Q.1 What is the primary advantage of transdermal drug delivery over oral administration?
Avoidance of first‑pass metabolism
Higher drug solubility requirements
Need for invasive surgery
Limited drug stability
Explanation - Transdermal patches bypass the gastrointestinal tract and liver, preventing the drug from being metabolized before reaching systemic circulation.
Correct answer is: Avoidance of first‑pass metabolism
Q.2 Which of the following mechanisms is most commonly used to enhance drug permeation through the skin?
Electroosmosis
Osmotic pressure
Chemical enhancers
Magnetic resonance
Explanation - Chemical permeation enhancers disrupt the lipid structure of the stratum corneum, increasing drug diffusion.
Correct answer is: Chemical enhancers
Q.3 In iontophoresis, the drug is delivered across the skin mainly by:
Diffusion through hair follicles
Electro‑repulsion of charged molecules
Thermal heating of the epidermis
Acoustic vibration
Explanation - Iontophoresis uses a low electric current to drive charged drug molecules away from the electrode of the same charge, propelling them through the skin.
Correct answer is: Electro‑repulsion of charged molecules
Q.4 Which layer of the oral mucosa is directly exposed to the external environment?
Basal lamina
Stratum corneum
Epithelium
Submucosa
Explanation - The oral mucosal epithelium is the outermost cellular layer that contacts the oral cavity; unlike skin, it lacks a thick stratum corneum.
Correct answer is: Epithelium
Q.5 What is the main limitation of transdermal patches for delivering large‑molecule drugs (e.g., peptides)?
Low electrical conductivity of the skin
Insufficient drug solubility in the patch matrix
Poor permeation through the stratum corneum
Rapid degradation by skin enzymes
Explanation - The stratum corneum acts as a size‑selective barrier; large molecules cannot readily diffuse through it without special techniques.
Correct answer is: Poor permeation through the stratum corneum
Q.6 Electroporation improves transdermal drug delivery by:
Generating heat to melt the lipid bilayers
Creating temporary aqueous pores in cell membranes
Increasing skin pH
Releasing drug from a polymeric matrix
Explanation - Short high‑voltage pulses cause reversible disruption of lipid structures, forming pores that allow larger molecules to pass.
Correct answer is: Creating temporary aqueous pores in cell membranes
Q.7 Which of the following is a common site for buccal drug delivery?
Hard palate
Gingival sulcus
Sublingual space
Uvula
Explanation - The sublingual region under the tongue has a thin epithelium and rich blood supply, making it ideal for rapid systemic absorption.
Correct answer is: Sublingual space
Q.8 In a transdermal patch, the ‘rate‑controlling membrane’ primarily functions to:
Enhance drug solubility
Regulate the flux of drug across the patch
Provide mechanical strength
Prevent bacterial contamination
Explanation - The membrane controls the drug release rate, ensuring a constant delivery profile over time.
Correct answer is: Regulate the flux of drug across the patch
Q.9 Which type of electrical current is typically used in iontophoresis for drug delivery?
Alternating current (AC)
Direct current (DC)
Pulsed current
Radiofrequency current
Explanation - A low‑intensity DC provides a steady electric field that drives charged drug molecules across the skin.
Correct answer is: Direct current (DC)
Q.10 The term ‘bioadhesive’ in mucosal drug delivery refers to:
A drug that adheres to blood cells
A polymer that sticks to mucosal surfaces
A device that generates heat
A formulation that releases drug only after digestion
Explanation - Bioadhesive polymers increase residence time of the dosage form on the mucosa, enhancing drug absorption.
Correct answer is: A polymer that sticks to mucosal surfaces
Q.11 Which of the following drugs is commonly delivered via transdermal patches?
Aspirin
Nitroglycerin
Ciprofloxacin
Metformin
Explanation - Nitroglycerin patches provide a steady release for angina treatment and are well‑studied transdermal systems.
Correct answer is: Nitroglycerin
Q.12 What is the main reason why the buccal mucosa is preferred over the gastric route for peptide drugs?
Higher enzymatic activity
Acidic pH degradation
Rich vascularisation and lower enzymatic activity
Presence of a thick keratinised layer
Explanation - The buccal mucosa offers a relatively enzyme‑free environment and a good blood supply, improving peptide stability and absorption.
Correct answer is: Rich vascularisation and lower enzymatic activity
Q.13 In microneedle patches, the primary function of the microneedles is to:
Create large wounds for drug diffusion
Pierce the stratum corneum without reaching nerve endings
Generate heat to melt the drug matrix
Act as electrical electrodes
Explanation - Microneedles create micro‑channels that bypass the barrier function while remaining minimally invasive and painless.
Correct answer is: Pierce the stratum corneum without reaching nerve endings
Q.14 Which physicochemical property most strongly influences a drug’s ability to permeate the skin?
Molecular weight
Color
Taste
pKa
Explanation - Smaller molecules (generally <500 Da) diffuse more readily through the lipid matrix of the stratum corneum.
Correct answer is: Molecular weight
Q.15 The term ‘first‑pass effect’ is irrelevant to transdermal delivery because:
The drug is degraded by skin enzymes
The drug bypasses the liver initially
The drug is released in a pulsatile manner
The drug is delivered directly to the brain
Explanation - Transdermal delivery introduces the drug into systemic circulation directly, avoiding hepatic metabolism that occurs after oral dosing.
Correct answer is: The drug bypasses the liver initially
Q.16 Which of the following is a key design consideration for a transdermal patch intended for 24‑hour use?
High volatility of the drug
Rapid burst release
Controlled steady‑state flux
Large patch size
Explanation - A 24‑hour patch must maintain a constant drug release rate to provide therapeutic levels throughout the dosing interval.
Correct answer is: Controlled steady‑state flux
Q.17 In the context of mucosal drug delivery, the term ‘permeation enhancer’ refers to:
A device that measures pH
A molecule that temporarily disrupts mucosal barrier
A polymer that solidifies the formulation
An enzyme that degrades the drug
Explanation - Permeation enhancers increase drug absorption by loosening tight junctions or fluidising lipids in the mucosal epithelium.
Correct answer is: A molecule that temporarily disrupts mucosal barrier
Q.18 Which electrical parameter is most critical to ensure safety during iontophoretic drug delivery?
Current density (mA/cm²)
Voltage amplitude (V)
Frequency (Hz)
Power factor
Explanation - Current density determines the amount of charge per unit area and must be limited (<0.5 mA/cm²) to avoid skin irritation or burns.
Correct answer is: Current density (mA/cm²)
Q.19 Which of the following statements about the sublingual route is TRUE?
It requires a highly lipophilic drug.
It avoids the hepatic first‑pass metabolism.
It provides the slowest onset of action.
It is limited to drugs with molecular weight >1000 Da.
Explanation - Sublingual absorption directly enters the systemic circulation via the veins under the tongue, bypassing the liver initially.
Correct answer is: It avoids the hepatic first‑pass metabolism.
Q.20 Which of the following materials is commonly used as a backing layer in transdermal patches?
Cellulose acetate
Polyvinyl alcohol
Silicone elastomer
Gelatin
Explanation - Silicone elastomers are impermeable, flexible, and skin‑compatible, making them ideal backing materials.
Correct answer is: Silicone elastomer
Q.21 The Henderson–Hasselbalch equation is useful in transdermal delivery to predict:
Skin temperature changes
Ionization state of a drug at skin pH
Electrical resistance of the patch
Viscosity of the adhesive
Explanation - Only the unionized fraction of a drug can readily diffuse through the lipophilic stratum corneum.
Correct answer is: Ionization state of a drug at skin pH
Q.22 Which mucosal site has the highest permeability for drug absorption?
Hard palate
Gingiva
Sublingual mucosa
Nasopharynx
Explanation - The sublingual region is thin, non‑keratinised, and highly vascularised, giving it superior permeability.
Correct answer is: Sublingual mucosa
Q.23 What is the main purpose of a ‘reservoir’ in a transdermal drug delivery system?
To store a large amount of drug for extended release
To increase the adhesive strength of the patch
To provide electrical stimulation
To act as a barrier to moisture
Explanation - A reservoir holds the drug in a liquid or gel form, allowing controlled diffusion through the membrane over many hours or days.
Correct answer is: To store a large amount of drug for extended release
Q.24 Which of the following is a major advantage of using microneedle arrays over conventional hypodermic needles?
Higher pain perception
Ability to deliver larger volumes of fluid
Reduced risk of infection and pain
Requirement of surgical skill
Explanation - Microneedles create micro‑channels that are painless and reduce infection risk because they do not penetrate deeply into the dermis.
Correct answer is: Reduced risk of infection and pain
Q.25 In transdermal drug delivery, the term ‘lag time’ refers to:
Time taken for the patch to adhere to skin
Delay before steady‑state drug flux is achieved
Duration of patch removal
Time required for drug degradation
Explanation - Lag time is the period needed for the drug to saturate the skin layers before a constant rate of diffusion is established.
Correct answer is: Delay before steady‑state drug flux is achieved
Q.26 Which of the following techniques uses ultrasound to increase skin permeability?
Sonophoresis
Electroporation
Iontophoresis
Microneedling
Explanation - Ultrasound waves create cavitation and micro‑streaming that temporarily disrupt lipid structures, enhancing drug transport.
Correct answer is: Sonophoresis
Q.27 What is the main reason that nicotine patches are formulated with a matrix system rather than a reservoir?
Matrix systems are cheaper to produce
They provide a more linear release profile for nicotine
Matrix systems prevent nicotine degradation
Reservoirs cannot hold nicotine
Explanation - Matrix patches embed the drug in a polymeric matrix, offering a steady release that matches nicotine replacement therapy requirements.
Correct answer is: They provide a more linear release profile for nicotine
Q.28 Which parameter is NOT directly affected by the presence of a permeation enhancer in a transdermal system?
Drug solubility in the formulation
Skin electrical resistance
Drug diffusion coefficient in the stratum corneum
Thickness of the adhesive layer
Explanation - Permeation enhancers modify skin barrier properties and drug solubility but do not change the physical thickness of the patch adhesive.
Correct answer is: Thickness of the adhesive layer
Q.29 A drug with a logP (octanol‑water partition coefficient) of 7 would be:
Highly hydrophilic
Moderately lipophilic
Highly lipophilic and likely to accumulate in the skin
Unable to cross any biological membrane
Explanation - Very high logP indicates strong lipophilicity, facilitating partition into the lipid‑rich stratum corneum but possibly limiting deeper penetration.
Correct answer is: Highly lipophilic and likely to accumulate in the skin
Q.30 Which of the following is a typical limitation of buccal drug delivery?
Rapid drug degradation by gastric acid
Limited surface area and saliva wash‑out
Requirement of surgical insertion
High incidence of allergic reactions
Explanation - The buccal cavity is small and constantly bathed in saliva, which can dilute and remove the drug before absorption.
Correct answer is: Limited surface area and saliva wash‑out
Q.31 When designing an electrically powered transdermal system, the term ‘impedance’ of skin refers to:
Mechanical resistance of the patch
Electrical resistance and reactance of the skin layers
Viscosity of the drug reservoir
Permeability coefficient of the drug
Explanation - Skin impedance combines resistive and capacitive properties, influencing the current flow during iontophoresis.
Correct answer is: Electrical resistance and reactance of the skin layers
Q.32 Which of the following is a key benefit of using a ‘polymeric gel’ as a drug reservoir in a transdermal patch?
It makes the patch non‑flexible
It allows high drug loading and controlled release
It eliminates the need for a backing layer
It increases the patch’s electrical conductivity
Explanation - Polymeric gels can dissolve large amounts of drug while providing a diffusion barrier that modulates release kinetics.
Correct answer is: It allows high drug loading and controlled release
Q.33 The term ‘bioavailability’ in the context of transdermal drug delivery refers to:
The fraction of drug that reaches systemic circulation unchanged
The speed at which the drug evaporates from the patch
The total amount of drug in the reservoir
The electrical charge carried by the drug
Explanation - Bioavailability is the proportion of administered drug that enters the systemic bloodstream in its active form.
Correct answer is: The fraction of drug that reaches systemic circulation unchanged
Q.34 Which of the following is a common method for assessing the permeation of a drug through skin in vitro?
Franz diffusion cell
Patch clamp technique
Electrocardiography
Magnetic resonance imaging
Explanation - The Franz diffusion cell measures drug flux across excised skin mounted between donor and receiver compartments.
Correct answer is: Franz diffusion cell
Q.35 In mucosal drug delivery, the ‘pH‑gradient’ between the formulation and the mucosal surface can affect:
Electrical conductivity of the patch
Ionization state of the drug and thus its permeability
Mechanical strength of the dosage form
Color of the formulation
Explanation - A pH difference can shift the drug’s ionization, influencing its ability to cross the mucosal epithelium.
Correct answer is: Ionization state of the drug and thus its permeability
Q.36 Which of the following is true about the stratum corneum?
It contains living keratinocytes
It is the main barrier to transdermal drug delivery
It is highly vascularised
It is absent in mucosal membranes
Explanation - The stratum corneum is a dead, keratin‑filled layer that provides the principal resistance to diffusion of substances through the skin.
Correct answer is: It is the main barrier to transdermal drug delivery
Q.37 Which of the following is an example of a drug that can be effectively delivered via the nasal mucosa?
Insulin
Caffeine
Epinephrine
Albuterol
Explanation - Albuterol is often administered intranasally for rapid systemic absorption in asthma treatment.
Correct answer is: Albuterol
Q.38 What is the main purpose of a ‘plasticizer’ in a transdermal patch matrix?
To increase the electrical conductivity
To improve flexibility and reduce brittleness
To enhance drug solubility
To act as a preservative
Explanation - Plasticizers lower the glass transition temperature of polymers, making the patch more flexible and comfortable to wear.
Correct answer is: To improve flexibility and reduce brittleness
Q.39 Which of the following best describes ‘controlled‑release’ in a transdermal system?
Drug is released only when the patch is removed
Drug is released at a predetermined constant rate
Drug is released in response to body temperature
Drug is released only after exposure to light
Explanation - Controlled‑release aims to maintain therapeutic plasma concentrations by delivering drug at a steady rate over time.
Correct answer is: Drug is released at a predetermined constant rate
Q.40 In electroporation, the high‑voltage pulse duration is typically in the range of:
Microseconds to milliseconds
Seconds to minutes
Nanoseconds to picoseconds
Hours
Explanation - Short high‑voltage pulses (µs‑ms) create reversible pores without causing permanent tissue damage.
Correct answer is: Microseconds to milliseconds
Q.41 Which factor does NOT influence drug absorption through the oral mucosa?
Mucosal blood flow
Drug lipophilicity
Skin temperature
Presence of saliva
Explanation - Oral mucosa is not skin; its temperature is relatively constant and less impactful than the listed factors.
Correct answer is: Skin temperature
Q.42 The term ‘patch adhesion’ is important because:
It determines the electrical output of the patch
It influences the drug release rate and user compliance
It controls the drug’s molecular weight
It defines the color of the patch
Explanation - Good adhesion ensures the patch stays in place for the intended duration, maintaining consistent drug delivery.
Correct answer is: It influences the drug release rate and user compliance
Q.43 A major reason for using a ‘matrix‑type’ transdermal patch for hormone therapy is:
Matrix patches allow for higher drug loading than reservoir patches
Matrix patches can be easily removed without residue
Matrix patches provide a more uniform drug release profile
Matrix patches require no backing layer
Explanation - Matrix systems disperse the drug throughout the polymer, leading to a smoother, more constant release suitable for hormones.
Correct answer is: Matrix patches provide a more uniform drug release profile
Q.44 Which of the following is a disadvantage of using high concentrations of chemical permeation enhancers?
Increased drug stability
Skin irritation and possible toxicity
Reduced drug solubility
Improved patch adhesion
Explanation - High levels of enhancers can disrupt skin integrity, leading to irritation, erythema, or sensitisation.
Correct answer is: Skin irritation and possible toxicity
Q.45 What is the purpose of a ‘rate‑controlling membrane’ in a reservoir transdermal patch?
To speed up drug diffusion
To limit the drug flux to a desired rate
To hold the adhesive in place
To act as a waterproof barrier
Explanation - The membrane's permeability dictates how fast drug molecules can leave the reservoir, enabling controlled delivery.
Correct answer is: To limit the drug flux to a desired rate
Q.46 Which mucosal surface is most suitable for systemic delivery of vaccines?
Gingival mucosa
Nasal mucosa
Hard palate
Esophageal mucosa
Explanation - The nasal cavity has a large surface area, rich vasculature, and immune-associated tissue, making it effective for vaccine delivery.
Correct answer is: Nasal mucosa
Q.47 The partition coefficient (K) of a drug between the stratum corneum and the vehicle influences:
The electrical resistance of the skin
The rate at which the drug enters the skin
The color of the patch
The mechanical strength of the patch
Explanation - A higher partition coefficient indicates the drug prefers the lipid phase of the skin, enhancing permeation.
Correct answer is: The rate at which the drug enters the skin
Q.48 Which of the following is NOT a typical characteristic of the buccal mucosa?
Non‑keratinised epithelium
High enzymatic activity
Rich blood supply
Thick stratum corneum
Explanation - Buccal mucosa lacks a thick keratinised layer, making it more permeable than skin.
Correct answer is: Thick stratum corneum
Q.49 In iontophoretic delivery, the ‘anode’ repels which type of drug?
Anionic drug
Cationic drug
Neutral drug
Hydrophobic drug
Explanation - The anode (positive electrode) repels positively charged (cationic) molecules, pushing them into the skin.
Correct answer is: Cationic drug
Q.50 What is the main advantage of using a ‘bioadhesive’ buccal tablet over a conventional tablet?
It dissolves faster in saliva
It remains attached to the mucosa longer, enhancing absorption
It does not require any drug
It can be swallowed whole
Explanation - Bioadhesion prolongs residence time, allowing more drug to permeate through the mucosal membrane.
Correct answer is: It remains attached to the mucosa longer, enhancing absorption
Q.51 Which of the following is a typical use of the ‘thermal ablation’ technique in transdermal delivery?
To melt the drug within the patch
To create micro‑channels in the skin using heat
To increase the pH of the skin
To sterilize the patch
Explanation - Thermal ablation briefly heats the skin surface, forming pores that facilitate drug entry.
Correct answer is: To create micro‑channels in the skin using heat
Q.52 Which of the following statements best describes the role of ‘viscosity’ in a transdermal gel formulation?
Higher viscosity always increases drug permeation
Viscosity does not affect drug release
Higher viscosity can slow drug diffusion out of the gel
Viscosity determines the electrical charge of the drug
Explanation - Viscous gels restrict molecular movement, often reducing the rate of drug release.
Correct answer is: Higher viscosity can slow drug diffusion out of the gel
Q.53 A drug that is ionised at the physiological pH of blood (7.4) will most likely:
Cross cell membranes easily
Be trapped in the skin layers
Show high oral bioavailability
Require a delivery system that bypasses the skin barrier
Explanation - Ionised drugs have low lipophilicity and cannot easily traverse the lipid‑rich stratum corneum.
Correct answer is: Be trapped in the skin layers
Q.54 In a Franz diffusion cell experiment, the ‘receiver chamber’ is typically filled with:
Skin tissue
A buffer solution mimicking blood plasma
The drug formulation
Air
Explanation - The receiver chamber contains a physiologically relevant medium to collect permeated drug for quantification.
Correct answer is: A buffer solution mimicking blood plasma
Q.55 Which of the following is a common challenge when delivering vaccines via the transdermal route?
Vaccine stability in the patch matrix
Excessive drug loading capacity
Rapid drug release
Absence of immune cells in the skin
Explanation - Biologics such as vaccines may degrade during storage or during the manufacturing of a patch, requiring special stabilization strategies.
Correct answer is: Vaccine stability in the patch matrix
Q.56 The ‘critical flux’ concept in transdermal delivery refers to:
The maximum flux beyond which the drug precipitates in the skin
The minimum flux needed to achieve therapeutic effect
The flux at which the skin’s barrier properties change
The flux at which the patch detaches
Explanation - At critical flux, the drug may alter skin structure, leading to non‑linear permeation behavior.
Correct answer is: The flux at which the skin’s barrier properties change
Q.57 Which of the following is a key advantage of using ‘nanocarriers’ (e.g., liposomes) in transdermal drug delivery?
They increase the size of the drug molecule
They enhance drug solubility and penetration through the skin
They make the patch impermeable
They reduce the need for adhesives
Explanation - Nanocarriers can encapsulate both hydrophilic and lipophilic drugs and interact with skin lipids to improve permeation.
Correct answer is: They enhance drug solubility and penetration through the skin
Q.58 Which of the following best explains why nicotine patches are limited to a maximum dose of about 21 mg per day?
Higher doses cause skin irritation and systemic toxicity
The skin cannot hold more than 21 mg of any drug
Nicotine degrades after 21 mg
Regulatory agencies set a universal 21 mg limit
Explanation - Excess nicotine can lead to adverse cardiovascular effects and skin irritation, limiting the safe dose delivered transdermally.
Correct answer is: Higher doses cause skin irritation and systemic toxicity
Q.59 Which of the following is NOT a typical method for enhancing drug permeation through mucosal tissues?
Use of mucoadhesive polymers
Application of ultrasound (sonophoresis)
Increasing the pH to extreme levels
Incorporation of permeation enhancers
Explanation - Extreme pH can damage mucosal tissues; safe permeation enhancement uses milder approaches.
Correct answer is: Increasing the pH to extreme levels
Q.60 In a transdermal patch, the ‘drug‑in‑adhesive’ (DIA) design means:
The drug is mixed directly into the adhesive layer
The drug is placed in a separate reservoir
The adhesive is applied after drug release
The patch contains no adhesive
Explanation - DIA systems embed the drug within the adhesive matrix, simplifying patch architecture and providing controlled release.
Correct answer is: The drug is mixed directly into the adhesive layer
Q.61 Which factor most directly influences the ‘lag time’ of a drug crossing the skin?
Patch color
Drug solubility in the vehicle
Skin temperature
Thickness of the stratum corneum
Explanation - A thicker stratum corneum increases the diffusion path, prolonging the lag time before steady‑state flux.
Correct answer is: Thickness of the stratum corneum
Q.62 Which of the following best describes ‘passive diffusion’ in the context of transdermal drug delivery?
Drug movement driven by an external electric field
Drug movement driven solely by concentration gradient
Drug movement driven by heat
Drug movement driven by mechanical pressure
Explanation - Passive diffusion relies on the natural gradient of drug concentration across the skin without external forces.
Correct answer is: Drug movement driven solely by concentration gradient
Q.63 Which of the following is a key parameter in the design of a microneedle for drug delivery?
Needle length sufficient to reach the dermis but not nerve endings
Needle color
Electrical resistance of the needle
Magnetic susceptibility
Explanation - Optimal microneedle length (typically 150–900 µm) penetrates the epidermis while avoiding pain receptors in deeper layers.
Correct answer is: Needle length sufficient to reach the dermis but not nerve endings
Q.64 The term ‘bioavailability’ for a transdermal system is typically expressed as:
Percentage of drug that reaches the skin surface
Percentage of the applied dose that reaches systemic circulation
Amount of drug left in the patch after use
Voltage required for iontophoresis
Explanation - Bioavailability quantifies how much of the drug administered via the patch actually enters the bloodstream unchanged.
Correct answer is: Percentage of the applied dose that reaches systemic circulation
Q.65 Which of the following is a potential side effect of long‑term use of transdermal nicotine patches?
Hair loss
Skin irritation at the site of application
Increased blood pressure
Decreased heart rate
Explanation - Prolonged contact can cause erythema, itching, or dermatitis at the patch site.
Correct answer is: Skin irritation at the site of application
Q.66 In the context of mucosal drug delivery, ‘first‑pass metabolism’ is:
Highly active because mucosal tissues contain many liver enzymes
Absent because the drug enters systemic circulation directly
Enhanced by the presence of saliva
A major barrier for buccal delivery
Explanation - Mucosal routes bypass the hepatic first‑pass effect, delivering drug directly into the systemic blood flow.
Correct answer is: Absent because the drug enters systemic circulation directly
Q.67 Which of the following technologies combines ultrasound and micro‑needles for enhanced transdermal delivery?
Sonophoresis
Electroporation
Hybrid microneedle‑sonic system
Iontophoresis
Explanation - Combining microneedles (to create channels) with ultrasound (to increase fluid movement) synergistically enhances permeation.
Correct answer is: Hybrid microneedle‑sonic system
Q.68 A drug with a high partition coefficient (K) but low diffusion coefficient (D) in skin will likely show:
Fast onset and high flux
Slow onset despite good affinity for the skin
No permeation at all
Rapid clearance from the body
Explanation - High K means the drug likes the skin, but low D limits its movement, leading to slower overall permeation.
Correct answer is: Slow onset despite good affinity for the skin
Q.69 Which of the following is a key difference between the buccal and sublingual mucosa?
Buccal mucosa is keratinised, sublingual is not
Sublingual mucosa has a richer blood supply
Buccal mucosa is thicker than sublingual
Sublingual mucosa has a higher pH
Explanation - The sublingual area is highly vascularised, allowing faster drug absorption compared to the buccal region.
Correct answer is: Sublingual mucosa has a richer blood supply
Q.70 Which of the following best describes the function of a ‘permeation enhancer’ like oleic acid in a transdermal patch?
It reduces the drug’s molecular weight
It creates pores in the stratum corneum by disrupting lipid packing
It changes the drug’s color
It increases the patch’s adhesive strength
Explanation - Oleic acid intercalates into lipid bilayers, fluidising them and forming pathways for drug diffusion.
Correct answer is: It creates pores in the stratum corneum by disrupting lipid packing
Q.71 When a transdermal system is designed for a drug with a short half‑life, the patch must:
Release the drug very slowly over weeks
Provide a rapid onset and maintain therapeutic levels
Contain a reservoir that can be refilled
Be applied only once a month
Explanation - Short‑half‑life drugs need a delivery system that quickly reaches and sustains effective plasma concentrations.
Correct answer is: Provide a rapid onset and maintain therapeutic levels
Q.72 Which of the following statements is TRUE about 'reverse iontophoresis'?
It extracts interstitial fluid components through the skin using a current
It delivers drugs deeper than traditional iontophoresis
It uses magnetic fields instead of electric current
It is only applicable for vaccination
Explanation - Reverse iontophoresis applies a small current to pull substances (e.g., glucose) out of the body for monitoring.
Correct answer is: It extracts interstitial fluid components through the skin using a current
Q.73 The 'therapeutic window' of a drug delivered transdermally refers to:
The range of temperatures at which the patch works
The concentration range between efficacy and toxicity
The physical size of the patch
The duration the patch can stay on skin
Explanation - The therapeutic window defines the plasma concentration limits where the drug is effective without being harmful.
Correct answer is: The concentration range between efficacy and toxicity
Q.74 Which of the following is a primary reason why transdermal delivery of insulin is challenging?
Insulin is too volatile
Insulin is a large, hydrophilic peptide
Insulin degrades in the skin’s acidic environment
Insulin has a very high logP
Explanation - Its size and polarity prevent efficient diffusion through the skin’s lipophilic barrier.
Correct answer is: Insulin is a large, hydrophilic peptide
Q.75 Which of the following is a method to evaluate the adhesive strength of a transdermal patch?
Peel test
Viscosity measurement
pH titration
Spectrophotometric analysis
Explanation - The peel test measures the force required to detach the patch from a substrate, indicating adhesive performance.
Correct answer is: Peel test
Q.76 A transdermal system that uses a 'reservoir' and a 'rate‑controlling membrane' is classified as:
Matrix patch
Monolithic patch
Reservoir patch
Adhesive patch
Explanation - Reservoir patches contain a drug reservoir separated from the skin by a membrane that controls the release rate.
Correct answer is: Reservoir patch
Q.77 Which of the following is an advantage of the nasal mucosal route for drug delivery?
Large surface area and rapid absorption
Absence of enzymatic activity
No need for formulation stability
Unlimited drug loading
Explanation - The nasal cavity offers high vascularisation and a relatively large absorptive area, enabling quick systemic uptake.
Correct answer is: Large surface area and rapid absorption
Q.78 In a drug‑in‑adhesive (DIA) transdermal patch, the drug release rate is primarily governed by:
Diffusion through the adhesive matrix
Electrical current applied
The thickness of the backing layer
The color of the adhesive
Explanation - Drug molecules move out of the adhesive by diffusion, which determines the overall release kinetics.
Correct answer is: Diffusion through the adhesive matrix
Q.79 Which of the following describes a major drawback of using high‑frequency ultrasound for skin permeabilisation?
It permanently damages the skin
It requires invasive surgical insertion
It may cause thermal injury if not properly controlled
It reduces drug solubility
Explanation - Excessive ultrasound energy can raise skin temperature, leading to burns or irritation.
Correct answer is: It may cause thermal injury if not properly controlled
Q.80 Which of the following is a commonly used bioadhesive polymer for buccal patches?
Polyethylene glycol (PEG)
Hydroxypropyl methylcellulose (HPMC)
Polystyrene
Polyvinyl chloride (PVC)
Explanation - HPMC exhibits mucoadhesive properties, making it suitable for buccal dosage forms.
Correct answer is: Hydroxypropyl methylcellulose (HPMC)
Q.81 When a drug’s molecular weight exceeds 1000 Da, which transdermal enhancement technique is most likely to be effective?
Simple passive diffusion
Iontophoresis
Microneedles
Thermal ablation
Explanation - Microneedles create micro‑channels that allow large molecules to bypass the stratum corneum barrier.
Correct answer is: Microneedles
Q.82 Which factor is most important for ensuring uniform drug distribution across a transdermal patch surface?
Even mixing of drug into the polymer matrix
Patch color uniformity
Thickness of the backing layer
Electrical resistance of the skin
Explanation - Homogenous drug dispersion prevents dose variability and ensures consistent delivery.
Correct answer is: Even mixing of drug into the polymer matrix
Q.83 The main purpose of incorporating a ‘plasticizer’ like triacetin into a transdermal patch is to:
Increase the drug’s potency
Reduce the patch’s flexibility
Increase the flexibility of the polymeric matrix
Make the patch waterproof
Explanation - Plasticizers lower the polymer’s glass transition temperature, making the patch more pliable.
Correct answer is: Increase the flexibility of the polymeric matrix
Q.84 Which of the following is a potential advantage of using a 'dual‑layer' transdermal patch (reservoir + matrix) for drug delivery?
It eliminates the need for a backing layer
It provides both immediate and sustained drug release phases
It makes the patch completely invisible
It reduces the drug’s molecular weight
Explanation - A dual‑layer design can release an initial dose from the matrix and maintain a steady flux from the reservoir.
Correct answer is: It provides both immediate and sustained drug release phases
Q.85 Which of the following statements about 'first‑pass metabolism' is correct in the context of transdermal drug delivery?
It significantly reduces drug bioavailability
It occurs in the skin before systemic circulation
It is avoided because the drug enters systemic circulation directly
It enhances drug potency
Explanation - Transdermal delivery bypasses the hepatic portal system, thus circumventing first‑pass metabolism.
Correct answer is: It is avoided because the drug enters systemic circulation directly
Q.86 For a drug that is highly water‑soluble but poorly lipophilic, which transdermal strategy would most likely improve its permeation?
Increase the drug’s concentration in the patch
Use a lipophilic permeation enhancer
Decrease the patch size
Add a high‑melting point polymer
Explanation - Enhancers that increase skin lipid fluidity help water‑soluble drugs partition into the lipophilic stratum corneum.
Correct answer is: Use a lipophilic permeation enhancer
Q.87 Which of the following best explains why the sublingual route can provide a faster onset of action compared to the buccal route?
Sublingual mucosa has a thicker epithelium
Sublingual area is less vascularised
Sublingual mucosa is thinner and more permeable
Buccal mucosa contains more enzymes
Explanation - The thin, non‑keratinised sublingual epithelium allows rapid drug absorption into the rich sublingual venous plexus.
Correct answer is: Sublingual mucosa is thinner and more permeable
Q.88 Which of the following is a typical limitation when using iontophoresis for large peptide drugs?
Excessive heat generation
Low electrical conductivity of peptides
Insufficient driving force due to low charge density
Rapid degradation of the patch adhesive
Explanation - Peptides often have few ionizable groups, reducing the effectiveness of electro‑repulsion forces in iontophoresis.
Correct answer is: Insufficient driving force due to low charge density
Q.89 Which of the following is a key reason for using a ‘bioadhesive’ polymer in a buccal tablet?
To increase the tablet’s hardness
To enhance drug stability in the gastrointestinal tract
To prolong residence time at the site of absorption
To make the tablet taste better
Explanation - Bioadhesive polymers stick to the mucosa, reducing clearance by saliva and improving drug uptake.
Correct answer is: To prolong residence time at the site of absorption
Q.90 When a transdermal patch is applied to an area with high hair density, the likely effect on drug delivery is:
Increased drug flux due to hair follicles
Reduced adhesion and possibly lower drug delivery
No effect at all
Complete blockage of drug permeation
Explanation - Hair can interfere with patch contact, decreasing adhesion and creating air gaps that impede diffusion.
Correct answer is: Reduced adhesion and possibly lower drug delivery
Q.91 Which of the following best characterises the ‘sink condition’ in in‑vitro skin permeation studies?
The receiving chamber contains a large excess of drug to maintain a concentration gradient
The donor chamber is emptied regularly
The temperature of the system is kept constant
The skin is kept under tension
Explanation - Sink conditions ensure that the drug concentration in the receiver remains low, preserving a constant driving force for diffusion.
Correct answer is: The receiving chamber contains a large excess of drug to maintain a concentration gradient
Q.92 Which of the following is a common reason for using a ‘hydrogel’ as a drug reservoir in a transdermal system?
Hydrogels provide high mechanical strength
Hydrogels are impermeable to water
Hydrogels can hold large amounts of hydrophilic drug and release it in a controlled manner
Hydrogels increase the patch’s electrical resistance
Explanation - Hydrogels' high water content makes them suitable for loading and releasing hydrophilic compounds.
Correct answer is: Hydrogels can hold large amounts of hydrophilic drug and release it in a controlled manner
Q.93 In a microneedle patch, the term ‘dissolving microneedle’ refers to:
A needle that remains permanently in the skin
A needle made from a polymer that dissolves after insertion, releasing the drug
A needle that emits ultrasound
A needle that creates permanent pores
Explanation - Dissolving microneedles embed drug within a biodegradable matrix that dissolves in interstitial fluid, eliminating needle waste.
Correct answer is: A needle made from a polymer that dissolves after insertion, releasing the drug
Q.94 Which of the following is NOT an advantage of transdermal drug delivery?
Steady plasma concentrations
Avoidance of gastrointestinal irritation
Ability to deliver very large proteins without modification
Improved patient compliance
Explanation - Large proteins generally cannot cross the skin barrier without special techniques like microneedles or electroporation.
Correct answer is: Ability to deliver very large proteins without modification
Q.95 Which of the following best describes the principle of ‘chemical permeation enhancers’ like Azone (laurocapram)?
They increase skin temperature
They temporarily disrupt the lipid order in the stratum corneum
They increase the drug’s ionisation
They act as antioxidants
Explanation - Azone inserts into lipid bilayers, fluidising them and creating pathways for drug diffusion.
Correct answer is: They temporarily disrupt the lipid order in the stratum corneum
Q.96 A major factor limiting the use of the nasal route for large molecules is:
Low surface area of the nasal epithelium
Presence of mucociliary clearance
High blood flow
Absence of enzymes
Explanation - Mucociliary clearance rapidly removes substances from the nasal cavity, reducing residence time for large molecules.
Correct answer is: Presence of mucociliary clearance
Q.97 Which of the following technologies is most suitable for delivering insulin through the skin without using needles?
Iontophoresis
Microneedles
Sonophoresis
All of the above
Explanation - Iontophoresis, microneedles, and sonophoresis have all been investigated as needle‑free strategies for insulin delivery.
Correct answer is: All of the above
Q.98 The term ‘bioavailability’ for a buccal tablet is most directly measured by:
The amount of drug dissolved in saliva
The plasma concentration‑time profile after administration
The taste acceptability of the tablet
The size of the tablet
Explanation - Bioavailability is assessed by comparing systemic exposure (AUC) after buccal dosing to a reference route.
Correct answer is: The plasma concentration‑time profile after administration
Q.99 Which of the following is a key advantage of using a 'polymeric matrix' over a 'reservoir' in a transdermal patch?
Higher drug loading capacity
Simpler manufacturing with fewer layers
Ability to store volatile drugs
Increased patch thickness
Explanation - Matrix patches integrate drug within a single polymer layer, reducing the number of components and steps.
Correct answer is: Simpler manufacturing with fewer layers
Q.100 Which of the following is a typical characteristic of the stratum corneum compared with the deeper epidermis?
Higher water content
Presence of living cells
Highly ordered lipid matrix
Rich blood supply
Explanation - The stratum corneum consists of dead corneocytes embedded in a tightly packed lipid matrix that provides the main barrier function.
Correct answer is: Highly ordered lipid matrix
Q.101 When designing a transdermal system for a drug with a short half‑life, a common strategy to maintain therapeutic levels is:
Use a high‑dose reservoir with a rapid release profile
Apply multiple patches simultaneously
Incorporate a zero‑order release mechanism
Add a permeation inhibitor
Explanation - Zero‑order release provides a constant drug flux, maintaining plasma concentration despite the drug’s rapid elimination.
Correct answer is: Incorporate a zero‑order release mechanism
Q.102 Which of the following best explains why the oral mucosa lacks a stratum corneum?
It is constantly exposed to saliva, requiring a softer surface
It needs to be more permeable for nutrient absorption
It is protected by teeth
It has a high density of hair follicles
Explanation - The absence of a keratinised barrier facilitates rapid exchange of substances between the oral cavity and bloodstream.
Correct answer is: It needs to be more permeable for nutrient absorption
Q.103 Which of the following is a key parameter measured during in‑vitro skin permeation studies using Franz diffusion cells?
Patch adhesion strength
Permeation flux (µg/cm²·h)
Electrical impedance of the skin
Patch color change
Explanation - Flux quantifies the rate at which drug passes through the skin per unit area, a primary outcome in permeation studies.
Correct answer is: Permeation flux (µg/cm²·h)
Q.104 A drug with a logP of 1.5 and molecular weight of 300 Da is most likely to be:
Suitable for passive transdermal delivery
Unsuitable for any transdermal system
Only deliverable by microneedles
Highly irritant to the skin
Explanation - A moderate logP and low molecular weight fall within the optimal range for passive diffusion across the skin.
Correct answer is: Suitable for passive transdermal delivery
Q.105 Which of the following best describes the function of ‘electroporation’ in transdermal drug delivery?
It heats the skin to increase diffusion
It uses high‑frequency sound waves
It applies short high‑voltage pulses to create transient pores
It relies on chemical solvents
Explanation - Electroporation temporarily disrupts the lipid bilayer, forming aqueous pathways for drug molecules.
Correct answer is: It applies short high‑voltage pulses to create transient pores
Q.106 In the design of a transdermal patch, the term ‘zero‑order kinetics’ indicates that:
The drug release rate decreases exponentially over time
The drug release rate is constant over time
The drug is released only after a lag period
The drug release is dependent on skin temperature
Explanation - Zero‑order kinetics means a constant amount of drug is delivered per unit time, independent of concentration.
Correct answer is: The drug release rate is constant over time
Q.107 Which of the following is a typical reason for selecting the buccal route over the sublingual route?
Buccal mucosa has a higher blood flow
The buccal area is larger, providing a bigger dosage surface
Sublingual mucosa has a thicker epithelium
Buccal route avoids all enzymatic degradation
Explanation - The larger buccal surface can accommodate larger dosage forms, though it may have slower absorption than sublingual.
Correct answer is: The buccal area is larger, providing a bigger dosage surface
Q.108 Which of the following statements about 'therapeutic index' is true for transdermal drug delivery?
A high therapeutic index means the drug is very potent
A low therapeutic index requires precise control over drug release
Therapeutic index is not relevant for transdermal systems
Therapeutic index determines the patch size
Explanation - Drugs with narrow safety margins need tightly regulated delivery to avoid toxicity.
Correct answer is: A low therapeutic index requires precise control over drug release
Q.109 Which of the following is a major advantage of using a ‘polymeric nanocarrier’ (e.g., dendrimer) in transdermal delivery?
It completely eliminates the need for a patch backing
It can encapsulate both hydrophilic and lipophilic drugs and enhance penetration
It makes the drug taste better
It increases the electrical conductivity of the skin
Explanation - Nanocarriers improve solubility, protect the drug, and interact with skin lipids to facilitate transport.
Correct answer is: It can encapsulate both hydrophilic and lipophilic drugs and enhance penetration
Q.110 In transdermal drug delivery, the term ‘lag time’ can be reduced by:
Increasing the thickness of the backing layer
Using a higher concentration of permeation enhancer
Reducing the drug’s solubility in the vehicle
Applying the patch to a hairless skin area
Explanation - Enhancers accelerate drug partitioning and diffusion, shortening the initial delay before steady‑state flux.
Correct answer is: Using a higher concentration of permeation enhancer
Q.111 Which of the following is a common reason for incorporating a ‘sweat‑resistant’ backing in a transdermal patch?
To improve drug solubility
To prevent water ingress that could affect adhesive performance
To increase the electrical conductivity of the patch
To make the patch biodegradable
Explanation - Sweat can degrade adhesives and alter drug release; a waterproof backing protects the system.
Correct answer is: To prevent water ingress that could affect adhesive performance