Infusion bags are widely used in clinical treatment with which the medicine can be directly applied to the venous blood increasing therapeutic effect. There are two main categories of infusion bags: PVC and Non-PVC. Today most of the non-PVC infusion bags are made of multi-layer copolymerized compound membrane, which contains PP, PE, PA and SEBS, etc. Non-PVC is the safest material of infusion bag by now. It is free of plasticizer, which doesn’t adsorb or react with the liquid medicine. In addition, non-PVC infusion bag is featured with low temperature resistance and alkali separation problem with the glass bottle will not happen to non-PVC infusion bags.

Sometimes during storage period, color change or sediments may occur to the fluid medicine inside the infusion bag when the ingredients including vitamin C, metal ions, bromide, alcohols, arylamine and phenothiazine etc. are oxidized. As a result, the medicine may become much less effective. Therefore, the infusion bag should have sufficient oxygen barrier property to protect the medicine from oxidization.

This article provides a simplified test method for oxygen barrier property of infusion bag. The samples are three-layer co-extruded infusion bags. The testing instrument used for the tests is Labthink’s VAC-V2 Gas Permeability Tester, which adopts differential pressure method where the sample is mounted in a gas transmission cell so as to form a sealed semi-barrier between two chambers. One chamber contains the test gas at a specific high pressure, and the other chamber, at a lower pressure, receives the permeating gas. The gas permeability of the sample can be calculated on the basis of pressure change.

Figure 1. Infusion Bag

The tests can be performed according to the following procedures.

(1) Cut 3 pieces of specimens from the provided infusion bag sample with sample cutter. The diameter of the specimen should be 97mm.

(2) Apply a thin layer of vacuum grease on the outer surface of the test chamber and then place a filter paper on the central area. The diameter of the filter paper should be 65mm.

(3) Place the specimens on the test chambers respectively.

Figure 2. Mount the Specimen

(4) Set test temperature, humidity and specimen thickness and other test parameters. Turn on the vacuum pump and temperature controller. Start test.

(5) The instrument will monitor the pressure change in the lower pressure chamber and calculate the test results automatically.

Through oxygen permeability tests, the manufacturer and the user of infusion bag can determine whether the oxygen barrier property of the infusion bag can meet their requirements for storage of the fluid medicine. And according to the test results, necessary modification can be made in manufacturing and application of infusion bags.

For more details about VAC-V2 Gas Permeability Tester, please visit www.labthink.com

About Labthink Instruments Co., Ltd:

Labthink Instruments Co., Ltd is one leading supplier of packaging testing instruments, which is headquartered in Jinan, China and operated in Boston, U.S.A.