Gastro-resistant tablets are specially formulated oral dosage forms designed to prevent the tablet from disintegrating or releasing its active ingredient in the acidic environment of the stomach, allowing it to pass to the intestine where the drug is then released and absorbed[1].
The main uses of gastro-resistant tablets include:
- Protecting stomach lining: These tablets help minimize adverse effects such as nausea or bleeding that can be caused by drugs irritating the gastric mucosa (e.g., non-steroidal anti-inflammatory drugs or NSAIDs)[1].
- Targeted intestinal delivery: Some drugs are intended for local action in the intestine, so gastro-resistant formulations ensure the drug is released and acts in the intestinal tract rather than being destroyed by stomach acid[1].
- Protecting acid-labile drugs: Some active pharmaceutical ingredients (e.g., certain proton pump inhibitors like omeprazole and pantoprazole) can be degraded or inactivated in the acidic pH of the stomach. Gastro-resistant tablets ensure these drugs reach the more neutral pH of the intestine where they are stable and can be absorbed[1][3].
- Improved bioavailability: For drugs rapidly degraded by gastric acid, gastro-resistant technology improves the amount of active drug available for absorption in the body[1].
How they work: Gastro-resistant (or enteric-coated) tablets are coated with polymers that are stable at acidic pH (found in the stomach, typically pH ~3), but dissolve rapidly at higher pH (alkaline environment of the small intestine, pH 7–9). This allows the drug to bypass the stomach and only release its active ingredient in the intestine[5].
Common examples: Omeprazole and pantoprazole (proton pump inhibitors) are typical drugs given in gastro-resistant/enteric-coated formulations. These drugs irreversibly inhibit the gastric acid (proton) pump in the stomach lining, but are acid-labile and would be destroyed without enteric covering[2][3][4][6].