Background A nondepolarizing muscle relaxant with an onset and offset profile similar to succinylcholine is desirable for pediatric anesthesia. The onset and offset of rapacuronium are rapid in children. In the current study, the authors determined its pharmacokinetic characteristics in children. In addition to administering rapacuronium by the usual intravenous route, the authors also gave rapacuronium intramuscularly to determine uptake characteristics and bioavailability. Methods Forty unpremedicated patients aged 2 months to 3 yr were anesthetized with halothane, 0.82-1.0% end-tidal concentration. When anesthetic conditions were stable, rapacuronium was injected either into a peripheral vein (2 mg/kg for infants, 3 mg/kg for children) or a deltoid muscle (2.8 mg/kg for infants, 4.8 mg/kg for children). Four venous plasma samples were obtained from each subject 2-240 min after rapacuronium administration. A mixed-effects population pharmacokinetic analysis was applied to these values to determine bioavailability, absorption rate constant, and time to peak plasma concentration with intramuscular administration. Results Plasma clearance was 4.77 ml x kg(-1) x min(-1) + 8.48 ml/min. Intramuscular bioavailability averaged 56%. Absorption from the intramuscular depot had two rate constants: 0.0491 min(-1) (72.4% of absorbed drug) and 0.0110 min(-1) (27.6% of the absorbed drug). Simulation indicated that plasma concentration peaks 4.0 and 5.0 min after intramuscular rapacuronium in infants and children, respectively, and that, at 30 min, less than 25% of the administered dose remains to be absorbed from the intramuscular depot. Conclusions In infants and children, rapacuronium's clearance and steady state distribution volume are less than in adults. After intramuscular administration, bioavailability is 56%, and plasma rapacuronium concentrations peak within 4 or 5 min.

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