The requirements for pharmaceuticals on flexible packaging film materials are as follows:
To prevent the deterioration of the contents, the main measures are: moisture-proof, gas barrier, light-blocking, sterile, and sealed.
To ensure the quality of the contents, as well as the safety of filling, packaging, and transportation processes, packaging materials are also required to have hygiene properties such as ensuring content stability, heat resistance, and no harmful substance migration.
The materials are required to have certain hygiene properties such as tensile strength, impact resistance, puncture resistance, and tear resistance.
Types of composited filmmaterials used in traditional Chinese and Western medicine:
Due to the inability of single-layer films to simultaneously meet all of the above functions, multi-layer composite films or coated films made from two or more layers are commonly used. The following are the main varieties of plastic composite film packaging for granules, powders, bulk drugs, capsules, etc., in traditional Chinese and Western medicine:
LDPE Film:
LDPE can be compounded with various polyolefins to make flexible packaging bags, such as medical liquid packaging bags, which are made of LDPE and ethylene-α-olefin copolymers.
Advantages: It can withstand high-temperature sterilization above 100°C, has good flexibility, and multi-layer composite films made of LDPE, adhesives, PA, etc., have similar advantages to PVC and PP, and are widely used.
BOPP Film:
PP film can be widely used as the inner and outer layers of medical flexible packaging composite films.
Advantages: Biaxially oriented polypropylene (BOPP) film has good transparency, heat resistance, and barrier properties. When used as the outer layer of a composite bag and combined with LDPE, EVA, EEA, EAA, or aluminum foil with good heat sealing properties, it can greatly improve the stiffness and physical mechanical properties of the composite film.
CPP Film:
Cast polypropylene film (CPP) has good heat sealing properties and is mostly used as the inner layer of composite packaging bags. After vacuum aluminum plating, it can be further compounded with BOPP, PET, OPA, PT, etc., and is an important material for drug packaging.
Advantages: Biaxially oriented polyester film (PET) has extremely high mechanical strength and rigidity, high heat resistance, excellent drug resistance, excellent transparency and gloss, low water vapor and oxygen permeability, and particularly good flavor retention, which other films cannot match.
Polyvinylidene chloride film (PVDC) is the best barrier film, divided into heat-resistant coated films, such as gas barrier PP, CPE, PET, and coated PVDC films. PVDC-coated composite films are widely used in pharmaceutical packaging and can play roles in moisture resistance, flavor retention, and moisture prevention.
Applications: In high-barrier pharmaceutical packaging, it is usually used as a coating material. Coating 2~4μm PVDC on PP, CPE, PET films can make it suitable for the manufacture of blister packaging films for drugs and composite packaging bags for granules, powders, and low-priced drugs.
Vacuum Aluminum FOIL Film:
Vacuum aluminum plating film is a soft packaging film product produced by evaporating aluminum onto various base films under high vacuum conditions, and the aluminum layer is very thin. PETP, CPP, PT, PI, PE, etc., are widely used in the outer packaging of important powder, granule, and bulk drugs. Among them, PETP, CPP, PE vacuum aluminum plating films are the most widely used.
Advantages: Vacuum aluminum-plated soft films not only have the characteristics of plastic base films but also have beautiful decoration and good barrier properties. Especially after various plastic substrates are aluminum-plated, their light transmittance, oxygen permeability, and water vapor permeability decrease by tens or hundreds of times, which can prevent drugs from becoming moldy and damp.
CTFE Film:
Fluorinated hydrocarbon films mainly refer to copolymers of chlorotrifluoroethylene (CTFE), which are non-flammable, have excellent barrier properties, and are transparent, with unique applications. There are currently two types of these films, namely CTFE ethylene trifluorochloroethylene copolymers.
Advantages: CTFE films remain flexible below -160°C, with a melting point between 180~204°C, depending on their taste and crystallinity.
Multi-layer Co-extruded Medical Packaging Films:
Multi-layer structured medical packaging films generally adopt a 9-layer structure of PE/adhesive/PA/adhesive/PE/adhesive/PA/adhesive/PE, where PP can be used instead of PA, and other structures are the same, with a thickness usually ranging from 0.05 to 0.4mm. Currently, the number of layers of co-extruded films is increasing, and several companies can produce 8-layer, 9-layer, or even 11-layer medical packaging films.
