What Are Differences Between PVC and PVDC

In the field of pharmaceutical packaging, the choice of materials is related to the safety and effectiveness of drugs. Medicinal polyvinyl chloride (PVC) and polyvinylidene chloride (PVDC) are both commonly used packaging materials. Although they both serve pharmaceutical packaging, the PVC and PVDC difference is obvious.

PVC and PVCDC

Medicinal PVC is a hard, transparent thermoplastic with good transparency and mechanical properties. It can clearly show the appearance of the medicine and is convenient for access and viewing.

At the same time, it has excellent processing performance and is easy to form. It can be made into blister packages of various shapes through thermoforming. However, the barrier properties of PVC are relatively weak, and its barrier capacity to gases such as oxygen and water vapor and moisture is limited.
PVDC is known for its excellent barrier properties. It has strong barrier properties against oxygen, water vapor, odor, etc. It can effectively prevent drugs from oxidation, moisture and odor, and better maintain drug stability.

However, PVDC material itself is relatively brittle, and its mechanical properties are poor when used alone. It often needs to be used in combination with other materials, which increases the cost and process complexity to a certain extent.

Packaging application

Due to the difference in material properties, the application of medicinal PVC and PVDC in pharmaceutical packaging has different focuses.

Medicinal PVC is often used for pharmaceutical packaging that does not require high barrier properties, such as some ordinary tablets and capsules, due to its good transparency and processing performance.

For example, common cold medicines and vitamin tablets have good storage stability at room temperature and dry environment. The use of PVC blister packaging can not only meet basic protection and display needs, but also has high economic efficiency.

Due to its excellent barrier properties, PVDC is more suitable for drugs with extremely high requirements for moisture and oxidation resistance, such as some biological products, antibiotics, cardiovascular and cerebrovascular drugs, etc. These drugs have complex ingredients and their stability is easily affected by the external environment. PVDC packaging can provide them with more reliable protection, extend the shelf life of drugs, and ensure the efficacy.

Combination with PTP aluminum foil

In blister packaging, PVC and PVDC are often used in combination with PTP aluminum foil to form a blister structure of "hard sheet + aluminum foil", but the combination mode and effect of the two with PTP aluminum foil are different.

The heat-sealing performance of medicinal PVC and PTP blister foil Is good. Through the heat-sealing process, they can achieve a firm combination to form a sealed blister package, providing certain protection for drugs. However, due to the limited barrier properties of PVC itself, in some drug packaging with strict storage conditions, the protection effect of only relying on the combination of PVC and PTP aluminum foil may not be ideal. The PVC laminated film is used.

When PVDC is combined with PTP aluminum foil, the combination of the two is also very tight. With the excellent barrier properties of PVDC, the strong combination with PTP aluminum foil greatly improves the barrier capacity of the entire packaging, and can provide more stringent protection for drugs. It is especially suitable for drugs that are sensitive to the storage environment, ensuring that the drugs maintain good quality during the validity period.