Four Major Requirements for Adhesives in Pharmaceutical Flexible Packaging — Take Note!

1. Excellent Safety and Hygiene Performance

It should be free of odor and non-toxic; if the drug directly contacts the adhesive, the adhesive should also be non-corrosive to the packaged drug. Since the products protected or packaged by pharmaceutical packaging materials are directly ingested, not only must the substrate be odorless, tasteless and non-toxic, but the adhesive used must also have the same properties. Therefore, the raw materials, auxiliary materials and solvents used to produce the adhesive should be safe and hygienic.

1. Excellent Bonding Performance

Since packaging materials differ in material type, adhesives are used to bond them together, and the adhesive must have excellent adhesion to materials of different types. The substrates used in pharmaceutical packaging laminates are numerous in kind and varied in performance, such as paper, fabric, aluminum foil and plastics, and plastics come in many brands with different surface characteristics and molecular structures. Faced with such numerous and complex materials, an adhesive must be capable of bonding two or more different materials at the same time.

1. Good Heat Resistance

Some pharmaceutical packaging materials are subjected to high temperatures during the packaging process. For example, when drugs are packaged in aluminum foil blister packs, the aluminum foil and polyvinyl chloride can only be heat-pressed and sealed at high temperatures of 150℃~220℃; some packaged retort foods need to be retorted and sterilized together with their packaging at high temperature, which requires the adhesive to withstand the test of high temperatures.

Excellent chemical resistance and resistance to media. The chemical composition of drugs themselves is very complex, and after packaging they must withstand high-temperature treatment and long-term storage. To keep the packaging material intact, in addition to the substrate itself having excellent chemical resistance and resistance to medium attack, the stability of the adhesive is also very important — it must resist the attack of various media and chemical components; otherwise, the laminate will delaminate and peel apart and lose its function.

1. Good Flexibility

When pharmaceuticals are packaged with flexible laminate materials, a soft package that is convenient to carry is important and should be foldable, and the adhesive should also have this property. If the adhesive film is hard, brittle and non-foldable, and does not match the substrate, the flexible packaging loses its usability.