Drug Delivery Systems

Question 1

Types of drug delivery systems (4)

Answer 1

Oral
Injection
Transdermal
Carrier based

Question 2

Drugs can be formulated to allow____

Answer 2

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

Question 3

Dosage Regimes

Answer 3

The dose, frequency and timing of administration

Question 4

Oral medcation

Answer 4

Via GI tract
Soltutions and suspensions: good for patient with swallowing difficulties
Absorption- rapid, depends on gastric emptying
Dispersion- coarse, insoluble or unpalatable particles

Question 5

Capsule and tablets

Answer 5

Involve various polymers and hydrogel formulation
Tablet break down is rate limiting step
Convenient, accuracy of dose, reproducible, mass prdodcution, drug stability
Enteric coat- delays disintegration until it reaches small intestine

Question 6

Modified release tablets

Answer 6

Maintains drug levels within the therapeutic range
Reduces need for frequent dosing
Sustained rate of release over a long period of time

Question 7

Prodrugs

Answer 7

Inactive derivatives of an active drug which requires to be metabolically activates
Prolongation of duration of action and avoids drug being degraded in gut

Question 8

Buccal and sublingual administration

Answer 8

Bypasses first pass metabolism
Sublingual- under tongue (GTN)
Buccal cavity- between gum and cheek

Question 9

Rectal Route

Answer 9

Useful in the young and old and those unable to swallow

For treatment of proctitis and to chieve systemic absorption and bypass pre-systemic metabolism

Question 10

Vaginal Route

Answer 10

Pessaries and cream

Question 11

Injection based

Answer 11

Fats systemic effect an bypasses first pass metabolism

Short half-life removed from the system quickly

Question 12

Transdermal

Answer 12

Bypass first pass metabolism

Creams, ointments and skin patches to achieve local effects: nicotine, contraception, HRT

Question 13

Inhalation

Answer 13

Deliver drugs directly to lungs for a local effect
Delivered directly to site of action, rapid, small doses, reduced ADR
Patient education is essential

Question 14

Carrier based

Answer 14

Vesicles
Micelles
Liquid crystals
Nano capsules
Nanospheres
Multi functional dendritic polymers

Question 15

Monoclonal antibodies

Answer 15

Act directly when they bind to antigen and induce an immunological response to cancer

Question 16

Liposomal

Answer 16

Synthesises from cholesterol
Spherical with lipid bilayer
Closed colloidal structures
Drug crystallised in aqueous fluid
Reduced toxicity and enhanced efficay

Question 17

Nanopatricle

Answer 17

targeted to precise location
Reduced toxicity
nanotube, nanoshell
Carbon nanotubules: bronchial asthma
Gold nanoparticles for cancer- free radical generation