Toical Drug Delivery W5

Question 2

What is the largest organ in the body?

Answer 2

The skin

Question 3

What is the weight of the skin?

Answer 3

2.5 kg

Question 4

What are the protective functions of the skin?

Answer 4

Protects internal body structures, limits entry of noxious chemicals, stabilizes body temperature and blood pressure

Question 5

What is the role of melanocytes in the skin?

Answer 5

Produce skin pigment protein (melanin)

Question 6

What is the stratum corneum?

Answer 6

The outermost layer of the epidermis, consisting of keratin-rich dead cells

Question 7

True or False: The stratum corneum is metabolically active.

Answer 7

False

Question 8

What is the thickness range of the stratum corneum on palmar and plantar surfaces?

Answer 8

200-800 microns

Question 9

What are the main components of the dermis?

Answer 9

• Collagen (70%)
• Elastin
• Fibrillin

Question 10

What are eccrine sweat glands responsible for?

Answer 10

Body temperature homeostasis and emotional response

Question 11

What is the function of sebaceous glands?

Answer 11

Produce a lipid-rich secretion called sebum

Question 12

What is the hypodermis?

Answer 12

Subcutaneous fat layer that acts as a mechanical protector, thermal insulator, and energy store

Question 13

Fill in the blank: Topical drug delivery involves the delivery of a medicament to the _______ or mucous membrane.

Answer 13

[skin]

Question 14

What is the primary barrier to drug absorption in topical delivery?

Answer 14

Stratum corneum

Question 15

What factors determine the rate of drug absorption across the skin?

Answer 15

• Concentration of drug applied
• Diffusion coefficient of drug
• Solute partition coefficient

Question 16

What equation predicts the rate of drug transport across the skin?

Answer 16

J = D * P * (ΔC / d)

Question 17

How can the rate of drug absorption across the skin be increased?

Answer 17

• Increase concentration of drug at skin surface
• Use supersaturated drug formulations
• Increase drug diffusion coefficient

Question 18

What is the purpose of a Franz diffusion cell?

Answer 18

To measure the rate of drug transport across the skin

Question 19

What does the Potts and Guy equation predict?

Answer 19

Drug transport rate based on molecular size and hydrophobicity

Question 20

What is the transdermal drug delivery market worth as of the year 2000?

Answer 20

$2 billion per year

Question 21

What are the two main categories of transdermal skin patches?

Answer 21

• Monolith (matrix) system
• Rate-limiting membrane system

Question 22

What is the significance of microneedle devices in drug delivery?

Answer 22

They allow large drug molecules like peptides/proteins to penetrate the skin without reaching nerve fibers

Question 23

What are the key advantages of transdermal patches?

Answer 23

• Avoids first-pass metabolism
• Consistent site of absorption
• Can stop dosing by removing the patch

Question 24

Fill in the blank: Hydrated skin is generally more _______ to drug.

Answer 24

[permeable]

Question 25

What formulation techniques can enhance transdermal drug delivery?

Answer 25

* Use of penetration enhancers * Ointments that restrict water loss * Supersaturated drug concentrations

Question 26

What is the role of skin hydration in transdermal drug transport?

Answer 26

Looser packing of SC lipids allows for less restrictive paths for drug diffusion

Question 27

True or False: All drugs can be effectively delivered across the skin.

Answer 27

False

Question 28

What is the function of hair follicles in drug delivery?

Answer 28

May increase permeability for certain drugs, especially hydrophilic ones

Question 29

What is the primary function of the stratum corneum?

Answer 29

Defense against external factors ## Footnote The stratum corneum has much less enzymatic activity.

Question 30

What technology utilizes tiny, invisible needles that penetrate the epidermis?

Answer 30

Microneedle Devices ## Footnote These devices do not reach the nerve fibers.

Question 31

What is the purpose of iontophoresis?

Answer 31

Driving of charged molecules through the skin using low electrical currents ## Footnote Typically uses a current of 0.5mA/cm².

Question 32

Which drug is used for hyperhidrosis?

Answer 32

Glycopyrronium bromide ## Footnote It is delivered using iontophoresis.

Question 33

What are the two types of drugs mentioned in relation to iontophoresis?

Answer 33

Cationic drug and Anionic drug ## Footnote These terms refer to the charge of the drugs used in the process.

Question 34

What factors determine drug penetration of the stratum corneum?

Answer 34

Many drug and formulation factors ## Footnote These factors include physicochemical parameters.

Question 35

What is an important consideration for many topical formulations?

Answer 35

Patient acceptability ## Footnote This affects the choice of formulation.

Question 36

Fill in the blank: Topical delivery can be used for _______ or systemic delivery.

Answer 36

[local] ## Footnote Local delivery is a significant aspect of topical formulations.

Question 37

What are the types of formulations mentioned for local delivery?

Answer 37

Many formulation types exist ## Footnote This is especially true for local delivery.

Question 38

Which chapters of essential readings focus on transdermal drug delivery?

Answer 38

Chapter 38 of Aulton's Pharmaceutics (3rd Edition) and Chapter 9.5 of Physicochemical Principles of Pharmacy (4th Edition) ## Footnote These chapters provide detailed information on transdermal delivery.