Process Analytical Technology

Process Analytical Technology (PAT) has been defined by the United States Food and Drug Administration (FDA) as a mechanism to design, analyze, and control pharmaceutical manufacturing processes through the measurement of critical process parameters and quality attributes.

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The FDA has outlined a regulatory framework^[1] for PAT implementation. With this framework - according to Hinz^[2] - the FDA tries to motivate the pharmaceutical industry to improve the production process. Because of the tight regulatory requirements and the long development time for a new drug, the production technology is "frozen" at the time of conducting phase-2 clinical trials.

Generally, the PAT initiative from FDA is only one topic within the broader initiative of "Pharmaceutical cGMPs for the 21st century - A risk based appraoch".^[3]

PAT implementation

The challenge to date with PAT for pharmaceutical manufacturers is knowing how to start. A common problem is picking a complex process and getting mired in the challenge of collecting and analyzing the data.

The following criteria serve as a basic framework for successful PAT roll-outs: (From A PAT Primer)

Picking a simple process. (Think Water for Injection (WFI) or Building Monitoring System (BMS)
All details and nuances are well understood and explained for that process.
Determine what information is easily collected and accessible through current instrumentation.
Understanding the appropriate intervals for collecting that data.
Evaluating the tools available for reading and synchronizing the data.

Long-term goals

The long term goals of PAT are to:

reduce production cycling time
prevent rejection of batches
enable real time release
increase automation
improve energy and material use
facilitate continuous processing

Currently near-infrared (NIR) spectroscopy applications dominate the PAT projects. A possible next-generation solution is Energy Dispersive X-Ray Diffraction (EDXRD) ^[4]. For a detailed review of PAT tools see Scott ^[5], or Roggo ^[6].