Using data to safeguard safety: Application practices of SPC in the pharmaceutical industry

I. Pharmaceutical Manufacturing: Why Process Stability Matters

In the pharmaceutical industry, the consequences of quality issues extend far beyond economic loss. They directly affect patient safety and expose companies to significant regulatory and compliance risks.

Compared with other manufacturing sectors, pharmaceutical production has several defining characteristics:

• Highly complex processes with numerous variables

• Extremely stringent quality requirements with minimal allowable variability

• Any abnormality may result in batch rejection, production shutdowns, or product recalls

• Strict regulatory oversight under frameworks such as GMP and authorities including the NMPA, FDA, and EMA

As a result, the core challenge of pharmaceutical quality management is not simply whether a product meets specifications, but whether:

The manufacturing process remains consistently controlled, stable, and predictable.

This is precisely where Statistical Process Control (SPC) delivers its fundamental value in the pharmaceutical industry.

II. The Role of SPC in Pharmaceutical Manufacturing

In pharmaceutical manufacturing, SPC is far more than a basic statistical quality tool. It serves as:

• A critical method for maintaining continuous process control

• A key data foundation within GMP systems

• A vital bridge connecting processes, equipment, quality, and regulatory compliance

By continuously monitoring Critical Process Parameters (CPPs) and Critical Quality Attributes (CQAs), SPC enables pharmaceutical companies to:

• Detect abnormal trends at an early stage

• Prevent deviations from escalating into quality incidents

• Provide objective, data-driven evidence for deviation investigations and CAPA activities

III. Typical Application Scenarios of SPC in Pharmaceutical Manufacturing

1. Raw Materials and Pre-processing

In active pharmaceutical ingredient (API) and finished dosage manufacturing, SPC is commonly applied to monitor:

• Key physicochemical attributes of raw and excipient materials

• Particle size distribution and moisture content

• Weighing accuracy and variability

SPC allows early identification of abnormal fluctuations in raw materials or pre-processing steps, preventing issues from propagating downstream into subsequent processes.

2. Finished Dosage Manufacturing Process Control

In solid and liquid dosage form manufacturing, SPC is widely used to monitor:

• Mixing time and blend uniformity

• Tablet weight, hardness, and thickness

• Fill volume accuracy and sealing quality

SPC helps distinguish between:

• Random variation, and

• Systematic shifts or equipment-related abnormalities,

thereby reducing batch-to-batch variability and ensuring consistent product quality.

3. Aseptic and Cleanroom-Related Processes

For sterile products and biopharmaceutical manufacturing, SPC plays a particularly critical role in monitoring:

• Environmental conditions (temperature, humidity, microbial levels, particle counts)

• Sterilization process parameters

• Operating status of critical equipment

Trend-based control charts enable early detection of potential loss-of-control conditions, helping prevent sterility failures before they occur.

4. Packaging and Labeling Processes

During the packaging stage, SPC is commonly applied to:

• Fill consistency

• Seal integrity

• Label positioning and readability

Effective process control at this stage significantly reduces compliance risks related to mislabeling, underfilling, or packaging defects.

IV. Key Characteristics of SPC in the Pharmaceutical Industry

1. Strong Compliance Orientation

SPC data is frequently used to support:

• GMP audits and inspections

• Deviation investigations

• Verification of CAPA effectiveness

By translating abstract GMP requirements into measurable and continuously monitored process indicators, SPC plays a critical role across all quality assurance activities. Data integrity, traceability, and audit readiness are especially essential.

2. Greater Focus on Trends Rather Than Single Limit Exceedances

In pharmaceutical manufacturing, many quality risks do not arise from isolated out-of-specification events, but from:

Gradual and long-term process drift.

SPC trend analysis enables proactive intervention before deviations formally occur.

3. Integration with Validation and Continued Process Verification

SPC is often implemented in conjunction with:

• Process Validation (PV)

• Continued Process Verification (CPV)

forming a core component of lifecycle process management.

V. Core Value Delivered by SPC to Pharmaceutical Companies

• Improved process stability and product consistency

• Reduced risk of batch deviations and product rejection

• Stronger support for GMP compliance and regulatory audits

• More efficient deviation handling and CAPA execution

• Establishment of a data-driven quality culture

As regulatory expectations continue to increase, SPC has evolved from an optional tool into a foundational capability within pharmaceutical quality systems.

VI. Conclusion: SPC as the “Second Line of Defense” in Pharmaceutical Quality

In the pharmaceutical industry:

Compliance is the baseline. Stability is the core. Data is the safeguard.

Through continuous monitoring and trend analysis, SPC enables manufacturers to take action before problems occur—protecting patient safety, reducing operational risk, and supporting long-term, stable production.

Truly mature pharmaceutical manufacturing does not rely on end-product testing alone, but on controlled and predictable processes.