What is a transdermal disk or patch primarily used for?

A transdermal disk or patch is primarily designed for the slow absorption of medication through the skin. This method allows medications to be absorbed into the bloodstream over an extended period of time, providing a steady and controlled release. This is particularly useful for managing chronic conditions, where maintaining stable drug levels can lead to better therapeutic outcomes and improved patient compliance.

The other methods of medication delivery mentioned do not align with the intended use of transdermal patches. For instance, oral delivery refers to medications taken by mouth, while solid pill forms encapsulate medications in a different way and are not suitable for transdermal delivery. Intravenous delivery offers immediate action by injecting medicine directly into the bloodstream, which contrasts with the gradual release characteristic of transdermal systems. Hence, the focus on slow absorption through the skin accurately captures the primary function of transdermal disks and patches.