title: On the correlation of output rate and aerodynamic characteristics in vibrating-mesh-based aqueous aerosol delivery.
abstract: Aerosolization of aqueous formulations is of special interest for inhalative drug delivery, where an adequate nebulizer performance represents a prerequisite for improving pulmonary therapy. The present study investigated the interplay of output rate and aerodynamic characteristics of different excipient-based formulations and its impact on the atomization process by vibrating-mesh technology (i.e. eFlow(®)rapid). Output rate and aerodynamic characteristics were manipulated by both dynamic viscosity and conductivity of the applied formulation. Supplementation with sucrose and sodium chloride caused a decline (down to ∼0.2 g/min) and elevation (up to ∼1.0 g/min) of the nebulizer output rate, respectively. However, both excipients were capable of decreasing the aerodynamic diameter of produced aerosol droplets from >7.0 μm to values of ≤5.0 μm. Thus, the correlation of output rate and aerodynamic characteristics resulted in linear fits of opposite slopes (R(2)>0.85). Finally, the overall number of delivered aerosol droplets per time was almost constant for sucrose (≤1×10(8) droplets/s), while for sodium chloride a concentration-dependent increase was observed (up to ∼3×10(8) droplets/s). Overall, the current findings illustrated the influence of formulation parameters on the aerosolization process performed by vibrating-mesh technology. Moreover, concentration and charge distribution of aerosol populations supposedly modify the final characteristics of the delivered aerosols.
authors.affiliation: Medical Clinic II, Department of Internal Medicine, Justus-Liebig-Universität, Giessen, Germany. Electronic address: moritz.beck-broichsitter@innere.med.uni-giessen.de.
authors.forename: Moritz
authors.initials: M
authors.lastname: Beck-Broichsitter
authors.affiliation: Medical Clinic II, Department of Internal Medicine, Justus-Liebig-Universität, Giessen, Germany.
authors.forename: Nina
authors.initials: N
authors.lastname: Oesterheld
authors.affiliation: Medical Clinic II, Department of Internal Medicine, Justus-Liebig-Universität, Giessen, Germany.
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Knuedeler
authors.affiliation: Medical Clinic II, Department of Internal Medicine, Justus-Liebig-Universität, Giessen, Germany.
authors.forename: Werner
authors.initials: W
authors.lastname: Seeger
authors.affiliation: Medical Clinic II, Department of Internal Medicine, Justus-Liebig-Universität, Giessen, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Schmehl
mesh_terms: D000280:Administration, Inhalation; D000336:Aerosols; D002626:Chemistry, Pharmaceutical / Q000379:methods; D016503:Drug Delivery Systems; D005079:Excipients / Q000737:chemistry*; D009330:Nebulizers and Vaporizers; D010316:Particle Size; D012965:Sodium Chloride / Q000737:chemistry; D013395:Sucrose / Q000737:chemistry; D013678:Technology, Pharmaceutical / Q000379:methods*; D014732:Vibration; D014783:Viscosity
chemical_list: D000336:Aerosols; D005079:Excipients; D012965:Sodium Chloride; D013395:Sucrose
keywords: Aerodynamic diameter; Aerosol coagulation; Output rate; Pulmonary drug delivery; Vibrating-mesh nebulizer