Pharmacology

Question 1

What is almost as important as the type of drug chosen in producing the therapeutic effect

Answer 1

The vehicle in which the drug is solubilised/ delivered

Question 2

Drug administration via the skin can be used to treat systemic disease. True or false

Answer 2

True

Question 3

What are the 3 major routes of administration for skin

Answer 3

Topical
Transdermal
Subcutaneous/ depot

Question 4

What kind of effect do topical treatments have

Answer 4

local effect but also can treat underlying tissues

Question 5

What type of effects do subcutaneous and transdermal treatments have

Answer 5

systemic effects (often prolonged)

Question 6

What route of administration is required to reach the skin barrier

Answer 6

Depot injection

Question 7

What is the single most important barrier to drug penetration

Answer 7

The stratum corneum

Question 8

What does the stratum corneum consist of?

Answer 8

Hardened, dead, keratinocytes surrounded by intercellular lipids forming 10-30 sheets of tissue that are constantly shed and renewed

Question 9

What are the corneocytes suspended in?

Answer 9

Lipids in lamellar structures / layers

Question 10

What are the bricks in the Brick and Mortar Model

Answer 10

Corneocytes

Question 11

What are adjacent corneocytes held together by? Where are these found?

Answer 11

corneodesmosomes (intercellular junctions)

living more inner layers of the skin

Question 12

What is the mortar made up of?

Answer 12

intracellular lipids in an intensely hydrophobic environment

Question 13

What is the ratio of different lipid content in the stratum corneum and why is this important?

Answer 13

1:1:1

any change in this can cause major changes to the skin

Question 14

What can the mortar act as?

Answer 14

A reservoir for lipid-soluble drugs (topical steroids)

Question 15

In what case does the drug have to travel across the stratum corneum

Answer 15

When you are trying to achieve either a local or a systemic effect.

Question 16

What is meant by topical route of administration

Answer 16

when a drug is applied directly to the surface of the skin

Question 17

When are topical drugs used?

Answer 17

superficial skin disorders - psoriasis and eczema 
skin infections 
itching 
dry skin
warts

Question 18

Name some vehicles for topical routes of admisistration

Answer 18

ointments
creams
gels
lotions
pastes
powders

Question 19

What dictates the choice of the vehicle

Answer 19

1. Physicochemical properties of the drug

2. the clinical condition

Question 20

What types of drugs are applied to relieve itching

Answer 20

H1 recepto antagonists

Question 21

What is oftenused to treat dry skin

Answer 21

Moisturising agents

Question 22

How do warts arise

Answer 22

Abnormal division of keratinocytes

Question 23

What is the point in having vehicles

Answer 23

A vehicle which may be suitable for wet/ oozing skin is probably not suitable for dry skin

Question 24

Drug absorption across the skin is a passive process. true or false

Answer 24

true

Question 25

what can be described by Fick's first law of diffusion

Answer 25

The rate of absorption of a drug across the skin

Question 26

What are 2 important facrots relating to the role of the vehicle

Answer 26

Solubility of the drug in the vehicle | Maximising the movement of the drug from vehicle to the stratum corneum

Question 27

What is Km

Answer 27

the equilibrium solubility of the drug in the stratum corneum relative to its solubility in the vehicle

Question 28

A very soluble drug will penetrate easily. true or false

Answer 28

false

Question 29

What type of base is vest for a lipothilic drug

Answer 29

Hydrophilic base

Question 30

What tends to break down the permeability barrier

Answer 30

hydration

Question 31

Are hydrophilic or lipothilic drugs better for absorption

Answer 31

lipothilic

Question 32

What provides the driving force for absorption

Answer 32

The soluble fraction of a drug

Question 33

Inclusion of what can enhance solubility and absorption

Answer 33

The inclusion of exipients

Question 34

Give an example of an excipient

Answer 34

propylene glycol

Question 35

Why are topically applied drugs generally poorly absorbed

Answer 35

Only a small fraction partitions into the stratum corneum

Question 36

What does an increased partitoning result from

Answer 36

a reduction in the barrier function of the stratum corneum

Question 37

What can be used to increase the solubility of hydrophobic drugs

Answer 37

Inclusion of excipients

Question 38

Name some factors that influence the absorption of topically applied drugs

Answer 38

``` The nature of the skin - the thickness Hydration of the skin Integrity of the epidermis Drug concentration The drug salt The vehicle ```

Question 39

Why can a pharmacist not substitute the vehicle

Answer 39

It has been prescribed just as much as the drug itself

Question 40

Why might a cream be used rather than an ointment

Answer 40

For cosmetic reasons

Question 41

Glucocorticosteroids signal via what and specifically what

Answer 41

Nuclear receptors - GRalpha

Question 42

What is meant by Subcutaneous Route

Answer 42

Drug delivered by a needle into the adipose tissue just beneath the surface of the skin

Question 43

What are some advantages of administering a drug subcutaneously

Answer 43

Absorption is relatively sore due to poor vascular supply Route of adminsitration for many protein drugs (insulin) Suitable for administration fof depot of drug under the skin that

Question 44

What is the main disadvantage of using subcutaneous route of administration

Answer 44

Injection volume is limited

Question 45

What are 4 advantages of a drug being administered topically for a systemic affect

Answer 45

Simple and non-sterile technique Steady-state plasma concentration over a prolonged period of time Avoids first pass metabolism terminated rapidly

Question 46

What is meant by transdermal drug delivery

Answer 46

Drug is incorporated into a n adhesive patch and applied to the epidermis

Question 47

What 4 types of drugs is Trasdermal drug delivery useful for

Answer 47

low molecular weight moderately lipophilic potent realtively brief half life

Question 48

What are some advantages of using transdermal drug delivery

Answer 48

Relatively few drugs are suitable | Chance of allerfies and cost

Question 49

Name some drugs wihch are administered transdermally

Answer 49

nicotine GTN fentanyl estradiol

Question 50

WHat is the puropse of using chemical enhancements in transdermal drug delivery

Answer 50

Increases permeability Low cost Can be incorporated into vehicles

Question 51

What are some disadvantages of transdermal drug delivery

Answer 51

Skin irritation/ toxicity | Not effective for highly water soluble drugs

Question 52

What agents tend to be used to enhance

Answer 52

Water - prolonged occlusion | A variety of solvents and surfactants (ethanol, and sodium dodecyl sulphate

Question 53

What is iontophoresis

Answer 53

application of low voltage electrical pulses to the skin via a surface electrode over a prolonged period of time

Question 54

What is meant by electroporation

Answer 54

very brief high voltage pulses lead to pore formation. Has the potential for the delivery of hydrophilic and changed molecules into the skin

Question 55

what is sonophoresis

Answer 55

the use of ultrasound to increased skin permeability

Question 56

How do microneedles work

Answer 56

they punch microscopic holes i nthe skin - largely experimental