Which administration method involves injecting medication into the subcutaneous layer of skin?

Injecting medication into the subcutaneous layer of skin is characteristic of the subcutaneous route. This method allows for the administration of a variety of medications, including insulin and certain vaccines, in a manner that is relatively easy and can be performed in an outpatient setting.

The subcutaneous tissue has a good blood supply, which allows for the gradual absorption of the medication into the bloodstream. This method is beneficial for patients who need long-term medication management since it typically enables sustained release of medication with lower dosing frequencies.

In contrast, the intradermal route involves injecting medication into the dermis, which is just below the outer layer of the skin and is used for specific purposes such as allergy tests or tuberculosis screening. The intramuscular route introduces medication into a muscle, allowing for more rapid absorption compared to subcutaneous injections, typically preferred for vaccines that need a quicker systemic effect. The transdermal route delivers medication through the skin via patches, which release drugs into the bloodstream over time but does not involve any injections.

Overall, the subcutaneous route is a fundamental method that provides effective medication delivery while ensuring patient comfort.