Lecture 6

Question 1

Local vs. Systemic ROA

Answer 1

• Local drug delivery:
– Drugs delivered locally to target tissue
without entering systemic circulation.

• Systemic drug delivery:
– Drug delivered to the whole body by means of blood circulation.

• Both local and systemic delivery can be achieved through different routes of administration.

Question 2

Choosing a Route of Administration

Answer 2

• Ultimate choice of route of administration depends on:
– Desired onset and duration of drug effect.
– Patient’s compliance and discomfort, etc.
– Disease state.

Question 3

Invasive vs. Non-Invasive Routes

Answer 3

• Invasive routes of administration physically compromise a barrier.
– IV, SC, IM

• Non-invasive routes of administration require the drug molecule to cross at least one cellular barrier.
– Oral
– Nasal
– Pulmonary
– Transdermal

Question 4

FDA Classification of Routes of Administration

Answer 4

• Broad classification of ROA:

– TOPICAL: For local effect, drug applied at
desired site of action.

– ENTERAL: For systemic effect, drug given via digestive tract.
• Includes oral, buccal and rectal.

– PARENTERAL: For systemic delivery, drug given through routes other than GI tract.
• Commonly refers to injections (IV, IM, SC).
• Includes inhalation.

Question 5

Advantages and Disadvantages of the Oral Route

Answer 5

Advantages
• CONVENIENT
• CHEAP
• VARIETY

Disadvantages
• SOMETIMES INEFFICIENT
• UNSUITABLE DRUG
• FIRST-PASS EFFECT
• FOOD
• LOCAL EFFECT
• UNCONSCIOUS PATIENT

Question 6

Advantages and Disadvantages of IV

Answer 6

• Advantages:
– Rapid
– Total dose
– Veins are ~insensitive to irritation

• Disadvantages:
– Suitable vein may be difficult to find
– Toxicity can be a problem
– Requires trained personnel
– Expensive

Question 7

Advantages and Disadvantages of SubQ

Answer 7

• Advantages:
– Can be given by patient, e.g. insulin.
– Absorption slow but usually complete, and improved by massage or heat.

• Disadvantages:
– Can be painful.
– Irritant drugs can cause local tissue damage.
– Max of 2 mL injection thus often small doses limit use.

Question 8

Advantages and Disadvantages of IM

Answer 8

• Advantages:
– Larger volume can be given by IM than SC
– A depot or sustained release effect is possible with IM injections

• Disadvantages:
– Trained personnel required for injections
– Absorption is sometimes erratic, especially for poorly soluble drugs

Question 9

Invasive versus non-invasive delivery

Answer 9

Invasive
– Injection with a needle
– Breaking / penetrating the skin
– Mechanical disruption of the skin

Non-invasive
– Oral is most common: 90% of products
– Nasal, pulmonary absorption, transdermal
– Common to all: passing across a mucosal or cellular barrier

Question 10

Basic Injection Devices

Answer 10

• Vials and Syringes
• Pre-Filled Syringes (PFS)

*designed to be patient friendly

Question 11

Pen injection device for immediate release

Answer 11

Formulation considerations
•Stability at room temperature for 1 month is required
•Typically aqueous solution fomulations

Device considerations 
•Disposable or reusable?
•Dose titration (dial a dose)
•Needle replacement / supply
•Possible needle shield

Question 12

The type of delivery system is governed by

Answer 12

1) duration of action,
2) site of action/medical need
3) formulation constraints

Question 13

Complex formulation solutions also mean an…

Answer 13

increased complexity for the patient / physician / pharmacist prior to administration