Ceutics quiz 1.1

Oral solid dosage forms

Tablets, capsules, powders — All must break apart before absorption.

Oral liquid dosage forms

Solutions, suspensions, emulsions — Liquids = faster onset because less to break down.

Topical dosage forms

Ointments, creams — Designed for skin; no systemic absorption unless formulated for it.

Other dosage forms

Suppositories, injections — Rectal/vaginal vs. direct systemic entry.

LADME acronym

Liberation, Absorption, Distribution, Metabolism, Excretion

Liberation

Drug is released from its dosage form — Tablet → pieces → dissolved drug

Absorption

Drug crosses a biological membrane into circulation — GI → blood.

Distribution

Drug spreads through tissues and fluids — Blood → organs.

Metabolism

Drug is chemically changed (mostly liver) — Body modifies the drug.

Excretion

Drug leaves the body (mostly kidneys) — Urine is the main exit route.

Where first-pass metabolism occurs

Liver — Oral drugs always visit the liver first.

Which dosage form does NOT undergo liberation

Solution — Already dissolved; nothing to break apart.

Why solutions skip liberation

Drug molecules are already free in liquid — Fastest onset among oral forms.

Physicochemical property that increases dissolution rate

Small particle size — More surface area = faster dissolving.

Why small particle size increases dissolution

Tiny particles expose more surface to fluid — Think: crushed tablet dissolves faster.

What must occur for an oral tablet to begin absorption

Liberation + dissolution — Tablet → disintegrate → dissolve → absorb.

Physicochemical properties influencing drug fate

Particle size, polymorphism, solubility, pH/ionization, stability, Log P

Effect of high crystallinity on dissolution

Slower dissolution — Crystals are tightly packed → harder to dissolve.

Effect of amorphous form on dissolution

Faster dissolution — Looser structure → dissolves easily.

Effect of Log P on drug behavior

Higher Log P = more lipophilic → better membrane crossing — Think: oily drugs slip through membranes

Effect of solubility on absorption

High solubility = fast dissolution = better absorption — Water-loving drugs dissolve quickly.

Route with 100% bioavailability and no biological barrier

Intravenous (IV)

First event for an injectable solution

Immediate entry into systemic circulation — No absorption step.

Which ROA bypasses first-pass metabolism

IV, IM, SL, buccal, transdermal, pulmonary — Anything not swallowed

Barrier for IM administration

Capillary membrane — Drug must cross into blood

Barrier for pulmonary administration

Alveolar membrane — Thin membrane → fast absorption.

Barrier for oral administration

GI tract + liver (first-pass) — Two barriers before reaching blood.