pulmunary delivery Flashcards
What is the rationale for pulmonary drug delivery?
It provides rapid onset, bypasses first-pass metabolism, requires a smaller dose, and can target both local and systemic effects.
Describe the anatomy of the lungs relevant to drug delivery.
Lungs have a large surface area (~100 m²) with 300 million alveoli and extensive capillary contact, which supports rapid drug absorption.
What is the typical pH and humidity in the lungs?
The lung environment has a pH of about 6.6 and 99% relative humidity.
Name some advantages of the inhaled route of drug delivery.
- Non-invasive
- avoids first-pass metabolism
- rapid action
- localized or systemic effects.
What are some disadvantages of the inhaled route?
- Low bioavailability (~8%),
- specific particle size requirements
- need for device coordination and some devices are bulky
- potential for side effects like oral thrush.
What types of dry powder inhalers (DPIs) exist?
Single-unit dose, multiple-unit dose, and multidose DPIs.
What particle size is ideal for pulmonary drug delivery?
Particles between 1-5µm are optimal for reaching the lungs without being phagocytosed.
Why is lactose often used in DPIs?
It acts as a carrier that is adhesive enough for stability but weak enough to allow drug release
What are some advantages of nebulizers?
They allow for large volume delivery, require no coordination, and are suitable for children and elderly patients.
List key manufacturing considerations for inhaled drugs.
Propellants, static electricity, and particle size control.
what is brownian diffusion?
the random movement of tiny particles (like molecules or small drug particles) as they constantly bump into other particles, such as air or liquid molecules.
What are key counselling points for patients using inhalers?
Shake the inhaler, inhale slowly and deeply, hold breath after inhalation, and rinse mouth if using steroids.
What are some current and future challenges in pulmonary drug delivery?
Systemic delivery (e.g., Afrezza), propellant issues, biopharmaceuticals, and controlled-release formulations.
