Alufoil is particularly suitable for blister packs because of its range of mechanical properties. Depending on the alloy and its treatment, alufoil can be made more brittle, tougher or more ductile. It can also be combined with other materials like paper or plastics. Blister packs are tamper-evident and can be designed to be ‘child-proof’ or to provide more secure access.
Most blister packs consist of a preformed plastic tray with an aluminium foil closure manufactured to facilitate the necessary ‘push-through’ characteristic. A recent development is the all-aluminium blister pack. The cold-formed trays are filled with the medicine in aqueous form and freeze dried into individual tablets, which adopt the shape of the individual alufoil compartment. All-aluminium packs are also used for diagnostic products, ointments, and light sensitive formulations where total barrier performance is required. As product counterfeiting has become an increasingly serious issue, holographic effects are now being used on more and more alufoil blister packs.