DPIs

Question 1

DPI design

Answer 1

• powder left in device - inefficient delivery
• decrease separation of coater carrier complex
• agglomeration of drug

Question 2

how do DPI work

Answer 2

• micronised drug mixed with carrier powder
• increase vol of dose - increase flow - decrease agglomeration
• drug carrier complex/agglomerates of pure drug must be de-agglomerated - when inhaled force breaks them

Question 3

single dose DPIs

Answer 3

• load individual doses - caps
• dose loaded then pierced and inhaled.
• when inhaled through - de agglomeration occurs
• spinhaler
• rotahaler
• aeroliser

Question 4

multiple dose DPI

Answer 4

• turbuhaler - pure drug no carrier

- accuhaler - used blisters

Question 5

advantages of DPI

Answer 5

easier use than pmdi
single dose
no propellant needed
not alot of excipients used 
dose counter

Question 6

disadvantages pf DPI

Answer 6

• need increase PIFR
• no children and old people
• sensitive to humidity