Blister packs are commonly used as unit-dose packaging for pharmaceutical tablets, capsules or lozenges. Blister packs can provide barrier protection for shelf life requirements, and a degree of tamper resistance . In the USA, blister packs are mainly used for packing physician samples of drug products, or for Over The Counter (OTC) products in the pharmacy. In other parts of the world, blister packs are the main packaging type since pharmacy dispensing and re-packaging are not common. A series of blister cavities is sometimes called a blister card or blister strip as well as blister pack. In some parts of the world the blister pack is known as a Push-Through-Pack (PTP). Main advantages of unit-dose blister packs over other methods of packing pharmaceutical products are the assurance of product/packaging integrity (including shelflife) of each individual dose and the possibility to create a compliance pack or calendar pack by printing the days of the week above each dose.
Blister packs are created by means of a form-fill-seal process at the pharmaceutical company or designated contract packer. A form-fill-seal process means that the blister pack is created from rolls of flat sheet or film, filled with the pharmaceutical product and closed (sealed) on the same equipment. Such equipment is called a blisterline.
Blister packs consist of two principal components : 1) a formed base web creating the cavity inside which the product fits and 2) the lidding foil for dispensing the product out of the pack.
Medical Blister trays differ from Pharmaceutical blister packs in that these are not push-through packs. The thermoformed base web is made of a thicker plastic sheet, generally between 500µ to 1000µ and can not be collapsed, thus forming a solid tray. The lidding film provides a peal-open feature and is generally porous to allow sterilisation. Such medical blister packs are used for medical devices, used in hospitals.
