USP <790> & <1790> Explained: How Knapp Kits Strengthen Visual Inspection Compliance

Introduction: Why Visual Inspection Compliance Is Under the Regulatory Spotlight

Visual inspection is no longer a “routine quality step”—it is a patient safety–critical control point. Global regulators now expect pharmaceutical manufacturers to prove, not assume, that their visual inspection programs are effective, reproducible, and scientifically justified.

With the introduction and enforcement of USP <790> (Visible Particulates in Injections) and USP <1790> (Visual Inspection of Injections), companies are required to demonstrate inspector qualification, probability of detection (POD), and ongoing inspection consistency.

This is exactly where Knapp Kits for Visual Inspection have become indispensable.

In this guide, we will break down:

• What USP <790> & <1790> really demand
• Why regulators expect Knapp Kits
• How Knapp Kits strengthen visual inspection compliance
• How to build an audit-ready inspection program

Understanding USP <790>: Visible Particulates Explained

USP <790> focuses on one core principle:

Injectable products must be essentially free from visible particulate matter.

Key Expectations of USP <790>

• Mandatory 100% visual inspection of injectable products
• Defined inspection conditions (lighting, background, duration)
• Trained and qualified visual inspectors
• Clear differentiation between critical, major, and cosmetic defects

What Auditors Look For

• Evidence that inspectors can reliably detect visible particulates
• Qualification records
• Defect libraries used during training

👉 This is where Knapp Kits for Visual Inspection provide documented, standardized particulate challenges.

Understanding USP <1790>: The Science Behind Visual Inspection

USP <1790> goes deeper—it explains how visual inspection should be designed, validated, and monitored.

USP <1790> Introduced a Paradigm Shift

Instead of subjective inspection, regulators now expect:

• Risk-based inspection strategies
• Probability of Detection (POD) evaluation
• Statistical justification of inspection effectiveness
• Lifecycle management of inspection programs

Core USP <1790> Requirements

• Use of qualified defect sets
• Repeatable inspection challenges
• Data-driven inspector qualification

✅ Knapp Kits for Visual Inspection are specifically designed to meet these expectations.

What Are Knapp Kits for Visual Inspection?

Knapp Kits are certified visual inspection kits containing known, standardized particulate defects used to:

• Train visual inspectors
• Qualify manual inspection processes
• Validate automatic inspection machines
• Conduct POD studies

Typical Knapp Kit Components

• Glass particles (various micron sizes)
• Metal particles
• Black & white particles
• Fibers (black, white, hair)
• Liquid and lyophilized formats
• Vials, ampoules, cartridges, PFS

Each defect is:

• Sourced from real primary packaging materials
• Measured using high-resolution microscopy
• Supplied with certification and traceability

Why Knapp Kits Are Critical for USP <790> Compliance

USP <790> demands proof that inspectors can detect visible particulates consistently.

How Knapp Kits Support USP <790>

• Provide realistic particulate challenges
• Establish inspector detection capability
• Standardize training across shifts and sites
• Reduce subjectivity in inspection outcomes

Without Knapp Kits, inspection programs rely on assumptions—something auditors no longer accept.

Why Knapp Kits Are Essential for USP <1790> Compliance

USP <1790> expects scientific validation of inspection performance.

Knapp Kits Enable:

• POD studies with repeatable results
• Inspector requalification programs
• Defect trend analysis
• Risk-based inspection optimization

This transforms visual inspection from an art into a measurable quality system.

Probability of Detection (POD): Where Knapp Kits Shine

POD studies measure:

How often an inspector detects a known defect under defined conditions.

Why POD Matters

• Required for inspector qualification
• Demonstrates inspection effectiveness
• Identifies training gaps
• Supports regulatory defense during audits

How Knapp Kits Enable POD

• Each defect container is inspected multiple times
• Results are documented and analyzed
• Data supports inspector pass/fail criteria

Knapp Kits for Visual Inspection are the backbone of credible POD studies.

Manual vs Automatic Visual Inspection: Role of Knapp Kits

Manual Visual Inspection

• Inspector qualification
• Training programs
• Requalification intervals
• Shift-to-shift consistency

Automatic Visual Inspection

• Machine sensitivity testing
• False reject evaluation
• Defect detection thresholds
• System revalidation

Knapp Kits are used in both scenarios, making them universally relevant.

Audit Readiness: What Regulators Expect to See

During USFDA, EU GMP, or WHO audits, inspectors commonly ask:

• How are visual inspectors qualified?
• What defect sets are used?
• How is POD established?
• How often is requalification done?
• Are defect kits certified and traceable?

Using Knapp Kits for Visual Inspection allows you to answer all of these with confidence.

Common Audit Observations Without Knapp Kits

• “Visual inspection training not scientifically justified”
• “No evidence of POD studies”
• “Defect library not representative”
• “Inspector qualification inadequate”

All of these are avoidable with a robust Knapp Kit–based program.

Best Practices for Implementing Knapp Kits

1. Establish a Defect Library

Include:

• Multiple particle types
• Varying sizes
• Both critical and cosmetic defects

2. Define Qualification Criteria

• Number of inspections per vial
• Acceptance thresholds
• Requalification frequency

3. Maintain Documentation

• Certificates of particulate matter
• Training records
• POD evaluation sheets

4. Integrate with SOPs

• Visual inspection SOPs
• Deviation handling
• Inspector retraining protocols

Why Leading Pharma Companies Choose Certified Knapp Kits

Top manufacturers prefer suppliers that offer:

• Audit-supportive documentation
• Free replacement of damaged defect containers
• USP-aligned particle sizing
• Technical training support
• Long kit shelf life (2–3 years)

This reduces compliance risk and operational stress.

Internal Linking Suggestions (On-Page SEO)

Link this blog to:

• Knapp Kit product page (primary CTA)
• Visual Inspection Training services
• GMP Audit Readiness consulting
• USP <790> and <1790> training pages

FAQ: Knapp Kits & Visual Inspection Compliance

Q1. Are Knapp Kits mandatory for USP <790>?

They are not named explicitly, but regulators expect equivalent standardized defect kits—Knapp Kits are the industry benchmark.

Q2. How often should inspectors be requalified?

Typically every 6–12 months, or after major deviations.

Q3. Can Knapp Kits be used for automatic machines?

Yes. Specific kits are designed for machine qualification.

Q4. Do Knapp Kits support audit responses?

Yes. Certified kits with POD data significantly strengthen audit defenses.

Conclusion: Knapp Kits Are No Longer Optional

USP <790> and <1790> have permanently changed expectations around visual inspection. Compliance today means data, evidence, and repeatability.

Knapp Kits for Visual Inspection provide:

• Scientific justification
• Auditor confidence
• Inspector consistency
• Patient safety assurance

Strong CTA

👉 Upgrade your visual inspection compliance today
Explore certified Knapp Kits for Visual Inspection designed to meet USP <790> & <1790> requirements and keep your facility audit-ready.

🔗 View Knapp Kit Product Page:
https://confiancapharmazon.com/product/knapp-kit-visual-inspection-kits-particles-particulate-matters/

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