Extended-release (ER only; no IR marketed)

The molecule ships only as an ER/DR product — no IR exists

Cymbalta (DR), Invega (OROS), Depakote (DR/ER)

The formulation IS part of the drug’s identity

crushing or substituting defeats the design

At a glance

No IR form is marketed — the release technology is built in

duloxetine, paliperidone, valproate (Depakote), tamsulosin, alfuzosin, mirabegron, fesoterodine, dimethyl fumarate, mesalamine, doxazosin GITS

Why ER-only exists

Acid-labile molecules need enteric protection

duloxetine degrades in gastric acid

Site targeting: release where the drug works

mesalamine formulations aim at ileum/colon

Tolerability: OROS paliperidone avoids the peaks an IR would give

Practical pearls

Never crush; OROS shells pass intact (warn patients)
Depakote DR vs ER are NOT mg-for-mg interchangeable

Self-check

Why does duloxetine only come as a delayed-release capsule?
The molecule is acid-labile — it degrades in gastric acid.
A patient reports an intact tablet in their stool after paliperidone. What do you tell them?
Expected: the OROS shell passes intact after releasing the drug.

Drugs in this class (10)

Tamsulosin ballicule — decagon mechanism diagram — Tamsulosin

Duloxetine ballicule — decagon mechanism diagram — Duloxetine

Valproate ballicule — decagon mechanism diagram — Valproate

Mirabegron ballicule — decagon mechanism diagram — Mirabegron

Doxazosin ballicule — decagon mechanism diagram — Doxazosin

Alfuzosin ballicule — decagon mechanism diagram — Alfuzosin

Paliperidone ballicule — decagon mechanism diagram — Paliperidone

Mesalamine ballicule — decagon mechanism diagram — Mesalamine

Fesoterodine ballicule — decagon mechanism diagram — Fesoterodine

Dimethyl fumarate ballicule — decagon mechanism diagram — Dimethyl fumarate

All drug classes · Open the interactive console ↗