Strip packaging

VIII. BLISTER AND STRIP PACKAGING A. The Blister Package... 

Laminates used in strip packaging are combinations of various plies created to obtain the properties not provided by one material alone. They use a minimum amount of materials and are cost-effective. However, they conflict with certain environmental issues, because recycling or reuse is virtually impossible. Examples of widely used laminations are polyester/foil/... 

Strip packages represent an alternative form of packaging for unit-dose medication. Strips can be produced from single- or multiple-ply laminated materials provided the two inner plies can be sealed by heat or pressure (e.g., cold self-adhesive seals). Materials can range from relatively permeable plies to those that incorporate a foil ply of sufficient thickness and effectiveness of seal so that an individual hermetic seal is produced for each dosage. Strip packages are produced at lower speeds and occupy greater volume than blisters. 

The cylindrical-type sealing process for strip packaging does not usually have a cooling cycle or quench surface, hence any pull on the seal ply will tend to weaken the seal while the sealant is still pliable. Therefore, it is desirable that the sealant have good hot tack or a high melt viscosity at processing temperatures. Hot tack is generally accepted to mean the adhesion quality of the sealant from the moment it leaves the seal head and the time it returns to its set or permanent condition. 

Demertzis P G, Johansson F, Lievens C and Franz R, 1997, Studies on the development of a quick inertness test procedure for multi-use PET containers - sorption behaviour of bottle wall strips. Packaging Technology and Science 10,45-58. 

SI 16 Seralyzer ARIS theophylline reagent strips, package circular 9/85. 

SI 17 Seralyzer aspartate transaminase reagent strips, package circular 7/85. 

SI 18 Seralyzer blood urea nitrogen reagent strips, package circular 6/85. 

Soft aluminium foil has a fairly low tensile and tear strength, so it is essential that very thin gauges are supported by paper or film. In general, foil of 0.025 mm and below has to be supported. For example, 0.025 mm foil laminated to 30 g/m2 LDPE is a widely used strip packaging laminate. In theory, 0.015 mm foil laminated to 30 g/m2 LDPE would be a more economical proposition. However, at this caliper any undue stretch would be likely to perforate and tear the foil. Hence it is possible to reduce the foil caliper only if support is increased, i.e. by the addition of a paper ply. Thus if cost savings are to be made the final laminate would probably be either... 

The preforming of foil based materials also occurs in certain strip packaging operations and for the tropicalised blister packs (i.e. a conventional blister is covered on the plaster (blister) side with shaped foil tray), thus enclosing the whole pack in foil. 

Similarly, strip packs consists of one or two plies, made from regenerated cellulose, paper, plastics, foil or any combination of these, whereby an item is inserted into a pocket area against a recess in a heated platen or roller. However, some systems now involve the use of preformed pockets thereby making it increasingly difficult to differentiate between blister and strip packaging (Figures 13.1 and 13.2). 

Strip packaging machines are far simpler and smaller than blister packaging units, usually simply consisting of a feed system, product insertion plus heat sealing, and a guillotining operation to size. 

Strip packaging machines are generally more flexible than blister packers changeover times are shorter and much lower in cost (except for the very widest machines). They are, therefore, more ideal for short runs. The largest machines with integral cartoning are similar in price to the fastest and largest blister units. 

Immerse the test package in a container containing coloured water (15-25°C) and place the container in the vacuum chamber. Apply the appropriate vacuum of 33 kPa (250 mm of mercury) for strip packages or 24 kPa (180 mm of mercury) for blister packages, for 30 s. Restore atmospheric pressure and remove the container from the vacuum chamber. Remove the test package from the container and blot off the excess water. Examine the package for ingress of water into the pockets. 

Dean, D.A., A review of blister and strip packaging of tablets and capsules, Interphex 1974. 

Multiple test strip package for easy loading into meter... 

The use of child-resistant containers (opened only with difficulty and know-how), strip packages (with pills and capsules sealed individually in a plastic strip), and safe storage have reduced the incidence of accidental poisoning, especially among children. 

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