Routes of Administration and Absorption

Question 1

Oral administration advantages

Answer 1

• Convenient
• Acceptable
• Safe
• Economical

Question 2

Oral administration disadvantages

Answer 2

• Unpredictable digestion
• Slow onset
• GI irritation
• Requires consciousness

Question 3

Parenteral administration routes

Answer 3

• SubQ (slowest)
• Intramuscular
• IV (fastest)

Question 4

Parenteral administration advantages

Answer 4

• Rapid
• Doesn’t require consciousness or cooperation
• Very accurate and predictable

Question 5

Parenteral administration disadvantages

Answer 5

• Pain
• Cost
• Danger of infection
• Essentially irreversible

Question 6

Other routes of administration other than oral and parenteral

Answer 6

Intrafecal

Intraventricular (CSF)

Absorption through skin and mucous memb:

• Inhalation
• Cutaneous
• Rectal-vaginal
• Intranasal
• Intraocular
• Sublingual—nitroglycerin prime ex.

Question 7

What factors influence passive diffusion of a drug

Answer 7

Size

–Small get through memb easier

Solubtility

–More lipid soluble=more readily absorbed

Degree of ionization

–Ionized molecule does not get through membrane

Question 8

HH equaiton

Answer 8

pH=pKa+log(Base/Acid)

Question 9

T/F

Physiologically,

HA=H⁺+A^-

Answer 9

False

Physiologically,

HA= +A^-

^{<span>H+ ion does not change the way the drug acts. H+ does however shift the equilibrium. More H+ means a shift towards reactants or non-ionized form. Non ionized form more soluble in membrane.</span>}

Question 10

What is an adjuvant

Answer 10

In formulation, anything other than the drug

Question 11

Sites of non-specific drug binding

Answer 11

Proteins in plasma

This binding is reversible but may affect drug getting to target, drug metabolism or excretion or may be displaced by other drugs

Question 12

Specific tissue barriers for drugs

Answer 12

Blood brain barrier:

–Excludes lipid insoluble and ionized drugs

Placental barrier:

–Excludes molecules >1000MW