Plastic packaging for the most popular pharmaceuti

Plastic packaging for drug packaging and its common plastic materials (Part 1)

first, plastic

plastic is one of the main packaging materials, and the history of plastic application in drug packaging is not too long. Many advantages of plastic determine that plastic has played and will play a major role in drug packaging. These advantages include light weight, not easy to break, easy to use, barrier effect on gas, easy compounding of different plastics and plastics with other materials, mature molding process, etc

1. Plastic resin

plastic resin is a plastic polymer compound. According to its structure and properties, it can be roughly divided into two categories: hot solid resin and thermoplastic resin. Most of the plastic packaging of drugs use thermoplastic resin

2. Additive

resin is the main component of plastics. In the process of plastic manufacturing, it is also necessary to add various additives, which generally include plasticizers, antioxidants, antistatic agents, lubricants, colorants, heat stabilizers, etc

II. The relationship between plastic packaging materials and drugs

drugs are a special commodity. As a packaging material (or container) that directly contacts drugs, it must be able to ensure the safety and efficacy of drugs, ensure the stability of drug quality, and meet the convenience needs of patients

between plastic packaging materials (containers) and the packaged drugs, Shen wanhongyuan, an analyst who did not want to be named, told that adaptability is a problem that drug manufacturers must solve when choosing packaging materials. Light, heat, humidity, microorganisms, oxygen and mechanical impact may all have adverse effects on the quality of drugs. The purpose of packaging is to prevent the impact of the above external factors on the quality of drugs in a certain intensity. This involves a barrier problem, including the barrier to light, microorganisms and gases. The purpose of making plastic bottles brown or white bottles with titanium dioxide is to block light. Aluminum foil in the composite film not only greatly improves the barrier to gas, but also completely blocks the light

the solid substrate of drugs is generally loose material, so it is processed into tablets, capsules and other preparations for taking. Many drugs are crystalline or amorphous powders before they are made into tablets and capsules, which are easy to absorb moisture and deliquesce. Solid preparations are vulnerable to the influence of water vapor and oxygen to varying degrees during storage and change their quality. Reduce the content, change the release degree, etc

at present, solid oral preparations are packed in multi-purpose bottles (mostly plastic bottles), blister packaging, strip packaging and other forms. For plastic bottles, in addition to material selection, they must have a certain thickness and thickness uniformity, and the bottle mouth has good sealing performance. For blister packaging, the formed hard piece must have a certain thickness. If the PVC hard sheet cannot meet the temperature resistance requirements, pet hard sheet or pvc/pvdc composite hard sheet can be used. Another layer of blister packaging is aluminum foil for drug packaging. The quality of the original foil used is better. It is generally believed that the thickness of more than 0.025mm is pinhole free. All kinds of composite films used in strip packaging should be carefully selected according to the characteristics of drugs. At present, the packaging of liquid oral liquid is still mainly glass bottles and plastic bottles. Plastic bottles of oral liquid are generally made of PP or pet, which can provide sufficient mechanical strength, avoid mechanical damage, and provide certain gas barrier and microbial barrier. Among them, PET bottles are better. The fragrance of syrup oral liquid packed in the bottle will not be lost through the bottle wall

migration is another problem involved in drug packaging materials. This kind of migration is often a two-way migration. The possible migration from plastics to packaged drugs includes monomers, plasticizers and other functional additives, residual solvents and so on. The migration of preparations to plastics may cause flavor defects, loss of preservatives and affect stability, and the migration of effective ingredients of drugs may cause content decline, etc. In order to ensure the safety of drug packaging materials and containers, quality standards have been formulated at home and abroad. There are also many provisions in the Pharmacopoeia, which not only stipulate the gas permeability and sealing, but also restrict the substances that may migrate and be toxic to the body. Such as the amount of heavy metals, water-soluble, alcohol soluble, ester soluble substances, and the abnormal toxicity of plastics

III. commonly used plastics for drug packaging

(1) polyethylene plastic

polyethylene is polymerized from ethylene monomer. It is the general name of ethylene polymer compounds. Polyethylene resin is generally colorless, odorless, non-toxic, small water absorption and strong cold resistance. It is the most commonly used plastic in the packaging of oral drugs. According to the density of polyethylene raw materials, there are three kinds of density: high, medium and low. Low density polyethylene is the first generation product, which is characterized by softness, good low temperature resistance and good heat sealing performance. However, the strength is relatively low, and the needle resistance and oil resistance are poor. It is often used as the inner sealing layer in the composite film for SP packaging

high density polyethylene is the second generation polyethylene. Like LDPE, it has good chemical stability, cold resistance, wear resistance and moisture resistance. It has higher strength than low-density polyethylene and slightly better oil resistance. Medical plastic bottles are generally made of high-density polyethylene. Due to the poor odor resistance and oil resistance of polyethylene, plastic bottles made of HDPE are generally not suitable for storing aromatic and greasy drugs. It is also not easy to store drugs that are particularly sensitive to oxygen or water vapor

even if there is monomer migration in polyethylene, there is no safety problem. As long as the variety and quantity of additives used are controlled, there is no problem in safety

(2) polypropylene plastic

polypropylene is colorless, odorless and non-toxic. It has strong heat resistance and chemical stability, and its tensile strength is greater than that of polyethylene. It is the only plastic in common use that can be boiled in water and disinfected at 130 ℃. Its disadvantage is poor cold resistance and transparency. It can be made into plastic bottles of solid preparations, plastic bottles of oral liquids, and infusion bottles by biaxial stretching method. It is manufactured by Shandong Sida high-tech wood-based panel experimental machine, etc. Polypropylene is often used as a single membrane in composite membranes. Polypropylene films used in composite films include stretch films and cast films. Biaxially stretched PP film has good transparency, bright and beautiful appearance. The disadvantage is that the tear strength is greatly reduced and the heat sealing property is not good. Therefore, biaxially stretched PP film is generally used as the outer surface of composite film. Cast PP film maintains the characteristics of good tear strength and heat sealing, and can generally be used as the inner seal of composite film

(3) PVC plastic PVC

PVC is polymerized from vinyl chloride monomer and is one of the earliest plastic varieties in the world to realize industrial production. The original form of PVC is transparent and hard. Only by adding enough plasticizers can it become soft. Polyvinyl chloride is an excellent barrier for oils, volatile and nonvolatile alcohols

most of the concerns about the safety of PVC are focused on the unpolymerized polyethylene monomer VCM (PVC infusion containers also have the migration of plasticizers, which will not be discussed here)

generally used as PVC packaging materials or containers for drugs or food, as well as the pellets used, the control of vinyl chloride monomer is relatively strict, generally ≤ 1ppm

(4) polyester

polyester is the general name of a kind of resin. The so-called "polyester" usually refers to one of them, namely polyethylene terephthalate (PET). Pet is transparent, with high strength, good heat resistance and low temperature resistance, non-toxic, light weight, excellent chemical stability, good barrier to water vapor and oxygen, good barrier to odor, and no pinholes. All of these are the advantages of pet in speed control calculation of hydraulic universal testing machine. The amount of additives in pet plastics is less than that of PE and PP, and the chances of migration are also less, which will not pose a problem in terms of safety. Pet is a good plastic for manufacturing beverage and condiment packaging bottles, and it is also the best plastic variety for manufacturing syrup and other oral liquid plastic packaging bottles. The outer single film of solid oral preparation packaging bottles, blister packaging molding materials and composite films for strip packaging is often made of pet

(5) other

in addition to the above commonly used plastics, some plastics with special functions are also used for drug packaging, such as polyvinylidene chloride (in fact, the polymer of vinylidene chloride and% vinyl chloride is used in packaging materials). Its outstanding advantage is its excellent gas barrier performance. The barrier to water vapor is several times - dozens of times that of polyethylene, polypropylene and polyvinyl chloride, and the barrier to oxygen is hundreds of times that of these plastics

polyvinylidene chloride (PVDC) is generally used in drug packaging:

1 Composite PVC hard sheet (pvc/pvdc hard sheet) to improve the barrier property of PVC hard sheet

2. Single layer and coating in the composite film used for strip packaging

in addition, there are also reports that PVDC is coated in the pharmaceutical plastic bottle made of PE or PP that affects the service life of the bulb to improve its barrier property

(to be continued)