Delivery of submicrometer and nanometer aerosols to the lungs using hygroscopic excipients or dual stream nasal delivery
Pharmaceutically engineered aerosols (e.g. submicrometer and nano-particles and droplets) containing a hygroscopic growth excipient or agent are employed to improve the delivery of respiratory aerosols to the lung. Inclusion of the hygroscopic agent results in near zero depositional loss in the nose-mouth-throat regions and near 100% deposition of the aerosol in the lung. Targeting of the aerosol to specific lung depths is also possible. In addition, methods and apparatuses for delivering aerosols to the lung are provided. The aerosol is delivered to one nostril of a patient while a relatively high humidity gaseous carrier is delivered to the other nostril, resulting in post-nasopharyngeal growth of the aerosol to a size that promotes deposition in the lung.
1. A method of targeted delivery of an active agent to a region of the respiratory system of a patient in need thereof, comprising
providing said active agent to said patient as individually aerosolized submicrometer particles or droplets which combine both
i) said active agent; and
ii) at least one hygroscopic excipient with a hygroscopic parameter i ex ρ ex /M ex of at least 7 kmol/m 3 ;
wherein said active agent and said at least one hygroscopic excipient are present in said individually aerosolized submicrometer particles or droplets in amounts sufficient to cause a predetermined amount of hygroscopic growth of said individually aerosolized submicrometer particles or droplets during passage through airways having natural airway humidity levels of said patient
wherein said individually aerosolized submicrometer particles or droplets have a growth coefficient i ex ρ ex /M ex ·vf ex +i aa ρ aa /M aa ·vf aa of at least 2.8;
where
i ex is the molecular dissociation constant of said at least one hygroscopic excipient,
i aa is the molecular dissociation constant of said active agent,
ρ ex is the density of said at least one hygroscopic excipient,
ρ aa is the density of said active agent,
M ex is the molar mass of said at least one hygroscopic excipient,
M aa is the molar mass of said active agent,
vf ex is the solute volume fraction of said at least one hygroscopic excipient, and
vf aa is the solute volume fraction of said active agent;
wherein said individually aerosolized submicrometer particles or droplets are at least 250 nm in size;
wherein submicrometer refers to size according to mass median aerodynamic diameter (MMAD);
and wherein said predetermined amount of hygroscopic growth caused by said amounts of said active agent and said at least one hygroscopic excipient results in said individually aerosolized submicrometer particles or droplets growing to an aerodynamic diameter which reaches or surpasses 2 μm in size.
2. The method of claim 1 , wherein said active agent is a medicament.
3. The method of claim 1 , wherein said active agent is a peptide.
4. The method of claim 1 , wherein said active agent is selected from the group consisting of agents for the treatment of asthma, agents for the treatment of respiratory disorders, anesthesia agents, nucleic acid molecules, anti-pain agents, anti-inflammation agents, anti-depressants, mood altering drugs, anti-viral agents, anti-bacterial agents, anti-fungal agents, anti-cancer agents, hormones, benzodiazepines and calcitonin.
5. The method of claim 1 , wherein said predetermined amount of hygroscopic growth is sufficient to cause targeted deposition of said individually aerosolized submicrometer particles or droplets in a region of said respiratory system of said patient selected from the group consisting of: nasal cavity, trachea, lung, alveolar airways, tracheobronchial airways, upper tracheobronchial airways, lower tracheobronchial airways, and lower tracheobronchial-alveolar airways.
6. The method of claim 1 , wherein said region of said respiratory system is the nasal cavity.
7. The method of claim 1 , wherein said region of said respiratory system is the trachea.
8. The method of claim 1 , wherein said region of said respiratory system is the lung.
9. The method of claim 1 , wherein said region of said respiratory system is the alveolar airways.
10. The method of claim 1 , wherein said region of said respiratory system is the tracheobronchial airways.
11. The method of claim 1 , wherein said region of said respiratory system is the lower tracheobronchial-alveolar airways.