WHO Prequalification of Quality Control Laboratories (PQCL) is among the most rigorous and globally respected designations a pharmaceutical testing laboratory can achieve. For laboratories that attain it, WHO prequalification opens access to international procurement markets, validates quality management systems at the highest level, and signals to pharmaceutical manufacturers worldwide that their products can be tested to international standards.
For pharmaceutical companies seeking WHO-prequalified testing partners, and for laboratories considering the path to prequalification, this guide explains what WHO-PQCL means, what it requires, and why it matters.
What Is WHO Prequalification of Quality Control Laboratories?
The WHO Prequalification Programme was established to ensure that medicines, diagnostics, and vaccines procured by international health programmes — UNICEF, UNFPA, Global Fund, PEPFAR — meet international standards of quality, safety, and efficacy.
The Quality Control Laboratories component (WHO-PQCL) focuses specifically on the testing laboratories that provide quality assurance for pharmaceutical products submitted to or supplied under WHO prequalification. A WHO-prequalified laboratory has been assessed by WHO inspectors and found to operate in compliance with:
- ISO/IEC 17025 (general laboratory competence)
- WHO Good Laboratory Practices (GLP)
- WHO good practices for pharmaceutical quality control laboratories (TRS 957 Annex 1)
- Specific capabilities required for the products and tests within the prequalification scope
WHO-PQCL is separate from:
- WHO prequalification of finished pharmaceutical products (FPP): Assessment of the drug product itself
- WHO prequalification of APIs: Assessment of active pharmaceutical ingredients
- WHO prequalification of IVDs: In vitro diagnostics
A pharmaceutical manufacturer seeking WHO prequalification of their product needs test data from laboratories that are themselves WHO-prequalified (or from the national medicine regulatory authority’s laboratory).
Why WHO Prequalification Matters
Access to International Procurement Markets
International health procurement agencies — UNICEF, UNFPA, Global Fund for AIDS, Tuberculosis and Malaria, and bilateral aid programs — procure pharmaceuticals exclusively from WHO-prequalified manufacturers. The test data supporting those products must typically come from WHO-prequalified laboratories.
For Indian pharmaceutical manufacturers exporting to developing countries through international health programs, WHO-prequalified testing is not optional — it is a prerequisite for market participation.
Enhanced Regulatory Acceptance
WHO prequalification is recognized by national medicines regulatory authorities (NMRAs) in more than 100 countries. Test data from WHO-prequalified laboratories carries automatic credibility in NRA reviews, simplifying regulatory submissions in markets that lack sophisticated internal laboratory capacity.
Benchmark Quality Standard
The WHO-PQCL assessment process is more demanding than NABL accreditation alone. It evaluates not just technical competence (ISO/IEC 17025) but also the laboratory’s quality management system against WHO-specific GMP requirements, capability to handle specific drug classes and dosage forms, and demonstrated performance through proficiency testing and reference standard management.
Achieving and maintaining WHO prequalification is therefore a rigorous proof of quality that goes beyond most national accreditation systems.
Competitive Differentiation
For contract testing laboratories, WHO prequalification distinguishes them in an increasingly competitive market. Pharmaceutical companies conducting WHO prequalification dossier submissions increasingly specify WHO-PQCL labs for their testing requirements.
Requirements for WHO Prequalification
ISO/IEC 17025:2017 Compliance
The laboratory must hold valid NABL accreditation (in India) or equivalent national accreditation under ISO/IEC 17025:2017. This is the baseline technical competence requirement — necessary but not sufficient for WHO prequalification.
WHO GLP and Good Practices for Pharmaceutical QC Laboratories
WHO Technical Report Series No. 957 Annex 1 (2010) — “WHO good practices for pharmaceutical quality control laboratories” — sets requirements beyond ISO/IEC 17025 specifically for pharmaceutical testing:
- Requirements for reference standards (primary, secondary, working) and their management
- Specific handling of pharmacopoeial methods vs. validated in-house methods
- Requirements for out-of-specification (OOS) investigations and invalid result handling
- Chain of custody documentation for pharmaceutical samples
- Requirements for stability storage conditions and equipment qualification
Scope of Methods and Equipment
The laboratory must have validated methods (or demonstrate capability for pharmacopoeial methods) for the specific tests within its prequalification scope. Typical pharmaceutical QC capabilities required include:
Chemical testing:
- HPLC/UPLC for assay and related substances (genotoxic impurities, degradation products)
- GC for residual solvents
- ICP-MS or ICP-OES for elemental impurities (ICH Q3D)
- Karl Fischer titration for water content
- UV/Vis spectrophotometry
Microbiological testing:
- Sterility testing (for injectables and sterile products)
- Bioburden determination
- Endotoxin testing (LAL method)
- Antimicrobial preservative efficacy
Physical testing:
- Dissolution testing (paddle, basket, flow-through cell methods)
- Disintegration testing
- Hardness, friability, weight variation (for tablets)
- Particulate matter (for injectables)
Quality Management System
The laboratory’s QMS must include:
- Calibrated, qualified equipment with documented maintenance
- Validated methods with associated validation data
- Proficiency testing participation with satisfactory results
- Internal audits and management review
- Personnel training records
- Document control and data integrity systems
- Change control for any changes affecting test results
- Complaint handling
Data integrity is particularly scrutinized by WHO inspectors following high-profile cases of data fraud. Systems must ensure data cannot be altered without documentation, raw data is retained, and electronic records are controlled.
Proficiency Testing
Active participation in WHO-specified proficiency testing programs is required. Results from these inter-laboratory comparisons must demonstrate satisfactory performance (z-scores within defined limits).
The WHO-PQCL Assessment Process
Step 1: Pre-Assessment Questionnaire The laboratory submits a detailed questionnaire to WHO describing its organizational structure, accreditation status, scope of capabilities, quality management system, and experience with the products in scope.
Step 2: Document Review WHO reviewers assess the quality manual, SOPs, method validation reports, equipment lists, and proficiency testing records. Deficiencies are communicated for correction before the on-site visit.
Step 3: On-Site Assessment A WHO assessment team (typically 2-3 assessors with pharmaceutical QC expertise) conducts a 3-5 day on-site inspection. The assessment covers:
- Tour of all laboratory areas
- Verification of equipment against the equipment list
- Review of calibration and maintenance records
- Review of method validation data
- Observation of testing activities (witness testing)
- Review of QMS documentation
- Data integrity assessment
- Reference standard management review
- Personnel interviews on competence and training
Step 4: Assessment Report and Follow-Up The assessment team produces a detailed report listing findings. Major and critical deficiencies must be corrected before prequalification can be granted. Minor deficiencies must be addressed within agreed timelines.
Step 5: Prequalification Grant WHO grants prequalification with a defined scope (products/tests) and validity period (typically 3 years). The laboratory appears in the WHO-published list of prequalified laboratories.
Step 6: Surveillance WHO conducts unannounced or announced follow-up assessments during the prequalification period. Unsatisfactory proficiency testing results or loss of national accreditation triggers additional assessment or suspension.
Auriga Research’s WHO Prequalification
Auriga Research has achieved and maintains WHO prequalification for pharmaceutical quality control testing. This positions us to support pharmaceutical manufacturers submitting products for WHO prequalification of finished pharmaceutical products — providing test data that WHO accepts as part of the prequalification dossier.
Our WHO-prequalified capabilities are part of our broader pharmaceutical testing portfolio, which includes chemical, microbiological, and physical testing across a wide range of pharmaceutical dosage forms and APIs.
Our accreditations are detailed on our about us page and in our facilities overview. For pharmaceutical manufacturers seeking WHO-prequalified testing support, our team can advise on testing requirements specific to the WHO prequalification process for your product category.
Contact us to discuss WHO-prequalified testing support for your pharmaceutical products, or request a quote to begin the testing engagement.
Conclusion
WHO Prequalification of Quality Control Laboratories represents the highest internationally recognized standard for pharmaceutical quality control testing. It demands compliance with ISO/IEC 17025, WHO Good Practices for pharmaceutical QC labs, validated methods, rigorous quality management, and demonstrated proficiency testing performance.
For pharmaceutical companies supplying international health programs and regulated export markets, choosing a WHO-prequalified laboratory is both a regulatory requirement and a quality assurance decision. For testing laboratories, achieving WHO prequalification is a significant but rewarding investment in quality systems that benefits clients and advances global health outcomes.
Auriga Research Team
Auriga Research is India's largest NABL-accredited testing network with laboratories in Delhi, Manesar, Bangalore, Baddi, and Bahadurgarh. Our team of scientists delivers accurate, regulatory-accepted results across pharmaceutical, food, water, environmental, and specialised testing.
About Auriga Research →