Quality Control Tests for Secondary Packaging Materials in Pharmaceuticals

Quality control (QC) for secondary packaging materials in pharmaceuticals is essential to protect products from environmental factors and physical damage. Effective QC ensures that materials like cartons, labels, and wraps maintain the necessary durability and stability, safeguarding the primary packaging and the product. Here’s an overview of the primary QC tests conducted on secondary packaging materials, including those specific to cartons.

1. Thickness Test

• Purpose: Measures the uniformity and durability of packaging materials, ensuring they can handle handling and transit stresses without compromising the product.
• Method: Using a micrometer gauge, the thickness of the material is measured at various points. The average thickness is then compared to the standards for quality and consistency. Uniform thickness ensures that each section of the material can withstand the expected pressures and protect the product effectively.

2. Water Absorptivity (COBB’s Test)

• Purpose: Evaluates how much water or moisture the material can absorb. High moisture resistance is critical for materials exposed to varying humidity levels to prevent weakening or deterioration.
• Method: The material is exposed to a specific amount of water for a defined time, usually up to one minute. After removing excess water, the material is weighed, and the weight difference indicates the water absorbed, measured in grams per square meter (g/m²). Lower absorption is preferred to maintain packaging stability under humid conditions.

3. Bursting Strength Test

• Purpose: Determines the material’s ability to withstand pressure without rupturing, which is essential during handling, stacking, and shipping.
• Method: A sample is clamped into a bursting strength tester, and pressure is gradually applied until it bursts. The measured bursting strength, usually recorded in psi or kPa, indicates the material’s resilience. High bursting strength ensures that the packaging can handle external pressures without splitting or rupturing.

4. Drop Test

• Purpose: Simulates the impacts that the packaging may experience during handling and transit, ensuring the protection of the product inside.
• Method: Fully loaded packaging is dropped from a specified height onto different surfaces, such as corners, edges, and flat faces, to assess its impact resistance. The packaging should remain intact, and the primary packaging should not be compromised, ensuring safe delivery of the product to its destination.

Additional Tests for Carton Integrity

Secondary packaging often includes cartons, which undergo additional QC tests to ensure they’re robust, user-friendly, and maintain print quality.

a) Compression Test

• Purpose: Evaluates the strength of cartons when stacked, ensuring they won’t buckle or collapse under pressure.
• Method: The carton is placed in a compression testing device, and force is applied until the carton begins to deform. This test determines the maximum load a carton can bear, ensuring safe stacking during storage and transit.

b) Edge Crush Test (ECT)

• Purpose: Measures the strength of the carton’s edges, essential for maintaining structural integrity in stacked conditions.
• Method: A strip from the carton edge is compressed to determine the force it can withstand before crushing. Higher ECT values indicate a stronger edge, meaning the carton can handle more weight without collapsing.

c) Print Quality and Adhesion Test

• Purpose: Ensures that printed information, such as labels and regulatory details, adheres well and remains legible throughout the distribution process.
• Method: A simple tape test involves applying and then removing adhesive tape on the printed areas to check if ink peels off. The test helps confirm that information remains readable and won’t degrade over time, ensuring regulatory compliance.