Particle Counting by Light Obscuration and Light Scattering

  • LiQuilaz S02 – The LiQuilaz S02 isa volumetric liquid particle counter that measures the entire liquid stream to observe particle present in the sample. Volumetric measurements provide greater accuracy for tighter process control and analysis of particle contamination. The SO2 features size sensitivities of 0.2ymto2ym. It provides high-precision analysis across a range of process chemicals.
  • LE 400-0.5 — is a volumetric liquid particle counter that utilizes technique of Single Particle Optical Sensing (SPOS). It uses a syringe pump to pull accurate and precise aliquots of sample through the particle sensor. Because it is a volumetric instrument, the LE 400 sensor measures the entire liquid stream to size particles from 0.5ym to 400ym.
  • LE1000 — The LE1000 sensor utilizes the similar technology as the LE400-0.5 (See Above) in the2 micron to 1000 micron range for large particulate

Particle Counting by Microscope

  • Optical Microscopy– The optical microscope, often referred to as the “light microscope”, uses visible light and a system of lenses to magnify images of small particles. Working range from 2ym and greater.
  • Clemex Microscope System —Camera based microscope system used to visually capture images of particles for static image analysis. The Clemex system can also be used as an NIST calibrated micrometer. Working range from 2 micron and greater.

Particle Identification

  • FT-IR– Fourier Transform-lnfraRed spectroscopy isa measurement technique whereby spectra are collected to identify particle composition. Spectra are collected based on measurements of the coherence of a radiative source, using time-domain or space-domain measurements of the electromagnetic radiation or other type of radiation. It can be applied toa variety of types of spectroscopy; at MML we use optical spectroscopy and infrared spectroscopy. Working range from 20 micron and greater.
  • Raman Spectroscopy -a spectroscopic technique used to reliably determine the chemical composition, number, shape and size of particles larger than 5 microns.
  • SEM/EDS– Scanning Electron Microscopy-Energy Dispersive Spectroscopy. A technique used for the elemental analysis or chemical characterization of a

Particle Counting by Flow Imaging

  • Flow Imaging– Technique for making particle measurements using digital imaging in a flowing fluid stream. The measurements that can be made include particle size, particle shape(morphology or shape analysis and grayscale or color, as well as distributions (graphs) of statistical population measurements. Working range of2 microns and greater usually applied to measurement of biologics and proteins.

Particle Size Distribution

  • FX-Nano– The FX-Nano sensor isa high concentration, non-volumetric particle size distribution analyzer capable of detecting particles as small as1 50 nanometers. The FX-Nano sensor requires concentrations above 1,000,000fmL, much higher than those allowed by traditional SPOS sensors
  •  Nano Tracking Analysis (NTA) – The NTA instrument utilizes nanoparticle tracking analysis (NTA) to measure the particle size distribution from 50nmto 2um in solution. The system captures the light scattered from individual particles diffusing in the buffer (Brownian motion) to determine particle size distribution (from 50 to 2000 nm) and relative concentration of the sample.
  • Mastersizer 2000– IVlastersizer 2000 uses the technique of laser diffraction and (mie) light scattering to measure a particle size distribution. It does this by measuring the intensity of light scattered as a laser beam passes through a dispersed particulate sample. This data is then analyzed to calculate the size distribution of the particles that created the scattering pattern. Working range of MML system is 80nmto1 mm.
  • DLS—Ina Dynamic Light Scattering (also known as photon correlation spectroscopy) measurement, temporal fluctuations in total scattered light intensity are analyzed to determine particle diPusion which is translated toa size distribution using The Stokes-Einstein equation. DLS can size particles from Snm to several microns.
  • Xigo– Xigo Nanotool uses patented nuclear magnetic resonance (NMR) technology to measure emulsion or foam droplet size and distribution, entirely without dilution. High concentration, highly viscous, opaque and light-sensitive emulsions can be measured directly as well as nano or micro emulsions that cannot be diluted due to their composition dependence.



During formulation and product development information on particulate matter, extractables, fines or aggregate problems or changes from ingredients in the PSD, can be determined with orthogonal methods based on any combination of new, state of the art instruments and methods, without the added expense of method validation or even development in early stages. Count on MML’s experience with orthogonal methods, to provide important useful information from Feasibility test results, from proven test methods.


We confer with you to determine the best combination of tests for the method validation of your sample material. ICH, FDA and Regulatory requirements are always at the foundation of the protocols we develop to pass the review of Regulatory authorities. Experience with instruments, methods and a variety of issues. We have the benefits of testing a wide variety of similar materials that benefit even CRO’s.


Methods developed in one plant on any instrument technology; do not always provide the same results at another facility, often with the same Mfr’s instrumentation. Our 30 years of experience with particle instrumentation and method development, can provide better insight into differences between systems or laboratory locations, resulting in quicker method transfer or verification. We participate and create reference studies and round robin comparisons for verification.


MML has been instrumental in developing the test methods and evaluations to determine the specifications for materials based on particle instrumentation. Statistical term can be tricky to apply to methods where tolerances for ensemble instruments are not exact in some areas. MML follows industry Guidance for reporting results using statistical methods to evaluate results or comparisons, but we base our recommendations on the limits and/or capabilities of the instruments chosen for the analysis, which adda measure of variability. In some cases orthogonal methods also contribute some variability, especially with today’s more complex biotechnology drug products. For very tight specifications, the uncertainty of the measurement may also be needed to establish confidence limits.


USP<729>ISO 8871USP<788>USP<1788>
ISO 1135USP<789>USP<787>EN45502
EP 2.9.20USP<790>USP<1790>USP<1787>
EP 2.9.19