Targeting different parts of the digestive system

Why are tablets coated?

Protection, taste masking, identification, mechanical strength, controlled release

What is film coating?

Thin polymer film sprayed onto tablets and dried

Which polymers are used for film coating?

Cellulose derivatives such as HPMC, HPC, HEC

What is enteric coating used for?

Prevent dissolution in stomach to protect drug or stomach

How do enteric polymers work?

Ionise at higher pH and dissolve in the small intestine

Why must omeprazole be enteric coated?

It is unstable in acidic gastric fluid

Why shouldn’t enteric‑coated tablets be crushed?

Destroys coating and exposes drug to stomach acid

Why avoid antacids with enteric‑coated omeprazole?

Raised gastric pH may dissolve coating prematurely

What are enteric‑coated granules?

Small coated particles that pass through the pylorus easily

What is a MUPS formulation?

Multiple unit pellet system — enteric‑coated pellets compressed into a tablet

Why are MUPS pellets advantageous?

Faster gastric emptying and more reliable intestinal delivery

What determines enteric polymer solubility?

pH relative to polymer pKa

What is the purpose of plasticisers in coating?

Increase flexibility and prevent cracking

What is the purpose of solvents in coating mixtures?

Dissolve polymer and allow spray application

Why do small particles empty from the stomach faster?

They pass through the pyloric sphincter more easily