USP 788 / USP 789 Particulate Matter Analysis
Particulate matter is a critical quality and safety indicator in injectable and ophthalmic preparations. Yet traditional compliance methods rely on manual microscopic counting, subjective analyst decisions, and semi-automated tools that introduce inter-operator variability and slow down QC workflows. Clemex's USP 788/789 module eliminates these bottlenecks with automated image analysis that detects, segments, and counts individual particles on membrane filters automatically — regardless of particle morphology, background complexity, or loading density.
Stop counting particles by hand. Clemex automates what used to take hours in minutes, with full pharmacopeial traceability.
Download USP Analysis Report Examples
Analytical Workflow
From Sample Preparation to Compliant Report
Clemex integrates into your existing USP 788/789 microscopic method workflow, automating the counting and sizing steps that traditionally require a trained analyst at the eyepiece.
Acquire / Load Images
Acquire images directly from the microscope or load existing images of filter samples. Clemex supports live capture and batch image import from membrane filtrates.
Particle Detection
Clemex detects and segments every particle visible on the membrane filter, identifying all objects within the pharmacopeially relevant size range.
Particle Analysis
Each detected particle is measured and classified by size and count per size threshold (≥ 10 µm, ≥ 25 µm). Results are normalized per mL or per container.
Generation of Analysis Report
Clemex generates a fully traceable report comparing particle counts against USP 788 or 789 limits, with pass/fail declaration, distribution chart, and audit trail.
Measurement Output
USP <788> — Particulate Matter in Injections
Clemex reports the exact parameters required by USP <788>. Select your product category at run setup and the correct limits and reporting units are applied automatically.
Particle Count: 10 to 25 µm
Total number of particles in the 10–25 µm size range detected on the membrane. Reported as raw count on sample, estimated count on filter, and normalized per mL.
Particle Count: 25 µm and Over
Total number of particles ≥ 25 µm detected on the membrane. Reported as raw count on sample, estimated count on filter, and normalized per mL.
Particles / mL & Particles / Container
Counts normalized per millilitre (LVP) or per container (SVP), automatically applied based on product type and sample volume entered at run setup.
Blank Count
Background particle count from a blank membrane control, filled manually or linked to an exported reference file and subtracted from sample counts.
Covered Area & Covered Ratio
Total scanned area (mm²) and the ratio of covered area to effective filtration area, confirming full membrane coverage as required by the pharmacopeial procedure.
Pass / Fail Declaration
Automated comparison against USP 788 limits per test type (LVP or SVP). Result declared independently per size category and as an overall run outcome.
Measurement Output
USP <789> — Particulate Matter in Ophthalmic Solutions
USP <789> adds a third size category and expresses all limits per millilitre. Clemex applies the correct channels and units automatically based on the sample volume entered at run setup.
Particle Count: 10 to 25 µm
Total number of particles in the 10–25 µm range detected on the membrane. Reported as raw count on sample, estimated count on filter, and normalized per mL.
Particle Count: 25 to 50 µm
Total number of particles in the 25–50 µm range. Reported as raw count on sample, estimated count on filter, and normalized per mL.
Particle Count: 50 µm and Over
Total number of particles ≥ 50 µm — an additional size category specific to USP 789 and not required by USP 788. Reported per mL.
Particles / mL
All USP 789 limits are expressed per millilitre across all three size categories, applied automatically based on sample volume entered at run setup.
Blank Count
Background particle count from a blank membrane control, filled manually or linked to an exported reference file and subtracted from sample counts.
Pass / Fail Declaration
Automated comparison against USP 789 limits per mL across all three size ranges. Result declared independently per category and as an overall run outcome.
Module Capabilities
Built for Pharmaceutical Compliance
Every feature of the USP 788/789 module is designed around the requirements of regulated parenteral and ophthalmic analysis environments.
21 CFR Part 11 / Annex 11 Compliance
Full electronic records and audit trail. Every analysis captures operator ID, timestamp, instrument ID, software version, and analysis parameters in a tamper-evident log, ready for FDA or EMA inspection.
Fully Automated Membrane Scanning
Motorized stage integration scans the entire effective filtration area in a defined raster pattern. No manual field selection, no missed areas. Scan completion is verified and logged per run.
Dual-Threshold Counting
Counts are generated simultaneously at both USP threshold sizes (≥ 10 µm and ≥ 25 µm ECD). Limit comparison and pass/fail designation are applied automatically against the configured product category.
Traceable Compliance Report
Every report includes sample ID, product category, volume, analysis date, analyst, particle counts per size class, limit comparison table, pass/fail result, and representative images of detected particles — in a single locked PDF with electronic signature support.
Background / Blank Subtraction
Blank membrane controls are analyzed prior to sample runs. Background counts are tracked and can be subtracted per procedure, ensuring environmental or reagent-borne particles do not contribute to product counts.
Dedicated to QC Laboratories & Production
The USP 788/789 module is purpose-built for quality control laboratories and production environments in the pharmaceutical and ophthalmic industries, designed to integrate seamlessly into existing GMP workflows without disrupting standard operating procedures.
Method Validation
Supporting Your IQ / OQ / PQ Documentation
Implementing Clemex for USP 788/789 includes a structured validation package designed to satisfy regulatory expectations at GMP-regulated pharmaceutical sites.
IQ Documentation
Installation Qualification templates covering hardware, software version, microscope calibration, and stage verification against NIST-traceable calibration slides.
OQ / PQ Support
Operational and Performance Qualification protocols with acceptance criteria. Reference particle suspensions (polystyrene latex standards at 10 µm and 25 µm) and expected count ranges provided.
System Suitability Tests
Daily / per-run system suitability checks using certified particle standards ensure validated performance is confirmed before each analytical sequence.
Change Control Support
Software updates are versioned and documented. Impact assessments and re-qualification protocols are provided for any software change that could affect analytical results.
Frequently Asked Questions
What is the difference between USP <788> and USP <789>, and how does Clemex handle both?
USP <788> covers particulate matter in injections (parenteral preparations), while USP <789> covers particulate matter in ophthalmic solutions. Both chapters include a microscopic particle count method using membrane filtration, but with different volume categories and acceptance limits. Clemex handles both through a single module with configurable product category selection. The operator selects the applicable chapter and product type at run setup, and the system applies the correct limits automatically for pass/fail determination.
One platform, both pharmacopeial chapters.
Does the Clemex method replace or complement light obscuration instruments?
Both chapters allow either light obscuration (LO) or the microscopic particle count (MPC) method, with MPC serving as the referee when results are in dispute or when LO is unsuitable. Clemex automates the MPC method. Many labs use LO for routine batch testing and deploy Clemex for referee analysis, validation studies, and samples where LO produces unreliable results — such as viscous biologics, opaque suspensions, or products prone to protein aggregation that causes false LO counts.
MPC is the pharmacopeial referee method. Clemex automates it.
Can Clemex be validated for 21 CFR Part 11 and Annex 11 compliance?
Yes. The Clemex platform incorporates the features required for electronic records under 21 CFR Part 11 and EU GMP Annex 11: secure user authentication with role-based access, electronic audit trails capturing all actions and parameter changes, locked and version-controlled analysis methods, and electronic signature support for report approval. Validation documentation packages (IQ/OQ/PQ templates, User Requirements Specification, risk assessments) are provided to support your site qualification.
Designed for regulated pharmaceutical environments.
How is the microscope stage scanning area defined for the membrane?
USP 788 and 789 require examination of the entire effective filtration area of the membrane — typically a defined zone based on the filter diameter and the assembly used. Clemex's automated stage scans this area in a systematic raster pattern at the required magnification (100× effective is standard for the 10 µm threshold). The scan boundary, stage coordinates, and completion confirmation are all logged in the analysis record for traceability.
Full effective filtration area, documented and traceable.
How does Clemex distinguish particles from membrane fibers and background artifacts?
This is one of the most critical challenges in the MPC method. Membrane background — including filter fibers, grid markings, and optical artifacts — can be misclassified as particulate contamination in threshold-based image analysis. Clemex's AI model was specifically trained on pharmaceutical membrane images including these real-world interference types. It applies morphological and contextual reasoning to distinguish true extrinsic particles from membrane structure, preventing false-positive counts that would invalidate a run.
AI trained on real membrane interference patterns.
Can the same system be used for both USP 788 and ASTM / ISO standards?
Yes. Clemex's image analysis engine is the same platform used across multiple particle measurement standards. The USP 788/789 module is a pre-configured application profile on the Clemex platform. Labs can also run ISO 4406 (hydraulic fluid cleanliness) or custom methods on the same hardware, with method separation enforced through role-based access and separate method files to prevent cross-contamination of configurations.
Multi-standard platform: USP, ISO, ASTM on shared infrastructure.
How long does a typical USP 788 membrane analysis take compared to manual counting?
Manual counting of a single membrane by a trained analyst typically takes 30–90 minutes depending on particle load, with the analyst fatiguing over time and introducing variability in later fields. Clemex completes the full motorized membrane scan and automated count in approximately 8–15 minutes per membrane depending on scan area and magnification. Since the result is generated without analyst time at the eyepiece, the analyst is free for other tasks while the system runs. For high-throughput QC labs testing multiple units per batch, the time savings compound significantly.
8–15 minutes vs. 30–90 minutes manual, with no analyst fatigue.
Ready to Automate Your USP 788 / 789 Testing?
Talk to a Clemex pharmaceutical specialist and see the module running on representative sample images. Validation support included.
