Regulatory demands, unexpected test results, and tight timelines can all put pressure on development teams. Particle characterisation is vital to reducing that risk—ensuring your materials and products meet safety, performance, and compliance expectations from the outset. Eurofins Medical Device Services network of laboratories offers comprehensive particle characterisation services tailored to support every stage of medical device development. Our scientists have decades of experience in analysing powders and particles across a range of applications, from verifying material quality to identifying contaminants. We work with clients of every scale, from startups unsure of regulatory requirements, to large developers facing time pressures and evolving timelines. Whatever your challenge, we provide expert insight, dependable turnaround times, and guidance throughout the testing process.

At Eurofins Medical Device Services network of laboratories, our capabilities cover the full spectrum of particle characterisation needs. We provide detailed analysis of raw materials, in-process samples, and finished powdered products. Our laboratories offer contaminant detection and documentation using advanced digital microscopy, as well as precise assessment of particle size distribution and surface morphology. We conduct elemental analysis and surface structure evaluations, support the qualification of raw material suppliers to inform the impact of process changes on product performance and consistency.

Our laboratories are equipped with advanced instrumentation capable of accurate analysis at every scale, from nanometres to bulk powders greater than 1 mm. We perform particulate matter testing aligned with USP <788> and other applicable standards across a wide range of devices, including implants, infusion systems, packaging materials, and more.

Particulate Matter Testing

Sample Types

The Light Obscuration Test is based on the principle of light obscuration and allows for the automatic determination of the number of particles according to their size. The test is performed in a biological safety cabinet, under conditions that limit foreign particulate matter.

Volume requirements: USP<788> /EP 2.9.19/JP 6.07: A minimum of 25 mL sample solution is required to meet the harmonised requirements. If the fill volume is >25 mL and only one container is >25mL, then only a single container is needed for testing. However, if the fill volume is <25mL, then a minimum of 10 containers are required. Dilution of the samples can be performed as required.

USP <787>: Can be used as an alternative to USP <788> and specifically addresses testing of therapeutic protein injections and related preparations. Smaller test volumes are allowed, and there is no specific volume requirement as compared to USP <788>. Specific sample handling instructions take into account potential issues associated with analysis of these types of materials.

Particle sizes: The compendial requirement is to enumerate particles at ≥10 µm and ≥25 µm, although particles in the range of ≥2 µm – 400 µm can also be enumerated.

USP <789>: Used specifically to address testing of ophthalmic solutions and related preparations. The test volume requirements are identical to USP <788>. Specific sample handling instructions take into account potential issues associated with analysis of these types of materials.

Particle sizes: The compendial requirement is to enumerate particles at ≥10 µm, ≥25 µm, and ≥50 µm.

Instrumentation: Testing utilises our HIAC 9703+ Liquid Particle Counting System.

Microscopic Particle Count Test

Our experts will utilise a Microscopic Particle Count Test when certain test articles cannot be analysed by the Light Obscuration method due to colour, reduced clarity and/or viscosity. This method can also be utilised in the event the product does not meet the USP criteria for the Light Obscuration Method.

Volume requirements: A minimum of 25 mL sample solution is required to meet the harmonised USP/EP/JP requirements. If the fill volume is >25 mL then only one container is needed for testing. However, if the fill volume is <25 mL than a minimum of 10 containers are required. Dilution of samples can be performed as required.

Particle Size: The compendia requirement is to detect particles at ≥10 µm and ≥25 µm. Particles < 10µm cannot be accurately detected using the Microscopic Particle Count Method.

Instrumentation: Testing utilises our Fein Optic IMA/USP 788 Pharmaceutical Microscope.

Particle Size Testing

Dynamic Light Scattering

Particle size distribution of sub-micron particles is measured at a 90-degree scattering angle using Dynamic Light Scattering.

Volume requirements: 0.1 g – 0.5 g per sample determination.

Particle sizes: 0.0003 μm - 5 μm.

Instrumentation: Malvern Zetasizer Nano ZS90.

Multi-Angle Light Scattering (MALS)

A static light scattering technique which can be used in conjunction with Size Exclusion Chromatography (SEC) as an in-line detection technique or it can be used for non-fractionated samples in the batch mode of operation.

Volume requirements: Approximately 100 μg (i.e., 100 μL injection of 1 mg/mL solution for in-line SEC operation) and1,000 μg (Direct 1000 μL infusion of 1mg/mL solution for batch mode operation).

Particle Sizes: 0.01 μm - 0.5μm.

Instrumentation: Wyatt Technologies HELEOS II.

Laser Light Diffraction

Particle size distribution is measured by the dispersion and absorption of light (red and blue) generated by a laser using either the wet or dry dispersion techniques.

Volume requirements: 0.1 g – 0.5 g per sample determination for wet dispersion. 0.5 g – 5 g per sample determination for dry dispersion.

Particle sizes: 0.01 μm – 600 μm for wet dispersion and 0.2 μm – 3,500 μm for dry dispersion.

Instrumentation: Malvern Mastersizer 3000 with Hydro MV wet dispersion unit and the Aero S dry dispersion unit, Malvern Mastersizer 2000, Microtrac S3500, Beckman Coulter LS 13 320.

Zeta Potential (Electrophoretic Light Scattering)

Zeta potential is a measurement of the electrokinetic potential in colloidal dispersions. The Zeta Potential is measured at a 90-degree scattering angle using Electrophoretic Light Scattering.

Volume requirements: 0.1 g – 0.5 g per sample determination.

Particle sizes: 3.8 nm - 100 μm.

Instrumentation: Malvern Zetasizer Nano ZS90.

Analytical Sieving
Sieving is usually the method of choice for classification of the coarser grades of single powders or granules. It is a particularly attractive method in that powders and granules are classified only on the basis of particle size, and in most cases, the analysis can be carried out in the dry state. Mechanical sieving is most suitable where the majority of the particles are larger than about 75 μm. For smaller particles, other means of agitation such as air-jet sieving may be more appropriate.

Volume requirements: 10g - 100g is generally required per test. However, if the information needed to perform sieve testing for a specific material (i.e. sample amount, sieve sizes and sieve time) cannot be provided, then approximately 500 grams will be required in order to perform feasibility/endpoint determination to establish the appropriate parameters prior to testing the material.

Particle sizes: Certified ISO 3310-1, ASTM E-11 sieves in sizes ranging from 25 μm to 2,000 μm. Larger sizes up to 11.20 mm may be purchased upon request.

Instrumentation: Endecotts Octagon 200 Test Sieve Shaker, W.S. Tyler Model RX-29 Ro-Tap Shaker andHosokawa Micron AirJet Sieve (Version II).