- October 01, 2000, Stanley Sacharow, Contributing Editor
Long dominated by PVC, the bottom web market for pharmaceutical blister packs now is facing increased competition from a variety of new materials.
Although a superb thermoforming material, PVC lacks intrinsic barrier and is facing increasing problems with environmentalists. Presently holding an estimated 75% of the total pharma market (PVDC/PVC amounts to an estimated 23%), PVC and its variants are used worldwide for most pharma items.
Aclar, with about 3% of the total market, has been manufactured by Allied Signal since the mid-1960s. Aclar is very similar to the most widely known fluoropolymer, Teflon, but it has the substitution of one fluorine atom for a chlorine one, imparting significantly different basic properties. It is a superb moisture vapor barrier, is quite expensive, and is widely used in combination with PVDC. It can be extrusion laminated or direct laminated.
In the early 90s, Allied Signal announced the development of the Rx series of homopolymer films. This development was made possible by the use of new polymerization techniques as well as through greater control of processing conditions.
By designing crystallinity and carefully engineering the molecular weights of the Rx materials, films are produced that exhibit much higher moisture barrier properties and also perform more consistently on blister manufacturing lines.
PP amounts to barely 1% of the worldwide pharma blister market. It's difficult to thermoform (a machine can be modified) and is used mainly by Bayer in Leverhusen, Germany, to package aspirin products. Recently, we have seen some additional users of PP blister stock, including Schwarz Pharma, Merak, Dr. Suwelack Skin and Health Care, Fa. Esai (Japan), and Biocur Arzheimihal GmbH.
The first PP monoblister to enter the Japanese market is used to package "Saclon Q" manufactured by Fa. Esai. Manufactured by BP Chemicals using licensed Japanese technology, PP monoblister stock might well be the "wave of the future." Ecologically preferable, easily printed, and having excellent MVTR, PP monoblister stock currently is receiving a significant amount of attention.
The introduction of cyclic polyolefins (COC0) by Ticona in Germany offers the pharma blister package yet another alternative. This new olefinic material currently is being evaluated by Procter and Gamble in the US and Bayer in Germany. The material offers an environmental alternative to PVC and has unlimited potential in the dynamic blister area.
In the area of cold forming, all aluminum foil blisters offer superb barrier protection to both moisture and oxygen. One drawback has been that cold forming produces large, shallow cavities requiring large blisters. Another has been its relative high cost. Recently introduced by BAW Aluminum (Germany) is a new concept for tooling that reduces cavity size and claims to reduce blister size by almost 20%.
This development coincides with a Pure Alu technology from Teich AG (Austria) that involves no films in the process. The Teich process allows for deep drawing, which significantly reduces both cavity and package size.
The cost savings come from reducing lead times and shortening manufacturing cycles; eliminating the dependence upon a polymer market that is subject to volatility; and gaining the ability to develop, produce, and control all manufacturing in-house. The process can be run on a conventional cold-forming machine at similar speeds.
All of the above developmental activity complements Lawson Mardon Singen's outstanding success with its "Formpack" aluminum blister material. Currently, this laminate is widely used for a variety of pharma products worldwide.
Stanley Sacharow has been in the flexible packaging industry for more than 35 years. His company, The Packaging Group, is an organizer of targeted conferences and a consultant to the international packaging/converting industry. Contact him at 732/636-0885; email@example.com.