Routes of administration

Question 1

List all routes of administration

Answer 1

-Sublingual + Buccal
-Ocular, Nasal,ear
-Intrathecal + epidural + Intrathymic +Intracardiac
-Inhalation
-Intravenous + inta-arterial + intramuscular
-Topical + subcutaneous
-Rectal + vaginal
- Oral

Question 2

Absorption

Answer 2

movement of drug from site of administration to the bloodstream

Question 3

What proteins are within the phospholipid bilayer?

Answer 3

Integral proteins imbedded in membrane
Peripheral proteins

Question 4

What molecules can pass through cell membrane?

Answer 4

Hydrophobic, small, uncharged molecules

Protein carrier needed for charged molecules and ions

Question 5

transport across biological membranes

Answer 5

Transcellular diffusion and passive and facilitated, endocytosis, efflux, paracellular

Question 6

Use of villi and microvilli

Answer 6

Increase SA = more absorption within small intestine

Question 7

What is gastric emptying?

Answer 7

• stomach pressure constant at start
• Stomach has plasticity
• 3ml pushed into Chyme and small intestine
• Is pushed in small amounts or back into stomach
  -Stops chances of indigestion

Question 8

What impacts gastric emptying process?

Answer 8

pH of stomach - More time to neutralise food if very acidic
Time of eating
Meal volume
Meal composition - Rich in carbs will move more quickly, fatty is slower

Question 9

How is gastric emptying regulated?

Answer 9

Neural reflexes
Hormonal mechanisms

Question 10

What is Gastric emptying rate?

Answer 10

Speed at which substance leaves the stomach after ingestion

Question 11

Why is a long GER bad?

Answer 11

Delays absorption rate of drug in small intestine, less bioavailability

Question 12

Why take food and aspirin at the same time?

Answer 12

Aspirin can irritate the stomach

Question 13

Why take amoxicillin before food?

Answer 13

Food can affect absorption, will interfere with absorption of penicillin, don’t want drug to be degraded

Question 14

Rate- limiting step

Answer 14

slowest step in series, controls overall rate and extent of appearance of the intact drug in the systemic circulation

Question 15

Different types of rate-limiting steps

Answer 15

• Disintegrating rate
  -Gastric emptying
  -Dissolution - high logP hardly dissolves
  -Permeability- low logP is hardly absorbed
  -Metabolism in the liver (first pass effect)

Question 16

How do ions pass through the small intestine?

Answer 16

Paracellular route in small amounts

Question 17

Advantages of tablets?

Answer 17

Non- expiring
easy to carry
easy to swallow
elegance
very accurate dosage
High chemical and physical stability
Can’t tamper with a tablet
Low cost packaging

Question 18

process of taking a tablet

Answer 18

Disintegration (RLS)
Deaggregation
Dissolution
Drug in solution
Gastric emptying

Question 19

Difference between tablet and capsule?

Answer 19

Capsule has a layer of gelatin (come in hard and soft capsules)

Question 20

Adv of capsule over tablets?

Answer 20

Capsule can be tasteless and odourless
Easier to swallow -smooth and slippery
Can be opened up and sprinkled on food
Can be printed on
Faster acting
Other dosage forms within the capsules

Question 21

Dissolution of capsule process

Answer 21

Excipients in capsule attract water molecules to dissolve them

Question 22

Quickest oral dosage form

Answer 22

solution - skips all rate- limiting steps can go straight into GI fluids for absorption

Question 23

How does non-keratinised cells help with absorption?

Answer 23

More permeable for rapid onset reaction
no extra layer to prevent drug absorption like the skin

Question 24

Examples of OTC oral tablets, buccal and sublingual tablets, capsules, suspensions and oral solutions?

Question 25

what type of route do drugs which are inhaled take?

Answer 25

Pulmonary delivery--> local or systemic

Question 26

when can a pharmacist supply POMs without a prescription?

Answer 26

In an emergency

Question 27

How to use a salbutamol inhaler

Answer 27

- remove cap - check does counter -hold upright and shake well - Breathe out gently -put in mouthpiece between teeth and close lip to form seal -start to breathe in slowly and press on canister firmly -continue to breathe in slowly and deeply -hold breath about 5-10 secs -while breathing remove from mouth -breathe out gently -replace cap

Question 28

local or topical drug administration

Answer 28

Asthma COPD Cystic fibrosis pulmonary hypertension lung infections

Question 29

Systemic application via lungs

Answer 29

CNS stimulation Anaesthetics diabetes pain and migraine appetite suppression

Question 30

How we deliver drugs to or via lungs

Answer 30

solid in gas e.g. smoke liquid in gas e.g. mist gases

Question 31

Branching of lungs

Answer 31

trachea to bronchi to respiratory bronchioles to alveolar ducts to atrium to alveoli

Question 32

How lung diseases impact drug administration via inhalation

Answer 32

lumen being narrower impacts the drugs pathway to being absorbed, restricts airflow. Caused by obstructive and restrictive lung diseases.

Question 33

what is inertial impaction

Answer 33

where the drug acts in the airways depending on particle size, momentum and angle of bifurcation

Question 34

what is the main reason for depositing in the lower airways

Answer 34

sedimentation due to gravity - impacted by breath-holding

Question 35

what is the dominant mechanism for particles < 0.5 micrometres

Answer 35

diffusion

Question 36

what influences lung deposition?

Answer 36

particle size particle size distribution particle density particle shape particle hygroscopicity - absorption of moisture (don't store in bathroom)

Question 37

what does cilia on epithelial cells do in terms of drug absorption?

Answer 37

reduces drug deposition = less drug absorption clears drug caught in mucus

Question 38

what reduces local drug conc in airways?

Answer 38

cilia, macrophage clearance, translocation past cell to other areas of body

Question 39

formulation selection for administration via lungs

Answer 39

check factors influencing lung deposition inhaler types quality control

Question 40

adv and disadv of local drug delivery to lungs?

Answer 40

adv: -carry around -directly to the organ -low dose required -rapid onset -fewer systemic side effects -non-invasive delivery disadv: -low efficiency of delivery -difficulty in breath coordination -can supress immune response (corticosteroid) -throat irritation

Question 41

Adv and disadv of systemic delivery of drugs via lungs

Answer 41

Adv: -Rapid onset of action -circumvents first pass effect -non-invasive delivery route -good for biopharmaceuticals Disadv: -low efficiency -difficulty using some devices -breathing difficulties - may need very low or very exact doses -expensive compared to oral therapies