Methods for optimizing the production of capsule filling (I)

If the ideal formulation for your product (drug, nutritional, vitamin, or dietary supplement) is a capsule, there are a number of things you should consider prior to manufacturing. While each of these points will vary depending on your application, taking them into account before you implement a large capsule filling line can help you reduce production errors and cut costs.

Capsule Materials

Manufacturers can choose from a variety of different capsule materials for filling operations. Two-piece gel packs use hard capsules made from gelatin or other easily dissolvable materials to encapsulate pharmaceuticals. These rigid capsules are divided into two halves, the body and the cap, which are filled with powder or granules.

Soft capsules are filled by a single-piece gel encapsulation method. These soft capsules are typically filled with liquid drug products, which can improve the bioavailability of insoluble drugs.

Most soft gels are made from gelatin or hydroxypropyl methylcellulose (HPMC), each requiring a different set of drying conditions. Gelatin capsules have a high moisture content and are therefore sensitive to excessive drying, while HPMC capsules can withstand more vigorous drying conditions. If the capsule is filled with a material that is hygroscopic, it is recommended to choose a capsule material with a lower moisture content to prevent unwanted changes in the filling material.

Humidity

Environmental conditions, such as humidity, can have a significant impact on the quality of the finished capsule. If the humidity level in the capsule manufacturing environment is too high, the capsules will not dry properly, resulting in inconsistencies between products and higher rates of non-compliant capsules.

Conversely, if the humidity in the drying environment is too low, the capsules may stick to the surface due to static electricity. Regional climate variations can introduce different cycles of high or low humidity, which can complicate the problem.

Regions such as Asia tend to be very challenging, as it is difficult to ensure consistent manufacturing conditions in such tropical climates. In Western Europe and North America, you will find very consistent dry periods in the winter when dehumidification requirements may be low, but once you enter the summer cycle, you may suddenly experience manufacturing difficulties with which you have no previous experience.

We recommend implementing a humidity control solution that is adapted to local climatic conditions. By eliminating environmental conditions as variables in the capsule filling and drying process, we can subsequently ensure a greater degree of consistency in the product.