Pharmaceutical Particle Characterization and Unknown Particle Analysis

Particle Recovery by Filtration | Microscopic Examination | SEM-EDS Analysis

Our service follows a structured approach: particle recovery through filtration, microscopic examination and characterization using scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS). Where suitable reference data are available, analytical findings are compared with known manufacturing materials to help identify potential contamination sources.

We work with samples supplied in vials, bags, ampoules, prefilled syringes (PFS) and other pharmaceutical containers, with sample suitability and recovery requirements assessed before analysis.

Understanding Unknown Particles in Pharmaceutical Products

A structured analytical investigation helps address key questions:

• What are the particle’s physical characteristics?
• Which elements are detected in the analysed region?
• Is the particle consistent with any suspected manufacturing material?
• Which potential sources require further investigation?
• Is additional testing needed to distinguish similar materials?

Our particle characterization service provides analytical evidence to support these assessments and help pharmaceutical quality, laboratory, production and engineering teams plan their next investigation steps.

Our Particle Characterization Process

1. Sample Review and Investigation Planning

We begin by reviewing the submitted sample information and the background of the investigation. This helps establish an appropriate recovery approach and analytical scope.

Relevant information may include:

• Product type and container format.
• Sample quantity and available volume.
• Where and when the particle was detected.
• Available photographs and initial observations.
• Suspected source materials or components.
• Existing material reference library data.

The recovery and analysis approach is selected according to the product matrix, particle characteristics and investigation objective.

2. Particle Recovery Through Filtration

The submitted product is processed using a suitable filtration method to retain particles or fibers for examination. The filtration membrane and handling approach are selected with consideration of the sample and subsequent analytical requirements.

Our recovery process addresses:

• Suitability of the filtration method for the product.
• Compatibility of the membrane with the sample and intended analysis.
• Retention and location of particles for microscopic examination.
• Minimisation of additional contamination during handling.
• Documentation linking recovered material to the submitted sample.

Where the product cannot be filtered directly, any necessary sample preparation is assessed before proceeding. Recovery feasibility depends on the product matrix and the nature and quantity of particulate matter present.

3. Microscopic Examination of Recovered Particles

Microscopic examination provides an initial assessment of visible characteristics, including:

• Colour and general appearance.
• Particle or fiber shape.
• Dimensions, where suitable measurement is possible.
• Surface features and structural appearance.
• Differences between recovered particles.

This stage helps locate the material of interest and select suitable particles for further characterization. Images and observations also provide a visual record for the investigation.

4. SEM-EDS Particle Characterization

SEM: Detailed Examination of Particle Morphology

SEM provides detailed images of the recovered particle, allowing assessment of its shape, surface texture and structural features. These observations support comparison with suspected source materials.

EDS: Elemental Characterization

EDS identifies detectable elements within the analysed region of the particle. The resulting elemental profile provides additional evidence for assessing the material’s nature and comparing it with reference samples.

SEM images and EDS findings are interpreted together, with consideration of sample preparation and possible contributions from the mounting substrate or coating.

5. Comparison with Known Materials and Reference Libraries

Potential reference materials may include:

• Equipment components and stainless-steel parts.
• Gaskets, seals and rubber stoppers.
• Tubing and filters.
• Glass containers and components.
• Gloves and packaging materials.
• Other relevant product-contact and non-contact parts.

This comparison helps narrow down possible sources and identify components that warrant further assessment. If suitable reference information is unavailable, client-supplied suspected materials may be considered for comparative analysis.

6. Analytical Reporting and Investigation Support

The report may include:

• Sample identification and container details.
• Particle recovery and filtration information.
• Microscopic images and observations.
• SEM images of selected particles.
• EDS spectra and elemental results.
• Comparative observations against reference materials.
• Interpretation, analytical limitations and suggested areas for further investigation.

The objective is to provide a clear connection between the submitted sample, recovered particle, analytical findings and potential source materials.

Sample and Container Types

• Vials: Samples containing visible or suspected particulate matter.
• Ampoules: Samples requiring particle recovery before examination.
• Pharmaceutical bags: Including samples where the product volume influences the recovery approach.
• Prefilled syringes (PFS): Samples requiring consideration of the product and container components.
• Other pharmaceutical containers: Assessed according to sample suitability and investigation requirements.

The analysis scope is agreed after reviewing the product matrix, available sample quantity and suspected contamination.

How This Service Supports Your Quality Team

Microscopic observations and SEM-EDS findings provide analytical evidence to supplement visual inspection and manufacturing records.

Focused Assessment of Potential Sources

Comparisons with relevant reference materials help your team prioritise suspected components and determine where further investigation is needed.

Connection Between Products and Manufacturing Materials

Recovered particles can be assessed alongside known product-contact and non-contact materials to investigate possible relationships.

Documented Findings for Technical Review

A structured report enables quality, laboratory, production and engineering personnel to review the analytical findings together.

Support for Corrective and Preventive Action Decisions

Particle characterization can inform root-cause assessment and CAPA planning when considered alongside process evidence and the wider investigation.

The Role of a Pharmaceutical Particle Reference Library

Once prepared, it provides a resource for comparing particles recovered during future investigations. For SEM-EDS analysis, the relevant reference information includes particle morphology and elemental composition.

A library does not automatically identify every unknown particle. Its usefulness depends on the materials included, the quality of the reference data and the suitability of the analytical techniques for the material being investigated.

Confianca Pharmazon also provides library preparation for product-contact and non-contact parts, helping pharmaceutical teams establish reference information before an unknown particle investigation arises.

Interpreting Results Correctly

A probable material match is not, by itself, confirmation of the exact contamination source.

Analytical findings should therefore be evaluated alongside:

• Equipment and component condition.
• Maintenance and replacement history.
• Product handling and manufacturing records.
• Packaging and environmental observations.
• Additional analytical results, where necessary.

This combined assessment supports a more defensible conclusion about the source of contamination.

Why Work with Confianca Pharmazon?

Information to Share When Requesting a Quotation

• Product description and container type.
• Number of samples and approximate volume.
• Photographs of the suspected particle, if available.
• Brief details of the observation or investigation.
• Any suspected source materials.
• Availability of a material reference library.
• Required reporting scope and preferred timeline.
• Relevant sample-handling or hazard information.

Please discuss sample submission requirements with our team before dispatch.