The majority of chemical testing is required on primary component. The type of testing required depends on the type of component used.
Water Attack Test
This test is used only with containers that have been exposed to sulphur dioxide fumes under controlled humidity conditions. Such treatment neutralizes the surface alkali. The glass becomes chemically more resistant. The principle involved in the water attack test is to determine whether the alkali leached from the surface of a container is within the specified limits or not. Since the inner surface is under test the entire container has to be used. The amount of acid that is necessary to neutralize the released alkali from the surface is estimated, the leaching of alkali is accelerated using elevated temperature for a specified time. Methyl red indicator is used to determine the end point.
Powdered Glass Test
It is done to estimate the amount of alkali leached from the powdered glass which usually happens at the elevated temperatures. When the glass is powdered, leaching of alkali is enhanced, which can be titrated with 0.02 N sulphuric acid using methyl red as indicator.
10 grams of sample is added with 50 mL of high purity water in a 250 mL flask. Place it in an autoclave at 121°C +/- 2°C for 30 minutes. Cool it under running water. Decant the solution into anther flask, wash again with 15 mL high purity water and again decant. Titrate immediately with 0.02 N sulphuric acid using methyl red as indicator and record the volume.
Hydrolytic Resistance of Glass Containers
Thermal Shock Test
Internal Bursting Pressure Test
The most common instrument used is American glass research increment pressure tester.
Drug filled container is placed in a container filled with colored solution (due to addition of dye) which is at high pressure compared to the pressure inside the glass container so that the colored solution enters the container if any cracks or any breakage is present.