Calibration: 5 Practical Tips for Success
Article By Darren Jones, Director & Senior Consultant for EPiC
Calibration is a critical part of GXP compliance.
Accurate instruments ensure reliable data, product quality, and patient safety.
Poor calibration practices can lead to data integrity issues, costly deviations, and regulatory findings.
Why Calibration Needs More Attention
Calibration is often an overlooked element of the Pharmaceutical Quality System (PQS). Many calibration certificates are incomplete, incorrect, or lack sufficient detail and, in many cases, they are not fully understood by site experts. This gap can lead to compliance risks and undermine confidence in critical data.
The Risks of Outsourcing Without Oversight
Calibration services are frequently outsourced, but key GMP decisions are sometimes inappropriately delegated as well. Who sets the calibration limits? Who determines how and when out-of-specification results are reported? These responsibilities should remain firmly under the control of the pharmaceutical company, not the service provider.
Pass or Fail? The Missing Information
Surprisingly, many calibration certificates do not state a clear Pass or Fail outcome. Instead, they simply list limits and raw data. In some cases, calibration results do not comply with the stated limits because calculations were never performed and no one within the company verified the data. This lack of oversight can have serious implications for product quality and regulatory compliance.
Understanding Limits and Calculations
Limits are often specified as ±2% of Full-Scale Deflection (FSD), but what does this mean in practice? Frequently, the method for calculating these limits is unclear, and the calculations themselves are neither recorded nor checked. Without proper documentation and verification, compliance cannot be assured.
Why It Matters
Accurate instrumentation is essential for achieving process control, which ultimately safeguards product quality. For this reason, calibration requirements must be clearly understood, properly documented, and effectively managed.
To help you strengthen your calibration program, here are five practical tips for success:
1. Use Multi-Point Calibration Across the Working Range
Single-point calibration can hide inaccuracies. Always perform multi-point calibration over the full working range of the instrument to confirm accuracy at all relevant operating points.
2. Set and Approve Calibration Limits Internally
Don’t leave limit-setting to your contractor. Define or approve the limits applied during calibration to ensure they meet your process requirements and regulatory expectations based on the equipment’s intended use.
3. Formalise Contracts with Clear Details
Your calibration provider contract should include:
- Instruments covered
- Calibration frequency
- Limits and ranges
- Reporting of out-of-specification results
Appendices with detailed tables can help manage this information effectively.
For more tips on managing calibration providers refer to EPiC Top Tips – Outsourced Activities – EPiC
4. Report Results “As Found” and “As Left”
Always document pre- and post-adjustment readings. This ensures you are alerted to any failed “as found” results, which could indicate potential impact on previously tested or manufactured products and would require further investigation.
5. Understand and Document Limit Calculations
Ensure limits are clearly defined in your SOPs, including how they are calculated (e.g., based on Full Scale Deflection). These calculations should be documented, checked, and evaluated against Pass/Fail criteria.
Summary & Key Takeaway
Calibration is more than a routine task, it’s a critical safeguard for data integrity and product quality. By applying these five tips, you can build a robust calibration program that meets regulatory expectations and reduces compliance risk.
How EPiC Can Help
Need support with calibration programs, audits, or training? EPiC’s team of former MHRA Inspectors and industry experts can help you design and implement a compliant, efficient calibration strategy.
Telephone: +44 (0)1244 980544 or email us at enquiries@epic-auditors.com