Intravenous Administration In Healthy Volunteers Research Articles

Inhaled fentanyl aerosol through a drug-device combination for breakthrough cancer pain: A multicenter, randomized, double-blind, placebo-controlled trial.

e24058 Background: Breakthrough cancer pain (BTcP) can significantly impact the life quality of the cancer patient. Wide-used rapid-onset opioids (ROOs) for BTcP are transmucosal fentanyl-based preparations. Inhaled fentanyl demonstrated similar pharmacokinetic properties as intravenous administration in healthy volunteers. Fentanyl aerosol can be generated via hand-held drug-device delivery system, providing rapid, consistent multi-dose administration. Fentanyl inhalant was explored as alternative treatment of BTcP in cancer patients in this study to evaluate its efficacy, safety, and tolerability in BTcP patients with well-controlled background cancer pain. Methods: Adults ≥18 years with cancer are eligible if they were experiencing persistent cancer- or treatment-related pain with above mild severity and 1-4 episode occurrences daily. Each patient was treated and observed for 6 BTcP episodes (4 with fentanyl inhalant, 2 with placebo). During each episode, patients were allowed to inhale up to six shots within 1 hour. Pain intensity was recorded using 11-point Numerical Rating Scale (NRS) at predefined time points. The primary endpoint was the time-weighted Sum of Pain Intensity Difference scores at 30 minutes (SPID30) after the first inhalation. Results: 335 BTcP episodes in 59 patients were treated. SPID30 was analyzed using mixed model of repeated measures with treatment (fentanyl inhalant or placebo), BTcP episode, baseline pain intensity score as fixed factors, and subject as random factor. Mean SPID30 ± SD was -97.4 ± 48.43 for fentanyl-treated episodes, and -64.6 ± 40.25 for placebo-treated episodes. Based on treatment adjustment in the mixed covariance model, significant difference (p < 0.001) was reported with mean treatment difference of -27.7 (LS-mean ± SD, -94.2 ± 4.49 for fentanyl and -66.5 ± 4.86 for placebo). It enlarged at 60 minutes (SPID60) with a mean treatment difference of -57.9 (LS-mean ± SD, -231.4 ±105.14 for fentanyl and -162.2 ± 91.21 for placebo, p < 0.001). Significant differences in PID for episodes treated with fentanyl versus placebo were seen 4 minutes after the first dosing and maintained up to 60 minutes. Other endpoints showed statistical significance favoring fentanyl treatment, including the proportion of NRS ≤ 3, NRS pain scores decreased ≥ 33% or ≥ 50% from baseline after completion of BTcP treatment within 30 minutes of first dose, and Pain Relief Score Within 30 Minutes of the First Dose (PR30). Only 4.4% of BTcP episodes required rescue medication in fentanyl group. Major adverse events were mild or moderate in severity and were typical for opioid drugs. Conclusions: Fentanyl inhalant is safe, effective, and well-tolerated for managing BTcP. It provides a non-invasive route for systemic drug delivery and can be self-administered or given by family caregivers as personalized and regular pain management. Clinical trial information: NCT05531422 .

New Drugs on the Horizon for Functional and Motility Gastrointestinal Disorders

New Drugs on the Horizon for Functional and Motility Gastrointestinal Disorders

Adult and infant pharmacokinetic profiling of dihydrocodeine using physiologically based pharmacokinetic modeling.

We previously analysed the serum concentrations of dihydrocodeine in a 1-month-old infant with respiratory depression after being prescribed dihydrocodeine phosphate 2.0 mg/day divided t.i.d. for 2 days. The purpose was to develop a full physiologically based pharmacokinetic (PBPK) model that could account for these and other drug monitoring results. Based on experiments in Caco-2 cell monolayers, the effective permeability of dihydrocodeine in human jejunum was established as 1.28 × 10-4 cm/s. The in vitro Vmax /Km values for dihydrocodeine demethylation mediated by recombinant cytochrome P450 2D6 and 3A4 were 0.19 and 0.066 μl/min/pmol, respectively, and for dihydrocodeine 6-O-glucuronidation mediated by recombinant UGT2B4 and 2B7, the Vmax /Km values were 0.14 and 0.22 μl/min/mg protein, respectively. Renal clearance was calculated as 5.37 L/h on the total clearance value multiplied by the fraction recovered in urine. The reported plasma concentration-time profiles of dihydrocodeine after intravenous administration in healthy volunteers were used to adjust the tissue partitioning ratios. The developed model simulated the pharmacokinetic profiles of dihydrocodeine after single and multiple oral administrations reasonably well in the same population. Subsequently, the validated model was used to simulate pharmacokinetic profiles for five pediatric cases, including the 1-month-old Japanese boy and a 14-year-old Japanese girl who took an overdose of dihydrocodeine phosphate (37 mg). The simulated pharmacokinetic profiles for five virtual pediatric subjects matching the age, gender, and P450 2D6 phenotype of each case approximately reflected the observed values. These results suggested that our dihydrocodeine PBPK model reproduced the results of clinical cases reasonably well for subjects.

Development and validation of a UPLC-MS/MS method for quantification of doxofylline and its metabolites in human plasma

A sensitive and specific ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for simultaneous determination of doxofylline and its two metabolites in human plasma. After protein precipitation with methanol, the chromatographic separation was carried out on an ACQUITY UPLC HSS T3 column, with acetonitrile and 0.1% formic acid in water as mobile phase at a flow rate of 0.30 mL·min−1. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via electrospray ionization (ESI) source, with target quantitative ion pairs of m/z 267.0→181.1 for doxofylline, 239.0→181.1 for theophylline-7-acetic acid and 225.1→181.1 for etofylline. The calibration curve was linear over the range of 2–3000 ng·mL−1 (r > 0.99). The LLOQ was evaluated to be 2 ng·mL−1. The method described herein allowed simultaneous determination of the three analytes for the first time and was successfully applied to the pharmacokinetic study of doxofylline and its metabolites after intravenous administration in healthy volunteers.

Abstract CT208: Absolute bioavailability of dacomitinib (PF-00299804): Comparison of oral and intravenous administration in healthy volunteers

Abstract Background: Dacomitinib (D) is a highly selective, irreversible small molecule inhibitor of the human epidermal growth factor receptor family of tyrosine kinases in clinical development for the treatment of non-small cell lung cancer (NSCLC). A 45-mg once daily oral dose is currently being evaluated in Phase 3 for NSCLC therapy in multiple settings. D has not previously been administered clinically as an intravenous dose. The absolute bioavailability (F%) of D in rats, dogs and monkeys was found to range from 56% to 100% at doses between 20 and 50 mg/kg. The current study was conducted to estimate the absolute bioavailability of D after oral administration (Test) relative to intravenous (IV, Reference) administration. Methods: A total of 14 healthy volunteers (HV) were enrolled in this Phase 1, open-label, 2-period, 2-treatment, fixed sequence study. Each HV received 2 treatments of D: Reference (20 mg IV infusion over 1 hour) and Test (45 mg oral), with a washout period of at least 16 days between each. Plasma samples to determine concentrations of D and its metabolite, PF-05199265, were collected at intervals up to 216 hours post-dose after IV or oral dose, and safety was assessed. F% was estimated as the ratio of dose-normalized adjusted geometric means of AUCinf for oral D and IV D using a mixed-effect model with treatment as a fixed effect and subject as a random effect. Corresponding 90% confidence intervals (CIs) were to be obtained from the same model. Results: The mean AUCinf, Cmax and CL/F for D after a single 45-mg oral dose were 1487 ng*hr/mL, 19.84 ng/mL and 30.27 L/hr, respectively. The mean AUCinf, Cmax and CL for D after a single 20-mg IV dose were 847 ng*hr/mL, 52 ng/mL and 23.61 L/hr, respectively. Mean pharmacokinetic parameters following a single oral dose in this study were similar to those observed in other single oral dose studies in HV. Conclusions: Assuming that clearance of D is similar via oral or IV administration at the administered doses, the absolute bioavailability of D was estimated to be 80.01% (90% CI: 74.90%, 85.47%). Single oral doses of D in both treatments were generally safe and well tolerated in the HV evaluated in this study. Citation Format: Nagdeep Giri, Robert R. LaBadie, Yali Liang, Tanya Boutros, Zelanna Goldberg, Carlo L. Bello. Absolute bioavailability of dacomitinib (PF-00299804): Comparison of oral and intravenous administration in healthy volunteers. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT208. doi:10.1158/1538-7445.AM2014-CT208

A pilot study assessing the bioavailability and pharmacokinetics of diazepam after intranasal and intravenous administration in healthy volunteers

Diazepam rectal gel (Diastat(®)) is the only FDA-approved product indicated for acute repetitive seizures. Despite its proven efficacy, most older children and adults object to this route of administration. As a result, many patients do not realize the benefit of a therapy that can improve outcomes and decrease healthcare costs. Intranasal administration of benzodiazepines offers a potential alternative. The primary objective of this study was to compare the bioavailability and pharmacokinetics of two novel intranasal (IN) diazepam (DZP) formulations versus intravenous (IV) administration in healthy volunteers. Twenty-four healthy volunteers were randomized into an open-label, three-way crossover study. 10mg doses of two investigational intranasal DZP formulations (solution, suspension) and a 5mg IV dose of commercially available DZP injectable, USP were given. A two-week washout period separated treatments. Plasma samples for DZP analysis were collected pre-dose and at regular intervals up to 240 h post-dose. DZP concentration-time data were analyzed using a non-compartmental pharmacokinetics approach. Exposure following administration of DZP IN solution (absolute bioavailability - 97%) was greater than the IN suspension (absolute bioavailability - 67%). Mean Cmaxvalues for the suspension and solution formulations were 221 ng/mL and 272 ng/mL, respectively. Median time to maximum concentration (Tmax) was 1h and 1.5h for suspension and solution formulation, respectively. Both investigational intranasal formulations were well tolerated. The results of this pilot study indicate that development of an intranasal diazepam formulation with high bioavailability, reasonable variability, and good tolerability is feasible.

Pharmacokinetic and Pharmacodynamic Properties of Buprenorphine After a Single Intravenous Administration in Healthy Volunteers: A Randomized, Double-Blind, Placebo-Controlled, Crossover Study

Background: Buprenorphine is used as an analgesic for postoperative and chronic pain. The usual sublingual dose is 0.2 to 0.8 mg, and the usual parenteral dose is 0.3 mg for acute postoperative pain. The pharmacokinetic and related pharmacodynamic properties of buprenorphine at these doses have not been characterized. Objective: The aim of this study was to assess the pharmacokinetic properties of buprenorphine 0.002 mg/kg IV (0.15 mg/70 kg) and its antinociceptive and psychomotor effects. Methods: Healthy male volunteers received 0.002 mg/kg buprenorphine IV in a randomized, double-blind, placebo-controlled, crossover design. Blood samples were collected at 0.5, 1, 1.5, 1.75, 2, 2.5, 3, 4, 5, 6, and 8 hours for the determination of plasma concentrations. Pharmacokinetic parameters were estimated by a compartmental model using specialized software. Antinociceptive and psychomotor effects were determined for 8 hours. Quantitative sensory testing with thermal and electrical (nociceptive flexion RIII reflex) stimulations was performed. The cold pressor test was used to assess pain tolerance to a tonic, intense pain stimulation. Psychomotor performance was assessed by the digit symbol substitution test (DSST). Participants also rated sedation on an 11-point numeric scale (0 = none to 10 = severe). A selective liquid chromatography-tandem mass spectrometry assay was developed for the determination of buprenorphine; the limit of quantification was 0.05 ng/mL using a 0.25-mL plasma aliquot. Participants were instructed to report adverse effects, which were recorded for type, time of onset, seriousness, and duration. Results: The study enrolled 12 participants, all of whom were white. Mean (SD) age was 26 (3.5) years, and mean weight was 67 (9) kg. None of the participants had a history of opiate abuse. Buprenorphine significantly increased the objective (nociceptive flexion RIII reflex) and subjective pain thresholds for >4 hours and pain tolerance (cold pressor test) for 2 hours. The mean (SD) RIII reflex threshold and subjective threshold at baseline were 31.6 (9.5) mÅ and 45.5 (22.3) mÅ, respectively. The maximum increases (mean [SD]) were +14.1 (17.5) mÅ for the RIII reflex ( P = 0.02) and +24.2 (21.7) mÅ for the subjective threshold ( P = 0.02), corresponding to mean (SEM) percentages of 53.7% (20.2%) and 74.7% (20.4%) of the baseline values, respectively. The maximum increases were observed at 120 minutes for both measures. The effect of buprenorphine on pain tolerance peaked at 30 minutes. Mean (SEM) latency before withdrawal of the hand was 69 (10) seconds, corresponding to a mean increase of 63.8% (14.4%) from baseline ( P = 0.003). Buprenorphine had a significant effect on the DSST. The mean maximum decrease in the total number of symbols drawn was −6 (14.5%; P = 0.005) at 1 hour. The participants reported high levels of sedation: at peak effect (120 minutes), mean scores increased from 2.9 to 6.4 (SEM 0.7) ( P = 0.005). Levels returned to baseline values by the end of the session, unlike for the nociceptive tests. The onset of effects occurred during the distribution phase for all the measures, and their duration was observed across a wide range of concentrations during the elimination phase. The most likely explanation for this finding is the high affinity of buprenorphine at μ-opioid receptors, and possibly distribution to the brain. Buprenorphine t l/2 was 2.75 hours. A secondary peak in concentration was observed at 90 minutes, suggesting enterohepatic circulation of buprenorphine. A 2-compartment model adequately described buprenorphine pharmacokinetics. Conclusions: A clinically relevant analgesic dose of 0.002 mg/kg (0.15 mg/70 kg) of buprenorphine had a significant effect on nociception and psychomotor performance in these healthy male volunteers. A 2-compartment model satisfactorily characterized buprenorphine pharmacokinetics, and we found evidence of enterohepatic circulation.

The Absolute Oral Bioavailability and??Population-Based Pharmacokinetic Modelling of a Novel Dipeptidylpeptidase-IV Inhibitor, Vildagliptin, in Healthy Volunteers

Vildagliptin is a potent, selective, orally active inhibitor of dipeptidylpeptidase-IV being developed for the treatment of type 2 diabetes mellitus. The objective of this study was to assess the absolute oral bioavailability of vildagliptin by comparing the systemic exposure after oral and intravenous administration in healthy volunteers. This was an open-label, randomised, two-period, two-treatment, crossover study in 11 healthy volunteers. Subjects received vildagliptin 50mg orally or 25mg as a 30-minute intravenous infusion on two occasions separated by a 72-hour washout period. Vildagliptin concentrations were determined by a specific assay in urine (lower limit of quantification [LLQ] = 5 ng/mL) and serial plasma samples (LLQ = 2 ng/mL) obtained up to 24 hours after dosing. Noncompartmental analysis and population pharmacokinetic modelling were performed. Both noncompartmental analysis and population pharmacokinetic modelling estimated the absolute oral bioavailability of vildagliptin to be 85%. Renal elimination of unchanged vildagliptin accounted for 33% and 21% of the administered dose 24 hours after intravenous and oral administration, respectively. Renal clearance (13 L/h) was approximately one-third of the total systemic clearance (41 L/h). Two peaks were observed in plasma concentrations at 1 and 3 hours after oral administration in nine of 11 subjects. Modelling based on the population approach identified two absorption sites with lag-times of 0.225 and 2.46 hours. Both absorption rate constants were slower than the elimination rate constant, indicating 'flip-flop' kinetics after oral administration. Bodyweight was identified as a factor with an impact on the volume of distribution of the peripheral compartment. Clearance was 24% greater in males (44.6 L/h) than in females (36.1 L/h). Vildagliptin is rapidly and well absorbed with an estimated absolute bioavailability of 85%. Two possible sites of absorption were identified, and the absorption rates were slower than the elimination rate, indicating a flip-flop phenomenon after oral dosing.

Safety and Pharmacologic Activity of a New Nitrate Ester, ITF 296, After Intravenous Administration in Healthy Volunteers

Safety and Pharmacologic Activity of a New Nitrate Ester, ITF 296, After Intravenous Administration in Healthy Volunteers

Safety and Pharmacologic Activity of a New Nitrate Ester, ITF 296, After Intravenous Administration in Healthy Volunteers

To evaluate the safety and pharmacologic activity of ITF 296 in humans, three groups of healthy male normotensive subjects were studied. The first two groups (six subjects each) received, in ascending order, three dose levels of ITF 296 by 30-min intravenous infusion (group I, 0.1, 0.5, 1.0 microgram/kg/min; group II, 2.0, 4.0, 6.0 micrograms/kg/min). The third group of eight subjects received, in ascending order, four dose levels of ITF 296 (10, 20, 40, 80 micrograms/kg) by 1-min i.v. injection. The study was double-blind, and placebo-controlled according to a within-patient, incomplete, unbalanced block design, such that each subject received the placebo once. Hemodynamics were assessed by means of Dynamap and BOMED. The following parameters were evaluated at different times before and after ITF 296 administration: systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), stroke volume index (SVI), cardiac index (CI), and systemic vascular resistance index (SVRI). Blood samples for kinetic assessment of ITF 296 were taken before and at different times after ITF 296 administration. The drug was well tolerated. Only a few mild (except for one, moderate) side effects (mainly headache and dizziness) were reported, usually at the higher dose levels. All safety clinical chemistry and hematologic parameters were unaffected. After i.v. infusion of ITF 296, blood pressure started to fall at the dose of 2 micrograms/kg/min, DBP being significantly reduced at doses above 1 microgram/kg/min. The effect lasted for up to 60 min after the end of the infusion. The increase in heart rate was only modest, although apparently dose-dependent. SVI was only slightly reduced, and the other hemodynamic parameters did not change. After bolus administration of ITF 296, SBP was significantly reduced starting at a dose of 20 micrograms/kg with higher doses producing a more marked effect (up to -15 mm Hg). DBP was significantly reduced only at the higher dose level of 80 micrograms/kg. The effect lasted for up to 60 min after bolus administration. HR was slightly increased after doses of 40 and 80 micrograms/kg. SVI was slightly reduced and a small transient decrease in CI was observed, whereas SVRI did not change. Satisfactory, linear kinetic correlation was found between total doses administered and AUCs measured. ITF 296 in healthy male normotensive volunteers was effective and well tolerated. The results of this study justify the planning of further studies in patients in order to test the anti-ischemic activity of the compound.