Why is aluminium foil the preferred material for pharmaceutical tablet blister packaging?
Aluminium foil provides an excellent barrier against moisture, oxygen, and light-critical factors in preserving drug stability. Its formability allows precise cavity shapes for tablets while maintaining seal integrity. The material is non-toxic and compliant with FDA/EMA regulations for direct drug contact. Additionally, it supports high-speed packaging lines due to its tensile strength and heat-sealing properties. Foil thickness typically ranges from 20–40 microns for optimal protection and cost-efficiency.
What are the key differences between cold-form and push-through aluminium foil blisters?
Cold-form foils are laminated with PVC or PVDC for deep-drawn cavities, ideal for moisture-sensitive drugs. Push-through foils (e.g., Alu/Alu blisters) use two aluminium layers for superior barrier properties but require higher tooling costs. Cold-form offers better visibility of tablets, while Alu/Alu provides 100% light protection. The choice depends on drug sensitivity and production scale-cold-form dominates for high-volume generics.
How does aluminium foil prevent drug counterfeiting in packaging?
Advanced foils incorporate holograms, micro-embossing, or laser-etched serial numbers for tamper evidence. Some use RFID tags embedded between foil layers for track-and-trace compliance (e.g., EU FMD). The material's opacity inherently hides tablet visibility until opened, deterring substitution. Anti-static coatings may be added to foil surfaces to prevent dust adhesion during printing.
What printing technologies are used on pharmaceutical aluminium foils?
Flexographic and gravure printing dominate, applying logos, dosage info, and batch numbers with FDA-approved inks. Digital printing is emerging for variable data (e.g., QR codes). Reverse-side printing protects ink from abrasion during blister forming. Critical parameters include ink adhesion (tested via tape peel tests) and thermal stability (for heat-sealing processes).
How do environmental regulations impact aluminium foil packaging for tablets?
While aluminium is infinitely recyclable, blister packs face challenges due to multi-material laminates. EU's SUP Directive encourages mono-material designs like pure Alu/Alu blisters. Lightweighting (reducing foil thickness by 10–15%) is a key industry trend to cut carbon footprint. Some manufacturers now offer bio-based coatings to enhance sustainability without compromising barrier performance.
