Particle-size data must represent the material—not just the instrument

Particle-size distribution testing can change significantly with dispersion conditions, agglomeration, refractive-index assumptions, obscuration, sample preparation, and the analytical model used to interpret the material. Reporting a single D50 value can conceal multimodal distributions or particle behavior that affects dissolution, blending, filtration, flow, and product performance. Triclinic Labs develops laboratory particle-size testing and powder-characterization methods using laser diffraction, microscopy, image analysis, morphology, surface-area measurements, and complementary solid-state techniques. Reporting includes the method conditions, distribution behavior, limitations, and interpretation needed for the manufacturing, development, or regulatory decision.

Overview of Particle-Size Distribution Testing and Method Development Services

Scientific principle and analytical basis

Particle-size analysis measures the distribution of particle dimensions. Laser diffraction reports volume-equivalent spherical diameter distributions; microscopy and image analysis add shape, agglomeration, habit, and particle-identity context.

When is it used?

Use it when particle size affects dissolution, inhalation or suspension performance, blend uniformity, filtration, drying, flow, compaction, coating, lot comparability, or cGMP release specifications.

What are limitations?

Laser diffraction assumes optical and shape models and can be sensitive to dispersion, refractive index, agglomerates, bubbles, obscuration, and sample preparation. It does not identify polymorph or chemistry by itself.

What sample amounts are needed?

Amount depends on dry/wet dispersion, concentration, replicate number, and method validation. Instrument ranges do not determine fixed sample amounts; sample needs should be scoped for each product and method.

What techniques compete with it?

Optical microscopy, static image analysis, SEM, BET specific surface area, powder flow, XRPD, Raman, and dissolution testing can compete or complement particle-size analysis depending on whether size, shape, chemistry, form, or performance is the decision driver.

What does FDA care about?

FDA cares whether the particle-size method controls a clinically or manufacturably relevant attribute, whether dispersion conditions are justified, and whether validation covers specificity, precision, robustness, and the intended sample matrix.

What are common mistakes?

Common mistakes include reporting only D50, missing multimodality, breaking or creating agglomerates during prep, choosing the wrong refractive index, ignoring morphology, and assuming particle size explains dissolution without checking form and residual solids.

What is Triclinic's experience with this technique

Triclinic uses particle-size and powder-characterization methods to support real-world decisions about milling, micronization, agglomeration, blending, dissolution, stability, and release specifications. The work is applied when particle size or distribution shape may affect manufacturability, bioavailability, content uniformity, filtration, handling, or lot comparability, and when the method must be appropriate for the material rather than simply reporting a number.

Specific instruments and capabilities for Particle-Size Distribution Testing and Method Development

The table below lists the specific platforms, brands, models, software, detectors, and capability notes relevant to this service area.

Instrument or platformBrand, model, software, or detectorAdditional capabilities and use
Laser diffraction PSDMalvern Mastersizer 3000 v.3.70 with Malvern Access Configurator v.2.20Particle-size distribution by volume-equivalent sphere diameter; dry range 0.1-3500 um and wet range 0.01-1400 um.
cGMP PSD methodsMalvern Mastersizer 3000 platform with method-development, verification, transfer, validation, and release-testing workflowsValidated particle-size methods, batch release results, and cGMP/non-GMP comparability studies.
Morphologically directed Raman supportRenishaw inVia / Thermo FT-Raman / Ondax low-frequency Raman platforms; 785 nm, 1064 nm, and THz-Raman optionsParticle-level chemistry and morphology correlation, MDRS-style component identification, and composition of selected particle populations.
Powder flowHall FlowMeter AS-300Flow-rate and apparent-density measurements for powders where PSD affects processability.
Optical and digital morphologyLeica M80, Leica DM2500P, Keyence VHX-2000E, and Pax-it2! v.1.4.3 softwareParticle-shape, agglomeration, habit, and topography observations to complement laser diffraction.
SEM/EDX morphologyThermo Phenom XL SEM/EDX and FEI Quanta 3D FEGHigh-resolution particle morphology and elemental confirmation for particles, contaminants, and agglomerates.

Laser Diffraction Particle-Size Distribution Example

This example shows how particle-size distribution data should be interpreted as a distribution, not a single number. In laser diffraction, a dispersed sample scatters light at angles related to particle size. The resulting distribution can support wet or dry method development, cGMP release testing, method verification, method transfer, and troubleshooting when particle size affects performance or processability.

Laser diffraction particle size distribution curve
Laser diffraction particle-size distribution example. The figure reports a volume-density distribution. D10, D50, D90, and D[4,3] may summarize the curve, but they do not replace inspection of the full distribution. Multimodality, fines, aggregates, dispersion conditions, and method settings can change how a powder filters, flows, dissolves, blends, or passes a specification. Source: Triclinic Labs particle-size characterization material.

Technical Resources and Publications

These examples include technical resources, regulatory guidances, or literature relevant to the technique. Download buttons are placed at the bottom-left of each example.

A Comprehensive Approach for Solid Form Selection in Preclinical Development and Beyond

Author: Melanie Bevill, Chris Seadeek, Nico Setiawan, Shawn Comella, Blaise Mibeck, and Steef Boerrigter

Publication date: November 2023

Abstract: Solid-form screening and selection connect crystallinity, stability, solubility, hygroscopicity, manufacturability, regulatory needs, and IP objectives. Analytical techniques should therefore be selected according to the development decision rather than a fixed instrument list.

Download this Application Note

ICH Q2(R2) Validation of Analytical Procedures and ICH Q14 Analytical Procedure Development

Author: International Council for Harmonisation / FDA

Publication date: 2024

Abstract: FDA notes that ICH Q2(R2) and Q14 describe validation and development principles for analytical procedures used to assess drug substance and drug product quality. These guidances frame FDA expectations for specificity, accuracy, precision, range, robustness, lifecycle management, and fit-for-purpose method evidence.

Download

Application of Low-Frequency Raman Spectroscopy to an Isoenergetic Polymorph Study

Author: Triclinic Labs

Publication date: 2019

Abstract: This white paper describes how low-frequency Raman can distinguish polymorphic forms using lattice-mode information not always available in conventional mid-frequency Raman. It supports using Raman as an orthogonal solid-form tool when XRPD, DSC, or FTIR are inconclusive.

Download this Whitepaper

Method Development for Laser-Diffraction Particle-Size Analysis

Author: Anne Virden, Pharmaceutical Technology

Overview: Sampling, wet and dry dispersion, optical models, concentration, measurement duration, repeatability, and reproducibility.

Talk with Triclinic Labs

Discuss the right analytical technique

Tell Triclinic what sample you have, what decision the data must support, what prior data are available, and whether cGMP, release, validation, or regulatory documentation is required.

Discuss a technique plan