Treprostinil pharmacokinetics in rats are extended using inhaled prodrug formulations
Bibliographic record
Abstract
Introduction : In a rat model of acute hypoxia-induced pulmonary arterial hypertension (PAH), inhaled lipid nanoparticle formulations of treprostinil prodrugs (TPD) were found to have a longer duration of activity (>>2h) compared to treprostinil (TRE). TPDs with alkyl chains of lengths C12, C14, and C16 yielded the longest extensions in activity. Here, we evaluated the plasma and lung PK in rats that received a single inhaled dose of these TPDs. Methods : Nebulized TRE solution and TPD formulations were administered (at 15 nmole/kg) to anesthetized-ventilated rats (6h studies) or to conscious rats by nose-only inhalation (24h studies). TRE and TPD concentrations in lung tissue and plasma were measured by HPLC/MS/MS. Results : Ventilated rats treated with nebulized TRE had the highest plasma C max (3.5 ng/ml) which occurred immediately after dosing and measurable levels of TRE were not seen beyond 4h in the plasma and by 6h in the lungs. Ventilated rats treated with nebulized TPDs had plasma TRE C max values ranging from 0.2 to 0.6 ng/mL. TPD lung levels at 6h ranged from 15 to 60 ng/mL. In the 24h studies, plasma concentrations of TRE when dosed with C14- and C16-TPDs were above 0.1 ng/mL for up to 24h, i.e., levels corresponding to activity in acute hypoxia studies. Conclusions : Inhaled TPDs are present in the lungs for an extended duration and are associated with the slow, sustained release of TRE into the blood. This PK profile is quite different than inhaled TRE and strongly suggests that long alkyl chain prodrug formulations of TRE will likely have prolonged pulmonary vasodilator activity in humans.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".