Performance of Large- and Small-Volume Valved Holding Chambers with a New Combination Long-Term Bronchodilator/Anti-inflammatory Formulation Delivered by Pressurized Metered Dose Inhaler
Bibliographic record
Abstract
The treatment of both the bronchoconstriction and inflammatory aspects of asthma simultaneously by a single pressurized metered dose inhaler (pMDI) represents a significant advance in convenience to the patient. However, a valved holding chamber (VHC) may still be needed to reduce the coarse component of the dose that is likely to deposit in the oropharyngeal region, and a small sized device may offer significant advantages to the patient from the standpoint of compliance with therapy. VHCs representing small (adult AeroChamber Plus with mouthpiece, 149-mL) and large (Volumatic, 750-mL) devices have been compared in an in vitro evaluation with Seretide/Advair (hydro-fluoro alkane [HFA]-formulated fluticasone propionate [FP = 125 microg/dose] and salmeterol xinafoate [SX = 25 microg/dose]) by Andersen Mark-II eight-stage impactor operated at 28.3 L/min following compendial methodology. Fine particle fraction, based on the size range from 1.1 to 4.7 microm aerodynamic diameter, from either large or small VHCs with either component (69-79%) was similar [p > or = 0.08], and significantly greater than that from the pMDI alone (approximately 40%) [p < 0.001]. Fine particle dose emitted by the VHCs for SX (8.2 +/- 0.8 microg for the AeroChamber Plus and 7.7 +/- 0.5 microg for the Volumatic) were comparable, and also similar to the fine particle dose delivered by the pMDI when used without a VHC (7.6 +/- 0.6 microg). Fine particle doses for the FP component delivered by the two VHCs (46.4 +/- 3.4 microg for the AeroChamber Plus and 46.3 +/- 2.7 microg for the Volumatic) were equivalent, but were slightly greater than the corresponding fine particle dose from the pMDI alone (39.1 +/- 2.6 microg). However, this difference (approximately 20%) is close to the limit of resolution based on intermeasurement variability and is unlikely to have clinical significance, given the interpatient variability seen with inhaled drug therapy. It is therefore concluded that either of these VHCs has equivalent in vitro performance with this combination formulation in terms of the portion of the dose emitted from the pMDI that is likely to reach the receptors in the lungs.
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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) | 0.000 | 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 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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".