Intravenous administration is the direct administration of drugs, fluids, nutritional mixtures, diagnostic reagents, and contrast agents, through the skin or mucous membranes, into any of the peripheral veins of the body or, through these, into some central vein of large caliber.
The word parenteral comes from the Greek words para, which means “outside of,” and enteron, which means “intestine,” and thus the term parenteral refers to all those routes of administration different to the oral route. However, while several routes fit this definition (ocular, vaginal, topical), the term is generally reserved for the administrations of drugs through the skin (or mucous membranes), by injection or infusion.
Figure 1shows the schematic representation of the main routes of drug administration. As it can be seen in the figure, there.
