Transdermal Drug Delivery Systems Overview

Questions and Answers

What is a significant advantage of transdermal drug delivery systems (TDDSs)?

They can deliver any type of drug effectively.

They allow drugs to bypass first-pass metabolism. (correct)

They are more invasive than other methods of delivery.

They require multiple daily applications.

Which of the following factors does NOT affect drug absorption through the skin?

Skin hydration level

Molecular weight of the drug

Color of the patch (correct)

Lipophilicity and hydrophilicity of the drug

Which drug is NOT commonly administered via transdermal patches?

Methylphenidate

Clonidine

Estradiol

Ibuprofen (correct)

What distinguishes membrane-controlled systems from monolithic TDDSs?

Membrane-controlled systems contain a drug reservoir. Signup and view all the answers

In the context of TDDSs, what is the role of percutaneous absorption enhancers?

They enhance drug delivery through the skin. Signup and view all the answers

Which factor limits the suitability of drugs for transdermal delivery?

Potency of the drug Signup and view all the answers

What is the primary purpose of the Franz diffusion cell in TDDS research?

To quantify drug release rates from formulations. Signup and view all the answers

Which statement about the first TDDS approved by the FDA is true?

It was released in 1979 for motion sickness. Signup and view all the answers

Study Notes

Overview of Transdermal Drug Delivery Systems (TDDSs)

TDDSs, or transdermal patches, deliver medication through the skin into the bloodstream for systemic effects.
First TDDS approved by the FDA was Transderm Scop (Baxter) in 1979 for motion sickness.

Mechanism and Advantages

Bypasses first-pass metabolism in the liver, potentially reducing side effects and enhancing drug efficacy.
Drug absorption is influenced by drug properties such as molecular weight, lipid and aqueous solubility, and skin hydration.

Types of TDDSs

Monolithic systems: Feature a drug matrix layer controlling drug release between the backing and frontal layers.
Membrane-controlled systems: Contain a drug reservoir, rate-controlling membrane, and backing, adhesive, and protective layers.

Drug Delivery and Absorption Enhancers

Percutaneous absorption enhancers (chemical and physical) can improve drug delivery through the skin.
The Franz diffusion cell is employed to study release rates from TDDSs and various formulations.

Benefits of TDDSs

Non-invasive administration of medications.
Provide extended therapy with a single application, which is beneficial for chronic conditions.
Easily identifiable in emergencies due to their visible nature.

Limitations

Suitable only for potent drugs, as skin permeability limits many medications.
Only small doses can be efficiently delivered through TDDSs.

Common Drugs Administered via TDDSs

Scopolamine: Used for motion sickness.
Nitroglycerin: Used for angina; TDDSs (Minitran, Nitro-Dur) provide controlled delivery for 24 hours. Recommended dosing involves 12-14 hours "patch on" and 10-12 hours "patch off" due to tolerance issues.
Clonidine: Treats hypertension; available in a four-layer patch (Catapres-TTS) effective for up to 7 days.
Estradiol: Administered for hormonal therapy.
Testosterone: Delivered for male hormone replacement.
Methylphenidate: Used for treating attention deficit hyperactivity disorder (ADHD).

Description

This quiz provides an in-depth overview of Transdermal Drug Delivery Systems (TDDSs), including their purpose, key features, and historical context. Learn about the benefits of using transdermal patches, such as bypassing first-pass metabolism and enhancing drug efficacy. Test your knowledge on FDA-approved TDDSs and their applications.