Liquidborne Particle Counting using Light Obscuration and Light Scattering Methods

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Liquidborne Particle Counting using Light
Obscuration and Light Scattering Methods
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What has been . . .

• Focus has been on injectable liquids
• Possibility to block capillaries and arteries
• Red Blood cells are about 5 µm
• Capillary (5 to 10 µm)
• Large veins (10 to 50 µm)
• Threat of microbial infection
• Allergic reaction to foreign substances

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Contaminants Reported in IV Solutions
Extrinsic
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Definition of Particulate Contaminants

• Unwanted insoluble matter that exist as
  randomly-sourced extraneous substances
• Excludes homogeneous monotonic materials that
  exist as a precipitate or suspension
• i.e. colloids, drug degradation or otherwise
  derived from a defined source and can be analyzed
  by chemical means
• Regarded as contamination and adulteration
  under Food and Drug Act
• the chemical composition of the particulate is
  varied, and
• would not be declared on the label
• Examples bits of paper fiber, fragments of
  filler material, etc

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Liquid Particle Counting Applications

• Final Product Testing USP lt788gt
• SVP or SVI (Small Volume Parenteral/Injectable)
• Ampoules, Vials
• LVP or LVI (Large Volume Parenteral/Injectable)
• IV (Intravenous) solutions
• Process contamination studies
• Decomposition studies (stability)
• DI or WFI Water
• Precision Cleaning Medical Devices
• Aqueous
• Other Chemicals

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Other Applications for Particle Counting

• Medical Devices
• Cleanliness of manufacturing environment
• Cleanliness of device before implantation
• pacemakers, stents, artificial arteries
• Cleanliness of reclaimed devices
• Design of particulate-based medicines
• Inhalation therapies
• Intentional occlusion of blood flow to cancers
• Time-based dosages
• Transdermal absorption

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Global Regulations Particles in Liquids

• USP lt788gt, EP 2.9.19, JP XV, KP, CP
• Primary method
• Optical Particle Counter OPC
• Light Obscuration Counter
• Secondary method
• Optical microscope
• Subjective
• Labor intensive
• Requires more time to process samples

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Proposed USP 787, USP 1787

• USP lt787gt
• Under discussion
• Focused on reducing necessary test volumes due to
  concerns of biotechnology manufacturers of cost
  for test
• Expensive and often very small dose factory
• for example 500 uL pre-filled syringe

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Proposed USP 787, USP 1787

• USP lt787gt
• Primary method ?
• Optical Particle Counter OPC
• Light Obscuration Counter
• Secondary method ?
• Optical microscope
• Subjective
• Labor intensive
• Requires more time to process samples

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Proposed USP 787, USP 1787

• USP lt787gt
• Small sample volume
• - 1 mL ??
• Concerns with variability
• - within production lots
• - in analytical methods

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Optical Particle Counter

• Optical Instrument
• Must move fluid through sensor
• Can quantify particles from 100 nm to 5000 µm
• Counts particles individually (one at a time)
• Cannot tell you composition
• But results are immediate

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Many shapes and sizes
Talc
Alumino-silicate with K and Ti
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Sizing Particles by Microscope
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Challenges of Protein-based Products

• Handling can change material !!!
• Agitation
• Heat and Light
• Contaminates
• Container Vials versus syringes/cartridges
• Shear forces
• Key concern is Aggregation
• Reduction of native form (impacts efficacy)
• Introduction of homogeneous aggregates
• Introduction of heterogeneous aggregates

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Challenges of Protein-based Products

• Transparency of most proteineous entities
• Refractive index
• NIST working on calibration material
• Not contamination but instead a shift from
  native form
• Not a solution as with small-molecule
  therapeutics
• Formation of quaternary structures dimers, etc.
• Protein complexes
• Reconstitution of lyophilized product

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Refractive Index

• Key is the ability to distinguish between the
  particle and the surrounding fluid
• - needs to be great enough
• Optical response is proportional to comparative
  index

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Refractive Index

• Key is the ability to distinguish between the
  particle and the surrounding fluid
• - needs to be great enough
• Optical response is proportional to comparative
  index

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Refractive Index

• NIST working on protein-like calibration material
• Probably 2 years away
• Exploring 2 methods of manufacture
• Need thread-like material
• Indices near water
• Stable over reasonable period

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II. Sample Handling
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Settling/Agitation

• Entrained gas
• - sonication probably not ideal with protein
  structures
• - light vacuum seems to work OK
• Settling
• Limits collection of particles
• - especially of greater mass
• - dependent on time and viscosity
• - improved collection with slanted containers

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Consistency of sample characteristics

• Temperature
• Settling
• Probe position

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Issues with Sampling Particles in Liquids

• Sampling Errors Account for most problems
• Accidental Contamination or Alteration by
  Technician

• 1. System Preparation
• Initial Cleanliness
• Calibration

• 3. Sample Handling
• Aggregation
• Settling
• Cavitation

2. Sample Preparation Contamination -
Particles - Gases - Liquids
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Particle Counter vs. Microscope

• Sizing of Particles
• Microscope Subjective size measurement
• Electronic consistent for specific particle
  type
• Particle orientation and movement
• Electronic large, long particles can be
  mis-read
• Calibration
• How to establish accurate sizing and counting
• Consistency (repeatability)

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Sizing Particles by Microscope
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HIAC Liquid Particle Counters

• Example HIAC 9703
• The industry standard liquid particle counter
  since 1997
• USP lt788gt was written specifically around HIAC
  technology
• Every major manufacturer of particle calibration
  standards uses the HIAC 9703

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HIAC Liquid Particle Counters

• Example HIAC 9703
• Improved sample mounting method for small vials
  or containers
• Detection of usual conditions such as bubbles or
  contamination
• Proven syringe sampler
• SVI and LVI sampling
• Addresses non-compendial applications, e.g. RD
  and other low frequency, small sample volume
  applications

• Reproducibility
• Repeatability

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Detection Ranges
1µm
0.1µm
10µm
100µm
Light Obscuration
Light Scattering
nm
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Light Obscuration

• Light Obscuration Sensors and system
• also known as Light Extinction
• also known as Light Blocking

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Principles Light Obscuration
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Principles Light Obscuration
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Principles Light Obscuration
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Particle Detection

• Like an air particle counter, the larger the
  particle, the larger the pulse that is created

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Principles Light Scattering
Detector Output
Detector
Light Trap
Laser Diode
Mirror
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Principles Light Scattering
Detector
Particle
Light Trap
Laser Diode
Mirror
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Advantages Light Scattering

• Good sensitivity from 0,1µm to 50µm
• Wide range of sample concentration
• Good rejection of false counts
• High sample flow rates

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Disadvantages Light Scattering

• More complicated construction higher cost
• Characteristics of particle surface (shiny,
  color) affect response

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Effect of colors and surfaces on Light Scattering
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Talc
Alumino-silicate with K and Ti
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Sizing Particles by Microscope
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General Comments on Liquid Counting

• Particle Counters Report Size
• But measure an Optical Response
• Difference in reported size compared to
  microscope
• Calibration Relates the Optical Signal to Size
• Difference between calibration material
  characteristics and real world particles

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General Comments on Liquid Counting

• Particle Counters Report Size
• But measure an Optical Response
• Differences in reported size compared to
  microscope
• Calibration Relates the Optical Signal to Size
• Difference between calibration material
  characteristics and real world particles

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LO results versus LS results

• Light Obscuration LO
• Good immunity to variations of surface and
  morphology
• Very stable
• Limit of quantitation circa 1.2 1.3 microns
• Light Scattering LS
• Results affected by surface characteristics and
  coloring
• Good stability
• Limit of quantitation sub-micron
• Problem can occur in the attempt to correlate
  results of these two methods above 1 micron

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Sampling Particles in Liquids

• Good, consistent results depend on
• Well-trained operators
• Careful technical methodology
• Constant effort needed
• Review ways to avoid or reduce errors due to
  sampling methods
• Usually cause false positives

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System Preparation

• 2-step Verification - optional
• Run 2 test solutions
• Blank (particle-free water)
• Aqueous solution containing known counts
• at 10 µm or 15 µm
• In the range of 1000 to 3000 counts per mL
• Frequency based on risk analysis
• Each morning
• Shift change
• Change of operator
• Other interval

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System Preparation

• Check for bubbles in sample lines and syringe
• Affects flow rate and calibration
• Verify correct calibration curve installed
• Different flow rates for same sensor
• Change of syringe size
• Some companies have multiple sensors
• Verify calibration is current
• Sensor resolution and response curve
• IST tests conducted USP, JP

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System Preparation

• Instrument Standardization Tests IST
• Five tests of system
• Volume accuracy
• Flow rate accuracy
• Calibration of sensor
• Resolution
• Count accuracy
• Required by USP and JP but not EP
• USP lt788gt 31
• at intervals of not more than six months.
• JP lt24gt
• at least once a year.

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Sample Preparation

• Removing residue of previous sample
• If previous sample contained particles, may be
  good plan to run a particle-free blank before
  the next sample
• Use liquid that is compatible with sample fluid
• An aqueous blank could trigger false counts in an
  oil-based sample by causing immiscible droplets
• Potential residue from previous sample can cause
  change of counts
• Data from first run of series is often discarded

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Sample Preparation

• Contamination
• Particles
• Gases
• Liquids

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Sample Preparation

• True Particle Sources
• Residue on glassware and equipment
• Ambient air
• Paper dust
• Glass
• Diluent
• Residue from previous sample
• Colloidal suspensions
• False Particle Sources
• RF signals or other electronic interference
• Bubbles from entrained gases

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Sample Preparation

• Work in controlled environment
• Use particle-free gloves
• Let water flow for 200 mL or more after opening a
  valve / tap
• Opening / closing valve generates particles
• Wipe the outside of containers before sampling
• Particles on surface of vials or ampoules
• Open vials and ampoules away from beaker or flask
• Particles from activity can fall into open
  container
• Wash outside of containers to reduce potential
  particle source

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Degassing sample

• Three common methods
• Allowing to stand in ambient air
• Risk of large particles settling
• Sonification ultrasound
• 80 to 120 watts USP lt788gt
• 30 seconds USP lt788gt
• Vacuum
• Bell jar or dessicator
• 0.6 0.8 atmospheres for 2 to 10 minutes

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Sample Preparation

• Possibility of decreasing true particle counts
• Settling
• Lack of agitation
• Position of probe in sample vessel
• Remaining material from previous sample run
• Sample with lower counts
• Blank

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Sample Handling

• Aggregation
• Settling
• Entrained gases

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Sample Handling

• Aggregation
• Samples held over time or at extremes of
  temperature can develop aggregates of smaller
  particles
• Exposure to light can also trigger this reaction
• Sub-micron particles can thus add to particle
  counts above 10 µm
• Suggestion
• Profile counts under 10 µm e.g. at 2 or 5 µm in
  addition to standard count sizes at 10 and 25 µm

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Sample Handling

• Settling
• Undercounting caused by
• Gravitational settling
• Failure to suspend particulate matter adhering to
  walls or stopper of container
• Standards have recommended procedure for
  agitation
• Multiple inversions of original container before
  decanting
• Constant motion of liquid during sampling
• Gently stir the contents of the container by
  hand-swirling or by mechanical means USP lt788gt

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Optical Particle Counter

• Instrument sensor
• Must move fluid through sensor
• Can quantify particles from 100 nm to 5000 µm
• Counts particles individually (one at a time)
• Cannot tell you composition
• But results are immediate

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Questions?
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Patent Pending
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New Hardware 9703

• Key features
• Auto stop for sensor elevator arm
• Small vial holding clamp
• Sample probe with reduced dead volume
• Back-flush and forward flush from front panel
• Supports MC-05 sensor (0.5 micron sensitivity)

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Software PharmSpec 3

• Key new features
• Compendial test support continues
• USP, EP, JP, KP looks same as previous PharmSpec
  versions
• Uses same log on as for Windows
• Improved Report format
• Improved Error Detection and Display

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Still the HIAC 9703 you know and trust only
better!

• Syringes
• 1 ml, 10 ml, 25 ml
• Flow rate settings
• 10 to 100 ml
• Sensors
• MC-05 is added
• Sampling Probes
• added shorter small-bore probe
• Instrument size / shape
• 50 of instruments are placed in laminar flow
  cabinets.
• Smooth, curved surfaces create less turbulence
  for the air flow

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Easier, Faster and Confident Sampling

• Use less sample, save valuable time - protect
  your investment
• Small vial clamp ensures that sample does not
  spill during testing
• Probe needle safety switch prevents probe damage
• New small needle probe with industrys smallest
  tare volume

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Easier, Faster and Confident Sampling

• Reduce uncertainty from data anomalies
• Bubble alarm notification
• Contamination alarm notification
• Advanced notification when service or
  calibration is due
• Invalid configuration notification

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HIAC just got easier!

• Less time needed for clean-up
• Automated flushing and cleaning routines
• Push a button, walk away and return to a clean
  sensor
• Export your data with ease
• Select one, several or all of your historical
  data records with our batch export utility
• Select PDF, Word, Excel, or text files
• Save time with electronic signature
• Stricter interpretation of 21CFR Part 11
  electronic signature process. WITHOUT more
  manual inputs
• Remembers user Login ID

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HIAC 9703 Flexibility

• Interchangeable sampling probes, syringes, and
  sensors
• Ensure you have one instrument to manage all
  applications
• Now supports MC05 sub-micron sensor
• Change configuration with no impact to instrument
  validation
• Customized reporting
• Customize the number of reviewers and approvers
  for compendial test reports
• Add company logo, user-defined descriptors
• Customized test recipes
• Procedure Builder enables the development of
  unique test recipes for your application
• Enables testing to marketing license-specific
  applications

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New Sampling Probe

• 3 probes available
• Tare
• ¼ ID 1.2 ml tare volume
• 1/16 ID 0.172 ml tare volume
• New small / short probe
• 1/16 ID 0.09 ml tare volume
• Tests can be performed on 1 ml of product!

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Small Vial Clamp

• Small Vial Clamp Platform
• Can be retrofitted
• Can be removed
• Ease of Use
• Use one hand to compress lever arms
• Use other hand to place sample in central
  location
• Decompress hand
• Clamp auto-centers and holds sample container

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Docking Module

• Docking Module
• Enables removal/disabling of the stir bar
  mechanism
• Enables field installation of small vial clamp
  outside of the laminar flow cabinet
• Avoid potential of re-qualification that can
  occur if instrument is moved
• Future developments to expand 9703 applications

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Sampling Safety Switch

• Sampling safety switch
• Ensures the sampling probe does not crash (and
  bend or break) into the docking module
• Ensures the probe does crash into or tip the
  sample container

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Liquidborne Particle Counting using Light
Obscuration and Light Scattering Methods