What is the difference between capsules and tablets?

The form of a medicine primarily affects its taste and ease of administration. Certain forms may be more or less comfortable for the patient. Additionally, they differ in effectiveness, speed of action, and composition. So, what should you choose when deciding between capsules and tablets?

Characteristics and Types of Tablets

Tablets are a solid, dosed form of medicine, most commonly produced by compressing uniform granules or powder particles. They can also be created through extrusion, pouring, or lyophilization. Each unit contains a single dose of one or more active substances. A distinguishing feature of tablets is their shape, typically a disc with convex top and bottom surfaces. Tablets are administered orally, meaning they are intended for swallowing. Some must be chewed, dissolved, or dispersed in water before ingestion. Some are designed for sucking, allowing the release of the active ingredient. Tablets were first introduced in medicine in 1874 by Rosenthal. Today, several types of oral tablets are distinguished, including:

• Uncoated tablets – single-layer tablets formed by a one-time compression of particles, or multi-layer tablets consisting of concentric or parallel layers. Multi-layer forms are produced by sequentially compressing mixtures of different compositions. These tablets have an unmodified release rate.
• Coated tablets – covered with a mixture of various substances, such as natural or synthetic resins, gelatin, gums, waxes, dyes, flavoring agents, and sugars. The coating is applied as a solution or suspension, with the solvent evaporating. These tablets have a smooth, polished surface.
• Enteric-coated tablets – delayed-release tablets resistant to gastric juices. The active substance is released only in the intestinal fluid.
• Effervescent tablets – uncoated tablets intended to be dissolved or dispersed in water before administration. They usually contain acidic substances and carbonates or bicarbonates.
• Modified-release tablets, including extended-release tablets – coated or uncoated, containing special excipients or formulated to modify the rate, site, or duration of active ingredient release. Types include delayed-release, prolonged-release, and pulsatile-release tablets.
• Tablets for preparing oral solutions or suspensions – uncoated or polymer (film) coated, designed for dissolution or dispersion in water before administration.
• Orally disintegrating tablets (ODTs) – uncoated, placed in the mouth to rapidly disintegrate before swallowing.

What Are Capsules?

Capsules are a solid dosage form consisting of a shell and a filling containing one or more active substances, often with added excipients. Each capsule contains a measured portion of medicine, either a single dose or part of a dose. This form of medicine comes in various shapes and sizes and is indivisible. Traditional capsule shells are made of gelatin. Based on their structure, capsules can be classified as hard or soft. The filling can be in solid form (e.g., powders, granules, pellets) or liquid form. The active ingredient may also be in a paste-like (semi-solid) consistency. The capsule’s contents must be physicochemically compatible with the shell, must not damage it, and must not affect the rate of dissolution or disintegration. Pharmacopoeias distinguish between oral capsules:

• Hard capsules,
• Soft capsules,
• Enteric-coated capsules,
• Starch capsules,
• DuoCaps,
• Modified-release capsules.

Capsules vs. Tablets – Differences

Which is better, capsules or tablets? The key difference between a capsule and a tablet is that a capsule is not compressed, meaning it can contain powders, granules, or liquids. A tablet is a hard, compact form of medicine that can be divided, which is helpful for those who have difficulty swallowing. Despite structural differences, both have similar properties. They are considered interchangeable, meaning a generic drug in capsule form can be registered as a tablet and vice versa.

If you are interested in the topic of supplements or medicine production, we invite you to read other articles on our blog. Learn more about what contract manufacturing is and how it works.