Water Vapor Transmission Rate Test Method of Aluminized Composite Film for Medicine Packaging

Labthink Instruments Co., ltd

C390 Infrared Sensor Method Water Vapor Transmission Rate Test System

Most of medicines should be kept in a dry place and protected from moisture to guarantee the quality and shelf life. Moisture may cause the medicine ineffective or even produce hazardous substances. Therefore, it is very necessary to test the moisture barrier property of the packaging materials for medicines.

The common medicine packaging include plastic composite film, aluminized composite film, blister pack, ampoules, plastic tubes and penicillin bottles, etc. Different medicines have different requirements on moisture barrier property of packaging materials. For example, power-form medicine and capsules packaging requires having high moisture barrier property while eyedrops and injection packaging don’t special requirement on moisture permeability. Therefore, testing the WVTR and selecting proper packaging materials is a basic requirement to guarantee the medicine quality and shelf life.

Test Methods

Currently there are mainly two categories of test methods for water vapor transmission rate i.e. gravimetric method (also known as cup method and divided into dry cup method and wet cup method) and sensor method (including electrolytic sensor method, infrared sensor method and humidity sensor method). In this study, we will use infrared sensor method.

Test Specimens

We will use aluminized composite film in our this study

Test Equipment

Labthink C390 Water Vapor Transmission Rate Test System, which is newly designed and upgraded recently with higher accuracy and efficiency

Test Principle

The test specimen is mounted in the diffusion cell, which is subsequently divided into a dry chamber and a controlled-humidity chamber. The dry side of the specimen is swept by a flow of dry nitrogen, and the water vapor permeating through the specimen from the controlled-humidity chamber is carried by dry nitrogen to the infrared sensor where proportion electrical signals will be generated. The water vapor transmission rate is obtained by analyzing and calculating the electrical signals. For package specimen, the dry nitrogen flow inside the specimen while the outside of specimen is in high humidity environment.

Test Procedure

(1) Cut 3 pieces of specimens from the sample material with sample cutter. Condition the specimens at 23±2℃ and 50±10% for 4 hours.

(2) Apply a thin layer of vacuum grease around the test chamber and clamp the specimen tightly on the surface of test chamber.

(3) Set test temperature(38℃), test humidity (90%), specimen name and other test parameters. Then click Test to start the test.

(4) Turn on the gas supply, adjust the flow rate of carrier gas until the humidity inside the test chamber reach specified value. When test is finished, the water vapor transmission rate of test specimen will be calculated and displayed automatically.

Test Results

The WVTR of these 3 specimens is 0.73 g/(m2•24h)、0.77 g/(m2•24h)、0.71 g/(m2•24h). We will consider the average value 0.74 g/(m2•24h) as the WVTR of the sample film.


The water vapor transmission rate of medicine packaging is an important factor that effects the medicine quality during storage and transportation. In this study, we tested the WVTR of aluminized composite film used in medicine packaging, introduced the Infrared Sensor Method Test Equipment C390, Which is intelligent and accuracy, easy to operate, has good reparability. Beside the WVTR, the oxygen transmission rate, seal strength, Leak property, COF of aluminized composite films also affect the medicine packaging performance. Labthink Instrument Company is a hi-tech company which is focus on R&D packaging testing equipment and providing test services. You can visit our website en.labthink.com for more details.

Water Vapor Transmission Rate Test Method of Aluminized Composite Film for Medicine Packaging
C390 Infrared Sensor Method Water Vapor Transmission Rate Test System

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