Noninjected

Noninjected is a term used in medicine and pharmacology to describe routes or procedures for delivering substances that do not involve needles or injections. It contrasts with injected routes such as intravenous, intramuscular, and subcutaneous administration. Noninjected delivery aims to introduce a drug or therapeutic agent through alternative pathways that bypass puncturing the skin.

Common noninjected routes include oral, sublingual or buccal, topical, transdermal, inhalation, and rectal or vaginal administration. Oral formulations include tablets, capsules, and liquids. Sublingual or buccal delivery uses tissues under the tongue or cheek for absorption. Transdermal patches release compounds through the skin. Inhalation delivers drugs to the lungs. Rectal or vaginal routes can provide local or systemic effects when other routes are unsuitable. While most vaccines are administered by injection, some vaccines can be delivered noninjected, such as certain oral and intranasal formulations.

Advantages of noninjected delivery include reduced pain, lower risk of needle-stick injuries, and greater convenience for self-administration. Limitations include variable bioavailability (notably for oral drugs due to first-pass metabolism and digestive degradation), slower onset, and formulation stability requirements. Some noninjected routes may cause local irritation or inconsistent dosing.

The choice between noninjected and injected administration depends on the drug’s pharmacokinetics, the therapeutic goal, and patient factors. Noninjected routes expand access and comfort but may not be suitable when rapid or precise systemic exposure is needed.