OPRA: Medicinal chemistry & biopharmaceutics
Medicinal chemistry and biopharmaceutics is about ~10% of OPRA — formulation and physicochemical principles that explain how drugs behave.
High-yield areas
- pKa, ionisation and how pH affects absorption
- Solubility, dissolution and the BCS classification
- Dosage forms, modified-release and why MR tablets aren't crushed
- Drug stability, degradation kinetics and shelf-life
How to study it
Anchor the chemistry to a clinical consequence — e.g. why an enteric coat protects an acid-labile drug — and it becomes far easier to recall under exam pressure.
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Start freeFrequently asked questions
How much of OPRA is medicinal chemistry?
Medicinal chemistry and biopharmaceutics is approximately 10% of the exam.
What does the medicinal chemistry and biopharmaceutics domain cover?
Drug physicochemical properties, solubility, ionisation and stability, dosage forms and delivery routes, modified-release formulation, and pharmaceutical microbiology.
Is it worth studying a 10% domain in depth?
It rewards targeted revision rather than deep study. The content is finite and highly repeatable, so a focused pass over formulation, stability and dosage forms usually secures most of the available marks.