Conoce las formas farmacéuticas: Cápsulas

Capsules: An Overview of Pharmaceutical Forms

Definition and Structure of Capsules

• Capsules are solid oral dosage forms with a soluble gelatin cover that contains a single dose of one or more active ingredients.

• They consist of two cylindrical pieces: the longer body holds the filling material, while the shorter piece is the cap.

Composition and Ingredients

• The contents can be powders, granules, or micro-spheres; liquid contents require soft capsules made from flexible gelatin films.

• Active ingredients are combined with excipients; if the active ingredient does not fill the capsule volume, diluents like lactose are added.

• Substances such as starch or kaolin help absorb moisture and facilitate disintegration after ingestion. Talc is commonly used as a lubricant to aid in filling operations.

Manufacturing Process

• Capsule production involves several phases: creating empty capsules, weighing and mixing solid ingredients, filling them, and quality control before packaging.

• Rigid gelatin capsules are made by cooking animal cartilage in water to produce concentrated gelatin solutions which form capsule bodies when cooled on stainless steel molds.

Filling Techniques

• Manual filling uses a technique called "picking," where each capsule is filled individually by immersing it into powder repeatedly until full.

• Semi-automated processes involve machines that fill multiple capsules at once using perforated trays for efficient powder transfer. Automated systems can produce up to 40,000 capsules per hour with precise weight control during encapsulation.

Advantages and Considerations

• Capsules are easy to swallow due to their smooth texture and can protect drugs from environmental factors like light and oxygen through various colors achieved via natural or artificial pigments.

• They dissolve quickly in the intestine (within 15 minutes), allowing for systemic absorption; however, they should be taken with sufficient water to prevent irritation in the digestive tract. Unlike tablets, capsules cannot be split or emptied without compromising their effectiveness.