Pharmaceutics Ii (Test 1): Transdermal Drug Delivery System Tdds

Front 1

What is TDDS?

Back 1

Transdermal Drug Delivery System.

Front 2

Define TDDS?

Back 2

Facilitates the passage of the therapeutic quantities of the drug substance through the SKIN to the general circulation for SYSTEMIC effects.

Front 3

TDDS is usually only suitable for drugs of what level of potency?

Back 3

Typically only for drugs of high potency.

Front 4

Drugs used in TDDS have to be a ? ? ? skin.

Back 4

They have to be a good penetrant of skin. Or they need a penetration enhancer.

Front 5

In the use of TDDS for drug application ? size has to be considered reasonable?

Back 5

Patch size has to be reasonable.

Front 6

How fast is the requirement for the onset of action for a drug before it is considered for application through the use of TDDS?

Back 6

It needs to be clinically prompt in its onset of action.

Front 7

A patch has to be ?-? and ? acceptable.

Back 7

Has to be non-irritating and aesthetically acceptable.

Front 8

List 6 advantages of the TDDS method of drug application?

Back 8

1. Avoidance of the First pass effect

2. A stable and controlled blood level

3. Termination at any time is conceivable

4. Long-term duration, ranging from a few hours to one week.

5. No interference with gastric and intestinal fluids or enzymes

6. Aids in the administration of drugs with:
A very short half-life;
A narrow therapeutic window;
Poor oral absorption

Front 9

List 2 disadvantages of the TDDS method of drug application?

Back 9

1. Limited to ONLY potent drugs

2. Some pts. develop contact dermatitis at site of application

Front 10

What is the largest organ of the body?

Back 10

Skin

Front 11

Anatomically the skin is a ? organ with ? distinct layers.

Back 11

It is a stratified organ with 3 distinct layers.

Front 12

List the 3 distinct layers of the skin?

Back 12

1. Epidermis

2. Dermis

3. Subcutaneous Fat Layer

Front 13

What is the slowest step of a drug permeating through the skin?

Back 13

The passing of the drug through the STRATUM CORNEUM is the RATE-LIMITING STEP.

Front 14

The stratum corneum is a ?-? membrane.

Back 14

It is a semi-permeable membrane.

Front 15

List 3 things that affect the passive diffusion of a drug through the stratum corneum.

Back 15

1. Concentration of the drug

2. Aqueous solubility

3. Oil-water partition coefficient

Front 16

Which drugs are good candidates for diffusion through the stratum corneum?

Back 16

Drugs with both aqueous and lipid solubility are good candidates.

Front 17

Drugs that pass through the stratum corneum may also pass through what else?

Back 17

May pass through the deeper dermis layers or to the blood.

Front 18

What is the term that describes "the absorption of substances from outside the skin to positions beneath the skin, including entrance to the blood stream"

Back 18

Percutaneous absorption.

Front 19

List the 4 components of TDDSs? Which 3 are the most important?

Back 19

1. Polymer matrix or matrices

2. The drug

3. Permeation enhancers

4. Other excipients

(1-3 are the most important)

Front 20

Give an example of an excipient seen in TDDSs?

Back 20

Adhesives

Front 21

What is the purpose of the polymer matrix in a TDDS?

Back 21

It controls the release of a drug from the device.

Front 22

What 2 types of polymers are used to make polymer matrices for TDDSs?

Back 22

1. Natural polymers

2. Synthetic polymers

Front 23

Give 5 examples of natural polymers?

Back 23

1. Cellulose derivatives

2. Gelatin

3. Shellac

4. Waxes

5. Gums and their derivatives

Front 24

Give 3 examples of sythetic polymers?

Back 24

1. Polyvinyl alcohol

2. Polyvinyl chloride

3. Polyrurea

Front 25

Describe 5 desirable PHYSIOCHEMICAL properties of a drug for transdermal delivery?

Back 25

1. mw <1000 daltons

2. The drug should have affinity for both lipophilic and hydrophilic phases, because the skin is composed of both of these

3. The drug should have a low melting point

4. Drug should be potent, should have a short half life.

5. Non-irritating

Front 26

What do permeation enhancers do?

Back 26

They help the drug penetrate the skin.

Front 27

List 5 ways that permeation enhancers increase skin permeation.

Back 27

1. Causing reversible damage to the stratum corneum

2. Optimizing the thermodynamic activity of the drug in the vehicle and/or skin

3. Increasing the drug diffusivity in the stratum corneum

4. Establishing a drug reservoir within the stratum corneum

5. Increasing the solubility of the active

Front 28

What are the 2 types of permeation enhancers?

Back 28

1. Chemical

2. Physical

Front 29

Describe how chemical permeation enhancers achieve increased skin permeation of a drug?

Back 29

These are compounds that promote skin permeability by altering the skin as a barrier to the flux of a desired penetrant.
They increase the skin permeability by reversibly damaging or altering the physiochemical nature of the stratum corneum.

Front 30

List the 3 groups that chemical permeation enhancers are classified by?

Back 30

1. Solvents

2. Surfactants

3. Misc. chemicals

Front 31

What are some examples of chemical permeation enhancers that fall under the classification of solvents?

Back 31

Water alcohols, like methanol and ethanol

Front 32

What are some examples of chem. perm. enh.s that fall under the classification of surfactants?

Back 32

1. Anionic surfactants (eg Sodium lauryl sulfate)

2. Nonionic surfactants (eg, Pluronic F127, Pluronic F68)

Front 33

Give an example of a chem. perm. enh. that falls under the classification of Miscellaneous chemicals?

Back 33

Urea (A hydrating and keratolytic agent)

Front 34

What are the two different physical methods of permeation enhancement?

Back 34

1. Iontophoresis

2. Sonophoresis

Front 35

What is Iontophoresis?

Back 35

A method of permeation enhancement that involves the use of charged chemical components across the skin membrane using an electric field.

Front 36

What is sonophoresis?

Back 36

A physical method of permeation enhancement that involves the use of high frequency ultrasound. It is thought to influence the integrity of the SC and thus affect its penetrability.

Front 37

List 2 miscellaneous excipients that may be observed in TDDSs?

Back 37

1. Adhesives

2. Backing membrane

Front 38

What is an adhesive?

Back 38

An exipient in TDDSs. The fastening of all TDDSs to the skin has so far been done by using a pressure sensitive adhesive.

Front 39

Four requirements of an adhesive that is going to be used as an excipient in a TDDS?

Back 39

1. Should adhere to the skin aggressively yet be easily removed.

2. Should not leave an unwashable residue on the skin

3. Should not irritate or desensitize skin

4. Phys. and chemical compatibility with the drug, excipients and enhancers of the device

Front 40

What is a backing membrane?

Back 40

It is an excipient seen in TDDSs. It is flexible and provides a good bond to the drug reservoir. They prevent drug from leaving the dosage form through the top, and accept printing.

Front 41

What are the two potential TDDS designs?

Back 41

1. Monolithic

2. Membrane-controlled systems

Front 42

How many layers are seen in monolithic TDDS designs?

Back 42

Three

Front 43

How many layers are seen in Membrane-controlled systems?

Back 43

Four

Front 44

List 5 characteristics of a monolithic TDDS design?

Back 44

1. Drug is incorporated into the MATRIX

2. Backing

3. Adhesive layer

4. Drug may or may not be added in excess

5. Excess drug maintains steady state of the drug for a long time.

Front 45

List 5 characteristics of a Membrane-controlled system?

Back 45

1. Drug RESERVOIR in liquid or gel form.

2. Backing

3. Adhesive layer

4. A RATE CONTROLLING MEMBRANE (THIS IS THE 4TH LAYER THAT REALLY DISTINGUISHES THIS FROM THE MONOLITHIC DESIGN)

5. Includes Transderm Nitro, Transderm Scop

Front 46

What controls the release of a drug in a membrane-controlled TDDS?

Back 46

Semi-permeable membrane.

Front 47

What controls the release of the drug from a monolithic TDDS design?

Back 47

Polymer

Front 48

The patch is ?.

Back 48

Occlusive

Front 49

List 6 marketed TDDSs?

Back 49

1. Scopolamine

2. Nitroglycerin

3. Clonidine

4. Estradiol

5. Nicotine

6. Fentanyl

Front 50

What is Scopolamine used to treat?

Back 50

For prevention of motion sickness.

Front 51

What is Nitroglycerin used to treat?

Back 51

Angina

Front 52

What is Clonidine used to treat?

Back 52

HTN

Front 53

What is Estradiol used to treat?

Back 53

Hormone Deficiency (Osteoporosis in postmenopausal women)

Front 54

What is Nicotine used to treat?

Back 54

Smoking cessation

Front 55

What is Fentanyl used to treat?

Back 55

For the mgmt of chronic pain in patients requiring opioid analgesia