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Sub-visible Particle Count

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BACKGROUND:

Injections, infusions and implantable medical devices may be contaminated with mobile and undissolved extraneous particles that may pose a danger to patients receiving the treatments.  To minimize the risk of harm to the patient, pharmacopoeias include methods for the determination of sub-visible particle counts and set limits.  At  Eurofins | ams, particle counting is carried out using techniques that are compliant with the USP and BP/EP pharmacopoeias for parenteral / injectable solutions, ophthalmic solutions, medical devices and water, these include:

  1. Sub-visible particle counting using a light obscuration particle counter
  2. Sub-visible particle counting investigation using a light microscope 

PRINCIPLE:

Sub-visible particle counting using a light obscuration particle counter 

This method is generally the method of choice and is carried out with the aid of a HIAC/ROYCO particle counter. It works on the principle of light blockage, which then automatically determines the size and number of particles present in a sample.  

Sub-visible particle counting investigation using a light microscope 

The sample undergoing test is filtered and the membrane filter is manually examined under binocular microscope for any particles. 

METHOD REFERENCE:

  1. Particle Contamination. Appendix XIII A. Sub-visible Particles. BP Current
  2. 2.9.19 Particulate Contamination. Sub-visible Particles. EP Current
  3. Particulate Matter in Injections. <788> USP Current.

SAMPLE REQUIREMENTS

  1. Container size >25 ml:  2-10 Containers
  2. Container size <25 ml:  10 or more containers required to obtain a pooled volume of not less than 40ml.
  3. Medical devices for infusion: 1-10 devices, as long as the total extracted volume is ≥ 40ml.
Test Protocols
Method Code Test Description Turnaround Time (TAT)
TMS - 001 - 02 Determination of Sub-visible Particle Counts by Light Obscuration 5 days
TMS – 002 - 00 Determination of Sub-visible Particle Counts by Microscopy 5 days