Blister packaging for tablets and capsules is one of the core applications of PVC rigid sheets in the pharmaceutical field, designed to balance drug protection, convenience, and safety. Below is a detailed introduction to the medicinal PVC rigid sheets produced by Anyang Feilong Pharmaceutical:

1. Blister Packaging Structure A typical pharmaceutical blister pack consists of a transparent PVC rigid sheet laminated with an aluminum foil backing layer: Outer Layer (PVC Rigid Sheet): Provides transparency, support, and formability. Inner Layer (Heat-Seal Coating): Typically PVDC (polyvinylidene chloride) or aluminum foil to enhance barrier properties (moisture, light, and oxygen resistance). Backing Material: Aluminum foil or paper-plastic composite for easy tearing and drug retrieval.

2. Advantages of PVC Rigid Sheets High Transparency: Facilitates visual inspection of drug integrity (e.g., color, shape). Excellent Formability: Precise thermoforming adapts to tablet/capsule dimensions, reducing movement and friction. Barrier Properties: Basic PVC sheets offer moderate water vapor barrier and require lamination with PVDC or aluminum foil (water vapor transmission rate can be reduced to <0.5 g/m2·24h). UV-blocking additives prevent degradation of light-sensitive drugs. Safety: Complies with pharmaceutical-grade standards (e.g., USP Class VI, EU 10/2011), ensuring no migratory toxicity. High heat-seal strength (typically ≥1.5 N/15mm) prevents rupture during transportation.

3. Key Production Process Points Material Selection: Food and pharmaceutical-grade PVC resin: Vinyl chloride monomer residue ≤1 ppm. Stabilizers: Calcium-zinc stabilizers replace traditional lead-based ones to avoid heavy metal contamination. Lamination Process: PVC sheets are combined with PVDC/aluminum foil via dry lamination or extrusion coating. Aluminum foil thickness typically ranges from 20-40μm, ensuring no pinholes (testing standard: ASTM D3985). Heat-Sealing Parameters: Temperature: 120-150°C (adjusted based on coating type). Pressure: 0.2-0.6 MPa to ensure uniform sealing.

4. Industry Standards and Certifications International Standards: ISO 15378: Quality management for primary pharmaceutical packaging materials. US FDA 21 CFR 177.2600: Safety standards for PVC materials in contact with food and drugs. Performance Testing: Seal Integrity: Vacuum leak test (e.g., ASTM D3078). Barrier Properties: Water vapor transmission rate (ASTM E96), oxygen transmission rate (ASTM D3985). Biocompatibility: Cytotoxicity testing (ISO 10993-5).

5. Alternative Materials and Environmental Trends Competitive Materials: PVC/PCTFE composite sheets: Polychlorotrifluoroethylene (PCTFE) offers superior barrier properties but at higher cost. PET/PE: Environmentally friendly but poor formability, often used for larger-sized drugs. Environmental Improvements: Halogen-free flame retardants: Replace chlorine-based systems. Recyclable designs: Development of mono-material blisters (e.g., all-PP structures), though not yet widely adopted as PVC alternatives.

6. Common Issues and Solutions Issue: Poor Blister Seal Cause: Insufficient heat-seal temperature/uneven pressure. Solution: Calibrate heat-sealer parameters and check mold flatness. Issue: Drug Discoloration or Degradation Cause: Additive migration in PVC. Solution: Switch to low-migration stabilizers and add PVDC coating. Issue: Difficulty Tearing Aluminum Backing Cause: Excessive foil thickness or uneven adhesive coating. Solution: Optimize foil thickness (e.g., 25μm) and adjust coating process.

7. Selection Recommendations High-Humidity Environments: Prefer PVC/PVDC composite sheets (5-10x improved water vapor barrier). Light-Sensitive Drugs: Use amber-colored PVC sheets with UV absorbers. Child-Resistant Packaging: Employ foil designs requiring tools for puncture (e.g., ISO 8317 standard). PVC rigid sheets remain the mainstream choice for pharmaceutical blister packaging due to mature technology and cost advantages. However, driven by environmental regulations, future trends may shift toward high-barrier, low-migration modified PVC or composite materials.