Blister Packaging in Pharmaceutical Industry

Blister Packaging in Pharmaceutical Industry.

Blister packaging is widely used in the pharmaceutical industry.

Advantages

Unit dose package.
It provides excellent environmental protection.
Good aesthetic appeal.
It offers individual protection until the dose is removed.
Lightweight.
Easy to dispense and print.
No risk of cross-contamination.
Cost-effective.
No opening or reclosing problems.
Tamper evident.

Disadvantages

Carton is required as a secondary package.
Recycling is not possible.
Elderly patients find difficult to tear the packaging system.

Ideal characteristics of blisters are as follows:

A backing membrane should be compatible with blister material.
It should meet the requirement of child-resistant packaging.
Should be puncture resistant.
It should be sufficient tensile strength.

The blister package is formed by heat softening. A sheet of thermoplastic resin and vacuum drawing the softened sheet of plastic into a mold. After cooling, the sheet is released from the mold and proceeds to the filling station of the packaging machine. The semi-rigid blister previously formed is filled with products and lidded with a heat-sealable backing material.

Blister machines utilize the fact that a plastic lm can be softened by heat and then formed in a mould by:
1. Mechanical forming between male and female moulds.
2. Vacuum or negative pressure – which draws the softened lm over or into a mould.
3. Pressure – in which compressed air forces the lm over or into a mould.
4. Combinations of the above.

The backing material or lidding is of type
1. Push through
2. Peelable type
For a push through type of blister, the backing material is usually heat-seal-coated aluminum foil.

Peelable type is having a high degree of puncture resistance to prevent a child from pushing the products through the lidding and must also have sufficient tensile strength to allow the lidding to be pulled away from the blister. It is a type of child-resistant package. For this, a material i.e. polyester or paper is used as a component of backing lamination.
Materials commonly used for the thermoformable blister are PVC/ PE combinations, polystyrene, polypropylene, polyvinylidene chloride.