Pharmaceutical Packaging Adhesives: Choosing the Right Adhesive for Cartons, Labels and Shipping Cases
 

Pharmaceutical packaging adhesives may be used for applications such as paper carton sealing, label attachment, and shipping case closure. Adhesive selection should be based on the bonding location, packaging construction, machine speed, and storage conditions. Each application should be evaluated separately before the adhesive is introduced into production.

Define the Intended Use of the Adhesive

Primary packaging is the packaging component that comes into direct contact with the pharmaceutical product. Secondary packaging surrounds the primary package and is not generally designed for direct product contact.

A paper carton containing blister packs is a common example of secondary packaging. Shipping cases are considered at an additional packaging level used for storage and distribution.

This article focuses on adhesives used for cartons, labels, and outer shipping cases.

Adhesives used in these applications should not automatically be considered suitable for:

• Direct contact with pharmaceutical products.

• Application to the human body.

• Assembly of medical devices.

Those applications require separate evaluation and appropriate supporting documentation.

How to Select Pharmaceutical Packaging Adhesives by Process

If you are using carton-gluing equipment with liquid adhesive, you can start by reviewing water-based adhesives. For heated dispensing systems, see Polyolefin hot melt adhesives when discussing adhesive grades designed for packaging applications.

Technical Criteria to Review Before Selecting an Adhesive

Adhesion to the Actual Packaging Surface

• Test samples should represent the actual paperboard, printing, and coating used in production.
• If the paper supplier changes or a different lamination or coating is introduced, the bond should be reassessed instead of assuming that the existing adhesive will continue to perform in the same way.
• For labels, evaluate both initial adhesion and edge lifting after storage.
• A label that looks acceptable immediately after application does not necessarily confirm satisfactory performance throughout the intended storage period.

Compatibility with Machine Speed and Compression Time

• Select the adhesive according to the time available between:
  - Adhesive application.
  - Surface assembly.
  - Compression or holding.
  - Transfer to the next production stage.
• For hot melt systems, do not increase temperature arbitrarily to compensate for an adhesive grade that does not match the machine cycle.
• During trials, record factors such as:
  - Adhesive bead consistency.
  - Stringing.
  - Excess adhesive or squeeze-out.
  - Frequency of equipment cleaning.
• These observations help evaluate both bond quality and production performance.

Stability Under Finished-Product Storage Conditions

• Packaging should be evaluated under the defined storage and transportation conditions for the finished product.
• If refrigerated or low-temperature storage is involved, test the adhesive bond under those conditions rather than relying only on room-temperature results.

Documentation and Technical Information to Prepare

Do not use a general “safe” statement as a substitute for confirming the adhesive's intended-use scope. Any manufacturer declaration or certification should be checked against the specific adhesive grade and the conditions under which the statement applies.

Note on tamper evidence: An adhesive bond may form part of a tamper-evident packaging design. This function must be evaluated as part of the complete packaging construction and cannot be determined solely from adhesive bond strength.

Recommended Testing Process Before Implementation

1. Define the adhesive location and acceptance criteria together with technical, quality, and production teams.

2. Prepare packaging samples representative of actual production.

3. Test the adhesive using the intended production equipment and record both the adhesive code and machine settings.

4. Inspect the bond after production and again after the defined storage and transportation conditions.

5. Retain the results and establish when re-evaluation is required following changes to the adhesive, paperboard, coating, or other critical process parameters.

* This is a recommended technical evaluation sequence. Specific approval requirements should be established by the manufacturer according to its own product and process controls.

Safety During Operation, Storage and Transportation

• For hot melt adhesives, avoid contact with molten adhesive and heated equipment. Use appropriate heat-resistant protective equipment.

• For liquid adhesives, minimize splashing onto the skin and eyes and follow the protective measures specified for the exact adhesive grade.

• Keep containers properly labeled and tightly closed and store them according to the manufacturer's instructions. Secure containers during transportation to reduce the risk of leakage.

• In the event of exposure, follow the product-specific first-aid instructions. If molten adhesive causes a burn, cool the affected area with clean water, do not peel off adhesive stuck to the skin, and seek medical assistance where necessary.

Frequently Asked Questions About Pharmaceutical Packaging Adhesives

• Can an Adhesive Used for Pharmaceutical Cartons Also Be Used for Labels?
  Only if the supplier confirms that the specific adhesive grade is suitable and testing demonstrates acceptable performance. Label construction, bottle surface, and labeling equipment may require a different adhesive system.

• Can the Same Adhesive Be Used for Both Paper Cartons and Shipping Cases?
  It may be possible if the adhesive meets the requirements of both applications. However, it should not be assumed that both applications have the same requirements simply because they involve paper-based materials.

• What Information Should I Provide When Requesting an Adhesive Recommendation?
  Provide: Packaging samples, Photos of the bonding location, Equipment type, Production line speed, Storage conditions.
  If a bonding problem is already occurring, include defect samples and information about when the issue appears so that the evaluation can focus on the most relevant factors.
   

Contact VALONA at 0906 880 267 or info@valona.com.vn to discuss pharmaceutical packaging adhesive solutions. Clearly defining the application from the beginning helps identify the appropriate adhesive grades for testing and supports the development of a suitable production process.