What is the term for a small adhesive patch or disc used for the administration of drugs?

The term for a small adhesive patch or disc used for the administration of drugs is indeed the transdermal system. This method allows drugs to be absorbed through the skin and into the bloodstream, providing a controlled release over an extended period. Transdermal patches are designed to deliver medication in a steady, gradual manner, which can improve patient compliance and minimize the fluctuations in drug levels that can occur with other delivery methods.

In contrast, an intravenous system involves directly administering medication into the bloodstream through a vein, which does not use a patch. The oral delivery system refers to medications taken by mouth, such as tablets or liquids, and also does not involve transdermal delivery. Finally, an inhalation system involves delivering drugs directly into the lungs, typically in the form of aerosols or vapors, which is also distinct from transdermal administration. Therefore, the transdermal system is the correct term for this specific method of drug delivery.