For a constant, time released systemic effect, some medications can be absorbed slowly through the skin. Which dosage form is this?

For a constant, time released systemic effect, some medications can be absorbed slowly through the skin. Which dosage form is this?

• A. Gels
• B. Ointments
• C. Transdermal patches
• D. Emulsions

Answer: (C)

Transdermal patches are designed to deliver a drug through the skin in a controlled manner to achieve a steady systemic level over time. The patch uses a rate-controlling mechanism to release drug slowly, allowing ongoing absorption into the bloodstream and a constant effect without frequent dosing. This approach takes advantage of avoiding the GI tract and first-pass metabolism, making it ideal for chronic conditions requiring stable plasma levels. Gels and ointments are typically formulated for local skin action or surface exposure and generally do not provide reliable, long-term systemic release. Emulsions are vehicles that can carry drug but aren’t inherently designed for controlled, systemic delivery over extended periods. Thus, the dosage form that fits the description of constant, time-released systemic absorption through the skin is the transdermal patch.

Transdermal patches are designed to deliver a drug through the skin in a controlled manner to achieve a steady systemic level over time. The patch uses a rate-controlling mechanism to release drug slowly, allowing ongoing absorption into the bloodstream and a constant effect without frequent dosing. This approach takes advantage of avoiding the GI tract and first-pass metabolism, making it ideal for chronic conditions requiring stable plasma levels.

Gels and ointments are typically formulated for local skin action or surface exposure and generally do not provide reliable, long-term systemic release. Emulsions are vehicles that can carry drug but aren’t inherently designed for controlled, systemic delivery over extended periods. Thus, the dosage form that fits the description of constant, time-released systemic absorption through the skin is the transdermal patch.