With the gradual advancement of the national compulsory immunization plan, veterinary vaccines have received more attention, and the quality of vaccine bottles used for vaccine packaging has also attracted attention. Relevant standards have been formulated and detailed regulations have been made on the testing items involved in vaccine bottles. Among them , the residual amount of ethylene oxide is one of them.

Ethylene oxide residue is an active chemical disinfectant. Due to its strong ability to penetrate deep and good sterilization effect, it is widely used in the sterilization of pharmaceutical packaging. However, ethylene oxide itself is a toxic gas, and there will be a certain amount of residue in the sterilized product. If it cannot be fully volatilized, it will cause harm to animals when the residual toxicity reaches a certain amount. Therefore, vaccine bottles that have been sterilized by ethylene oxide need to be tested for residual amounts to determine the safety of the packaging.

100ml PP vaccine vial

250ml PE plastic vaccine bottle

The residual amount of ethylene oxide is detailed in the T/CVDA 3-2019 "Veterinary Liquid Vaccine Polypropylene Bottle" standard:

Sample preparation: Remove the packaging from this product, inhale the distilled water with the marked volume (V), and equilibrate it for 1 hour at 37°C ± 1°C.

Preparation of control stock solution: Take an externally dry 50ml volumetric flask, add 30ml of water, add a stopper, and weigh to the nearest 0.1mg. Use a syringe to inject 0.6ml of ethylene oxide reference substance (purity greater than 99.7%), shake gently, cap the bottle, and weigh. The difference between the two weighings is the weight of ethylene oxide. Add water to the mark and dilute this solution to 1g/L as a control stock solution. Dilute to a solution with an ethylene oxide content of 1µg/ml as a control solution.

Place 5 ml each of the control solution and sample in a headspace bottle, and place them in equilibrium at 60°C ± 1°C for 20 minutes. Take 1 ml of liquid gas and inject it into the gas chromatograph, record the chromatogram, and measure the peak areas of the reference substance and sample. The peak area of the control solution should be larger than the peak area of the sample.

The residual amount of ethylene oxide should be ≤1µg/ml.

The quality of vaccine bottles is a direct factor in ensuring the effectiveness and safety of vaccines and ensuring the immune effect of animals. The residual amount of ethylene oxide is only one of its quality standards. To meet the standard requirements, vaccine bottle manufacturers need to Control is the top priority in production, and high-standard packaging helps the healthy development of the animal husbandry industry.