Lyophilization Validation: A Regulatory Perspective

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Ellen HuangCBER/OCBQ/DMPQ

CASSS CMC Strategy ForumJuly 19, 2016

Overview• Objective• Definition of lyophilization• Observations and challenges• Lyophilization process validation• Aseptic processing• Cleaning and sterilization• Orphan products• Alternative containers

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Objective• The objective of this presentation is to

present an overview of FDA’s expectations for validating the lyophilization process

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What is Lyophilization• A process in which water is removed from

a product after it is frozen and placed under a vacuum, allowing the ice to change directly from solid to vapor without passing through a liquid phase.

• The process consists of three separate, unique, and interdependent processes; freezing, primary drying (sublimation), and secondary drying (desorption).

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Annealing• Optional step(s), that typically follows the

freeze step where the product is warmed up to allow crystals to grow

• Performed because crystalline component may not be completely crystallized– Provides necessary cake structure or more

stability to the protein • Facilitates faster sublimation, thus

optimizing the process5

Lyophilization• In general, lyophilization is used for drug

products to provide for greater stability and increase the product’s shelf life.

• Prior to use, the product is reconstituted with the appropriate diluent.

• Lyophilization is sometimes used on drug substance, especially for long-term storage, e.g., multiple conjugates

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Observations and Challenges• Establishing a commercial lyophilization

process can be challenging• Successful validation requires robust

development studies, equipment qualification, and process validation

• Not enough focus on developing the freezing phase, the most important phase of the cycle

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Observations and Challenges• Inappropriate bracketing strategies (e.g., load

size or number of lyophilizers)• Inadequate empty chamber shelf temperature

and product temperature mapping• Insufficient sampling for quality and uniformity

– Sample locations unknown• Worst-case load not repeated• Scale-up or technical transfer issues• Vial/container imperfections 8

Equipment Qualification• Empty chamber temperature mapping

– Thermocouples (TC) are typically placed in the four corners and center of each shelf

– Identify cold and hot spots– Expect limited variability on each shelf and

between shelves (usually about 1-2°C)– Temperature range should exceed actual

lyophilization temperatures• Leak rate test• Condenser capacity 9

The Process Validation Continuum

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Stage 1: Process Design through iterative risk assessment, quality characterization and process characterization cycles, with the objective of establishing a commercial process with sufficient control to consistently produce drug substance and drug product meeting defined specification manufacturing phases linked through comparability

Stage 2: Process Qualification that is sufficiently comprehensive and robust to provide conclusive evidence that the commercial process as designed consistently achieves specified product quality in the commercial production environment

Stage 3: Continued Process Verification Continuous

process and product monitoring Trending and

annual product reviews Deviation

management Change control Validated process

improvements State of control

INDPre-IND Phase I Phase IIb BLAPhase III Post-marketingPhase II

Stage 1: Process DesignProcess Design: The commercial manufacturing process is defined during this stage based on knowledge gained through development and scale-up activities• Understand the product and critical properties of

the formulation – Thermal characterization (collapse temperature,

eutectic temperature, and/or glass transition temperature)

– Stability of the product– Properties of the excipients used

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Development Studies• Laboratory, pilot, and at-scale scale

studies to support commercial cycle • Design of experiment studies to

understand impact of parameters (e.g., shelf temperature, pressure, time, and ramp rate) and design space for the product

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Stage 2: Process QualificationAt this stage, the process design is evaluated to determine if the process is capable of reproducible commercial manufacturing.

– Combines qualified facility, equipment, utilities, and trained personnel with the Process Performance Qualification (PPQ) (may include at-scale engineering runs)

• To demonstrate product uniformity and the ability to repeat and consistently manufacture product.

• Product uniformity is demonstrated through product temperature mapping and extended sampling/testing of reconstituted product. 13

Product Temperature Mapping• TC are typically placed in the product in the four

corners and center of each shelf– Can use “seeded” runs– Use of an appropriate surrogate

• Temperature profile diagrams useful in determining when primary and secondary drying have completed– Need to add additional time to primary drying since

containers with TC nucleate at higher temperature• Usually performed as engineering runs since

using TC throughout the load is not aseptic14

Temperature Profile Diagram

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Freezing Primary Drying Secondary Drying

Trappler, E. H. (2007). Validation of Lyophilization. In F. J. James P. Agalloco, Validation of Pharmaceutical Processes (p. 388). CRC Press.

Extended Sampling• Sample vials typically from four corners

and center of each shelf• Sample locations should be known• Testing often includes residual moisture,

reconstitution time, cake appearance (no collapsed cake or melt back), and reconstitution appearance,

• Can be performed as part of PPQ / conformance runs 16

Cake AppearanceDiscernible Effects -

SyringesDiscernible Effects -

Vials

PDA Course No. 282, Validation of Lyophilization (May 2015)17

Boundary Studies• Studies where shelf temperature and

chamber pressure were offset from commercial set-points– High and low shelf temperature– High and low chamber pressure

• Sometimes time is also varied during these studies

• Not required for fixed cycles but provides confidence in lyophilization process

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How many runs?• It depends

– Typically three runs are performed on the maximum load and one run is performed on the minimum load

– How much supportive development work– How many factors there are (e.g., number of

lyophilizers, dosage strength, etc.) and how study is bracketed

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Bracketing Strategy• Load size (maximum and minimum)• Multiple lyophilizers

– Demonstrate equivalence between the units– Typically 3+1+1

• Multiple dosage strengths– Consider thermal characteristics between

dosage strength• Fill volume• Different vials size or manufacturers 20

Stage 3: Continuous Process Verification (CPV)

CPV: Ongoing assurance is gained during routine production that the process remains in a state of control.• Continued monitoring and sampling of process

parameter and quality attributes– Analyze and trend the data– Once sufficient data has been gathered, can reduce

monitoring with justification– Monitor changes in process inputs, including materials

and container/closure components• Imperfections in the vial can have negative impact on crystal

formation during freezing. 21

Aseptic Processing• Transportation of vials from the filling line to

the lyophilizer should be done aseptically since vials are partially stoppered

• Media challenges should include transportation, loading, holding, partial vacuum, stoppering, and unloading the lyophilizer, however:– Media should not be frozen as this may kill

organisms– Hold time does not need to be the actual duration

of lyophilization cycle22

Cleaning• Perform between each run• Clean-In-Place (CIP) or manual cleaning

– CIP cycle: initial rinse, recirculation, final rinse, drying

– CIP CV should demonstrate total chamber coverage (riboflavin)

• WFI is preferred– If cleaning agent is used, must demonstrate

removal from the chamber• Cleaning process should be validated

– Use worst-case soil– Procedure for potential spills 23

Sterilization• Lyophilizer should be sterilized after

cleaning • Typically observe steam sterilization (SIP)

(overkill approach)• Sterilization process should be validated

– Heat distribution and biological indicators– Demonstrate Sterility Assurance Level of 10-6

• Chamber should be dry after SIP24

Orphan Products• Use of an appropriate surrogate or

perform with seeded runs• Less PPQ runs may be submitted in

submission since product is manufactured infrequently– Perform additional runs in the future to

support the PPQ• No exemption from CGMP compliance

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Alternative Containers: Trays• Membrane Trays (e.g., LYOGUARD®)

– Tray with a PTFE membrane– Usually has low fill depth -> Larger shelf

contact area– Temperature mapping requires more than one

TC per container– Typically seen used for drug substance

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Alternative Containers: Syringes• Pre-Filled Syringes and Dual Chamber

Syringes• Syringe has less/no contact with the shelf, so

heat transfer will be different than a vial. Therefore, syringes respond more slowly to shelf temperature changes.

• Consider type of syringe holder and loading configuration

• Validation expectation same as vial27

Acknowledgements• Nicole Trudel• Randa Melhem, PhD• Qiao Bobo, PhD• Tony Lorenzo• Debbie Trout• Jay Eltermann• Laurie Norwood• Mary Malarkey 28

Definitions• Collapse Temperature (Tc) – The temperature

above which the frozen formulation undergoing lyophilization loses macroscopic structure and collapses; below this temperature, the solute/solvent mixture is able to retain its structure, even when it is not supported by surrounding ice, which is removed via sublimation during primary drying.

• Eutectic Temperature (Te) – The point at which the product only exists in the solid phase, representing the minimum melting temperature. Not applicable to amorphous material. 29

Definitions• Glass Transition Temperature (Tg or Tg’) – the

temperature above which the formulation undergoing lyophilization

• Metastable – pertaining to a body or system existing at an energy level above that of a more stable state and requiring the addition of a small amount of energy to induce a transition to the more stable state.

• Sublimation – The transition of a substance (such as ice) from a solid state directly to the vapor state (such as water vapor) without first passing through an intermediate liquid phase.

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