The Pharmaceutics and Compounding Laboratory

Final Processing

Once the capsules have been compounded and the capsule closed, the pharmacist may want to "seal" the capsule. The best way is to use "locking" capsules, where the body and cap lock together, making it very difficult to open the capsule again. If using locking capsules, during the filling process the cap is not completely closed onto the body in the weighing procedure to determine the weight of powder in the capsule. The locking is done only one time and that is after the capsule is correctly filled.

If  locking capsules are not used, a seal can be made by touching the outer edge of the body with a moist towel to soften the gelatin. Alternatively, a cotton swab dipped in warm water can be rubbed around the inner edge of the cap. When the cap is closed on the body, it is slightly twisted to form the seal.

When compounding and sealing are complete, the capsules may need cleaning to remove fingerprints, traces of body oils, or loss powder from the capsule. Fingerprints and oils cannot be effectively cleaned from capsules so the best way to prevent these problems is to wear gloves during the compounding process. Any clinging powder can be removed by rolling the capsules between the folds of a towel.

Another proposed cleaning method is to put the capsules in a container filled with sodium bicarbonate, sugar, or sodium chloride, and gently roll the container. Then the container contents can be poured into a ten-mesh sieve where the "cleaning salt" will pass through the sieve.

Capsules should be visually inspected and checked for:

  • Uniformity - check capsules for uniformity in appearance and color.
  • extent of fill - check capsules for uniformity of extent of fill to ensure that all capsules have been filled.
  • locked - check capsules to ensure that they have all been tightly closed and locked.