inhaled drug delivery Flashcards
what are the types of treatment for asthma/COPD?
1- bronchodilators- beta 2 adrenergics 2-Anticholinergics (Antimuscarinics) 3-Anti -inflammatories-Corticosteroids 4-Non-steroidal antiinflammatories• 5-Monoclonal antibodies 6-Leukotriene antagonists
what is PMDIs?
pressurised metered dose inhalers
most popular type of inhalers]the formulation tends to be in suspension apart from Qvar
aproximately how much of the drug gets delivered to the lungs?
20%
why may one person who uses an inhaler get a fungal infection?
due to steroid deposition on the tongue- wrong inhaler technique- systemic absorption
what are the nasal compartments deposition clearance and pathology mehcanisms?
deposition-Impaction Diffusion/ Brownian motion Interception Electrostatic clearance usually by sneezing/ blocking nose pathophisiology-Inflammation Ulceration Cancer
what are the Tracheobronchial(trachea, ciliated bronchi & bronchioles) compartments deposition clearance and pathology mehcanism
deposition-impaction Diffusion/ Brownian motion Interception Electrostatic Sedimentation
clearance- cough out
caused by- bronchospasm/ ulceration or cancer
what are the Pulmonary(non-ciliatedrespiratory bronchioles, alveolar ducts and alveoli) deposition clearance and pathology mechanisms?
sedimentation
Diffusion/ Brownian motion Interception Electrostatic
Solubilisation
Phagocytosis(hours to years)
cause- inflammation Oedema Emphysema Fibrosis Cancer
what are the routes for lung clearance?
dissolution/ direct passage into blood/ phagocytosis/ macrophages facilitated airways
what does successful inhilation depend on?
patient, device and formulation
what are particle properties that may influence lung delivery?
diameter intertial impaction sedimentation brownian motion interception electrostatic presopitation
what is the particle size/diameter usually given as?
‘mass median aerodynamic diameter’ (MMAD)
what is internal inpactation?
when airflow changes direction, particle will continue in original direction due to inertia
what is Brownian motion?
Hitting of colloidal particles by molecules/atoms of surrounding medium –random motion
what is interception?
if dimensions of particle similar to the anatomical dimensions of the lung tubes. Important for elongated particles such as fibres.
what is electrostatic precipitation?
aerosol particles will be charged and hence will be attracted to surfaces of opposite charge. Charge may also influence direction of flow.
