Plastic bottles are widely used as packaging for medicine, which are featuring with light weight, high strength, good seal integrity, moisture resistance and many other advantages. In contrast with glass containers, plastic bottles can be directly used to pack the medicine without cleaning or drying. There are many specifications for plastic bottles for medicine, ranging from 10ml to 1000ml. And the colors and shapes of the plastic bottles for medicine are also various. With the increasing categories of medicine and more using requirements, functionality and intelligence have become the main trend for the development of plastic bottles for medicine.

Figure 1. Plastic Bottles for Medicine

The common materials used for plastic bottles for medicine include PE, PP and PET, etc., which are widely used for oral solid medicine and oral liquid medicine, such as tablets, granules, capsules and syrup, etc. The properties e.g. oxygen barrier property of plastic bottles made of different materials may be distinct from each other obviously. Especially for some medicines that contain ferrite, alcohol, ethers, aromatic amine, pyrazolones and phenothiazine, which are liable to be oxidized, the packaging materials should have sufficient oxygen barrier property. Otherwise, those ingredients mentioned above may be oxidized and the medicine may change in color and compromised in efficacy. Therefore, it is necessary to test the oxygen barrier property of plastic bottles for medicine before use.

This article provides one simplified test method of oxygen barrier property of plastic bottles for medicine. The testing instrument is Labthink’s C230H Oxygen Transmission Rate Test System.

This instrument uses a coulometric detector to determine the oxygen transmission rate. The specimen is mounted as a sealed semi-barrier between two chambers at ambient atmospheric pressure. One chamber is slowly purged by a stream of nitrogen at a given temperature and relative humidity and the other chamber is purged by a stream of oxygen at the same temperature as the nitrogen stream but may have a different relative humidity than the nitrogen stream. In this case the environment would more closely simulate actual shelf conditions. As oxygen gas permeates through the film into the nitrogen carrier gas, it is transported to the coulometric detector where it produces an electrical current, the magnitude of which is proportional to the amount of oxygen flowing into the detector per unit time. Note: For the package specimens, nitrogen flows inside the package while oxygen flow outside the package.

Figure 2. C230H Oxygen Transmission Rate Test System

The tests can be performed according to the following procedures.

(1)   Fix one specimen in the special sample fixture and then fix the specimen on a test support for package test. Seal the specimen and connect it to the instrument with pipes. Then cover the specimen and test support with a sealing bag.

(2)   Set specimen name, test temperature, test humidity and other test parameters.

(3)   Click Start Test to start the test.

(4)   Turn on the gas supply. Adjust the humidity and carrier gas flow rate.

(5)   When the test is finished, the test results will be calculated and displayed automatically.

For more details about C230H Oxygen Transmission Rate Test System, 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.