Softgel Drying & Moisture Control: An OEM Manufacturing Review

Define the endpoint before discussing drying time

A drying brief should describe the condition the capsules need to reach, not only the number of hours they will spend in a room. Specify which shell, fill, shape, and size are under development. Ask the manufacturing team which measurements and handling checks will determine whether that particular capsule is ready for the next step.

Do not copy temperature, humidity, or moisture limits from an unrelated product. Define acceptance criteria through appropriate development work and method selection. FDA's dietary supplement manufacturing guidance addresses specifications, process controls, and production records. For a buyer, the practical question is how the proposed drying decision will be supported and documented for this formula.

Treat shell moisture and fill behavior together

An experimental study of soft gelatin capsules examined how shell preparation and drying relate to water movement into the fill. That observation is a reason to evaluate the assembled capsule, rather than viewing the shell as an isolated packaging component. It does not provide a universal drying schedule for every oil or shell system.

Ask which moisture-related measurements are meaningful for the selected materials and whether the method measures the shell, fill, or combined capsule. Establish sample preparation and reporting units. Two reports carrying the same moisture heading may be difficult to compare if one uses intact capsules and the other examines a separated shell under a different method.

Make sampling representative of the drying load

The drying plan should identify sample locations and times so the evaluation reflects the load being processed. Discuss tray arrangement, loading practices, capsule movement, and how differences in exposure will be assessed. The appropriate layout and controls depend on the proposed process; a buyer should request the rationale rather than prescribing a generic arrangement.

Consider a trial where capsules near one sample location pass a handling check but a different location remains tacky. Keep those samples separate and traceable instead of averaging away the observation. Review the loading and environmental records with the measurements. The investigation should establish whether the endpoint is consistently reached before a routine drying instruction is approved.

Evaluate physical condition without substituting for analysis

Record capsule appearance, sticking, deformation, and seam condition using a defined inspection procedure. Agree on how observations will be classified and photographed, with a representative sample retained. Touch or appearance can provide useful process information, but neither independently demonstrates moisture content, ingredient potency, or suitability for the intended shelf life.

A method for assessing capsule hardness or flexibility should identify the sample age and evaluation conditions. Compare results obtained on the same basis. If the process changes, determine which measurements need repeating. A capsule that appears easy to handle at one point in time still needs evaluation through the subsequent holding and packing steps.

Control the handoff into packaging

Drying completion is not the end of moisture planning. Specify interim storage, maximum proposed holding periods, container or liner choices, and the conditions for transferring capsules into the pack. Ask how the team will recognize and document a change during holding. Include representative packaging samples in the development review so the handoff does not become an untested gap.

When scheduling a commercial order, allow time for the agreed endpoint checks instead of promising a fixed release date based only on elapsed drying time. The batch record should connect the formula revision, load identification, observations, test results, and authorized disposition. That connection makes drying approval understandable when the brand later compares production lots or investigates a complaint.

Common questions