Selecting suitable ampoule packaging materials for cosmetics requires comprehensive consideration of multiple factors. The following are some key points: **I. Product Characteristics** 1. **Compatibility of Ingredients**    - Firstly, the ingredients of the cosmetics should be taken into account. If the product contains ingredients that are reactive to the packaging materials, careful selection is needed. For example, cosmetics containing high-concentration acidic ingredients (such as some exfoliating serums with fruit acids) may react chemically with metal packaging, leading to product deterioration or packaging corrosion. Glass materials usually have good compatibility with various ingredients and possess extremely high chemical stability. They will not react chemically with the ingredients in cosmetics, ensuring the purity and quality of the product. Therefore, they are a relatively safe choice for cosmetics with complex ingredients or active ingredients.    - Some plastic materials may interact with certain organic solvents or lipid components. For example, polyvinyl chloride (PVC) may release harmful substances when in contact with some fragrance ingredients. While plastic materials such as polyethylene (PE) and polypropylene (PP) have relatively high tolerance to most cosmetic ingredients, for some special ingredients, such as high-concentration alcohols or certain new active ingredients, compatibility tests may still be required. 2. **Protection of Environmentally Sensitive Ingredients**    - For cosmetics containing environmentally sensitive ingredients, the barrier properties of the packaging materials are crucial. For example, ingredients such as vitamin C and retinol (vitamin A alcohol) are easily oxidized and are sensitive to light, oxygen, and moisture. Glass and metal packaging perform excellently in blocking air and light. Glass ampoule packaging can effectively block the penetration of air, moisture, and light, providing a good preservation environment for the product and facilitating the maintenance of the potency of active ingredients. Metal packaging, such as aluminum ampoule packaging, has good light-blocking and moisture-proof properties, which can effectively protect these ingredients that are sensitive to light and moisture, prevent photodegradation and moisture absorption, and extend the product's shelf life.    - Although some plastic packaging can improve its barrier properties against oxygen and moisture by adding barrier layers, generally speaking, its barrier properties are relatively weaker compared to glass and metal materials. If the product is very sensitive to environmental factors, special treatment methods are required when using plastic packaging, such as multi-layer coextrusion technology to enhance its barrier properties, or the selection of plastic composite materials with high barrier properties. 3. **Texture and Fluidity of the Product**    - The texture and fluidity of cosmetics also affect the selection of packaging materials. For liquid cosmetics with good fluidity, such as serums and toners, the design of the opening of the packaging material and the control of the flow rate are important. Glass and plastic ampoule packaging can precisely design the bottle mouth and dropper components to facilitate the taking of the product and ensure the smooth outflow of the product while avoiding waste or dripping.    - For cosmetics with a thicker texture, such as some high-concentration gel-like serums or those containing particulate ingredients, the packaging material needs to have sufficient strength to withstand the pressure of the product. Metal packaging or thicker-walled glass packaging may be more appropriate in this case because they have high strength and rigidity and can prevent the packaging from being deformed during storage and transportation due to the pressure of the product. **II. Functional Requirements of Packaging** 1. **Accuracy of Dose**    - If the cosmetics require precise control of the usage dose each time, the shape and design of the packaging material should facilitate the achievement of this function. Glass and plastic ampoule packaging can ensure the accuracy of the dose through scale lines, precise dropper designs, etc. For example, for some eye care serums, the usage dose requirement is very precise. Using glass ampoule packaging with a graduated dropper allows consumers to clearly see the amount taken each time, thus ensuring the effectiveness of the product's use.    - It may be relatively difficult to achieve dose accuracy with metal ampoule packaging, but through reasonable internal structure design, such as the use of a quantitative piston device, the purpose of precisely controlling the dose can also be achieved. 2. **Hygiene and Safety Requirements**    - Considering that cosmetics come into direct contact with the skin, the hygiene and safety of the packaging are of utmost importance. The one-time-use feature of ampoule packaging provides a strong guarantee for the hygiene and safety of the product. Glass and plastic materials can ensure hygiene through strict disinfection and aseptic packaging processes during production. For example, plastic ampoule packaging can be produced in a sterile environment by using a thermoforming process, and the material itself can be disinfected by irradiation, etc.    - Metal packaging also needs to ensure the smoothness and flatness of its internal surface to prevent bacteria from growing and remaining. Meanwhile, the packaging material should meet relevant hygiene standards, such as the standards for food and drug-grade packaging materials, to ensure that it will not have any adverse effects on the contents of the product. 3. **Portability and Convenience of Use**    - For cosmetics that need to be carried frequently, the lightness and ease of use of the packaging material are key factors. Plastic ampoule packaging has the advantages of being light and not easily broken, which is convenient for consumers to carry. For example, travel-sized cosmetics ampoules usually adopt plastic packaging, which is convenient for consumers to put in their handbags or suitcases without worrying about breakage.    - Although glass packaging is relatively heavy and fragile, some small glass ampoule packaging, if equipped with appropriate protective devices such as foam boxes or hard paper boxes, can also meet the requirements of portability to a certain extent. Meanwhile, the transparency of glass packaging allows consumers to intuitively see the state and color of the product, increasing the credibility and attractiveness of the product, which is also an advantage during use. Metal packaging has high strength, but its weight and cost are relatively high. However, its good protection performance and special texture can also strike a balance between portability and convenience of use for some high-end or special-purpose cosmetics. **III. Cost Factors** 1. **Material Cost**    - The cost of glass materials varies depending on the quality and process. High-quality borosilicate glass has a relatively high cost and is mainly used for high-end cosmetics or products with extremely high requirements for packaging quality. Ordinary soda-lime glass has a lower cost, but it may be slightly inferior in terms of strength and chemical stability.    - The cost of plastic materials is usually lower, especially when produced on a large scale. Common plastic materials such as polyethylene (PE) and polypropylene (PP) have relatively affordable prices and can be efficiently produced through various molding processes such as injection molding and blow molding, which gives plastic ampoule packaging a great cost advantage and is suitable for mid- to low-end cosmetics or products that are price-sensitive.    - The cost of metal packaging is relatively high mainly because the price of metal raw materials is high and the processing process is complex. Aluminum packaging has certain applications in cosmetic ampoule packaging due to its good performance, but the cost factor limits its use in some lower-priced products. 2. **Production Cost and Efficiency**    - The production process of plastic packaging is relatively simple. It can be mass-produced by high-speed injection molding or blow molding equipment, with high production efficiency, which can reduce the unit product production cost. Moreover, the scrap rate of plastic materials during the molding process is relatively low, further saving costs.    - The production process of glass packaging is relatively complex. It requires high-temperature melting of glass raw materials, and the molding process has high requirements for equipment and technology, with a relatively slow production speed. However, the mold life of glass packaging is long. If the production scale is large, after the mold cost is apportioned, the unit cost can also be controlled to a certain extent.    - The production process of metal packaging is complex. For example, aluminum packaging requires multiple processes such as stamping and stretching, with relatively low production efficiency, which leads to high production costs. However, for some high-end cosmetics, brand owners may pay more attention to the product's quality and image and are willing to bear high production costs in exchange for a unique packaging effect. **IV. Environmental Factors** 1. **Recyclability and Renewability**    - With the enhancement of environmental awareness, the recyclability of packaging materials has received increasing attention. Glass is a highly recyclable material. Recycled glass can be remelted to make new packaging products. When selecting glass ampoule packaging, it is advisable to consider whether it adopts an easily recyclable design, such as a unified specification and material, which is convenient for recycling treatment.    - The recyclability of plastic materials varies depending on the type. Some plastics such as PET (polyethylene terephthalate) have good recyclability, while others such as PVC due to containing chlorine elements, the recycling process is relatively complex. Now, more and more degradable plastic materials are being applied to cosmetic packaging. These materials can decompose under certain conditions, reducing long-term pollution to the environment.    - The recycling utilization rate of metal packaging (such as aluminum) is relatively high, and the energy consumption for recycling aluminum is relatively low. Adoping metal packaging can to some extent reflect the brand's environmental awareness and also meet the requirements of sustainable development. 2. **Potential Impact on the Environment**    - If plastic packaging cannot be properly recycled, it may cause long-term pollution to the environment. Some plastics are difficult to degrade in the natural environment and will form white pollution. Therefore, when selecting plastic ampoule packaging, it is necessary to consider its potential impact on the environment throughout its life cycle and try to select degradable or easily recyclable plastic materials.    - Although glass packaging is a relatively environmental-friendly material in itself, the production process requires a large amount of energy for melting glass raw materials. If a cleaner and more efficient way of using energy, such as using renewable energy, can be adopted in the energy utilization aspect, its impact on the environment can be further reduced. Metal packaging also produces certain environmental impacts during the production process, such as energy consumption and waste discharge during metal ore mining and processing. However, through reasonable production management and resource recycling utilization, these impacts can be alleviated.