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Principles of Disease > Drug Delivery Systems > Flashcards

Flashcards in Drug Delivery Systems Deck (77)
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1

Name the type of drug delivery systems available

Oral
Injection based
Transdermal
Carrier based

2

In what forms/formulations can drugs be given to patients (7)

Tablets or capsules
Solutions or suspensions
Ointments and creams
Inhalation
Injections
Suppositories
Pessaries

3

What types of tablets/capsules are there

Regular
Modified release
Prodrugs
Enteric coated

4

How can a drug delivery system be formulated

To allow selective targeting of a tissue site
To avoid pre- or systemic metabolism
To allow a 24 hour action

5

What do drug formulations allow

A treatment regime to be tailored to a patients needs, pharmacological characteristics and disease state

6

What determines the drug delivery system used

The dose of the drug to be given
The frequency of administration
The timing of administration

7

What should be considered when choosing a dosage regime (7)

Find out the recommended dose (BNF/BNFc)
Is there impaired renal function
Is there impaired hepatic function
Age and weight
Disease to be treated
Drug toxicity
Give a starting dose and increase dose to achieve the desired effect

8

What are commonly used oral delivery systems (5)

Solutions
Suspensions
Capsules
Tablets
Modified release tablets

9

Where is absorption through using oral delivery systems

GI tract

10

When are solutions and suspensions a useful form of administration

In the young, elderly and patients with swallowing difficulties

11

How can solutions and suspensions be given

Through a nasogastric tube or PEG tube

12

What is the rate of absorption for drugs administered through a nasogastric tube or PEG tube

Extremely rapidly

13

What is absorption dependent on

Gastric emptying and is most rapid from the small intestine

14

Describe suspensions

Dispersions of coarse drug particles in a liquid phase
The dose can be contained in a small volume

15

What are suspensions good for

Drugs which are insoluble unpalatable as they are better tolerated

16

What limits the rate limiting step in the absorption of tablets

Dissolution or tablet break down

17

What are the advantages of tablets and capsules

Convenience
Accuracy of dose
Reproducibility
Drug stability
Ease of mass production

18

What does the enteric coating of tablets do

It delays disintegration of the tablet until it reaches the small intestine

19

Why are some tablets enteric coated

Protect the drug from stomach acid (e.g. Omeprazole)
Protect the stomach from the drug (e.g. Aspirin)

20

Why are prolonged release formulations useful

Most disorders required prolonged therapy
Maintains drug levels within a therapeutic range
Reduces the need for frequent dosing
Compliance is improved
Improved nursing and doctor compliance

21

How can the time course for a drug in the body be prolonged

By giving the drug in a form that has a slower but sustained rate of release
This type of preparation contains more of the active drug but releases it more slowly over a prolonged period

22

Name some oral preparations

Verapamil
Diltiazem
Isosorbide mononitrate
Lithium
Carbamazepine

23

Name some parenteral perparations

Intramuscular injections of flupentixol or risperidone

24

Name some surgical implants

Progesterone contraception
Testosterone

25

What are prodrugs

Synthesised inactive derivatives of an active drug which requires to be metabolically activated after administration

26

What are the advantages of prodrugs

Prolongation of duration of action
Avoidance of degradation of the drug in the gut

27

When are buccal and sublingual administration ideal

For drugs which have extensive pre-systemic or first pass metabolism

28

What are sublingual tablets

Small and dissolve slowly under the tongue or in the buccal cavity (e.g. GTN)

29

What can be administered through the rectal route

Suppositories, Creams and Liquids

30

When is the rectal route useful

In the young or old
Patients unable to swallow