Routes Of Administration

Question 1

Name the 5 routes of administration?

Answer 1

Oral, Rectal, Parental, Topical and Respiratory

Question 2

What’s the most common oral route?

Answer 2

Peroral, involves swallowing medication to be absorbed in GI tract

Question 3

Name 2 disadvantages of the oral route?

Answer 3

-drug may not be completely absorbed
-hostile conditions eg. pH, microbiome
-absorption variability due to food intake
-slower onset of action

Question 4

Give an advantage and disadvantage of rectal route.

Answer 4

+ alternative for drugs inactivated by GI fluids
+ alternative when oral route for patient is precluded eg. vomiting

• inconvenient

Question 5

Name 3 parental forms of administration.

Answer 5

Intravenous, intramuscular and subcutaneous

Question 6

What is the topical route?

Answer 6

Application onto skin for local effect (eg. creams) OR systemic absorption (eg. patch)

Question 7

Name 2 forms of respiratory administration.

Answer 7

Intranasal and pulmonary

Question 8

What are 2 advantages of oral administration?

Answer 8

-convenient/simplest
-high surface area
-good blood supply

Question 9

What are 3 advantages of tablets?

Answer 9

-convenient to take
-better chemical stability compared to liquid
-relatively cheap to produce

Question 10

Name 3 types of modified-release tablets.

Answer 10

~pulsatile
~delayed-release
~prolonged-release

Question 11

Name the 7 types of tablets.

Answer 11

~disintegrating
~gastro-resistant
~modified-release
~effervescent
~dispersible
~sublingual and buccal
~lozenges and pastilles

Question 12

Name commonly used excipients.

Answer 12

~filler (bulk)
~disintegrant (starch swell w/ H20)
~binder (adhesive for tablet)
~lubricant (between machinery)
~glidant (inter-particulate)

Question 13

Give 3 advantages and 2 disadvantages of capsules.

Answer 13

+easily to identify (colours)
+minimal excipient needed
+high drug loading is possible
-not suitable for highly soluble substances
-more costly than oral tablets

Question 14

What is the main solvent used in oral solutions and why is it good?

Answer 14

Water

-lack of toxicity
-low cost
-must be distilled water

Question 15

What are the 6 excipents used for oral solutions?

Answer 15

-Viscosity enhancers
-Preservatives
-Sweetners
-Antioxidants
-Flavouring agents
-Colouring

Question 16

What are the factors affecting chemical degradation of solutions?

Answer 16

-pH
-High Temperature
-UV light (containers that reduce light transmission)
-Catalysis
-Oxygen (Antioxidants)

Question 17

What role does co-solvents play in oral solutions?

Answer 17

Enhance water solubility for drugs that are not water-soluble

Question 18

What are the 4 ways to enhance drug solubilty?

Answer 18

-pH modifications
-Co-solvents (alcohol)
-Complexations (cyclodextrins)
-Surfactants (micelles)

Question 19

What are the 3 causes for particle movement in suspension?

Answer 19

-Brownian Motion / Diffusion (only small particles)
-Gravity (sedimentation - only larger particles)
-External agitation (shaking by patients)

Question 20

What types of drugs cannot be administered IV?

Answer 20

-water in oil emulsions

Question 21

What are 3 advantages of parental route of administration?

Answer 21

-rapid onset of action
-high bioavailaibity
-suitable for unconscious patients
-infusion allows prolonged release

Question 22

What are 3 disadvantages of parental route of administration?

Answer 22

-requires healthcare professional
-needle phobia
-manufacturing is more costly
-shelf-life is shorter

Question 23

What are the vehicles for injections?

Answer 23

• ‘water for injections’
• ‘saline for injections’ (infusions due to large volume)
• co-solvent system
• solubilising agents

Question 24

What are 3 advantage and disadvantages of inhaled route?

Answer 24

+ Rapid Absorption
+ Avoids harsh GI enviroment
+ Avoids Hepatic first metabolism

• complex delivery device (high cost)
• Dose may not be consistnet
• Mucus clearance (not suitable for long lasting formulations)

Question 25

What are the 3 phases of drug adminstration for inhaled route?

Answer 25

1) Deposition
2) Dissolution
3) Absorption

Question 26

What are the 3 mechanisms for particle deposition for inhaled route?

Answer 26

• Inertial Impaction >5um
• Gravitational Sedimentation 1um-5um
• Brownian Diffusion 0.5um-1um

Question 27

What does mucociliary clearance mean for absorption of inhaled drugs?

Answer 27

drug must absorb within 24hours as mucus will clear the drug out after 24hours

Question 28

Give 3 advantages of the nasal route?

Answer 28

-Easy administration
- Direct route to brain is possible
- low enzymatic activity
- Avoids first-pass effect
- potential for rapid onset of action

Question 29

What are the 3 chambers of the eye?

Answer 29

• Anterior
• Posterior
• Vitreous

Question 30

What produces tears?

Answer 30

lacrimal gland

Question 31

What are the 3 different types of ocular delivery?

Answer 31

• Cornea
• Periocular
• Intravitreal

Question 32

What are 3 disadvantages of ocular route?

Answer 32

• tears
• blinking (fluid clearance)
• maximum dose 20-30ul

Question 33

What are 3 advantages of ocular route?

Answer 33

• patient can administer
• potential for rapid onset of action
• Avoid first pass metabolism

Question 34

What are formulation considerations with the ocular route?

Answer 34

• close to neutral pH
• isotonic
• particle free
• sterile