Upload
others
View
5
Download
0
Embed Size (px)
Citation preview
10/11/2005
1
ENGINEERING RESEARCH CENTER FOR
STRUCTURED ORGANIC PARTICULATE SYSTEMS
RUTGERS UNIVERSITYPURDUE UNIVERSITYNEW JERSEY INSTITUTE OF TECHNOLOGYUNIVERSITY OF PUERTO RICO AT MAYAGÜEZ
PQRI workshop on “Sample Sizes for Decision Making in New
Manufacturing Paradigms”
Challenges of Statistical Analysis/Control in a Continuous Process
Fernando Muzzio, Professor IIDirector, ERC-SOPSRutgers University
2
Why Continuous Manufacturing?
• Smaller equipment• No scale up• No wasted batches• Better quality control• Meaningful PAT• More uniform processing
• Controllable segregation?• Faster development?
3
Feeder size, Screw type, feed rate
Raw material properties
Blender size, design, Blender speed, flow rate
Blender size, Blender speed, design, flow rate
Design, Feeding Speed, Tabletting speed
Tabletting (Speed, compression force, thickness)
Lubricant Mixing (Blender speed, design, flow rate, humidity, shear)
Roller compaction (Design, speed, flow rate, Gap between rolls, compaction pressure)
σ2i
σ2i
PSDBlend homogeneity (RSD)
PSD,Blend homogeneity, HydrophobicityFlow properties
PSD,Hydrophobicity, Flow properties
Direct Compression
Roller Compaction
Weight variability, Dissolution, HardnessContent Uniformity
Tablet sizeCompression speedComposition
σ2i
Milling (Mill size, Mill type, Speed, flow rate)
PSD
Ribbon density, Composition
Feeding
API Blending
Lubricant Blending
Feed frame
Tabletting
Throughput?
4
PAT for continuous secondary pharmaceutical manufacturing
Roller CompactionRibbon density (NIR, X-Ray, Ultrasound)
MillingGranule Size Distribution (Laser diffraction) Wet granulation and drying
Granule size distribution (Laser Diffraction)Moisture content (NIR)
Pneumatic transfer
BlendingBlend uniformity (NIR)Blender hold-up (Load sensor)
Gravimetric feedingFlow rate (Feeder Load sensor)
DCDG
WG
TablettingContent Uniformity (CU) (NIR)HardnessDensity
Ultrasound, X-ray
5
PAT for continuous secondary pharmaceutical manufacturing (cont.)
• Feedingo Feed rate variabilityo Feeder refill
• Blendingo Blend uniformity (NIR)o Blender hold-up (Load sensor)
• Roller compactiono Ribbon density profile (NIR, Ultrasound, X-ray)o Ribbon thickness (Gap between rollers)
• Millingo Particle size distribution (Laser diffraction)
• Wet Granulation and Dryingo Granule Size distribution (Laser diffraction)o Moisture content (NIR)
• Tablettingo Weight (Load sensor)o Hardness, density (Ultrasound)
(Load sensor)
6
Challenges
• Real time automated control is REQUIRED– Underdeveloped sensors – Lack of models
• No experience regarding performance of pharma materials in these systems
• Lack of a regulatory framework
7
Requisites of Continuous process
• More flexibility in continuous processing in terms of throughput and control
• Development of compact process models for individual unit operations
• Identification of manipulated and controlled variables
• Model based control to ensure efficient operation under closed loop conditions
• Production throughput (Capacity of Tablet press, size of tablet)
• Equal flow rate through all the units
10/11/2005
8
ENGINEERING RESEARCH CENTER FOR
STRUCTURED ORGANIC PARTICULATE SYSTEMS
RUTGERS UNIVERSITYPURDUE UNIVERSITYNEW JERSEY INSTITUTE OF TECHNOLOGYUNIVERSITY OF PUERTO RICO AT MAYAGÜEZ
Feeders
Blender
TabletPress
Delta V Control System
Multi-pointNIR
Malvern Insitec
OpticalTablet thicknessMeasurement
9
PAT Approach
• Gravity influenced flow of powder on metal chute placed right after the blender to make the NIR measurement possible
• A remote NIR probe with 5 measurement spots was used
9
Mixer outletProbe
Tablet press inletChute
10
Measurement configuration - VTT
• The probes measured from a distance of about 15 cm
• 600 µm fibers were used in both illumination and collection
• Illumination spot size ~5 mm
• Collection spot size ~ 8 mm
Probes
Chute
Mixer outlet
1111
Measurement equipment
• Multipoint NIR measurement system was used
– 5-point probe, measurement spot Ø 3 mm
– Fiber-optic light source
– NIR spectral camera
ChutePowder
Mixer
Collection fiber
bundles Real-time calculation
module
Illumination fiber
bundles
5 measurement spots
Light source
Spectral camera
Schematic of the 3x5 probe measurement system
To process control
Probe
1212
Results: 10 % APAP concentration
• Mixer was operating at 10 % APAP
• Again some peaks of high APAP concentration visible
0 20 40 60 80 100 120 140 160-5
0
5
10
15
20
25
30
35
Time [s]
Pre
dict
ed c
once
ntra
tion
[%]
Smoothed APAP concentration (ref. 10.0 %)
1313
Results: 20 % APAP concentration
• Mixer was operating at 20 % APAP• Nice ramp from 10 % concentration to 20 %• No peaks of high APAP concentration visible
0 20 40 60 80 100 120 140 1600
5
10
15
20
25
30
35
Time [s]
Pre
dict
ed c
once
ntra
tion
[%]
Smoothed APAP concentration (ref. 20.0 %)
14
SBC calibration results for caffeine
• Response spectrum (blue, scaled), shown for reference
• Regression vector (green) picks up caffeine features
14
1000 1100 1200 1300 1400 1500 1600
-50
0
50
100
150
200
250
300
Wavelength [nm]
b ve
ctor
Response and regression vectors
0 2 4 6 8
-1
0
1
2
3
4
5
6
7
8
9 RMSEC : 0.92905 cc : 0.93239 CV : 24.6356 R2 : 0.8497 #of smpl : 110
Reference concentrationPr
edic
ted
conc
entra
tion
Prediction vs. reference
gb
• Prediction scatter plot• The slope had to be adjusted (0.8927)
since the scattering properties of pure caffeine and the 0 – 8 % blend are different
1515
Results from the continuous blending trials
0 20 40 60 80 100 120 140 1600
1
2
3
4
5
6
7
Time [s]
Pre
dict
ed c
once
ntra
tion
Caffeine concentration vs. time
12345Average
Concentration measurement
16
Impulse responses
Blender speed 30 %
16
Blender speed 80 %
Continuous mixingof pure CaHPO4
Add 7g caffeinein blender inlet
Measure the timeresponse afterblender
0 50 100 150-1
-0.5
0
0.5
1
1.5
2
2.5
Time [s]
Pre
dict
ed c
once
ntra
tion
Caffeine concentration vs. time
12345Average
0 10 20 30 40 50 60 70 80-2
0
2
4
6
8
10
12
14
Time [s]
Pre
dict
ed c
once
ntra
tion
Caffeine concentration vs. time
12345Average
1717
Overall scheme for DC (In-line NIR/Raman/PSD Sensing)
Multipoint NIR / Raman / Partice size
API & excipient characterization
Process
control
• Ultimate goals• 100 % inspection• Closed-loop feedback
control• Methodology for design
and construction of continuousmanufacturing lines
• Measurements• Multipoint NIR• Particle size• Multipoint Raman
• Methodology for measurements needs
• Robust but easycalibration
• Sampling• Process and
measurementunderstanding
• Real-time computing & process connectivity
18
Approach for optimizing PAT method
20
22 )()( σσσ += xx mixingtotal
SizeSamplex _=
)()()(
.
)(
20
2
20
2
20
2
aLnxLnRSDLnxRSDxfRSD
Total
total
total
+=−
=−
=−
βσ
ασ
σβ
Experimentally measured
•Unknown parameter•Determined by optimizing R2 (result of regression)
Power law relationship between the normalized variance and sample size
Linearization:
Methodology to assess the relationship between blend uniformity (variance in concentration) and sample size
19
Dataset-1 (3% Gran APAP UV Spec)
RSD vs. sample size
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0.1
0 0.2 0.4 0.6 0.8 1
RS
D
Sample size(g)
•Confidence intervals are for the Std deviation which were normalized by the mean
20
Dataset-1 (3% Gran APAP UV Spec) (Cont.)
Ln (RSD2) vs Ln (Sample size) R2 vs. σ20
y = -0.66x - 7.913R² = 0.820
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
-4 -2 0 2
Ln(R
SD2 )
Ln (Sample size)
Series1
Linear (Series1)
00.10.20.30.40.50.60.70.80.9
0 0.0001 0.0002 0.0003 0.0004 0.0005
R2Method Error (σ2
0)
σ20 = 0 (Best case)
21
Dataset-2 (3% Gran APAP NIR)
RSD vs. sample size
0
0.05
0.1
0.15
0.2
0.25
0 0.2 0.4 0.6 0.8
RS
D
Sample size(g)
22
Dataset-2 (3% Gran APAP NIR) (Cont.)
Ln (RSD2) vs Ln (sample size)
R2 vs. σ20
y = -0.663x - 8.247R² = 0.639
-10
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
-6 -4 -2 0 2
Ln(R
SD2 )
Ln (Sample size)
Ln(Rsd^2)
Linear (Ln(Rsd^2))
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0 0.00005 0.0001 0.00015
R2
Error (σ20)
σ20 = 0 (Best case)
23
Comparison between In-line NIR and UV Spectroscopy
0
0.02
0.04
0.06
0.08
0.1
0.12
0 0.2 0.4 0.6 0.8 1
RS
D
Sample size(g)3% NIR
•This methodology provides the number of NIR measurements to be averaged to measure blend uniformity at the desired sample size (unit dose).
Unit dose (1 Tablet)
24
Conclusions
• To minimize the required experiments for identifying the optimum “plan” for the production of a new product:
– Characterize basic material properties
– Use all the existing knowledge (experimental data and modeling techniques) that connect material properties to unit operation performance to identify appropriate equipment designs and operating conditions
25
Take Home
• In continuous processing, every component needs to operate simultaneously and at the same rate
• One bottleneck is the need to feed small rates of cohesive powders– Solution – pre-conditioning
• PAT challenges
Slide 25