Printed matter on hard gelatin capsules is the text, symbols, logos, or codes applied to the capsule shell. It can be:
- Alphanumeric characters (e.g., product code, strength)
- Company logos or trademarks
- Unique symbols
- Color bands or stripes
Why Do Capsules Have Printing?
The primary purposes are:
- Identification
- Enables healthcare professionals and patients to quickly identify the product, dosage strength, and manufacturer.
- Differentiation
- Helps distinguish between products that may be similar in color or size.
- Anti-Counterfeiting
- Acts as a deterrent against product tampering and counterfeit medicines.
- Regulatory Compliance
- Many regulatory authorities (e.g., FDA, EMA) require imprint codes for oral solid dosage forms.
- Traceability
- Assists in recall situations to pinpoint affected lots.
How Is Printing Applied?
Common printing methods include:
- Offset Printing: Capsule rotates against an inked plate that transfers the print.
- Ink Jet Printing: Controlled droplets create characters or codes.
- Pad Printing: An image is transferred from a plate via a silicone pad onto the capsule.
The printing ink must be:
- Pharmaceutical grade
- Non-toxic and compliant with pharmacopeial standards (e.g., USP, EP)
- Approved for ingestion
Controls & GMP Requirements
Printed capsules require strict controls to avoid mix-ups or errors:
🔹 Incoming Inspection
- Verify imprint correctness
- Confirm color, shape, and readability
- Check certificates of analysis
🔹 Storage
- Segregate by product, strength, and imprint
- Use clear labeling and dedicated storage areas
🔹 Process Controls
- Line clearance before use
- Two-person verification of imprint codes and appearance
- Sampling and visual inspection during filling
🔹 Documentation
- Record imprint codes and lot numbers in the batch record
- Document any deviations
🔹 Verification
- Vision inspection systems can automatically check imprint presence and legibility during production
Common Risks
- Mix-up with plain (unprinted) capsules
- Printing errors (wrong code, smudging, missing imprint)
- Ink migration or fading