How are tablets different from capsules?

Pharmaceutical Manufacturing – Tablets vs. Capsules

Tablets and capsules are two common oral dosage forms used in pharmaceutical manufacturing, and they have distinct characteristics that set them apart. Here are the main differences between tablets and capsules:

Tablets

  • Form: Tablets are solid dosage forms prepared by compressing a mixture of active pharmaceutical ingredients (APIs) and excipients into a compact form.
  • Composition: Tablets contain the API as well as various excipients, such as binders, diluents, disintegrants, lubricants, and sometimes coatings, to aid in the tablet’s formation, stability, and drug release.
  • Appearance: Tablets are generally flat, round, or oval in shape with smooth surfaces. They come in various colors, depending on the presence of colorants.
  • Administration: Tablets are swallowed whole with water and should not be chewed or crushed unless specifically designed as chewable or orally disintegrating tablets.
  • Drug Release: The drug release from tablets can be immediate, extended, or modified, depending on the formulation. Different types of tablets allow for various drug release profiles to meet specific therapeutic needs.
  • Stability: Tablets are generally more stable than capsules due to their compact and solid nature, and they have a longer shelf life.
  • Advantages: Tablets offer accurate dosing, ease of handling, mass production feasibility, and better stability.
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Capsules

  • Form: Capsules are oral dosage forms that enclose the drug substance within a gelatin or vegetarian shell, known as the capsule shell.
  • Composition: Capsules consist of two parts: the capsule shell and the drug formulation. The drug can be in the form of powders, granules, pellets, or even liquids, depending on the desired drug release profile.
  • Appearance: Capsules are typically cylindrical in shape and are available in various sizes depending on the amount of drug to be encapsulated.
  • Administration: Capsules are swallowed whole with water, but they can also be opened and the contents (e.g., powder or pellets) mixed with food or drink for patients who have difficulty swallowing.
  • Drug Release: Capsules can have different drug release profiles, depending on the formulation. They can be immediate-release, extended-release, or delayed-release.
  • Stability: Capsules may be less stable than tablets, especially if they contain moisture-sensitive drug substances. The gelatin capsule shell can be vulnerable to environmental factors.
  • Advantages: Capsules are useful for drugs with poor solubility or taste, allow for combination therapies (by combining different formulations within the same capsule), and provide flexibility in drug release profiles.
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In conclusion, tablets and capsules are both widely used oral dosage forms in pharmaceutical manufacturing, each with its advantages and suitability for specific drug formulations. The choice between tablets and capsules depends on factors such as the drug’s properties, desired drug release profile, patient preferences, and manufacturing considerations.