How to Choose an Empty Capsule: Material, Size and Filling Fit

Capsule Selection Guide · 2026-08-13

Choosing an empty capsule is a specification task, not a one-field decision. Shell material, fill characteristics, capsule size, release profile, storage conditions and line compatibility should be reviewed together before a production order is approved.

1. Start with shell material

Yuexi's empty gelatin capsules use pharmaceutical-grade gelatin and are offered for powders, granules and pellets. HPMC vegetarian capsules are plant-derived, contain no animal gelatin and have lower moisture, which makes them a useful option when vegetarian positioning or moisture-sensitive fills are part of the brief.

  • Review the ingredient format: powder, granule or pellet.
  • Confirm whether an animal-free shell is required.
  • Consider moisture sensitivity and the planned storage environment.
  • Do not infer compatibility from the shell name alone; confirm the actual formulation with the capsule supplier.

2. Match the release profile to the product brief

Standard gelatin and HPMC shells serve general empty-capsule applications. When the brief requires intestinal rather than gastric release, an enteric product should be evaluated. Yuexi's enteric gelatin page describes a pH-sensitive coating, two-hour acid resistance and disintegration within 45 minutes in intestinal fluid. Treat those as product specifications that still need to be confirmed for the intended formulation and test method.

3. Select size from the formulation, not from a guess

Capsule size must be checked against the target dose, the bulk density and flow of the fill, and the filling equipment. Yuexi lists sizes 000, 00, 0, 1, 2, 3 and 4 for its empty gelatin and enteric gelatin capsule ranges. A supplier can confirm available sizes, but a formulation or filling trial is the safer basis for the final choice.

4. Confirm production and storage fit

The Yuexi manufacturing flow includes raw-material preparation, gel-solution preparation, dipping and demolding, trimming and joining, printing, secondary inspection, packaging and finished-product testing. For a purchasing specification, add the filling-line model, expected storage temperature and humidity, packaging format, inspection criteria and samples required for line trials.

5. Decide color and printing after the technical fit

Color and printing support product identification, brand recognition and distribution traceability, but they should follow the material, size and filling decision. Yuexi's custom printing service covers capsule colors, logos, product names and other marks using capsule printing inks. Confirm artwork, contrast, print position and approval samples before production.

A practical request-for-quotation checklist

  • Shell material and any animal-free requirement
  • Fill format and moisture sensitivity
  • Target release profile
  • Preferred size plus formulation or filling-trial data
  • Filling-machine model and line-trial quantity
  • Color, printing artwork and sample-approval needs
  • Storage, packaging and inspection requirements

Sending this information with the enquiry gives the capsule supplier a clearer basis for recommending samples and confirming the specification. Yuexi can then review the requested material, size, release profile, color and printing against its current product range.

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