Oral Drug Delivery Systems

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Questions and Answers

At what pH does Eudragit dissolve to release the drug in the GI tract?

pH 6

pH 5 or lower

pH 7 or greater (correct)

pH 8

Which polymer is used in the SUBA system to facilitate delayed release?

Methylcellulose

Polyvinyl alcohol

Hypromellose phthalate (correct)

Eudragit

What is the primary purpose of utilizing Eudragit in Asacol?

To increase the drug's half-life

To provide local action in the lower GI tract (correct)

To enhance drug absorption in the stomach

To dissolve rapidly in the oral cavity

What form of itraconazole is utilized in the SUBA system for improved solubility?

Amorphous form Signup and view all the answers

Why is it generally unacceptable to switch between different modified release products of the same drug?

They may have different release characteristics Signup and view all the answers

What is the primary purpose of extended release products?

To make the drug available over a longer time Signup and view all the answers

Which of the following best describes a characteristic of non-dissolving matrix systems?

They may pass through the body intact or end up in the feces. Signup and view all the answers

Which system is classified as a delayed release product?

Enteric-coated products Signup and view all the answers

How does a wax matrix system primarily function to prevent gastrointestinal irritation?

By preventing drug release in the stomach. Signup and view all the answers

What type of polymer is used in swelling erodible matrix systems?

Hydrophilic polymers Signup and view all the answers

What key feature does the Geomatrix system offer for prolonged drug release?

Modulating barriers controlling hydration rate Signup and view all the answers

Among the following options, which is NOT a method of oral controlled release?

Sublingual delivery systems Signup and view all the answers

What is the primary function of gastro retentive systems?

To ensure prolonged drug release in the stomach Signup and view all the answers

Which technology is utilized in coated particle systems to manage drug release?

Dissolving or non-dissolving coats on drug pellets Signup and view all the answers

What is unique about the SODAS system as developed by Elan?

It utilizes uniform spherical beads with multilayered coatings. Signup and view all the answers

In which type of system does the drug release occur through an osmotic core?

Osmotically controlled systems Signup and view all the answers

What role does the membrane play in membrane-controlled pellets?

It regulates drug release primarily through zero-order kinetics. Signup and view all the answers

What characterizes the CODAS system used in medications like Verelan PM?

It allows for a delayed release in correlation with biological rhythms. Signup and view all the answers

What type of release do enteric-coated delayed release systems primarily facilitate?

Release in the small intestine Signup and view all the answers

Which medication is an example of a product that employs the SODAS system?

Ritalin LA Signup and view all the answers

How does the AccuForm system release medication?

By creating a large gel-like mass that swells Signup and view all the answers

Which of the following correctly describes the role of ion exchange systems?

They release drugs through an ion-exchange mechanism. Signup and view all the answers

Study Notes

Oral Drug Delivery and Advanced Technologies

FDA Terminology: FDA uses "extended release" and "delayed release" for oral drugs.
Extended Release: Drug is released over a longer period.
Delayed Release: Drug is released at a time other than immediately.
Enteric-Coated Products: A classic example of delayed release, releasing the drug in the intestines.

Types of Oral Controlled Release Systems

Matrix Systems: Drug is incorporated into a matrix material.
- Non-dissolving matrices: Pass through the body undissolved.
- Dissolving matrices: Dissolve in the body releasing the drug.
- Release rate: Typically proportional to the square root of time.
- Wax matrices: Contain lipid wax with embedded drug. Used for preventing GI irritation (e.g., potassium chloride, iron supplements).
- Swelling, Erodible matrices: Use hydrophilic polymers. Bioerodible, leaving no residue. Geomatrix system increases surface area for prolonged drug effect. Paxil CR uses this system.
Gastro Retentive Systems: Keep the drug in the stomach for longer.
- Mechanism: Achieved through swelling, high density, or floating systems.
- Swelling System: Common approach to retain in stomach, preventing it from entering the intestines, releasing the drug to absorb, using Polymers. AccuForm system utilizes swelling polymers to create a large gel-like substance, Metformin GR, Glucophage XR, Fortamet are examples.
Coated Particle Systems: Coating drug particles to regulate release.
- Dissolving coats: Drug pellets coated with material that slowly dissolve.
  - Ex: coating a drug solution onto beads. Controlled by coating thickness (e.g., Expansial system by GlaxoSmithKline, Ornade Spansules)
- Non-dissolving/dissolving coat systems: Combination (e.g., SODAS system, Ritalin LA, Concerta).
Chronotherapy: Delivers medication at the optimal time (e.g., Verelan PM & CODAS for angina and heart failure).
Membrane-Controlled Systems: Tiny pellets surrounded by a membrane for controlled release (zero-order).
- Example: Toprol XL (metoprolol succinate) - can be broken. Hybrid systems combine features of membranes and matrices (e.g., IPDAS by Elan, Naprelan - naproxen)
Osmotically Controlled Systems: Two compartments, osmotic drug core, and polymeric push compartment.
- GITS (Gastrointestinal Therapeutic System): Draws fluid in through a semipermeable membrane, expanding polymer forces drug out (e.g. Prodiara XL, concerta).
Ion Exchange Systems: Uses resins with charged functional groups (e.g., Pennkinetic, Tussionex containing hydrocodone, Delsym containing dextromethorphan)

Delayed Release Systems

Enteric Coating: Coating to delay the drug release until it reaches the intestines (e.g., Asacol, SUBA - itraconazole). Eudragit is an example.

Important Considerations

Modified release products have varied plasma profiles; switching products isn't recommended.
Pharmacists must be aware of product properties when dispensing.

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Description

Explore the concepts of oral drug delivery, including key FDA terminology such as extended release and delayed release. Learn about various controlled release systems, including matrix systems and enteric-coated products, as well as their unique characteristics and applications. This quiz will enhance your understanding of advanced drug delivery technologies.