Mark W. Nagel1, Jason A. Suggett1 & Jolyon Mitchell2
1Trudell Medical International, 725 Baransway Drive, London, Ontario, N65 5G4, Canada
2Jolyon Mitchell Inhaler Consulting Services Inc., 1154 St. Anthony Rd., London, Ontario, N6H 2R1, Canada
Summary
An in vitro study was undertaken to assess what changes occurred to the aerosol deposition patterns from a pMDI (fluticasone propionate (FP); 125 μg/actuation) delivered alone or via an AeroChamber* Plus Flow-Vu* VHC/mouthpiece, when the tongue was intentionally omitted from a model anatomic adult oropharynx. A modified fast screening abbreviated Andersen impactor (T-FSA) operated at 28.3 L/min ± 5% sampled the aerosol emitted at the exit of the oropharynx of the model-on-test, to capture the size profile of medication likely to have deposited past the carina and therefore potentially available for lung delivery. The pMDI alone simulated ‘perfect’ coordination with no delay while a 2-s delay was simulated following pMDI actuation when the VHC mouthpiece was attached to the model. Five replicate measurements were made with the models with and without the tongue present in the oropharyngeal cavity with 5 doses delivered per measurement. FP was recovered from the pMDI actuator, VHC interior, model airway, as well as the T-FSA and assayed by a validated HPLC-spectrophotometric procedure. The pMDI alone deposited 81.6 ± 10.9 and 64.0 ± 5.1 in the oropharyngeal airway with and without tongue respectively, causing the mass delivered to Stage 5 (1.1- 4.7 μm) to increase from 11.7 ± 1.5 to 35.5 ± 1.0 µg. Delivery via the VHC demonstrated a smaller difference between the mass of FP recovered from Stage 5 (29.6 ± 6.1 – tongue present vs. 36.5 ± 2.2 µg – tongue absent), indicating less impact on likely lung dose.
Key Message
Tongue position can affect lung delivery of aerosolized medications. We compared aerosol deposition within an adult oropharyngeal model compared to a modified version where the tongue structure was removed. We showed tongue presence can impact aerosol deposition, although the magnitude of the effect is reduced when a VHC is present.