Automation Aspects of PAT Installation
w/ Case Study
Pete Miilu, Pfizer
Marc Surprenant, Pfizer
Intro/Background
Automation and Control Strategy:
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Levels of Automation
• Process Monitoring
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Instrument monitors the process to determine when the end point is met
Monitoring and Analysis of data
• Process Control
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Instrument monitors and adjusts the process based on results
Full implementation of PAT
• Ultimate Goal is Real Time Release
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Integration with Distributed Control System
• Communication
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Hardwired Input / Output
Serial
Ethernet (OPC)
• Recipe Management
• Data Retention
Data Strategy
Several aspects to consider:
• Who are the users?
• Operators for process control decisions
• Require go/no-go decision [bytes]
• Require limited data & trending [KB]
• Engineers for process improvement
• Require results data [KB]
• Require trending capabilities [MB]
• Lab personnel for instrument maintenance and calibration
• Require raw and spectral data [GB]
• Require trending capabilities [MB]
• Data retention
• Different for each type of data?
• Important for long-term supportability when dealing with frequent
samples of high-data-volume assays
• Limited retention for raw data can be justified using calibration and
maintenance procedures which meet requirements for demonstrating
instrument performance
Case Study Background
Operational Setting:
• Batch Solvent Recovery Distillation Process
• Recovered solvent quality verified with manual sampling
and analysis using process lab
• In process lab analysis results obtained in one to two
hours
• During lab analysis distillate is directed to a “slop” tank
until quality is verified
• Manual sampling does not allow distillate collection at the
time it meets specification
Case Study Background
PAT Solution:
• Continuous sampling and analysis required
• Achieved by implementing an on-line gas
chromatograph on the distillate stream
• On-line GC capable of collecting and reporting
composition of the distillate every four to eight
minutes (near real time)
GMP Classification of System
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Direct vs. Indirect vs. No Impact
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Case Study
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Classified as an Indirect Impact system because the system is not used
to demonstrate compliance with any registered parameters or attributes
Downstream direct impact systems ensure compliance with registered
parameters
Benefits of Indirect Impact Classification
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Ultimately this decision is based on the way that Operations intends to
use the information produced by the system
CQA provides standard tools for determining classification
Allows commissioning-only approach to testing
Lower project & long-term support costs
Opportunity costs
•
If/when the business finds that the system is capable of replacing the
registered downstream assays, then a system qualification must be
performed, in addition to a process validation.
Ta – Da! The Final Incarnation
Implementation
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Qualified:
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Direct Impact System’s Critical Components:
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Product contact – piping and pump
Analytical Instrument
Critical software functions
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PC Hardware
Data Historian Interface
Challenges
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Methods of Analysis
Commissioned only:
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DCS Interface
DCS Recipe Control
Vendor Software critical functions
Breadth of team’s background and experience with C&Q
Agreeing on System/Component Impact Assessments
Assigning ownership of support responsibilities
OPC & network security
Assigning ownership of components during project
Operations’ learning curve
Learnings
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C&Q is valuable, but requires up-front planning
Investment in vendor training for instrument is a must
Once the project is complete – the work begins
OPC is a valuable technology platform for data exchange
Leave a backup control strategy!!
DCS to Instrument Integration
Lab Specialist:
Manually Calibrate
the GC (at
instrument HMI or
at Workstation)
DCS:
Start sample
supply pump
DCS:
Check GC
Communication and
Alarm Status
AlarmStatus &
ComState Good?
Yes
DCS:
Disable all GC Streams
(Synchronous write)
DCS:
Enable GC Stream for Analysis
(Synchronous write)
No
Operations:
Notify Lab Specialist
and/or acknowledge
DCS prompt to
“Continue with manual
GC?”
Operations:
Start DCS recipe
DCS:
Start the GC (Synchronous
write)
GC:
Begin sampling
and analysis
GC:
Calculate Results and set
Sample Time
DCS:
Monitor GC and Compare to
Recipe Parameters
DCS:
Does result
meet spec?
Yes
Operator:
Confirm DCS prompt
“Switch to product cut?”
No
DCS:
Set the GC to HOLD
State (Synchronuos
Write)
Epilogue
• Experiencing issues with calibration
drift – instrument/analytical support
are working to resolve
• Relying on both PAT and backup
control strategy
• Expect fully operational and reliable
system by EOY2008