10/16/2015
`
`Inspection Guides > Lyophilization of Parenteral (7/93)
`
`U.S. Food and Drug Administration
`Protecting and Promoting Your Health
`
`Lyophilization of Parenteral (7/93)
`
`GUIDE TO INSPECTIONS OF LYOPHILIZATION OF PARENTERALS
`
`Note: This document is reference material for investigators and other FDA personnel. The
`
`document does not bind FDA, and does no confer any rights, privileges, benefits, or
`
`immunities for or on any person(s).
`
`INTRODUCTION
`
`Lyophilization or freeze drying is 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).
`
`The advantages of lyophilization include:
`
`Ease of processing a liquid, which simplifies aseptic handling
`
`Enhanced stability of a dry powder
`
`Removal of water without excessive heating of the product
`
`Enhanced product stability in a dry state
`
`Rapid and easy dissolution of reconstituted product
`
`Disadvantages of lyophilization include:
`
`Increased handling and processing time
`
`Need for sterile diluent upon reconstitution
`
`Cost and complexity of equipment
`
`The lyophilization process generally includes the following steps:
`
`http://www.fda.gov/IC EC l/Inspections/lnspecfi onGuides/ucm074909.htm
`
`1/23
`
`FRESENIUS KABI 1026-OOO1
`
`

`
`10/16/2015
`
`Inspection Guides > Lyophilization of Parenteral (7/93)
`
`- Dissolving the drug and excipients in a suitable solvent, generally water for injection (WFI).
`
`- Sterilizing the bulk solution by passing it through a 0.22 micron bacteria-retentive filter.
`
`- Filling into individual sterile containers and partially stoppering the containers under aseptic
`
`conditions.
`
`- Transporting the partially stoppered containers to the lyophilizer and loading into the chamber
`
`under aseptic conditions.
`
`- Freezing the solution by placing the partially stoppered containers on cooled shelves in a
`
`freeze-drying chamber or pre-freezing in another chamber.
`
`- Applying a vacuum to the chamber and heating the shelves in order to evaporate the water from
`
`the frozen state.
`
`- Complete stoppering of the vials usually by hydraulic or screw rod stoppering mechanisms
`
`installed in the lyophilizers.
`
`There are many new parenteral products, including anti-infectives, biotechnology derived products,
`
`and in-vitro diagnostics which are manufactured as lyophilized products. Additionally, inspections
`
`have disclosed potency, sterility and stability problems associated with the manufacture and
`
`control of lyophilized products. In order to provide guidance and information to investigators, some
`
`industry procedures and deficiencies associated with lyophilized products are identified in this
`
`Inspection Guide.
`
`It is recognized that there is complex technology associated with the manufacture and control of a
`
`lyophilized pharmaceutical dosage form. Some of the important aspects of these operations
`
`include: the formulation of solutions; filling of vials and validation of the filling operation; sterilization
`
`and engineering aspects of the lyophilizer; scale-up and validation of the lyophilization cycle; and
`
`testing of the end product. This discussion will address some of the problems associated with the
`
`manufacture and control of a lyophilized dosage form.
`
`PRODUCT TYPEIFORMULATION
`
`Products are manufactured in the lyophilized form due to their instability when in solution. Many of
`
`the antibiotics, such as some of the semi-synthetic penicillins, cephalosporins, and also some of
`
`the salts of erythromycin, doxycycline and chloramphenicol are made by the lyophilization process.
`
`Because they are antibiotics, low bioburden of these formulations would be expected at the time of
`
`batching. However, some of the other dosage forms that are lyophilized, such as hydrocortisone
`
`sodium succinate, methylprednisolone sodium succinate and many of the biotechnology derived
`
`products, have no antibacterial effect when in solution.
`
`http://www.fda.gov/IC EC lllnspections/lnspecfi onGuides/ucm074909.htm
`
`2/23
`
`FRESENIUS KABI 1026-OOO2
`
`

`
`10/16/2015
`
`Inspection Guides > Lyophilization of Parenteral (7/93)
`
`For these types of products, bioburden should be minimal and the bioburden should be determined
`
`prior to sterilization of these bulk solutions prior to filling. Obviously, the batching or compounding
`
`of these bulk solutions should be controlled in order to prevent any potential increase in
`
`microbiological levels that may occur up to the time that the bulk solutions are filtered (sterilized).
`
`The concern with any microbiological level is the possible increase in endotoxins that may develop.
`
`Good practice for the compounding of lyophilized products would also include batching in a
`
`controlled environment and in sealed tanks, particularly if the solution is to be held for any length of
`
`time prior to sterilization.
`
`In some cases, manufacturers have performed bioburden testing on bulk solutions after
`
`prefiltration and prior to final filtration. While the testing of such solutions may be meaningful in
`
`determining the bioburden for sterilization, it does not provide any information regarding the
`
`potential formation or presence of endotoxins. While the testing of 0.1 ml samples by LAL methods
`
`of bulk solution for endotoxins is of value, testing of at least 100 ml size samples prior to
`
`prefiltration, particularly for the presence of gram negative organisms, would be of greater value in
`
`evaluating the process. For example, the presence of Pseudomonas sp. in the bioburden of a bulk
`
`solution has been identified as an objectionable condition.
`
`FILLING
`
`The filling of vials that are to be lyophilized has some problems that are somewhat unique. The
`
`stopper is placed on top of the vial and is ultimately seated in the lyophilizer. As a result the
`
`contents of the vial are subject to contamination until they are actually sealed.
`
`Validation of filling operations should include media fills and the sampling of critical surfaces and
`
`air during active filling (dynamic conditions).
`
`Because of the active involvement of people in filling and aseptic manipulations, an environmental
`
`program should also include an evaluation of microbiological levels on people working in aseptic
`
`processing areas. One method of evaluation of the training of operators working in aseptic
`
`processing facilities includes the surface monitoring of gloves and/or gowns on a daily basis.
`
`Manufacturers are actively sampling the surfaces of personnel working in aseptic processing
`
`areas. A reference which provides for this type of monitoring is the USP XXII discussion of the
`
`Interpretation of Sterility Test Results. It states under the heading of "|nterpretation of Quality
`
`Control Tests" that review consideration should be paid to environmental control data,
`
`including...microbial monitoring, records of operators, gowns, gloves, and garbing practices. In
`
`those situations in which manufacturers have failed to perform some type of personnel monitoring,
`
`or monitoring has shown unacceptable levels of contamination, regulatory situations have resulted.
`
`http://www.fda.gov/IC EC lllnspections/lnspecfi onGuides/ucm074909.htm
`
`3/23
`
`FRESENIUS KABI 1026-OOO3
`
`

`
`10/16/2015
`
`Inspection Guides > Lyophilization of Parenteral (7/93)
`
`Typically, vials to be lyophilized are partially stoppered by machine. However, some filling lines
`
`have been noted which utilize an operator to place each stopper on top of the vial by hand. At this
`
`time, it would seem that it would be difficult for a manufacturer to justify a hand-stoppering
`
`operation, even if sterile forceps are employed, in any type of operation other than filling a clinical
`
`batch or very small number of units. Significant regulatory situations have resulted when some
`
`manufacturers have hand-stoppered vials. Again, the concern is the immediate avenue of
`
`contamination offered by the operator. It is well recognized that people are the major source of
`
`contamination in an aseptic processing filling operation. The longer a person works in an aseptic
`
`operation, the more microorganisms will be shed and the greater the probability of contamination.
`
`Once filled and partially stoppered, vials are transported and loaded into the lyophilizer. The
`
`transfer and handling, such as loading of the lyophilizer, should take place under primary barriers,
`
`such as the laminar flow hoods under which the vials were filled. Validation of this handling should
`
`also include the use media fills.
`
`Regarding the filling of sterile media, there are some manufacturers who carry out a partial
`
`lyophilization cycle and freeze the media. While this could seem to greater mimic the process, the
`
`freezing of media could reduce microbial levels of some contaminants. Since the purpose of the
`
`media fill is to evaluate and justify the aseptic capabilities of the process, the people and the
`
`system, the possible reduction of microbiological levels after aseptic manipulation by freezing
`
`would not be warranted. The purpose of a media fill is not to determine the lethality of freezing and
`
`its effect on any microbial contaminants that might be present.
`
`In an effort to identify the particular sections of filling and aseptic manipulation that might introduce
`
`contamination, several manufacturers have resorted to expanded media fills. That is, they have
`
`filled approximately 9000 vials during a media fill and segmented the fill into three stages. One
`
`stage has included filling of 3000 vials and stoppering on line; another stage included filling 3000
`
`vials, transportation to the lyophilizer and then stoppering; a third stage included the filling of 3000
`
`vials, loading in the lyophilizer, and exposure to a portion of the nitrogen fiush and then stoppering.
`
`Since lyophilizer sterilization and sterilization of the nitrogen system used to backfill require
`
`separate validation, media fills should primarily validate the filling, transportation and loading
`
`aseptic operations.
`
`The question of the number of units needed for media fills when the capacity of the process is less
`
`than 3000 units is frequently asked, particularly for clinical products. Again, the purpose of the
`
`media fill is to assure that product can be aseptically processed without contamination under
`
`operating conditions. It would seem, therefore, that the maximum number of units of media filled be
`
`equivalent to the maximum batch size if it is less than 3000 units.
`
`http://www.fda.gov/IC EC lllnspections/lnspecfi onGuides/ucm074909.htm
`
`4/23
`
`FRESENIUS KABI 1026-OOO4
`
`

`
`10/16/2015
`
`Inspection Guides > Lyophilization of Parenteral (7/93)
`
`After filling, dosage units are transported to the Iyophilizer by metal trays. Usually, the bottom of
`
`the trays are removed after the dosage units are loaded into the Iyophilizer. Thus, the dosage units
`
`lie directly on the Iyophilizer shelf. There have been some situations in which manufacturers have
`
`loaded the dosage units on metal trays which were not removed. Unfortunately, at one
`
`manufacturer, the trays warped which caused a moisture problem in some dosage units in a batch.
`
`In the transport of vials to the Iyophilizer, since they are not sealed, there is concern for the
`
`potential for contamination. During inspections and in the review of new facilities, the failure to
`
`provide laminar flow coverage or a primary barrier for the transport and loading areas of a
`
`Iyophilizer has been regarded as an objectionable condition. One manufacturer as a means of
`
`correction developed a laminar fiow cart to transport the vials from the filling line to the Iyophilizer.
`
`Other manufacturers building new facilities have located the filling line close to the Iyophilizer and
`
`have provided a primary barrier extending from the filling line to the Iyophilizer.
`
`In order to correct this type of problem, another manufacturer installed a vertical laminar flow hood
`
`between the filling line and Iyophilizer. Initially, high velocities with inadequate return caused a
`
`contamination problem in a media fill. It was speculated that new air currents resulted in rebound
`
`contamination off the floor. Fortunately, media fills and smoke studies provided enough meaningful
`
`information that the problem could be corrected prior to the manufacture of product. Typically, the
`
`lyophilization process includes the stoppering of vials in the chamber.
`
`Another major concern with the filling operation is assurance of fill volumes. Obviously, a low fill
`
`would represent a subpotency in the vial. Unlike a powder or liquid fill, a low fill would not be
`
`readily apparent after lyophilization particularly for a biopharmaceutical drug product where the
`
`active ingredient may be only a milligram. Because of the clinical significance, sub-potency in a vial
`
`potentially can be a very serious situation.
`
`For example, in the inspection of a lyophilization filling operation, it was noted that the firm was
`
`having a filling problem. The gate on the filling line was not coordinated with the filling syringes,
`
`and splashing and partial filling was occurring. It was also observed that some of the partially filled
`
`vials were loaded into the Iyophilizer. This resulted in rejection of the batch.
`
`On occasion, it has been seen that production operators monitoring fill volumes record these fill
`
`volumes only after adjustments are made. Therefore, good practice and a good quality assurance
`
`program would include the frequent monitoring of the volume of fill, such as every 15 minutes.
`
`Good practice would also include provisions for the isolation of particular sections of filling
`
`operations when low or high fills are encountered.
`
`http://www.fda.gov/IC EC l/Inspections/lnspecfi onGuides/ucm074909.htm
`
`5/23
`
`FRESENIUS KABI 1026-OOO5
`
`

`
`10/16/2015
`
`Inspection Guides > Lyophilization of Parenteral (7/93)
`
`There are some atypical filling operations which have not been discussed. For example, there have
`
`also been some situations in which lyophilization is performed on trays of solution rather than in
`
`vials. Based on the current technology available, it would seem that for a sterile product, it would
`
`be difficult to justify this procedure.
`
`The dual chamber vial also presents additional requirements for aseptic manipulations. Media fills
`
`should include the filling of media in both chambers. Also, the diluent in these vials should contain
`
`a preservative. (Without a preservative, the filling of diluent would be analogous to the filling of
`
`media. In such cases, a 0% level of contamination would be expected.)
`
`LYOPHILIZATION CYCLE AND CONTROLS
`
`After sterilization of the lyophilizer and aseptic loading, the initial step is freezing the solution. In
`
`some cycles, the shelves are at the temperature needed for freezing, while for other cycles, the
`
`product is loaded and then the shelves are taken to the freezing temperature necessary for product
`
`freeze. In those cycles in which the shelves are precooled prior to loading, there is concern for any
`
`ice formation on shelves prior to loading. Ice on shelves prior to loading can cause partial or
`
`complete stoppering of vials prior to lyophilization of the product. A recent field complaint of a
`
`product in solution and not lyophilized was attributed to preliminary stoppering of a few vials prior
`
`to exposure to the lyophilization cycle. Unfortunately, the firm's 100% vial inspection failed to
`
`identify the defective vial.
`
`Typically, the product is frozen at a temperature well below the eutectic point.
`
`The scale-up and change of lyophilization cycles, including the freezing procedures, have
`
`presented some problems. Studies have shown the rate and manner of freezing may affect the
`
`quality of the lyophilized product. For example, slow freezing leads to the formation of larger ice
`
`crystals. This results in relatively large voids, which aid in the escape of water vapor during
`
`sublimation. On the other hand, slow freezing can increase concentration shifts of components.
`
`Also, the rate and manner of freezing has been shown to have an affect on the physical form
`
`(polymorph) of the drug substance.
`
`It is desirable after freezing and during primary drying to hold the drying temperature (in the
`
`product) at least 4-50 below the eutectic point. Obviously, the manufacturer should know the
`
`eutectic point and have the necessary instrumentation to assure the uniformity of product
`
`temperatures. The lyophilizer should also have the necessary instrumentation to control and record
`
`the key process parameters. These include: shelf temperature, product temperature, condenser
`
`temperature, chamber pressure and condenser pressure. The manufacturing directions should
`
`http://www.fda.gov/IC EC l/Inspections/lnspecfi onGuides/ucm074909.htm
`
`6/23
`
`FRESENIUS KABI 1026-0006
`
`

`
`10/16/2015
`
`Inspection Guides > Lyophilization of Parenteral (7/93)
`
`provide for time, temperature and pressure limits necessary for a Iyophilization cycle for a product.
`
`The monitoring of product temperature is particularly important for those cycles for which there are
`
`atypical operating procedures, such as power failures or equipment breakdown.
`
`Electromechanical control of a Iyophilization cycle has utilized cam-type recorder-controllers.
`
`However, newer units provide for microcomputer control of the freeze drying process. A very basic
`
`requirement for a computer controlled process is a flow chart or logic. Typically, operator
`
`involvement in a computer controlled Iyophilization cycle primarily occurs at the beginning. It
`
`consists of loading the chamber, inserting temperature probes in product vials, and entering cycle
`
`parameters such as shelf temperature for freezing, product freeze temperature, freezing soak time,
`
`primary drying shelf temperature and cabinet pressure, product temperature for establishment of fill
`
`vacuum, secondary drying shelf temperature, and secondary drying time.
`
`In some cases, manufacturers have had to continuously make adjustments in cycles as they were
`
`being run. In these situations, the Iyophilization process was found to be non-validated.
`
`Validation of the software program of a lyophilizer follows the same criteria as that for other
`
`processes. Basic concerns include software development, modifications and security. The Guide to
`
`Inspection of Computerized Systems in Drug Processing contains a discussion on potential
`
`problem areas relating to computer systems. A Guide to the Inspection of Software Development
`
`Activities is a reference that provides a more detailed review of software requirements.
`
`Leakage into a lyophilizer may originate from various sources. As in any vacuum chamber, leakage
`
`can occur from the atmosphere into the vessel itself. Other sources are media employed within the
`
`system to perform the lyophilizing task. These would be the thermal fluid circulated through the
`
`shelves for product heating and cooling, the refrigerant employed inside the vapor condenser
`
`cooling surface and oil vapors that may migrate back from the vacuum pumping system.
`
`Any one, or a combination of all, can contribute to the leakage of gases and vapors into the
`
`system. It is necessary to monitor the leak rate periodically to maintain the integrity of the system.
`
`It is also necessary, should the leak rate exceed specified limits, to determine the actual leak site
`
`for purposes of repair.
`
`Thus, it would be beneficial to perform a leak test at some time after sterilization, possibly at the
`
`beginning of the cycle or prior to stoppering. The time and frequency for performing the leak test
`
`will vary and will depend on the data developed during the cycle validation. The pressure rise
`
`found acceptable at validation should be used to determine the acceptable pressure rise during
`
`production. A limit and what action is to be taken if excessive leakage is found should be
`
`addressed in some type of operating document.
`
`http://www.fda.gov/IC EC I/Inspections/lnspecfi onGuides/ucm074909.htm
`
`7/23
`
`FRESENIUS KABI 1026-OOO7
`
`

`
`10/16/2015
`
`Inspection Guides > Lyophilization of Parenteral (7/93)
`
`In order to minimize oil vapor migration, some Iyophilizers are designed with a tortuous path
`
`between the vacuum pump and chamber. For example, one fabricator installed an oil trap in the
`
`line between the vacuum pump and chamber in a Iyophilizer with an internal condenser. Leakage
`
`can also be identified by sampling surfaces in the chamber after lyophilization for contaminants.
`
`One could conclude that if contamination is found on a chamber surface after lyophilization, then
`
`dosage units in the chamber could also be contaminated. It is a good practice as part of the
`
`validation of cleaning of the lyophilization chamber to sample the surfaces both before and after
`
`cleaning.
`
`Because of the lengthy cycle runs and strain on machinery, it is not unusual to see equipment
`
`malfunction or fail during a lyophilization cycle. There should be provisions in place for the
`
`corrective action to be taken when these atypical situations occur. In addition to documentation of
`
`the malfunction, there should be an evaluation of the possible effects on the product (e.g., partial or
`
`complete meltback. Refer to subsequent discussion). Merely testing samples after the
`
`lyophilization cycle is concluded may be insufficient to justify the release of the remaining units. For
`
`example, the leakage of chamber shelf fluid into the chamber or a break in sterility would be cause
`
`for rejection of the batch.
`
`The review of Preventive Maintenance Logs, as well as Quality Assurance Alert Notices,
`
`Discrepancy Reports, and Investigation Reports will help to identify problem batches when there
`
`are equipment malfunctions or power failures. It is recommended that these records be reviewed
`
`early in the inspection.
`
`CYCLE VALIDATION
`
`Many manufacturers file (in applications) their normal lyophilization cycles and validate the
`
`lyophilization process based on these cycles. Unfortunately, such data would be of little value to
`
`substantiate shorter or abnormal cycles. In some cases, manufacturers are unaware of the eutectic
`
`point. It would be difficult for a manufacturer to evaluate partial or abnormal cycles without knowing
`
`the eutectic point and the cycle parameters needed to facilitate primary drying.
`
`Scale-up for the Iyophilized product requires a knowledge of the many variables that may have an
`
`effect on the product. Some of the variables would include freezing rate and temperature ramping
`
`rate. As with the scale-up of other drug products, there should be a development report that
`
`discusses the process and logic for the cycle. Probably more so than any other product, scale-up
`
`of the lyophilization cycle is very difficult.
`
`There are some manufacturers that market multiple strengths, vial sizes and have different batch
`
`sizes. It is conceivable and probable that each will have its own cycle parameters. A manufacturer
`
`that has one cycle for multiple strengths of the same product probably has done a poor job of
`
`http://www.fda.gov/IC EC I/Inspections/lnspecfi onGuides/ucm074909.htm
`
`8/23
`
`FRESENIUS KABI 1026-OOO8
`
`

`
`10/16/2015
`
`Inspection Guides > Lyophilization of Parenteral (7/93)
`
`developing the cycle and probably has not adequately validated their process. Investigators should
`
`review the reports and data that support the filed Iyophilization cycle.
`
`LYOPHILIZER STERILIZATIONIDESIGN
`
`The sterilization of the lyophilizer is one of the more frequently encountered problems noted during
`
`inspections. Some of the older lyophilizers cannot tolerate steam under pressure, and sterilization
`
`is marginal at best. These lyophilizers can only have their inside surfaces wiped with a chemical
`
`agent that may be a sterilant but usually has been found to be a sanitizing agent. Unfortunately,
`
`piping such as that for the administration of inert gas (usually nitrogen) and sterile air for backfill or
`
`vacuum break is often inaccessible to such surface "sterilization" or treatment. It would seem very
`
`difficult for a manufacturer to be able to demonstrate satisfactory validation of sterilization of a
`
`lyophilizer by chemical "treatment".
`
`Another method of sterilization that has been practiced is the use of gaseous ethylene oxide. As
`
`with any ethylene oxide treatment, humidification is necessary. Providing a method for introducing
`
`the sterile moisture with uniformity has been found to be difficult.
`
`A manufacturer has been observed employing Water For Injection as a final wash or rinse of the
`
`lyophilizer. While the chamber was wet, it was then ethylene oxide gas sterilized. As discussed
`
`above, this may be satisfactory for the chamber but inadequate for associated plumbing.
`
`Another problem associated with ethylene oxide is the residue. One manufacturer had a common
`
`ethylene oxide/nitrogen supply line to a number of lyophilizers connected in parallel to the system.
`
`Thus, there could be some ethylene oxide in the nitrogen supply line during the backfilling step.
`
`Obviously, this type of system is objectionable.
`
`A generally recognized acceptable method of sterilizing the lyophilizer is through the use of moist
`
`steam under pressure. Sterilization procedures should parallel that of an autoclave, and a typical
`
`system should include two independent temperature sensing systems. One would be used to
`
`control and record temperatures of the cycle as with sterilizers, and the other would be in the cold
`
`spot of the chamber. As with autoclaves, lyophilizers should have drains with atmospheric breaks
`
`to prevent back siphonage.
`
`As discussed, there should also be provisions for sterilizing the inert gas or air and the supply
`
`lines. Some manufacturers have chosen to locate the sterilizing filters in a port of the chamber. The
`
`port is steam sterilized when the chamber is sterilized, and then the sterilizing filter, previously
`
`sterilized, is aseptically connected to the chamber. Some manufacturers have chosen to sterilize
`
`the filter and downstream piping to the chamber in place. Typical sterilization-in-place of filters may
`
`require steaming of both to obtain sufficient temperatures. In this type of system, there should be
`
`http://www.fda.gov/IC EC lllnspections/lnspecfi onGuides/ucm074909.htm
`
`9/23
`
`FRESENIUS KABI 1026-0009
`
`

`
`10/16/2015
`
`Inspection Guides > Lyophilization of Parenteral (7/93)
`
`provisions for removing and/or draining condensate. The failure to sterilize nitrogen and air filters
`
`and the piping downstream leading into the chamber has been identified as a problem on a
`
`number of inspections.
`
`Since these filters are used to sterilize inert gas and/or air, there should be some assurance of
`
`their integrity. Some inspections have disclosed a lack of integrity testing of the inert gas and/or air
`
`filter. The question is frequently asked how often should the vent filter be tested for integrity? As
`
`with many decisions made by manufacturers, there is a level of risk associated with the operation,
`
`process or system, which only the manufacturer can decide. If the sterilizing filter is found to pass
`
`the integrity test after several uses or batches, then one could claim its integrity for the previous
`
`batches. However, if it is only tested after several batches have been processed and if found to fail
`
`the integrity test, then one could question the sterility of all of the previous batches processed. In
`
`an effort to minimize this risk, some manufacturers have resorted to redundant filtration.
`
`For most cycles, stoppering occurs within the lyophilizer. Typically, the lyophilizer has some type of
`
`rod or rods (ram) which enter the immediate chamber at the time of stoppering. Once the rod
`
`enters the chamber, there is the potential for contamination of the chamber. However, since the
`
`vials are stoppered, there is no avenue for contamination of the vials in the chamber which are now
`
`stoppered. Generally, lyophilizers should be sterilized after each cycle because of the potential for
`
`contamination of the shelf support rods. Additionally, the physical act of removing vials and
`
`cleaning the chamber can increase levels of contamination.
`
`In some of the larger units, the shelves are collapsed after sterilization to facilitate loading.
`
`Obviously, the portions of the ram entering the chamber to collapse the shelves enters from a non-
`
`sterile area. Attempts to minimize contamination have included wiping the ram with a sanitizing
`
`agent prior to loading. Control aspects have included testing the ram for microbiological
`
`contamination, testing it for residues of hydraulic fluid, and testing the fluid for its bacteriostatic
`
`effectiveness. One lyophilizer fabricator has proposed developing a flexible "skirt" to cover the ram.
`
`In addition to microbiological concerns with hydraulic fluid, there is also the concern with product
`
`contamination.
`
`During steam sterilization of the chamber, there should be space between shelves that permit
`
`passage of free flowing steam. Some manufacturers have placed "spacers" between shelves to
`
`prevent their total collapse. Others have resorted to a two phase sterilization of the chamber. The
`
`initial phase provides for sterilization of the shelves when they are separated. The second phase
`
`provides for sterilization of the chamber and piston with the shelves collapsed.
`
`http://www.fda.gov/IC EC I/Inspections/lnspecfi onGuides/ucm074909.htm
`
`10/23
`
`FRESENIUS KABI 1026-0010
`
`

`
`10/16/2015
`
`Inspection Guides > Lyophilization of Parenteral (7/93)
`
`Typically, biological indicators are used in lyophilizers to validate the steam sterilization cycle. One
`
`manufacturer of a Biopharmaceutical product was found to have a positive biological indicator after
`
`sterilization at 1210C for 45 minutes. During the chamber sterilization, trays used to transport vials
`
`from the filling line to the chamber were also sterilized. The trays were sterilized in an inverted
`
`position on shelves in the chamber. It is believed that the positive biological indicator is the result of
`
`poor steam penetration under these trays.
`
`The sterilization of condensers is also a major issue that warrants discussion. Most of the newer
`
`units provide for the capability of sterilization of the condenser along with the chamber, even if the
`
`condenser is external to the chamber. This provides a greater assurance of sterility, particularly in
`
`those situations in which there is some equipment malfunction and the vacuum in the chamber is
`
`deeper than in the condenser.
`
`Malfunctions that can occur, which would indicate that sterilization of the condenser is warranted,
`
`include vacuum pump breakdown, refrigeration system failures and the potential for contamination
`
`by the large valve between the condenser and chamber. This is particularly true for those units that
`
`have separate vacuum pumps for both the condenser and chamber. When there are problems with
`
`the systems in the lyophilizer, contamination could migrate from the condenser back to the
`
`chamber. It is recognized that the condenser is not able to be sterilized in many of the older units,
`
`and this represents a major problem, particularly in those cycles in which there is some equipment
`
`and/or operator failure.
`
`As referenced above, leakage during a lyophilization cycle can occur, and the door seal or gasket
`
`presents an avenue of entry for contaminants. For example, in an inspection, it was noted that
`
`during steam sterilization of a lyophilizer, steam was leaking from the unit. If steam could leak from
`
`a unit during sterilization, air could possibly enter the chamber during lyophilization.
`
`Some of the newer lyophilizers have double doors - one for loading and the other for unloading.
`
`The typical single door lyophilizer opens in the clean area only, and contamination between loads
`
`would be minimal. This clean area, previously discussed, represents a critical processing area for a
`
`product made by aseptic processing. In most units, only the piston raising/lowering shelves is the
`
`source of contamination. For a double door system unloading the lyophilizer in a non-sterile
`
`environment, other problems may occur. The non-sterile environment presents a direct avenue of
`
`contamination of the chamber when unloading, and door controls similar to double door sterilizers
`
`should be in place.
`
`Obviously, the lyophilizer chamber is to be sterilized between batches because of the direct means
`
`of contamination. A problem which may be significant is that of leakage through the door seal. For
`
`the single door unit, leakage prior to stoppering around the door seal is not a major problem from a
`
`http://www.fd