poLypRopyLene is Best
Peter Forsmark, Technical Director, Recipharm (stockholm, sweden) explains why polypropylene
blister packs are better than aluminium and PvC blisters now that the technical barriers to
manufacturing them have been overcome.
lister packs made entirely of
PP (polypropylene) have many
advantages compared with
aluminium and PVC blisters,
the most common type on the market.
Among these advantages are lower weight
and production costs, higher performance
and less environmental impact throughout
the production process. Polypropylene
monoblisters typically consist of two plastic
films with different properties, such as Etimex
Purelay Pharm and Purelay Lid films (Figure 1).
The ‘Pharm’ film is a PP thermoforming film that
is similar to the PVC or PvdC (polyvinylidene
chloride)-coated PVC films used in an
aluminium/PVC blister, whereas the PP push- Figure 1: Monoblister formation, comparing Al/PVC with PP blister packs.
through lidding film seals the blister and serves
the same purpose as the aluminium. Examples
of when PP monoblisters have replaced PVC/
PP MOnOBLIsTeRs DO nOT CuRve DuRIng LATe-
aluminium blisters are Reliv and Alvedon, two
paracetamol products widely used in Sweden. sTAge PRODuCTIOn, MAkIng IT eAsIeR TO
One advantage that PP monoblisters have
compared with aluminium/PVC types is that sLOT THeM InTO CARTOns OR OTHeR PACkeTs.
they do not curve during late-stage production,
making it easier to slot them into cartons or other PP thermoforming films are also better than in 1995, Recipharm (then Recip) has been
packets. This is because they are made of a PVC in other respects. They are less dense, strongly committed to being an environmental
single material, and do not suffer from differential lighter and more transparent, and the stiffness trendsetter in the pharmaceutical industry.
expansion between the aluminium and PVC. of PP is better suited to pushing tablets from Recip was one of the first pharmaceutical
The thermoforming and sealing films each have the packaging. In addition, PP thermoforming companies to be certified according to
advantages compared with aluminium and PVC. films produced by heating and quenching the ISO 14001 in 1997 and, in 2001, Recipharm
PP thermoforming films are more cost-effective polypropylene have excellent thermoforming undertook a product lifecycle analysis to assess
than PVC films coated with PVdC sealant wrap behaviour and barrier properties. The PP