capsulefilling

Capsulefilling refers to the process of placing an active pharmaceutical ingredient (API) and excipients into empty capsules to form finished dosage forms. It commonly uses hard-shell capsules, comprised of two interlocking parts, and soft gelatin capsules, which are formed as a single piece around the fill. The goal is accurate dosing, content uniformity, and stability throughout the product's shelf life.

Hard-capsule filling is typically achieved with automated equipment that presents cap and body components, doses a measured amount of powder, pellet, or granule material, and then closes the capsule. Variants include dosator-based systems for fine powders, auger or cup-fillers for granules, and servo-controlled feeders to improve dosing accuracy. Soft capsules are produced by rotary die machines that simultaneously form the gelatin shell and inject the liquid or paste fill, sealing the capsule as the shell sets.

Process design emphasizes flowability and blend uniformity of the fill material, capsule compatibility, moisture control, and dust management. Premature opening or cross-contamination must be prevented. Cleaning, material handling, and in-process checks are critical to ensure uniform fill weight and compliance with pharmacopeial requirements.

Quality control and regulatory oversight govern capsule-filling operations. Key tests include weight variation and content uniformity, disintegration and dissolution, stability, and microbial limits where applicable. Documentation, batch traceability, and adherence to good manufacturing practice (GMP) are required. Validation studies cover equipment qualification, process validation, cleaning validation, and containment measures for potent or hazardous ingredients.