In the world of pharmacy and medicine, a capsule is a solid dosage form where the medication is enclosed in a soluble container or “shell.”

Derived from the Latin word capsula (meaning “little box”), these are among the most common ways to deliver medicine because they are easy to swallow and can mask the unpleasant taste or odor of the drugs inside.

1. Types of Capsules

In the pharmaceutical industry, capsules are generally divided into two main categories:

2. How a Capsule Works in the Body

When you swallow a capsule, it follows a specific path to deliver the medication:

Ingestion: The capsule travels down the esophagus into the stomach.

Disintegration: Once in the stomach, the shell begins to dissolve. This usually takes 10 to 20 minutes.

Dissolution: The shell breaks open, releasing the medication. If it is a powder, it dissolves in the stomach acid; if it is a liquid (softgel), it is released immediately for absorption.

Absorption: The dissolved medicine moves into the small intestine, where it passes through the intestinal wall and enters the bloodstream to be transported to the target organ.

Note on Enteric Coating: Some capsules have a special “enteric coating” designed to resist stomach acid. These only dissolve once they reach the higher pH environment of the small intestine to protect the stomach or ensure the drug isn’t destroyed by acid.

3. Key Advantages

• Taste Masking: They completely hide the bitter taste of many active ingredients.

• Fast Acting: They generally dissolve faster than tablets because the contents aren’t as tightly compressed.

• Protection: The shell protects sensitive ingredients from light and oxygen.

• Versatility: They can carry combinations of different drugs in one container.