Blister packaging machineries used in pharma industry

In pharmaceutical industries, the conventional materials used for packaging of drugs and medicines consist of various types of glass, pet bottles, injectable, ampoules, bulk packs etc. But, after the discovery of blister packing, the concept of packaging in pharmaceutical industry has been changed enormously mainly due to the numerous benefits of blister packing.

Generally, blister packing is light weight and occupies very less volume compared to glass which is often used for packing medicines. This saves a significant amount of transportation cost. Moreover, blister packing provides better sealing to the medicines that need to be stored in dry and moisture free environment, which extends the shelf life of drugs and medicines which also can be stored for a longer time without damage.

 Dose accuracy can be easily maintained in blister packing and the blister packaging can be easily automated to maximize the protection of packaging safety. In addition to the high degree of process automation, there are a number of safety testing devices, including box and manual identification and detection that can greatly improve the safety and health of blister packing users. Blister packaging also provides good quality sealing for the tablets and capsules. In fact, the quality of blister packing meets the slogan, “Better Quality of Life through Better Packaging” of the World Packaging Organizations (WPO).

India's per capita packaging consumption is less than US$ 15 against the worldwide average of nearly US$ 100. There are about 600-700 small and medium packaging machinery manufacturers in Indian, which partially fulfil the country’s demand whereas the packaging machinery imports in India are US$ 125 million, though the Indian packaging machinery exports are also rapidly growing. On January 6, 2014 the Economic Times had reported that the annual turnover of Indian packaging industry would touch $ 32 billion by 2025 from then worth $ 24.6 billion. In the world scenario, the total turnover of packaging industry was about $ 550 billion where Indian share was about $ 24.6 billion per annum in 2014.

In pharmaceutical industries two basic types of blister packages are used. The first category comprises of cavity made up of clear, thermoformed plastic and the lid, made up of clear plastic or a combination of plastic, paper, and or foil. The second type of blister package contains foil as an essential component of webs and its cavity which is created by cold stretching. The first category blisters are called cold form blister whereas, the second category is called thermoform blisters or thermoform–fill–seal.

Blister packaging is manufactured by using a) plastics materials viz., poly-vinyl chloride (PVC), PET polyethylene terephthalate (PET), amorphous polyethylene terephthalate (APET), high density poly ethylene (HDPE), acrylonitrile butadiene styrene (ABS) etc and b) aluminium sheets or foils. Aluminium foil provides the best option for assured protection from light.

The process of manufacturing and the machines used for manufacturing blister packing depends on the type of blister packing as discussed above. The operations involved in the manufacturing of blister packing of web and cavity type are as follows.

• Thermoforming of the base web,
• Automatic filling of tablets and capsules,
• Sealing the top web to the base film,
• Cutting to finished shape, and
• Discharged of finished packs.

The machines used for the manufacturing of blister packaging is very complicated. Generally it solely designed and fabricated by the manufacturer and patented. In general, a blister package manufacturing machine contains the following systems which are controlled by a consolidated control system.
This type of blister packing manufacturing machines are capable of handling both poly-vinyl-chloride (PVC) and poly-propylene (PP). Generally, PP is difficult to run on a standard blister machine and cannot be processed as fast as PVC. If a company runs PP and needs new equipment, it must go through a validation process and must perform various tests on PP to satisfy the regulatory requirements. Because of this, PP is generally not used in pharmaceutical blister packaging.

Thermoform–fill–seal machines can operate at speeds more than 1000 packages per minute. Programmable logical controls (PLC) or distributed control system (DCS) are used to control filling and forming equipment with other downstream machinery for cartooning and wrapping. These controls also feed tablets or liquids into the unit-dose blisters, ensuring that an exact volume is put into each.

These machines also use integrated vision systems to maintain the accuracy of the fill and the integrity of the product in the blister and can accommodate several types of lid stocks and base stocks, allowing the manufacturer to obtain better compatibility between the medicine and its packaging material as well as better patient compliance. Blister packaging machines typically operate with intermittent motion.

The seal is made during the dwell time required for thermoforming. Two pieces of foil are sealed together to make blister packs. The temperature and pressure inside the packaging machine cause one seal layer to force onto another seal layer i.e., cover foil to form a friction-locked bond. The purpose of this type of sealing is to provide a tight bond between the blister tray and the packaging foil. Medicines which are sealed in this way are protected from both dust and moisture. The foil is also used to imprint the manufacturer’s name, batch number, manufacturing and expiry date of the medicine, and the name of course; the name of the medicine.

Cold form blister package is made of aluminium foil, film, paper or multi-material backing that is adhered to a sheet of plastic blisters. A less common type of blister is the foil-foil lamination used for products that are particularly susceptible to moisture and/or light. These are cold-pressed into shape.

Products that require the highest degree of protection are packed in an all-foil package. The use of cold-formable foils is growing because more moisture-sensitive drugs are on the market. Cold-formable foil is finding favour because it is the only material that provides a 100 per cent barrier to moisture, oxygen, and light. This helps to expand and for the applications, in which blisters can be used, allow the blister packaging suitable for sensitive products.