Laboratory Services >> Sterile Products Testing >> Sub-visible Particle Count

Sub-visible Particle Count

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BACKGROUND:

Injections or infusions may be contaminated with mobile and undissolved extraneous particles which may then 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.

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.