standard operating procedure leak testing

1. PURPOSE & SCOPE
To lay down the procedure to check the leak test in blister and strip

2. RESPONSIBILITY
Production / QC supervisor

3. AUTHORITY
QA manager

4. PROCEDURE
1) INTRODUCTION
An important process control in the packaging of tablets and capsule in strips of laminated metal foil and other water impermeable

materials is the test for integrity of sealing of strips. Defects in strips which may due to faulty sealing or due to cracks and

pinholes in the laminate may be detected by a test which is based on the permeation of water through the leaks,

cracks and pinholes when the strips are immersed in water in a container under reduced pressure. This document gives the details of the test.
2) EQUIPMENT
The testing assembly consists of the following :
2.1 A vacuum desiccator half filled with water
2.2 Vacuum Pump fitted with a gauge

2.3 Stiff rubber tubing connecting the desiccator to the pump
2.4 A suitable non-corroding weighting device such as a stainless steel roll
2.5 A suitable housing for the entire assembly such as a wooden box to contain the glass in the event of an implosion of the desiccator under vacuum.
3) FREQUENCY OF TESTING
The frequency of testing is decided by the nature of the product being tested for moisture sensitive products the tests should

be performed a half hourly intervals during the packing run.

4) SAMPLING
The number of strips to be taken for each test will depend on the number of pockets in each track of die roles of the strip packing machine.

It should be ensured that atleast one tablet from each pocket of each track is included in every test. Thus, if we have a

strip of 10 tablets in two rows of five and the machine has 6 tracks with 15 pockets in each track of the die roll a total of 90 tablets in 9 strips should be sampled.

5) TESTING
5.1 The required number of strips should be collected from the machine and tied to the weighing device by means of rubber band.
5.2 The desiccator should be half filled with water. The bundle of strips should be placed inside the desiccator and it should be ensured that it is submerged in water.
5.3 The desiccator should be covered with the lid and the containing box should also be closed.
5.4 The rubber tubing should be attached to the lid of the desiccator and then connected to the vacuum pump. The pump should be switched on and the air inside the desiccator should be evaluated till a minimum vacuum of 381-mm (15”) of mercury is obtained. The stop cork of the desiccator should then be closed and the rubber tubing disconnected.
5.5 The vacuum should be maintained for atleast 30 seconds. Air should be gently passed into the desiccator till complete equilibrium is obtained.
5.6 The cover of the box should be opened and the desiccator lid gently slid. The bundle of strips should be removed and adhering water wiped dry with a clean dry duster.
5.7 The strips should be cut open and the contents examined carefully. The number of capsules or tablets, which have become sticky or moist should
be counted and calculated as a percentage of the total number tested.

standard operating procedure leak testing

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