Development and application of medical aluminum tube

Medical aluminum tubes can be divided into two types: soft aluminum tubes and hard aluminum tubes. The soft aluminum tube is also called the “tube”, which is softened and used for packaging creams, ointments, eye ointments and other dosage forms, while the hard aluminum tube is not softened and used for packaging such as Effervescent tablets, tablets, capsules, sprays and other dosage forms of containers.These two types of containers are made of pure aluminum products (the aluminum content shall not be less than 99.5%). The aluminum materials have a wide range of sources and have excellent properties specific to metals: good light-shielding and air tightness, which can fully meet the special requirements of medicines: easy Recycling will not pollute the environment and conform to the concept of environmental protection. Therefore, in today’s highly developed materials science, it still has irreplaceable advantages. It has a wide range of applications and good development prospects in many pharmaceutical packaging materials at home and abroad.


The production, application and development history of aluminum soft tube is relatively long, and it has undergone three generations of replacement. The predecessor product is the lead-tin hose (strictly speaking, it should be the predecessor of the aluminum tube). Lead can cause serious harm to the human body, and tin resources are less, so it has long been eliminated by the market. The second generation is aluminum soft tube. Because of the poor sealing, this kind of product cannot isolate the drug from the air. The exposed aluminum material and the drug are prone to chemical reactions, which directly involve the safety of the drug. Therefore, such products have long been eliminated in foreign countries. The domestic market is rapidly decreasing. Replaced by third-generation products. The State Food and Drug Administration has stipulated that aluminum tubes must have inner coating, thin-top sealing film, printing and tail coating, which is the third-generation product.


Compared with the second-generation product, the technical level of the third-generation aluminum tube is essentially different and improved. It has a thin top sealing film and a sealing coating at the tail, which can ensure that the medicine does not come into contact with air or do not come into contact with the air during the storage period. There will be any leakage or drying up. The inner wall coating can effectively isolate the direct contact between the drug and the metal aluminum, and provide a reliable guarantee for the efficacy and safety of the drug within the validity period; multi-color printing technology (more than 8 colors in foreign countries , The domestic general 4-8 colors) make the appearance more beautiful. In recent years, aluminum tubes with plastic cleaning heads and sharp-mouth ointment tubes with cleaning heads have also been developed, which can avoid the blackening of aluminum produced due to the friction of the threaded mouth, and effectively improve the cleanliness of medicines and the safety of medication.


With the entry of WTO and the listing of over-the-counter drugs (OTC), the excellent properties of the third-generation aluminum tube products are closer to and in line with consumer needs and market development, and the application prospects are broad. Hard aluminum cans are also widely used in foreign countries because of the same excellent characteristics as hoses. The original production and application of hard cans in China is basically blank, generally replaced by glass or plastic. However, due to the development of Sino-foreign joint pharmaceutical companies in recent years, there have also been aluminum tablets and aerosol cans produced with imported equipment, and they have begun to be used in large quantities. , Thereby improving the safety and aesthetics of the medicine, and also improving the grade of the medicine, and batches of products have entered the foreign market. With the expansion of market demand and dosage forms, as the level of consumer demand increases, the market prospects of hard aluminum tubes are also very optimistic.


Pharmaceutical packaging is an integral part of medicines. The more basic and important principle is that it must meet the quality requirements of the medicines packaged, especially its safety and convenience and reliability when used by consumers. Both hoses and hard cans are packaging materials that directly contact drugs and are used directly without cleaning. They are classified as a class of products in the drug management regulations. Therefore, in addition to the appearance quality, the inherent technical level and quality level of the product are also important factors that must be investigated and verified when selecting applications. There are many combinations of inner coating materials, all of which belong to thermosetting resins. Among them, epoxy-phenolic resin, epoxy-amino resin, epoxy-ethylene and other resins with good performance and high quality are mainly added. Sometimes an appropriate amount of titanium dioxide is added. Epoxy resins play a major role in the coating, and linear bisphenol A resins with high molecular weight are generally used. For example, the epoxy resin of type E-03 has an average molecular weight of 3750. This resin has a lot of polar genes in the molecule. After curing, the polar interaction with the metal molecules produces a very strong binding force, which is sufficient. It can resist the erosion of some strong polar solvents and moisture, thereby enhancing the physical stability of the coating to the drug; because the original covalent chain is not destroyed during the curing process, the material shrinkage rate is low (less than 2%), and the internal stress is small , The performance is stable, and the compatibility and chemical stability with various drugs are expanded; there is no ester chain in the molecule after curing, which enhances the alkali resistance (generally coatings are often unstable to alkaline substances); longer molecules The chain is easy to rotate inside, and the coating is flexible, so that it will not break and fall off during use. Tail seal refers to the sealing layer at the end of the hose (the hard tank does not have this process). Its tightness is also an important means to meet the special requirements of drugs. It can effectively prevent drug leakage, and is especially suitable for isotonic preparations or gel preparations. Bases with strong leakage, such as ophthalmic ointments, are now generally sealed with tail seals to improve their tightness. The material of the tail seal layer is generally acrylate copolymer, mostly water-based paint. The coating has a certain degree of flexibility and can fill the tiny gaps in the aluminum tube seal and block all possible leakage “channels”.After comparative experiments, the aluminum tube sample with tail seal layer is filled with kerosene. Then it was hung, and all samples did not leak in one year, and more than half of the samples without tail seals leaked in less than one month.


Because the third-generation products have applied many new technologies, new processes and new materials, their external quality level has also been greatly improved compared with previous products. For example, the application of polyester resin (or polyurethane) coatings and new printing inks has made aluminum The outer wall of the tube is decorated with better brightness, abrasion resistance and weather resistance, and adapts to China’s wide geographical area and large climate differences; multi-color printing technology expands the product’s ability to adapt to complex patterns and texts, and increases the aesthetic effect , Has improved the product grade, and reduced the possibility of counterfeiting to a certain extent. Aluminum-plastic composite pipes, which are widely used in the market, are widely used in the daily chemical industry because of their beautiful appearance. Regarding the question of whether it is suitable for pharmaceutical packaging, people in the industry generally believe that composite tubes have obvious shortcomings relative to the special requirements of drugs. Because in addition to environmental protection reasons, composite tubes have not effectively solved the “rebound” so far, and the outside air has also taken advantage of the deficiency to enter.


As we all know, the entire process of pharmaceutical packaging materials and pharmaceutical production and canning is completed in a clean environment, with its hygiene and safety considerations. However, a large amount of unpurified air from the outside world caused by the “rebound” phenomenon of the composite tube enters the tube to directly contact the medicine, which is obviously inappropriate, and it is inevitable that secondary pollution of the medicine will occur. Regardless of high-grade pharmaceutical aluminum tubes or aluminum cans, to achieve high-efficiency, high-quality, and stable production levels, the equipment currently has to rely on imported high-speed automatic production lines, and corresponding production factors such as raw materials, processes, and quality management are also proposed. In order to meet higher requirements, in the process of selecting suppliers, the comprehensive capabilities of the production enterprise should be fully investigated. There must be a stable, reliable, and continuous production line, a clean plant that meets the requirements of drugs, advanced production technology, and excellent It is believed that companies that meet these conditions will also have the ability to produce high-quality products. Good medicines must have good packaging, and these good companies and their products should be the priority targets for selection


Post time: Nov-02-2021