Application prospect of the hottest polymer in pha

Application prospect of high polymer in drug blister packaging

at present, the application share of polymer packaging (plastic packaging) in the market is increasing day by day. In the future, the general trend of drug polymer packaging development shows: from container application to composite flexible packaging materials, occupy and dominate the market. Today, the development of polymer materials used in drug flexible packaging in China is very rapid, With the continuous emergence of new materials and the continuous improvement of people's understanding of the use of materials, polymer materials are also updated. For example, PVC, the base material of blister flexible packaging, which is widely used in the market, is an amorphous polymer. Some data show that its main characteristic in processing and Application is that it has no obvious melting point, Heat to 120 ℃ -150~ (2) it has plasticity. Because of its poor thermal stability, it must be added with alkaline stabilizer to neutralize hydrogen chloride, so as to inhibit its autocatalytic cracking reaction. In general, PVC has the advantages of chemical resistance, wear resistance, flame resistance, self extinguishing, high strength, electrical insulation, insulation, low price, wide sources and so on. PVC hard sheet for drug blister packaging is made of PVC resin, with certain processing aids added, through extrusion and compression The extended processing method produces products that meet the pharmaceutical requirements. As the substrate of blister packaging, it can separate each tablet, pill and capsule independently, making it the smallest drug packaging unit. The accuracy and safety of using drugs have been greatly improved. Moreover, due to the simple processing method, small investment, easy processing and molding, the production cost of pharmaceutical enterprises has been reduced and the production efficiency has been greatly improved, From the initial stage of application to now, most pharmaceutical enterprises choose this material to package tablets, pills and capsules. In the 1990s, the original PVC hard film packaged drugs had poor water vapor barrier performance. Therefore, it is not suitable for drug packaging with moisture-proof and vapor proof requirements, especially the pill, powder and particle packaging of traditional Chinese medicine products are more sensitive to the requirements of water vapor and moisture, and the packaging materials should be carefully selected. In addition, in the long-term processing and use of PVC, people recognize its negative impact on the environment for human survival and organisms.

vinyl chloride monomer (VCM) will be produced when PVC polymerizes monomers. In the process of burning PVC products, dioxin hydrochloride is produced. The hydrogen chloride produced after decomposition pollutes the living environment. Its monomer, plasticizer and stabilizer will have a serious impact on human body and the environment. In developed countries, such as Germany, pharmaceutical manufacturers no longer use PVC as blister packaging, and Japan also limits the production of PVC products. PVC as blister packaging material is about to be upgraded. It is urgent to choose new high molecular polymer packaging materials to protect the usability and safety of drugs

1 high barrier new polymer material for drug blister packaging

1.1 polyvinylidene chloride packaging material (PVDC)

homopolymer polyvinylidene chloride (PVDC) of vinylidene chloride is difficult to process. Although it has excellent gas barrier performance, it cannot be industrialized. Therefore, the commonly referred to PVDC refers to the copolymer polymer material with vinylidene chloride (VDC) as the main body. The VDC content of PVDC used in drug packaging is about 90%, and the commonly used monomers are acrylic acid, acrylate, etc. These comonomers have played the role of internal plasticization, improved the processability of PVDC, and did not cause serious reduction in its barrier performance. The processing industry of PVDC began in the late 1930s and was first realized by Dow Chemical Company of the United States. At that time, it coincided with World War II, and PVDC was mainly used for military packaging. Later, with the rapid development of world industry, PVDC has shown extremely excellent performance in the quality assurance and shelf life extension of drugs and foods. Therefore, the safety of PVDC has been unknown for decades. Its dominant position as a high barrier material has never been weakened. The outstanding function of drug packaging materials lies in the selection of barrier performance. PVDC has high polymer density, regular structure and high crystallinity, so it has excellent gas tightness, Excellent moisture and vapor resistance, good oil, drug and solvent resistance. Due to the copolymerization modification, PVDC can not only coextrusion composite, but also blow film, so as to composite with other materials to form a composite flexible packaging material with excellent barrier performance

1.2 polyethylene terephthalate (PET)

this polymer packaging material is called polyester for short. It is the general name of polymer compounds with ester bonds in the main chain in the chemical structure. It is formed by condensation of diols or polyols with dibasic acids or polybasic acids. It can also be made from substances containing hydroxyl and carboxyl groups in the same molecule. At present, pet used is linear polyester, which has the highest hardness among thermoplastics. It has good thermal stability and wear resistance. Its melting point is between 255 ℃ -260 ℃, and its creep resistance and rigidity are better than many engineering plastics. Its water absorption is very low, its linear expansion coefficient is small, and its dimensional stability is very high. Although the air permeability is higher than that of PVDC, it is still one of the materials with good gas resistance as a drug packaging material. For 25um thick PET film, the oxygen permeability is 2.9cm/h MPa atmospheric pressure, and its hygroscopicity is low: soaking in water at 25 ℃ for a week, the water absorption is 0.6%, and good dimensional stability is maintained. British j.r.whinfield first obtained high molecular weight polyester PET with high melting point and good crystallinity based on the research of w.h.carothers of Du Pont Co. in the United States. He applied for a patent in 1941 and published his patent in 1946. It was first produced on a pilot basis in ICI, UK, with the trade name terylene (fiber). The output of pet is one step ahead of DuPont, which was named daeron (fiber) in 1948; In 1953, icico first carried out the pilot production of PET film, named melinex. In 1954, Du Pont also produced film, named Mylar. Then Germany and France both sold under their own trade names. Japan first produced pet with the introduction of ICI patent in 1959, and the production of film reached 2050t in 1963. The early pet manufacturers in China include Shanghai polyester factory, Beijing No.5 chemical plant, Nanjing organic chemical plant, etc. As the base material of drug blister, PET material is superior to PVC hard sheet in terms of mechanical strength, transparency, bacterial resistance and cold resistance, and its water absorption and toxicity are less than PVC. Therefore, the heat sealing sheet using PET as the blister packaging base material is safer and more barrier than PVC, which is more conducive to the preservation of drugs in wet, damp and steam environments

1.3 new cyclic olefin copolymer packaging material (COC)

cyclic olefin copolymers have changed the impression that polyolefins are crystalline but not transparent in the past. They have the common advantages of crystalline and amorphous polymers, such as high transparency, high heat resistance, good optical and electrical properties, low water absorption and permeability, good biocompatibility, less dissolved matter, etc., and have a broad space for applications in drugs and food. Polymers containing cyclic olefin monomers have been known for several years, but at that time, due to the difficulty in controlling the uniformity and molecular weight of the polymer during synthesis, the proportion of impurities often increased, the effective utilization rate of waste was too high, and the output could not be improved, and few truly commercialized products were put on the market. Nowadays, soft linear olefins are copolymerized with hard cyclic olefin monomers and their proportions can be adjusted freely, so they have the common advantages of both amorphous and crystalline polymers. However, although it has good thermoforming properties, it is easy to break itself, so it is often compounded with polypropylene (PP) to maintain its shape, and it can also be compounded with chlorotrifluoroethylene homopolymer. COC can be molded on most high-performance thermoforming equipment now. Because of its easy molding performance, COC has become an ideal alternative product for heat sealing blister packaging and cold forming aluminum-plastic composite. Its application provides a material with high moisture resistance and good thermoforming performance, which can be shaped like PVC hard sheet, but it does not contain chlorine and other halogen elements, and has no pollution to the environment. At the same time, it has good dimensional stability. It is a crystal transparent material, which is still transparent after dyeing as a blister package

1.4 chlorotrifluoroethylene homopolymer composite packaging material (Aclar)

aclar composite uses new homopolymer materials, and the molding performance of the coextrusion copolymer is similar to the performance of the bearing surface used for composite, and the mold surface can be used with or without coating. However, if the mold angle is small or the part is complex, the mold with wrinkles or coatings on the surface will help the material to be evenly distributed in the whole mold cavity. The guide wheel on the AC (7) workbench collides with the column, and the lar barrier material can meet a wide range of packaging requirements. Aclar barrier material will not melt or adhere to the mold, but the friction coefficient is high, which will complicate the design of the mold. If the shape of the forming mold is complex, it is recommended to install thimbles in the mold. In addition, the surface of the preheating plate should also have wrinkles and a smooth coating to reduce the drag of the heat sealing unit on the material. It is suitable for PVDC molds and preheating plates, as well as the application of Aclar materials

1.5 polypropylene packaging sheet (PP)

with the popularity of the concept of environmental protection, polypropylene sheet has gradually become a popular new material in the field of international drug packaging. The modified polypropylene sheet has excellent air tightness, transparency, insulation, high impact strength and good processing performance, and is non-toxic and harmless. This product will be widely used in medicine, food and other fields instead of PVC hard sheets. Polypropylene has good transparency, stiffness and appearance effect, excellent gas and water barrier performance, which can ensure that the contents have a long shelf life. The drug coated sheet has excellent processing performance, mature technology, high production efficiency, excellent recycling function, and is conducive to environmental protection. It can effectively avoid the damage of gas, light and other media to the composition of drugs, adapt to any climate region, and is especially suitable for high-end, new-type drugs that are easy to decompose and undergo chemical changes, and can effectively protect the quality of drugs. It is suitable for the packaging of pills, tablets, suppositories, capsules, lozenges and other drugs, and it is easy to open

reprinted from: Chinese Medicine