What is the difference between a pill and a capsule?

Pills and capsules are both solid dosage forms used to administer medications or dietary supplements, but they differ in their composition, appearance, and manufacturing processes:

1. Composition:
   • Pills (Tablets): Pills, also known as tablets, are solid dosage forms made by compressing or molding active ingredients and excipients into a cohesive, solid mass. The ingredients are typically mixed together and compressed under high pressure to form tablets of various shapes, sizes, and colors. Pills may contain a variety of additives such as binders, disintegrants, lubricants, and coatings to improve stability, dissolution, and swallowability.
   • Capsules: Capsules are solid dosage forms consisting of a shell (capsule) containing active ingredients in powder, granule, or liquid form. Capsules can be made from different materials such as gelatin, hydroxypropyl methylcellulose (HPMC), or starch. The active ingredients are enclosed within the capsule shell, which is usually made from two halves that are filled and then sealed together.
2. Appearance:
   • Pills (Tablets): Pills are typically flat or biconvex in shape, with smooth or scored surfaces. They may have embossed markings or imprints for identification purposes. Pills come in various shapes (round, oval, rectangular, etc.) and sizes, depending on the dosage and formulation.
   • Capsules: Capsules come in two main types: hard capsules and soft capsules. Hard capsules are usually cylindrical or oblong in shape, consisting of two separate halves (body and cap) that are filled and then joined together. Soft capsules have a flexible, gelatinous shell filled with liquid or semi-solid ingredients.
3. Manufacturing Process:
   • Pills (Tablets): Pills are manufactured through a process called compression or molding. The ingredients are blended together, and the resulting mixture is compressed into tablets using tablet presses or molding equipment. The tablets may undergo additional processes such as coating or polishing to improve appearance, stability, or taste.
   • Capsules: Capsules are manufactured using encapsulation machines that fill and seal the capsule shells. The active ingredients are loaded into the capsule shells, which are then sealed to enclose the contents. Soft gelatin capsules are formed by encapsulating liquid or semi-solid fill materials, while hard capsules are filled with dry powder or granules.
4. Administration and Dissolution:
   • Pills (Tablets): Pills are typically swallowed whole with water or another liquid. Once ingested, the tablet dissolves in the gastrointestinal tract, releasing the active ingredients for absorption into the bloodstream.
   • Capsules: Capsules are also swallowed whole with water or another liquid. The capsule shell dissolves or disintegrates in the gastrointestinal tract, releasing the contents for absorption. Soft capsules containing liquid or semi-solid fill materials may dissolve more rapidly than hard capsules filled with dry powders or granules.

In summary, pills (tablets) and capsules are both solid dosage forms used to administer medications or dietary supplements, but they differ in composition, appearance, manufacturing processes, and dissolution characteristics. The choice between pills and capsules depends on factors such as the nature of the active ingredients, patient preferences, formulation requirements, and manufacturing considerations.