In the pharmaceutical field, drug packaging is a key line of defense to ensure drug efficacy and extend shelf life. Among them, blister packaging has become the mainstream choice for solid preparations such as tablets and capsules due to its unique protection and convenience.
The core advantage of PTP blister foil lies in its excellent barrier properties:
Moisture and oxidation resistance: Aluminum foil has extremely low oxygen permeability and moisture permeability, which can effectively isolate moisture, oxygen and light in the air to prevent drug ingredients from degrading or deteriorating. For example, cardiovascular drugs, antibiotics and other humidity-sensitive drugs must rely on the high barrier properties of aluminum foil.
Safety and compliance: Aluminum foil with food-grade coating ensures no migration risk when in direct contact with drugs, and meets the strict standards of pharmacopoeias of various countries (such as USP, EP, ChP).
Printing and labeling function: Clear drug information, batch number and anti-counterfeiting logo can be printed on the surface of aluminum foil to enhance brand recognition and drug safety.
However, aluminum foil also has certain limitations, such as hard texture and need to be used with heat-sealing layer (such as PVC or composite film) to achieve the sealing and opening functions of blisters.
PVC is one of the most commonly used substrates in blister packaging, and its outstanding properties include:
Transparency and aesthetics: PVC is transparent, which makes it easy for consumers to directly observe the status of the drug and enhance their sense of trust.
Flexibility and formability: Good ductility allows it to be easily punched into blisters of various shapes to meet the size requirements of different tablets and capsules.
Cost advantage: Compared with other materials, PVC is cheap and suitable for large-scale production.
However, PVC has weak barrier properties, and it is difficult to meet the packaging needs of high-demand drugs when used alone. Therefore, in practical applications, it is often combined with PVDC coating or aluminum foil to make up for its shortcomings.
PVDC is called "gold in packaging materials". Its core advantages are:
Ultra-high barrier properties: The barrier capacity for oxygen, water vapor and odor far exceeds that of ordinary plastics, which is more than 10 times that of PVC. It is especially suitable for drugs that are extremely sensitive to humidity and oxygen (such as vaccines and biological agents).
Chemical resistance: It can resist corrosive substances such as acids and alkalis to ensure the compatibility of drugs and packaging materials.
Heat sealing and stability: It still maintains good sealing performance at high temperatures and is suitable for high-speed automated packaging production lines.
In practical applications, PVDC is often coated on the surface of PVC (such as PVC/PVDC composite film) or laminated with aluminum foil to form "double protection".
PTP aluminum foil + PVC: Aluminum foil provides barrier properties, PVC provides flexibility and heat sealing properties, and the combination of the two can meet the packaging needs of most conventional drugs.
Blister PVC PVDC + aluminum foil: In scenarios with high barrier requirements (such as drugs in tropical areas), composite film and aluminum foil are superimposed to form a "triple protection" to significantly extend the shelf life of drugs.
Environmental protection trend: With the popularization of the concept of sustainable development, some companies have begun to explore the composite application of degradable materials (such as PLA) and traditional materials, but PTP aluminum foil and PVC/PVDC are still the mainstream.