It is known that blister packaging can be used to store and deliver a wide range of items. Among the many types of items that can be stored and delivered in blister packs are pharmaceutical products, such as tablets, pills, capsules, and other related items. Conventional blister packages include a blister tray that is typically a thermoformed plastic sheet with a plurality of blister cells or depressions formed therein. Typically, after items are placed in the cells, the items are retained and protected in the respective cells by securing a backing sheet to the blister tray. The backing sheet is often a thin layer of metal foil, plastic, paperboard, or other material secured to the back of the blister tray, thereby sealing the cells. In other types of blister packages, the contents are placed in substantially puncture-proof foil containers that can be covered with foil or paperboard backing.
In many blister packages, the foil backing is thin enough to be punctured mechanically, or ruptured by pressing the blister so that the encapsulated item penetrates the foil backing. If the backing sheet is made from, for example, paperboard, or similar material, then the backing often includes gates in the backing sheet that covers the openings of respective blister cells. In practice, each gate is deformed or manipulated so that it ruptures or partially separates from the surrounding paperboard to allow the item contained within the blister cell to be pushed out of the blister cell for use.
While the conventional blister packaging is viewed by many to be suitable for most applications, there are several design deficiencies. The conventional packages provide removal of the items from the blister cells, but offer little in the way of resisting child tampering. Child resistance is a feature that is desired, particularly for dose pharmaceutical packaging.
To address the desirability of child resistance, many blister packaging designs employ materials of increased rigidity, compared to conventional non-child-resistant packages. For example, in increased-rigidity packages, the backing sheet and/or the blister cells can be made thicker and/or more resistant to pressure. As such, a young child is unlikely to be able to generate the pressure required to force the package contents through the increased-strength materials. In addition to the benefits in terms of child-resistance, increased rigidity can provide additional protection for the enclosed materials, which may be, as is the case with pharmaceuticals, fragile and susceptible to breakage.