Routes Of Administration: Inhalation

• What is the emergency supply of salbutamol?

  In an emergency, as a pharmacist working in a registered retailpharmacy, you can supply prescription-only medicines (POMs) withouta prescription at the request of a relevant prescriber or a patient
• What are the two routes to pulmonary drug delivery?

  *local or topical drug administration*systemic application via the lung
• What are local pulmonary drug administrations used to treat?

  • Asthma
  • COPD
  • Cystic fibrosis
  • Pulmonary hypertension
  • Lung infections?
• What are systematic applications via the lung used to treat?

  • CNS stimulation
  • Anaesthetics
  • Diabetes
  • Pain and migraine
  • Appetite suppression
• What have been the downsides to systemic: inhaled insulin?

  Because of the route ofadministration, manyrespiratory adverse effectswere reported, includingincreased risks ofrespiratory infection,cough, pharyngitis, andrhinitis
• How does airflow differ with different branching?

  Airflow decreases with increased branching
• What are the types of lung disease?

  *obstructive lung disease*restrictive lung disease
• What are some obstructive lung diseases?

  Asthma* COPD* Cystic fibrosis
• What are some restrictive lung diseases?

  • nterstitial lung disease, suchas idiopathic pulmonary fibrosis
  • Obesity
• How are drugs delivered to the lungs?

  Particles entering the respiratory tract are prevented from reaching theterminal bronchioles and alveoli by mechanisms which cause them to becaught by the mucous sheath lining the tubules
• When does inertial impaction happen?

  Inertial impaction tends to occur in the upper airways when the velocityand mass of the particles cause them to impact the airway surface
• What does impaction depend on?

  • The particle’s momentum (dependent upon size!)
  • The position of the particle in the airstream of the parent branch
  • The angle of bifurcation (°θ)*can be influenced to some degree by hyperventilation
• How does particle size impact chance of impaction?

  • 10 μm particle has a 50% chance of impaction
  • 5 μm – 20%
  • 3 μm – 10%
  • 1 μm – 1%
• What is sedimentation dominant for + how are particles suspended?

  • Particles suspended in a gas are subject to the vertical gravitationalforce
  • Sedimentation is the dominant mechanism for particles depositing in thelower/peripheral airways
• What is sedimentation influenced by?

  • Tends to be influenced by breath-holding, which allows more time for gravity to have an effect
• How does particle size affects % of sedimentation?

  • mportant for particles 0.5 μm < daero < 5 μm
  • 2 μm – 55%
  • 1 μm – 29%
  • 0.5 μm – 10%
• What is diffusion + how does particle size affect this?

  • Diffusion = dominant mechanism for particles < 0.5 μm
  • The smaller the particles, the more they deposit via diffusion in theperipheral lung and alveolar space
• What are some minor mechanisms of deposition?

  • Interception for elongated particles
  • Charge reflection for charged particles
• What is an aerodynamic diameter?

  Diameter of a sphere with the same terminal velocityin air or some other relevant fluid as the particle.
• What is the aerodynamic equation?

  • Aerodynamic diameter (dae) is dependent on the geometric diameter(dg), shape factor (1 for spheres) and density (ρ) of the particle
• what factors influence lung deposition?

  • Particle size
  • Particle size distribution
  • Particle density
  • Particle shape
  • Particle hygroscopicity
• How does deposition differ from absorption (upper airways)?

  deposition: *mucociliary escalator (local drug concentration ↓)

  absorption:*drug dissolution (local drug concentration ↑)
• How does deposition to absorption differ in (alveolar region)?

  deposition:*macrophage clearance (local drug concentration ↓)

  absorption:*translocation/efflux (local drug concentration ↓)
• What is the formulation selection breakdown of a beclomethasone dipropionate metered dose inhaler?released: 60%

  released: 60%deposited: 20%permeated: 2%efficacy: 0.24%
• What are the different inhaler types?

  • Pressurized metered-dose inhaler + (spacer)
  • Accuhaler / Diskus
  • Handihaler
  • Respimat
  • Turbohaler
  • (Nebuliser)
• What is entailed in quality control?

  • Deposition of emitteddose
  • Content uniformity
  • Aerodynamic particlesize distribution
  • Spray pattern
• What are the advantages of local delivery of drugs to the lungs?

  • Drug delivered directly to target organ
  • Lower doses may be required for optimal effect
  • Rapid onset of action
  • Fewer systemic side effects
  • Non-invasive delivery
• What are the disadvantages of local delivery of drugs to the lungs?

  • Low efficiency of delivery
  • Difficulty in breath coordination, manual handling of device, orbreathing through the device
  • Corticosteroid use can suppress immune response
  • Throat irritation is possible
• How does an OTC inhalator work?

  • When a patient draws air into the mouth through the mouthpiece,nicotine is vaporised and absorbed by the buccal mucosa into thebloodstream
• How do you use a Nicorette inhalator?

  • Line up the markers and pull each end in the opposite direction
  • Insert the cartridge into the mouthpiece and twist to close securely
  • When you have a craving take a shallow puff about every 4 secondsor take 2 deep puffs every minute. Each cartridge lasts forapproximately 40 minutes of frequent puffing