Choose an entry route and trace absorption, circulation, tissue distribution, metabolism, and excretion.
Sources and model limits
Original schematic. Positions show relationships; structures and concentrations are not to scale.
Julien's Primer of Drug Action · 15 · 1 · Follow a drug through the body · PDF 8, 10, 11, 12, 13 · 1.1, 1.3, 1.4
Course notes and existing practice
Learning objective
Compare enteral routes and explain why oral absorption varies.
Routes involving the gastrointestinal tract
The deck groups oral and rectal delivery as enteral routes. It groups injection, inhalation, skin delivery and mucosal delivery outside the gastrointestinal tract. Route names describe where a drug is administered; they do not by themselves establish onset, duration or safety.
Formulation and absorption
An oral formulation must release drug that remains available for absorption. Dissolution, stomach conditions, intestinal surface area and food can affect this process. A protective coating can change where drug is released. The lecture contrasts liquids and solids, but formulation-specific behavior matters more than a universal ranking. Rectal delivery avoids swallowing and stomach exposure, yet absorption can be variable and incomplete; avoiding the stomach is not the same as avoiding all first-pass metabolism.
Enteral route
An administration route involving the gastrointestinal tract, including oral and rectal delivery in this course.
Professor deck 04, PDF pages 7, 8, 9. Course material is paraphrased. Qualifications and excluded clinical generalizations are documented in the Pharmacokinetics editorial record. Source review does not establish clinical validation.
Examples and practice explanations are original study aids, not professor quotations, exam requirements or medication instructions.
Section: Original fictional examples, mathematical model explanations and unscored practice. Not professor quotations, clinical advice or validated assessments.
Oral and rectal administration: professor source
Paraphrase
Reviewed
Page 7
Section: PDF pages 7, 8, 9. Embedded text reviewed; diagram-only pages inspected visually. Paraphrase with explicit editorial boundaries; source conformance is not independent clinical validation.