What is Alu Alu Foil and Why it is used in Blister Packaging

Have you ever found your capsule damaged in a blister pack even after the whole pack being intact?

Have you ever been surprised why even before opening the pack, the capsule or tablet has got damaged?

Yes, the reason is the high sensitivity of the material to the outer weather. Some Active Pharma Ingredients (API) used for the manufacturing of medicines are very sensitive to moisture, air, gases, and light. Such medicines need to be packed in such a way that they can be totally protected from the environment.

In order to serve this high barrier need of the packaging material, Alu Alu Foil or also known as Cold Forming Blister Foil is used widely in the Pharmaceutical Industry.


WHAT IS ALU-ALU FOIL?

alu alu blister foil, alu alu base foil specification




Alu Alu Blister Foil or CFF (Cold Forming Foil) is a film which is a multilayered structure consisting of Oriented Polyamide OPA (Nylon), Aluminium Foil and PVC film, which are stuck together using an adhesive. The typical Alu Alu Foil specification is as follows:

  1. OPA (Nylon) film 25 Micron / Adhesive / Aluminum Foil 45 Micron / Adhesive / PVC 60 Micron

  2. OPA (Nylon) film 25 Micron / Adhesive / Aluminum Foil 50 Micron / Adhesive / PVC 60 Micron

  3. OPA (Nylon) film 25 Micron / Adhesive / Aluminum Foil 60 Micron / Adhesive / PVC 60 Micron


Alu -Alu Foil is used in Pharmaceutical Packaging to pack medicines that are very hygroscopic and sensitive to light and need a very high level of barrier protection. In the Alu Alu Blister pack, both the lidding and the base material consists of Aluminium Foil which makes it possible to protect the medicine from water vapor in the atmosphere, oxygen, and strong light.

It is also called as a Cold Form Blister because in the Alu Alu foil manufacturing process, the laminate is pressed in the mould without the help of any extra heat and is formed purely by Cold Form Technique. Forming pins are used to form the cavity in this film for the particular tablet or the capsule and then it is sealed with Aluminium Lidding material.


ALU ALU BASE FOIL FEATURES:

Cold Forming Foil, Alu Alu Foil for Blister Packaging.


Some of the major beneficial features of Alu alu base foil are as follows:

     1) It provides 100 % protection as a barrier against light,
         oxygen, water vapor and other gases, microorganisms etc.

2) It offers excellent formability

3) It has a very high degree of thermal stability

4) Due to silver shine, it gives high aesthetic appeal

5) Gives strong sealing with aluminium lidding foil

6) The nylon (OPA) film has the multi-axial forming property which doubles the formability of Cold Forming foil.


Usually, the PVC film in Cold Forming foil is used as the contact layer to seal to the aluminium lidding foil on the pharmaceutical blister pack.

PVC does not shrink or spring during cold forming as it is very stiff and hence it helps the cavity to hold its shape after the cold forming process is complete.


IS THE ALU ALU BLISTER PACKING THE PERFECT CHOICE FOR YOUR MEDICINE?


The sensitive and costly medicines like Cefixime Tablets, Ofloxacin Tablets and Ciprofloxacin Tablets are packed using Alu Alu blister packing.

Even after being the most expensive packaging option, to fulfill the barrier protection requirements of the APIs, it is accepted as the best option. It offers high degree of thermal stability, superb thermo-formability, high malleability which helps to form deep drawing blister cavities, it is sealable with regular aluminium lidding foil and hence is the best option to increase the shelf life of the expensive drugs and enables effective delivery to the customer.


Approximately, 25% of the medicines in the market are highly sensitive and require maximum protection from moisture, oxygen, UV, thermal degradation.

Still, to determine whether a particular product needs a high level of protection and Alu alu packing, stability testing can be done.

ALU ALU PACKAGING VS BLISTER PACKING


Regular Blister Packing:

aluminium blister packaging, blister lidding foil, difference between alu alu and blister packaging

Regular blister packaging is the most common type of pharmaceutical packing for capsule and tablet blisters in which one side of the blister pack is aluminum lidding foil and the other side is PVC film (plastic) or the other structures (laminates) of PVC Film like PVC/PVDC or PVC/PE/PVDC (Triplex Laminate).

Advantages:

  • The cost of regular blister packing is low as compared to alu alu blister packing.
  • The capsule or the tablet is visible in it as the PVC used is mostly transparent.

Disadvantages:

  • Regular Blister Packing may not be suitable for some light sensitive medicine as the plastic side (PVC Side) of this package is transparent and exposes tablet / capsule to light.
  • With rising temperatures, the permeability of PVC films generally increases which leads to a higher WVTR(Water Vapour Transfer rate)

    Tablets and capsules like ibuprofen, paracetamol and amoxicillin are packed in regular blister packing.


Alu-Alu Blister Packing:

alu alu blister packing, cold forming foil, alu alu strip packing

Unlike regular blister packing, Alu-Alu Blister Packing has aluminum foil on both the sides. It has a WVTR (Water Vapour Transmission Rate) of virtually 0 g/m2/day at 38°C/90%RH (Relative Humidity) whereas a standard PVC film has a WVTR of 3.1g/m2/day at the same atmospheric conditions.

Advantages:

  • It is suitable for medicines which are UV light sensitive, highly hygroscopic or requires extra protection against heat and cold.
  • Nylon Film, which is the component of Alu Alu base foil, has very high mechanical resistance against tearing and punctures. This ensures the fracture free forming capabilities leading to zero defect.
  • It offers long term resistance to de-lamination

Disadvantages

  • Cold formed Foil Packing cost is higher than standard blister packing.
  • It is impossible to form a near 90 degree angle with aluminium foil and hence the resulting blister pack has larger than necessary size of the cavities and blister cards.

    Mostly the effervescent and other highly sensitive and hygroscopic drugs like acetylcysteine, ciprofloxacin are packed in alu alu base foil.

We have created a detailed blog on ‘Why aluminium foil is 100% recommended for Pharmaceutical Packaging. Please visit the following link for more details :

https://packagingfoils.com/aluminium-foil-for-pharmaceutical-packaging/

OTHER HIGH BARRIER OPTIONS TO ALU ALU BLISTER PACKAGING

Some ultra-sensitive medicines which are customized for very hot or very humid climates need an extra level of protection. This kind of need is fulfilled by Tropical Blister Films.

To increase the barrier protection against light, oxygen and moisture, tropicalization, the enhancement process of the thermoforming base by addition of a cold form lining is done.

To bridge the gap between the regular low price thermoform materials and Alu Alu cold forming foil, recently new high barrier polymers like PCTFE (Aclar) and some new structures of PVDC are introduced. Though the barrier protection capabilities are increased with these new films but they have not yet matched the barrier properties of Alu Alu.

One more new alternative is cyclic olefin copolymers (COCs), which has 10 times more water vapour barrier capacity than that of PVC and double than that of PVDC coated PVC Film.


CONCLUSION:

Looking at all the barrier protection properties that an Alu Alu blister packing can offer, to date, it is the most preferred way chosen by all the pharmaceutical companies to protect their valuable medicines from getting spoiled due to the environment.


Frequently Asked Questions related to Alu Alu Blister Packaging Foil

What is OPA in Alu Alu Foil?

Alu Alu foil is manufactured using 3 layer structure. The Top layer is OPA i.e. ORIENTED POLYAMIDE (Nylon), followed by Aluminium Foil and then PVC film ( Standard Structure: OPA / Aluminium Foil / PVC Film).

Why OPA is used in the manufacturing of Alu Alu Foil?

OPA (Nylon) Film has multi-axial forming properties. OPA film offers very high mechanical resistance against puncture and tearing, which ensures good fracture-free-forming characteristics, without any forming defects.

What is the thickness of OPA film in Alu-Alu Foil?

The commonly used thickness of OPA (Nylon) Film is 25 microns in the production of Alu Alu base foil for Pharmaceutical Blister Packaging.

What is the most commonly used specification of Alu alu blister packaging films?

There are various structures in which alu-alu base foil is manufactured as per the barrier protection requirements, type and size of filling cavity required, machine type and machine speed etc. However, the most commonly used structure is 25 micron OPA / 45 micron Aluminium Foil / 60 micron PVC Film.

What type of blister packing machine is used for Alu Alu Blister Packaging?

Alu alu blister foil is commonly used by Pharmaceutical companies. It is packed using Flat Bed Blister Packing machine.

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