KAPS Drug Formulation and Development 1 — Questions and Answers

Question 1: Which excipient is commonly used to enhance the dissolution rate of poorly soluble drugs?

Magnesium stearate
Polyvinylpyrrolidone (PVP) (Correct answer)
Talc
Silicon dioxide

Correct answer: Polyvinylpyrrolidone (PVP)

Polyvinylpyrrolidone (PVP) is a commonly used pharmaceutical excipient, particularly as a binder and solubilizer. Its hydrophilic nature and ability to form complexes with poorly soluble drugs help to increase their wettability and dispersion, thereby enhancing their dissolution rate. This makes PVP highly effective in improving the bioavailability of challenging drug compounds.

Question 2: What is the primary purpose of enteric coating on tablets?

To mask the taste of the drug
To enhance drug solubility
To protect the drug from stomach acid (Correct answer)
To improve tablet hardness

Correct answer: To protect the drug from stomach acid

Enteric coatings are specialized polymer layers applied to oral dosage forms, such as tablets or capsules, that are designed to resist dissolution in the acidic environment of the stomach. Their primary purpose is to protect acid-labile drugs from degradation by gastric acid or to prevent stomach irritation caused by certain drugs. The coating dissolves only in the higher pH environment of the small intestine, allowing for targeted drug release.

Question 3: Which formulation technique is commonly used for sustained-release drug delivery?

Micronization
Matrix system (Correct answer)
Granulation
Freeze-drying

Correct answer: Matrix system

A matrix system is a widely used formulation technique for achieving sustained-release drug delivery. In this system, the drug is uniformly dispersed within a polymeric matrix, which controls its release rate through diffusion, erosion, or a combination of both. This allows for a prolonged therapeutic effect by maintaining drug concentrations within the desired range over an extended period.

Question 4: Why are nanoparticles increasingly used in drug delivery systems?

They are cheaper to produce.
They improve the stability of volatile drugs.
They enhance bioavailability and targeting. (Correct answer)
They are compatible with all drugs.

Correct answer: They enhance bioavailability and targeting.

Nanoparticles are increasingly used in drug delivery because their small size allows for better absorption and distribution within the body. They can protect drugs from degradation and enable targeted delivery to specific cells or tissues, which enhances the drug's bioavailability. This targeted approach minimizes systemic side effects and increases drug concentration at the desired site of action.

Question 5: Which method is typically used to prepare liposomes for drug delivery?

Thin-film hydration (Correct answer)
Spray drying
Lyophilization
Granulation

Correct answer: Thin-film hydration

Thin-film hydration is a common and foundational method for preparing liposomes. This technique involves dissolving lipids in an organic solvent, evaporating the solvent to form a thin lipid film, and then hydrating this film with an aqueous solution containing the drug. The lipids then self-assemble into spherical vesicles, encapsulating the drug within their aqueous core or lipid bilayer.

Question 6: What is the role of surfactants in pharmaceutical suspensions?

To act as a preservative
To enhance viscosity
To improve stability and dispersion (Correct answer)
To increase pH

Correct answer: To improve stability and dispersion

Surfactants play a critical role in pharmaceutical suspensions by reducing the interfacial tension between the solid drug particles and the liquid vehicle. This action helps to wet the particles more effectively and prevents them from aggregating or settling rapidly. By improving dispersion and preventing caking, surfactants enhance the physical stability and ensure uniform dosing of the suspension.

KAPS Drug Formulation and Development 1

Which excipient is commonly used to enhance the dissolution rate of poorly soluble drugs?