Route of Administration
Definition
Which path a compound takes in the studies that report it: intravenous, subcutaneous, intramuscular, intranasal, oral or topical, as named in the literature. Route decides how much reaches circulation and how fast, so two papers on one molecule by different routes are not comparable.
Terms used in this definition
Other entries this definition refers to.
What this means for research sourcing
This term describes handling relevant to laboratory research protocols only — Volta compounds are supplied strictly for in vitro research use.
Related Terms in Administration
Intramuscular (IM)
Into muscle tissue, better perfused than subcutaneous fat and so faster to absorb in the studies that compare the two. It is used in the literature where a formulation calls for it rather than as a default.
Intravenous (IV)
Straight into a vein, which by definition delivers the whole amount to the circulation and is the reference point every other route's bioavailability is measured against. In studies it is performed under clinical supervision.
Intranasal
Across the nasal mucosa. Trials of Semax, Selank and oxytocin use this route because it avoids gastric and hepatic degradation and because the olfactory epithelium offers a path toward the central nervous system.
Intranasal Delivery
What the intranasal route costs in practice. Bioavailability in the studies spans roughly 2 to 30% depending on the molecule, the volume and the excipients, and a figure from one paper does not transfer to another compound.
Sublingual
Under the tongue, where the oral mucosa absorbs directly into venous drainage and so bypasses first-pass hepatic metabolism. Peptides have been investigated this way with mixed results, because mucosal permeability falls sharply with molecular size.
Topical Peptide
A peptide formulated to be applied to skin, in a cream, serum or patch. Copper peptides and the cosmetic sequences are the common examples. Penetration past the stratum corneum is poor for most peptides without a permeation enhancer or a device.
Transdermal
Through the skin and into systemic circulation, as distinct from topical, where the skin is the target. Peptides cross passively very poorly because of their size and polarity, which is the problem microneedle work exists to solve.
Titration
Stepping an amount up or down across a study arm to find where the dose-response curve gives effect without unacceptable tolerability. Approved incretin labels specify fixed escalation schedules for exactly this reason. In analytical chemistry the same word means a volumetric assay, as in Karl Fischer titration.