Transdermal Drug Delivery Systems (TDDS)

TDDS is also known as what?
A. Skin tablets
B. Skin patches
C. Transdermal creams
D. Topical ointments

B. Skin patches — TDDS are designed to deliver drugs through the skin and into the bloodstream.

2. What is the main route of drug penetration in TDDS?
A. Blood vessels
B. Sebaceous glands
C. Stratum corneum
D. Sweat ducts

C. Stratum corneum — It’s the main barrier and site where passive diffusion occurs.

3. What does “percutaneous absorption” mean?
A. Direct skin injection
B. Drug delivery through the stratum corneum
C. Oral absorption via saliva
D. Nasal drug delivery

B. Drug delivery through the stratum corneum — Percutaneous absorption involves drug diffusion across the skin.

4. The stratum corneum behaves as a _______.
A. Hydrophilic barrier
B. Semipermeable membrane
C. Permeable sponge
D. Fat layer

B. Semipermeable membrane — It controls diffusion of drugs across the skin.

5. Which of the following is a chemical enhancer for TDDS?
A. Ethanol
B. Acetone
C. Caffeine
D. Benzene

B. Acetone — It increases skin permeability by altering stratum corneum lipids.

6. How do chemical enhancers improve drug absorption?
A. Increase skin hydration
B. Change lipid structure
C. Damage stratum corneum
D. All of the above

D. All of the above — They increase hydration and alter lipids to reduce skin resistance.

7. Which of the following is not a percutaneous enhancer?
A. Dimethylformamide
B. Propylene glycol
C. Sodium lauryl sulfate
D. Glycerin

D. Glycerin — It moisturizes but doesn’t enhance drug permeability.

8. Iontophoresis delivers drugs using what principle?
A. Pressure
B. Electric field
C. Heat
D. Enzymatic reaction

B. Electric field — It uses current to push charged drugs across the skin.

9. Which drug is commonly delivered using iontophoresis?
A. Lidocaine
B. Aspirin
C. Amoxicillin
D. Paracetamol

A. Lidocaine — A local anesthetic often administered via iontophoresis.

10. Sonophoresis enhances drug delivery using what?
A. Low voltage
B. High-frequency ultrasound
C. Magnetic field
D. UV radiation

B. High-frequency ultrasound — It increases skin permeability through sound waves.

11. Which of the following is an advantage of TDDS?
A. Avoids first-pass metabolism
B. Requires sterile application
C. Limited drug potency
D. Painful administration

A. Avoids first-pass metabolism — The drug bypasses the liver, improving bioavailability.

12. Which is not an advantage of TDDS?
A. Increased bioavailability
B. Controlled blood levels
C. Rapid onset and offset
D. Requires large doses

D. Requires large doses — TDDS are suitable only for potent drugs needing small doses.

13. Which property allows rapid termination of drug therapy in TDDS?
A. Washable patch
B. Immediate drug diffusion
C. Patch removal
D. Skin hydration

C. Patch removal — Simply taking off the patch stops further drug absorption.

14. Which is a common disadvantage of TDDS?
A. Drug instability
B. Contact dermatitis
C. Rapid elimination
D. Poor oral absorption

B. Contact dermatitis — Allergic skin reaction can occur at the patch site.

15. What is the ideal molecular weight for TDDS drugs?
A.

A.

16. Why are ionic drugs not feasible for TDDS?
A. They’re too large
B. They can’t cross lipid membranes
C. They are unstable in skin
D. They evaporate quickly

B. They can’t cross lipid membranes — The stratum corneum favors nonpolar, lipophilic molecules.

17. What pH should a drug for TDDS ideally have?
A. 1–2
B. 4.2–5.6
C. 7–8
D. 9–10

B. 4.2–5.6 — Matches normal skin pH, preventing irritation.

18. Ideal patch size for TDDS should be less than:
A. 100 cm²
B. 60 cm²
C. 40 cm²
D. 20 cm²

C. 40 cm² — Keeps the patch practical and comfortable for the user.

19. Drugs with what half-life are suitable for TDDS?
A. Long (>10 hrs)
B. Short (

C. Moderate (2–7 hrs) — Enough for controlled, continuous release without buildup.

20. What kind of drug dose suits TDDS?
A. Several grams
B. Few milligrams per day
C. 1–2 liters solution
D. None of the above

B. Few milligrams per day — Only potent drugs are suitable for TDDS.

21. In single-layer drug-in-adhesive patches, where is the drug located?
A. Separate reservoir
B. Backing membrane
C. Adhesive layer
D. Release liner

C. Adhesive layer — It both sticks to skin and controls drug release.

22. The multi-layer drug-in-adhesive system differs because it has:
A. Two backing layers
B. Additional drug layer separated by membrane
C. Extra adhesive film
D. None of the above

B. Additional drug layer separated by membrane — Allows dual drug control.

23. Which TDDS delivers drug in a zero-order rate?
A. Matrix system
B. Drug reservoir in-adhesive
C. Single-layer patch
D. None of the above

B. Drug reservoir in-adhesive — Controlled membrane ensures constant release.

24. The drug matrix in-adhesive type uses:
A. Liquid drug reservoir
B. Semisolid matrix
C. Gas-permeable layer
D. Oil reservoir

B. Semisolid matrix — Drug is dispersed within a polymer-based matrix.

25. The monolithic system controls drug release by:
A. A rate-controlling membrane
B. Drug dissolution
C. Polymer matrix diffusion
D. Chemical enhancer

C. Polymer matrix diffusion — The matrix regulates how fast the drug moves out.

26. A monolithic system without excess drug means:
A. Drug below solubility level
B. Drug at or above solubility limit
C. No drug at all
D. Excess drug crystals visible

B. Drug at or above solubility limit — Ensures saturation for effective diffusion.

27. Which system maintains a constant release rate as long as reservoir remains saturated?
A. Matrix
B. Monolithic
C. Membrane-controlled
D. Adhesive

C. Membrane-controlled — Saturation in reservoir keeps drug diffusion steady.

28. The polymer matrix in TDDS must be:
A. Reactive
B. Inert and biocompatible
C. Soluble in blood
D. Thick and rigid

B. Inert and biocompatible — It must not react or cause irritation.

29. The penetration enhancer should:
A. Be pharmacologically active
B. Be toxic
C. Work unidirectionally
D. Prevent drug entry

C. Work unidirectionally — Should only allow drug entry, not loss of body fluids.

30. Which is not a good property of penetration enhancers?
A. Non-irritating
B. Predictable action
C. Pharmacologically active
D. Rapid and reversible

C. Pharmacologically active — It should not have its own drug effect.

31. Which adhesive property is most essential?
A. Reactive to drug
B. Pressure-sensitive
C. Water-insoluble
D. Sticky permanently

B. Pressure-sensitive — It should adhere with minimal pressure and peel off easily.

32. The backing membrane must be:
A. Permeable to drug
B. Impermeable to drug and enhancers
C. Reactive with drug
D. Transparent to UV

B. Impermeable to drug and enhancers — Prevents leakage and degradation.

33. The backing layer should also:
A. Allow water to escape
B. Retain skin moisture
C. Be absorbent
D. Dissolve on use

B. Retain skin moisture — Keeps site hydrated for better penetration.

34. What is the common method for preparing TDDS?
A. Solvent casting
B. Freeze drying
C. Evaporation
D. Extrusion molding

A. Solvent casting — Used to form uniform thin films for patches.

35. The minimum film thickness for a transdermal patch is:
A. 0.01 mm
B. 0.001 mm
C. 1 mm
D. 10 mm

B. 0.001 mm — Ensures adequate flexibility and consistency.

36. The Rolling Ball Tack Test measures:
A. Flexibility
B. Adhesive stickiness
C. Drug release
D. Permeability

B. Adhesive stickiness — It determines how fast the adhesive grabs a surface.

37. The Folding Endurance Test evaluates:
A. Patch color
B. Peel resistance
C. Mechanical strength
D. Patch thickness

C. Mechanical strength — Determines how many folds a patch can withstand before breaking.

38. The Peel Adhesion Test measures:
A. Tack value
B. Elasticity
C. Flexibility
D. Water content

A. Tack value — The force needed to separate joined adhesive surfaces.

39. Tensile strength measures:
A. Color fading
B. Stretching ability
C. Water absorption
D. Film transparency

B. Stretching ability — Tests how much the patch can stretch before breaking.

40. The in vitro diffusion cell measures:
A. Drug permeation
B. Skin irritation
C. Patch thickness
D. Tackiness

A. Drug permeation — It checks how well the drug passes through a membrane.

41. The Paddle Over Disc Method is used for:
A. Drug release studies
B. Skin pH testing
C. Adhesive peel test
D. Solvent stability

A. Drug release studies — It evaluates how quickly a drug leaves the patch.

42. TDDS stability testing follows which guideline?
A. BP
B. USP
C. ICH
D. FDA

C. ICH — It specifies conditions for stability studies like temp and humidity.

43. The temperature for TDDS stability studies is:
A. 25°C
B. 30°C
C. 40°C ± 0.5°C
D. 60°C

C. 40°C ± 0.5°C — Accelerated condition for stability testing.

44. Relative humidity for stability testing should be:
A. 25% ± 5%
B. 50% ± 10%
C. 75% ± 5%
D. 90% ± 10%

C. 75% ± 5% — Ensures realistic storage simulation.

45. Samples in stability studies are tested every:
A. 7 days
B. 15 days
C. 30 days
D. 60 days

C. 30 days — Drug content is analyzed monthly.

46. Which drug is used in patches for menopausal symptoms?
A. Nitroglycerin
B. Estrogen
C. Selegiline
D. Clonidine

B. Estrogen — Used for hormone replacement and contraceptive therapy.

47. Nitroglycerin patches are used for:
A. ADHD
B. Hypertension
C. Angina pectoris
D. Depression

C. Angina pectoris — They deliver nitroglycerin to prevent chest pain.

48. Clonidine transdermal patches are used to treat:
A. Depression
B. Pain
C. Hypertension
D. Menopause

C. Hypertension — Clonidine lowers blood pressure via steady absorption.

49. Selegiline patches are prescribed for:
A. Parkinson’s disease / Depression
B. Angina
C. Hypertension
D. Pain

A. Parkinson’s disease / Depression — MAO-B inhibitor patch for mental disorders.

50. Fentanyl transdermal patch is a:
A. NSAID
B. Opioid analgesic
C. Sedative
D. Muscle relaxant

B. Opioid analgesic — Provides continuous pain control.

51. Methylphenidate patches treat:
A. Hypertension
B. ADHD
C. Anxiety
D. Depression

B. ADHD — Provides steady stimulant release for attention control.

52. What property of TDDS ensures controlled blood level maintenance?
A. Variable release
B. Constant membrane control
C. Rapid dissolution
D. Absorption enhancers

B. Constant membrane control — Maintains stable plasma concentration over time.

53. What happens if a patch’s backing membrane fails?
A. Increased drug stability
B. Drug leakage and degradation
C. Improved efficacy
D. Extended life

B. Drug leakage and degradation — The backing membrane prevents exposure to air.

54. What is the rate-limiting barrier in percutaneous absorption?
A. Dermis
B. Stratum corneum
C. Epidermis
D. Hair follicle

B. Stratum corneum — Controls how fast drugs can diffuse into deeper layers.

55. What are the two types of monolithic systems?
A. Diffusion and dissolution
B. With and without excess drug
C. Adhesive and non-adhesive
D. Single and double layer

B. With and without excess drug — Determines if the system maintains saturation.

56. Which test measures how easily a patch sticks under slight pressure?
A. Peel test
B. Rolling Ball Tack Test
C. Diffusion cell
D. Folding endurance

B. Rolling Ball Tack Test — Ball rolling distance indicates adhesive tackiness.

57. A penetration enhancer should allow skin to:
A. Stay permanently altered
B. Rapidly recover after removal
C. Lose water content
D. Remain damaged

B. Rapidly recover after removal — Skin barrier must return to normal quickly.

58. Which of the following statements about TDDS is false?
A. Avoids first-pass effect
B. Suitable for potent drugs
C. Delivers ionic drugs easily
D. Maintains steady plasma levels

C. Delivers ionic drugs easily — Ionic drugs have poor lipid permeability.

59. What parameter is analyzed in in vitro drug release testing?
A. Adhesion
B. Dissolution rate
C. Skin irritation
D. Film flexibility

B. Dissolution rate — It checks how fast the drug leaves the patch matrix.

60. Why are TDDS easily identified in emergencies?
A. They glow under UV
B. They are labeled and visible
C. They contain sensors
D. They emit odor

B. They are labeled and visible — External visibility makes them easy to locate and remove.