Syringe Glide Force Test for Break Loose and Glide Force

Syringe glide force testing plays a crucial role in ensuring the smooth and reliable functioning of syringes, especially in medical and pharmaceutical applications. The glide force, which refers to the force required to move the plunger smoothly within the syringe barrel, is a key indicator of syringe performance. This test is especially important for assessing the quality of lubricated syringes and the efficiency of the lubrication system, such as silicone oil inside the barrel or plunger stoppers.

What is Glide Force Testing?

Glide force testing measures the amount of force needed to move the plunger inside an empty syringe barrel. This test evaluates the quality and consistency of the lubrication or lack thereof between the plunger stopper and the syringe barrel. It is vital to ensure that the syringe performs correctly during use, especially in medical procedures where smooth plunger movement is critical for accurate dosing and patient safety.

Glide Force and Break Loose Force

Break Loose Force

This is the initial force required to overcome the friction between the plunger stopper and the syringe barrel, essentially the force needed to start the plunger’s movement.

Glide Force

Once the break loose force is overcome, the glide force is the continuous force needed to maintain smooth plunger movement throughout the syringe barrel. The glide force test region is the section between the break loose region and the sharp increase in force at the end of the stroke.

The Significance of Break Loose and Glide Force

The glide force test plays a pivotal role in ensuring syringe quality. A syringe with too high a glide force may indicate insufficient lubrication, leading to difficulties in plunger movement, which can affect the accuracy of drug delivery. Conversely, a syringe with an abnormally low glide force may signal over-lubrication, potentially leading to contamination or issues during drug administration.

As per ISO 11040, the glide force test also helps manufacturers meet required specifications for medical devices, ensuring that their syringes are safe for use in various clinical applications. This test is especially critical in testing sterile syringes, which are often pre-assembled and ready for filling.

The Procedure for Break Loose and Glide Force Testing

The glide force test follows a defined procedure to ensure accurate and reliable results. Below is a simplified version of the testing process:

Step 1: Insert the plunger stopper into the empty syringe barrel using either a vent tube or vacuum stoppering method.
Step 2: The plunger rod is then attached to the plunger stopper.
Step 3: The syringe is placed in an appropriate adapter plate on a force measurement device (tensile and compression testing machine).
Step 4: A designated test speed, typically around 100 mm/min, is set for the test.
Step 5: The test is conducted, and the force required to move the plunger is measured. The glide force is the region between the break loose force and the point where the force sharply increases at the end of the stroke.
Step 6: Multiple samples are tested to ensure consistency.

Common Mistakes in Glide Force Testing

While glide force testing is straightforward, there are common errors that can affect the accuracy of results:

Incorrect Test Speed: The test speed should match the conditions under which the syringe will be used. A test speed of 100 mm/min is standard, but different speeds may be required based on customer needs or product specifications.
Improper Plunger Stopper Installation: Ensuring that the plunger stopper is securely and correctly installed is crucial for accurate testing. Misalignment can lead to inconsistent results.
Low Sampling Rate: A low sampling rate (below 100 Hz) may fail to detect peak forces accurately. This can result in incorrect glide force measurements.

FAQs About Syringe Glide Force Test

1: What is the difference between break loose force and glide force?
Break loose force is the force required to initiate movement, while glide force is the force needed to maintain consistent plunger movement.

2. What is the purpose of the syringe glide force test?
The syringe glide force test measures the resistance to the plunger’s movement inside the syringe barrel, which helps assess the lubrication quality and overall usability of the syringe.

3. What equipment is needed for the syringe glide force test?
A universal tensile and compression testing machine, such as the MST-01 Syringe Tester, is required to perform the glide force test accurately.

4. How do I interpret the glide force test results?
The test results are interpreted by comparing the measured glide force to predetermined acceptable limits. The maximum and average glide forces should fall within these limits for the syringe to be considered compliant.

Related Products

MST-01 Syringe Plunger Glide Force Tester

Reference

ISO 11040-4