Antistatic valved holding chambers do not necessarily offer similar aerosol delivery performance
Bibliographic record
Abstract
RATIONALE: Adoption of materials to mitigate medication losses due to electrostatic charge accumulation on VHCs has been associated with improved reliability of output. We investigated if this change has resulted in similar in vitro performance, simulating poor coordination of inhalation with inhaler actuation, for which VHCs are prescribed. METHODS: Each VHC (n=5 devices/group) tested out-of-package. 5-actuations of fluticasone propionate (125 µg FP/actuation; Flovent®-HFA, GSK plc) was delivered at 30-s intervals to the VHC on test, sampling via a cascade impactor (CI) after 2, 5 and 10-s delay intervals, using a proprietary “delay” apparatus. FP was recovered from the CI and assayed by HPLC-spectrophotometry. Fine particle mass <4.7 µm aerodynamic diameter ( FPM <4.7 µm ) provided a measure of the therapeutically beneficial medication capable of reaching the lungs. RESULTS: Values of FPM 4.7 µm (µg FP; mean ± SD) are summarized in the Table. FPM 4.7 µm for the pMDI alone (no delay) was 46.2 ± 2.1 µg. Fine Particle Mass (µg/actuation) after Various Delay Intervals Following Inhaler Actuation VHC/manufacturer Delay Interval (s) 2 5 10 AeroChamber Plus®/Trudell Medical International 42.2 ± 3.1 39.7 ± 1.3 35.7 ± 2.0 Antistatic Pocket Chamber®/nSpire Health Inc. 24.1 ± 4.0 21.4 ± 1.8 20.9 ± 3.0 OptiChamber® Diamond®/Philips-Respironics Inc. 35.0 ± 3.2 29.2 ± 1.7 23.0 ± 2.8 Vortex®/PARI Respiratory Equipment Inc. 39.9 ± 2.9 29.1 ± 4.7 19.1 ± 4.8 CONCLUSIONS: Although antistatic materials enable VHCs to be used without pre-washing, there are still large differences in output. Regardless of delay length, the AeroChamber Plus® VHC most closely matched the benchmark FPM 4.7 µm for the pMDI without VHC.
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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 | 0.002 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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".