DIY & Capsule Creation

The quality of empty capsules is just as much influenced by storage as it is by the manufacturing process; whether or not you are keeping the capsules at home or managing a large quantity for a production facility, knowing the correct capsule storage conditions will stop sticking, brittleness, and shell degradation before any capsule has been filled.

What are the best storage conditions for empty capsules?

Put unused capsules in a cool, dry, dark place in a sealed or airtight container and keep the capsule shells away from direct sunlight, heat sources, and areas where the temperature or humidity may vary.

Both the gelatin and the HPMC capsule shells need a relative humidity of at least 35 per cent; below this level the gelatin capsules lose moisture, become brittle, and crack when they are handled or filled.

What causes capsules to stick together?

When the humidity level during storage goes beyond the recommended range for that kind of capsule, the capsules tend to stick together. If the relative humidity is above 65%, gelatin capsules absorb moisture which causes the shells to soften, warp, and fuse. This is the defect most frequently reported in cases where capsules have been improperly stored.

HPMC vegetarian capsules can withstand a relative humidity of up to 70% and temperatures as high as 30°C / 86°F, which means they are more tolerant of warm or humid conditions than gelatin capsules. Both types are available from Capsuline in bags and in boxes to meet both home and bulk storage requirements.

What is the correct way to store empty capsules during the summer?

The summer heat together with high humidity causes the storage conditions for gelatin capsules to go outside the safe range more quickly than in any other season, and indoor humidity in the United States can reach above 65% during the summer, particularly in areas without air conditioning.

Practical steps for summer storage:
●    Move capsule inventory to an air-conditioned room
●    Place desiccant packets inside sealed storage containers
●    Keep capsules away from windows, exterior walls, and HVAC vents
●    For bulk storage, elevate containers off concrete floors to avoid condensation

Tip for summer: In areas with a consistently high temperature or humidity, formulators might find that HPMC vegetarian capsules are more suitable for their environment than gelatin capsules since HPMC can tolerate a broader range of temperatures and humidity.

Does the contents of capsules expire? What is the shelf life of empty capsules?

Unlike active ingredients, empty capsule shells do not have an expiry date but will break down after a period of time if stored outside of the conditions recommended for storage. Empty capsules that are stored correctly generally remain usable for two years or longer. However, capsule shells that are exposed to too much humidity, too much dryness, or high temperatures can break down in just a few weeks.

Signs of Poorly Stored Capsules

Getting Storage Right, from Day One

Correct storage begins even before the capsules get to your shelf. Capsuline offers both gelatin and HPMC vegetarian capsules in bags and in boxes, so you can select the packaging that best matches your storage arrangement, whether you have a small home setup or a high-volume production facility. Browse our full range of empty capsules to find the one that suits your formulation and storage conditions.

Ready to save this for your team or production floor? The infographic below covers everything above , storage conditions, humidity risks, seasonal tips, and warning signs, in one shareable reference.