James E. Akers is the president of Akers Kennedy & Associates, PO Box 22562, Kansas City, MO 64113, akainckc@aol.com.

James E. Akers

There's been a steady stream of compliance documents from global regulatory authorities concerning aseptic processing. These regulations require the healthcare and pharmaceutical industries to do the impossible—unequivocally establish the sterility of the materials we produce. Although this goal seems logical and laudable to the ill-informed, it defies available, real-scientific capabilities. The expectation seems to be based either on personal opinion or untested hypothesis, discounting the realities that such proof might entail. 

A common perspective underlying regulatory documents that call for a "proof" of sterility is the belief that industry can somehow use microbiological analysis and other select and, often-subjective, tests to prove that sterility has been attained. Such proof does not technically exist and is not scientifically possible. There are dangers implicit in regulatory authorities requiring industry to attempt to prove the unprovable. These misguided efforts create circumstances in which industry can never truly accomplish the intended objective and, as such, can always be found to have made insufficient efforts to support sterility-assurance programs. 

Users of isolation technology, for example, have been asked to increase environmental monitoring (EM) to extreme levels because existing monitoring programs established for manned cleanrooms cannot detect contamination. Scientifically and legally, these standards have left industry with both feet firmly planted in mid-air. The result, as evidenced from recent inspections, is that if an inspector wishes to use these documents to insist that a firm lacks "sterility assurance," then there is virtually no way the manufacturing firm can defend itself. 

It is always possible to start an inspection report with the following statement, "The firm failed to demonstrate sterility assurance in that...." It's impossible to objectively prove or disprove this allegation. Sterility is an absolute concept, and its presence cannot be proven, regardless of the effort to do so. 

Examples of unprovable regulatory citations include claims of inadequate air visualization (smoke studies), claims regarding the conduct of media fills, the acceptability (or not) of a specific aseptic intervention, and charges regarding the adequacy of environmental monitoring. Metrics for smoke-test success are absent. This test is strictly an eye-ball exercise in which one party may see one thing and another sees something quite different. Although smoke tests are valuable for fine-tuning certain elements of critical-zone performance, they rarely lead to real performance improvements. 

Airflow is another example. Airflow in cleanrooms is some-times incorrectly called "laminar," but in practice, laminarity cannot be achieved. No matter how well-designed or qualified an isolator or cleanroom is, there always will be turbulence and eddy currents. There is no objective standard for the point at which adequacy no longer exists or at which turbulence might affect sterility assurance, if it ever does. 

Media-fill conduct is yet another issue without an endpoint. In recent years, regulators have required larger and longer media fills and placed an increased emphasis on using media fills as long as the longest production run. However, change does not enable proof of sterility. No media fill, no matter how large or intensive, can ever prove sterility. New conditions can always be added to a media-fill program, even if those conditions are atypical. Recently, FDA has expected that the production and filter sterilization of media parallel the compounding and filtration of product. Yet, media and product are two very different materials with different attributes. The most obvious of these differences is that media will amplify the presence of contamination, which the majority of products will not do. Also, media may contain insoluble particu-late in quantities not seen with most aqueous formulations which means prefiltration is a must. There is nothing to be gained from ever larger media fill tests with activities that really don't relate to process simulation being required 

Another prevailing notion is that some aseptic processing interventions are inherently bad. There's no question that heroic efforts during aseptic processing should be avoided. But what makes a particular intervention good or bad? We have no useful metrics, to assess the difference, yet such categorization is all too swift and final. Furthermore, media-fill tests, no matter how intensive, cannot reliably demonstrate (or validate) that an intervention is low-risk, nor can they unequivocally prove that an intervention is bad. Neither media-fill or eyeball tests are inherently sound arbiters of sterility assurance. In absolute terms, they are both inadequate for such a task. Destroying a batch because an intervention is arbitrarily assumed to be "bad" is not much different than accepting a different batch made with a series of "good" interventions. 

EM has been increasing as a consequence of regulatory pressure for at least 20 years, but there is never any consideration of diminishing return or even patient risk arising from EM-related interventions. Quite simply, it is not possible to monitor quality into product (something we've known since the very origins of validation in the 1970s) and it will never be possible to use EM to prove sterility. EM is neither sensitive nor accurate enough to pinpoint when intervention might put a patient at risk. EM has significant and inherent, technical limitations and we have likely passed the point of diminishing return on it within even manned cleanrooms. This is an acknowledged fact that's never contemplated in current regulation. 

The absolutist thinking regarding sterility assurance plays a significant role in standards development. Both industry and regulatory authorities would benefit from a serious dialogue about the nature of aseptic processing regulation. Intensity and length of effort cannot alone ensure sterility. Monitoring, even if continuous, and smoke tests, even if comprehensive, cannot ensure sterility. Unfortunately, subjective evaluation of such data can result in regulatory observations that are not pertinent and may be irrelevant. 

The authors are raising this issue now because we believe that evolving aseptic-processing technology has rendered the traditional evaluative methods less useful. These more advanced processes consistently operate below the limits of detection for the presently available microbiological assays. 

As processes have improved and "zero" results have become the norm, the regulatory reaction has been to multiply the test and in-process workload which, while intuitively logical, is scientifically inappropriate and, unfortunately, valueless. We suggest that rapid microbiology, drawing increasing attention by industry, only provides the same imprecise information about the aseptic process we already have, albeit somewhat sooner. The use of that "information" is what the authors are concerned about, not the time it takes to obtain it. Rapid microbiology is very useful technology, but it cannot overcome the sampling limitations that exist. No analytical method (microbiological, chemical, or physical), regardless of how advanced and sensitive, can measure the complete absence of something. Sterility is, by definition, the complete absence of viable contamination. 

The authors seek to highlight the increasingly arduous regulatory spiral into which we have been drawn. The most practical way forward is to carry out honest and detailed dialogue between all stakeholders. In many technical endeavors, there's a time at which paradigm shifts are required. Discipline of aseptic processing is now at such a point. Continuing to follow the same path of the past two decades will neither improve end-user safety nor the economics of manufacture. 

A process-centric approach for superior performance

To successfully manufacture sterile products by aseptic means, it's necessary to redefine the process controls essential for success. Central to the authors' suggested approach is the use of the Akers-Agalloco (A-A) method for aseptic-processing risk analysis to support the evaluation and selection of the specific means for aseptic-process design and execution (1,2). Our preference for this over other methodologies is based upon the absence of inference from EM results. Katayama et al, in their review of aseptic-processing risk models, identified the A-A method as having the closest correlation to the operational performance evidenced for a variety of different installations (3). 

Central to aseptic processing is the understanding that there are numerous factors that can influence the outcome (see Figure 1). 

Figure 1: Influences on aseptic processing (Adapted from L. Mastrandrea, Ref. 9). 

The authors believe it's the decisions, selections, and approaches—made with respect to each of the factors depicted in Figure 1—that have the greatest effect on results. Poor choices, regardless of the monitoring outcomes associated with them, must be acknowledged as unsound. Our approach differs from those derived from EM expectations because of our focus on personnel and their impact on contamination levels. The rankings in the A-A method devolve from a singular focus on the operator. From that perspective, the authors established the following basic precepts to the A-A risk method and the recommendations outlined below (4, 5):  

Interventions are to be avoided at all times in aseptic processing

Interventions always mean increased risk to the patient

The "perfect" intervention is the one that doesn't happen. 

In turn, these steps should be followed with respect to aseptic processing: separate personnel from the aseptic environment; limit employees' interaction with sterile materials; where possible, entirely remove personnel from the aseptic environment; and combinations of the above. The means for accomplishing these goals are embodied in following methodologies (6):  

The use of automation technology to reduce or eliminate personnel interventions and, thus, personnel-borne contamination

The use of separative technologies to minimize the impact of personnel-derived contamination.

These methods are central to our recommendations for the supportive elements of aseptic processing. In defining these elements, the authors are adapting a quality-by-design (QbD) approach as defined in recent regulatory documents (7,8). The details for QbD in aseptic processing are somewhat different from the applications of this concept in the typical formulation or synthesis process. As we outlined in the first half of this paper, the establishment of direct linkage between a monitored condition and the outcome, with respect to an aseptic process, is uncertain. The situation, with respect to the definition of physical-design elements, is very similar. Contemporary aseptic-processing facility and process design include several seemingly rigorous design expectations for performance, including such precepts as:  

Air velocities of 90 FPM (0.45 m/sec) ± 20% for ISO 5 air in critical environments

Air changes of > 150 per hour in critical environments

Pressure differentials of NLT 0.05" water column between different classifications.

These expectations, and others like them, should be considered suggestions rather than definitive requirements because they have less correspondence to the process outcome than EM. The authors' recommendations for QbD, with respect to aseptic processing, are non-numeric because it is our strong belief that there are no ready means to demonstrate their suitability. Instead, we suggest that QbD for aseptic processing be driven toward eliminating the impact of personnel on the process. The means to accomplish this vary depending on the particular aspect of the overall process under consideration. 

The following recommendations for various aspects of the aseptic processing facility adhere to our central premise of reducing the potential adverse impact of personnel on the core aseptic process. They are not intended to be inclusive—other suggestions could be added. 

Facilities should be designed for easy sanitization/decontami-nation through proper use of construction materials, ease of access, and design details that facilitate cleaning

Facility layouts should minimize the potential for mixups and cross-contamination 

Air system should provide adequate air pressurization to preclude the ingress of contamination from surrounding less-clean environments

Airflow patterns should facilitate the removal and exclusion of contamination from critical environments

Air systems should be supplied with HEPA filters that are periodically integrity tested

Differential pressure should be monitored and alarmed to demonstrate continuous integrity of the core aseptic area

Temperature and humidity should be controlled to maximize personnel comfort during operations consistent with product stability/safety requirements

Interlocks should be used to prevent pressure reversal

Advanced aseptic-processing designs such as closed restricted access barrier systems (RABS) and isolators, should be given preference in selection of processing environments

All facility and environmental surfaces should be resistant to the potential corrosive action of sanitizing and decontamination agents

The aseptic portion of the facility should be maintained in clean state at all times and periodically sanitized or decontaminated

Isolators and closed RABS should be treated with sporicidal agents on a periodic basis.

A minimum of materials should be retained in the aseptic portion of the facility

Smoke studies, air-velocity measurements, expectations for unidirectional airflow, absence of eddy's, and other subjective expectations imposed on aseptic-processing HVAC systems should be recognized as useful, but non-definitive means for assessing aseptic processing environmental performance.

Product-contact surfaces of equipment must be sterilized using a validated method (vibratory feed systems may be exempted from this requirement provided they are high level decontaminated with a sporicidal agent in-situ)

Sterilization-in-place and clean-in-place should be used wherever possible

Equipment should be assembled to the fullest extent possible prior to sterilization

Articles

The authors propose a process-centric approach for carrying out aseptic-processing and suggest further dialogue. This articles contains bonus online-exclusive material.

The Myth Called "Sterility"

A visit to a pharmaceutical aseptic processing operation in the 1970s would have some automation on display, but certainly nothing like what is possible today. Just three decades ago, automation consisted primarily of filling, stoppering, and capping of vial products, or filling and heat-sealing of ampules. Filling of syringes, to the extent it was done at all, involved extensive manual intervention. Lyophilization required completely manual transport of filled and partially stoppered vials from the end of the filling line to the lyophilizer. Once the containers arrived at the lyophilizer, the unit had to be completely loaded by hand, starting generally from the top shelf and working to the bottom, with the operators often ascending and descending ladders to reach the top shelves of the large-production lyophilizers. Of course even this task was a major advance over what one would have seen in the 1940s, when aseptic processing was predominantly a manual operation using rudimentary clean booths or glove boxes.  

By the late 1970s, there was a greater awareness emerging regarding the impact of gowned operators in aseptic processing, and some industry scientists began to state this fact clearly and publicly. A 1988 article entitled, "A Review of Current Technology in Parenteral Manufacturing," written by members of the PDA research committee, stated forcefully that the principal contamination concern in aseptic processing was personnel-related contamination. This article noted that emerging technologies were already mitigating contamination risk. It was in that same decade that the authors became fully aware of the impact of personnel-borne contamination and took part in projects in which the processing equipment was specifically designed to mitigate that risk through the application of automation (1).  

Early experiences in automation as a risk-mitigating factor

In 1981, one of us (Akers) took a position in which he was responsible for environmental monitoring and media fill. The aseptic processing operation in this facility was quite diverse and consisted of vials, ampuls, drop-dose products (both otics and ophtalmics), powders, and ointments. The basic mode of production was generally the same in all cases. Glass or plastic containers as well as caps, stoppers, dropper tips, and ointment tubes were sterilized by dry heat, ethylene oxide gas, or moist heat. After sterilization in bags or trays, these components were manually transferred to the filling rooms and then loaded by operator interventions onto accumulators or into parts hoppers. Process filters were also autoclaved and connected to the wetted path aseptically by operators; in fact, all setup activities were manual. In addition, all on-line sampling, weight checking, and equipment adjustment during processing were fully manual and required near-constant intervention.  

It is both important and interesting to note that the practice of process simulation was at that time in its infancy as an absolute requirement and in fact had not yet become a standard practice for ointments. Typical media fill acceptance criteria were no more than one contaminant per each 1000 units filled. In our facility, successful media fills (i.e., those that met the acceptance criteria) were in the majority, but perfect media fills were a rarity. It should be noted as well that no media fill required more than a 3000 unit sample size. Typical line speeds were in the 40–60 unit/min range.  

It was obvious as we studied media-fill outcomes that ampul processes provided the best results. Interestingly, ampul lines consisted of only one component and generally required fewer people and fewer interventions. Plastics, tubes and–to a lesser extent–vials were more challenging and required more personnel and a higher level of intervention intensity. However, the media fills that caused the most concern were those that involved lyophilization, which not surprisingly required more personnel and more interventions because the lyophilizer chambers had to be loaded manually. Thus, we knew empirically in the early 1980s what subsequent risk analysis studies have confirmed; namely, that manual lyophilizer loading was (and in some cases still is) a significant aseptic risk factor.  

After a few years, a new vial line was installed that for the first time introduced automatic vial washing, continuous dry-heat tunnel for sterilization, and depyrogenation of glass vials. This far more advanced processing line operated at up to 300 vials/min and required only two operators, while the older vial lines it replaced required as many as six people working constantly. This processing line also featured far better stopper feeding and needed far fewer line interventions. The results were dramatic. As a result of the higher speed, media-fill tests expanded in sample size to 5000 units or more, and zero contamination results became far more common (2). In addition, although the cleanroom design and gowning conditions remained unchanged, environmental monitoring results were quite obviously improved in every facet. This fact was attributed to the lower personnel population in the filling room and the less vigorous work required because vial supply, previously a laborious task, had been fully automated. 

Not long after the introduction of this improved and more automated vial line, a continuous ampul line was introduced and the improved performance was even more striking. Because of the very high speed operation and changing regulatory requirements, management made the decision to conduct media fills that lasted one full hour. As a result, media-fill sample size increased to approximately 25,000 units. Only one operator was required to run the line, and by and large they were only required to observe the line and to correct infrequent jams. An important lesson was learned and a lasting impression was made: Automation and the elimination of interventions reduced risk, not just theoretically but in practice as the results emphatically demonstrated (3, 4).  

During the late 1980s, Shibuya Kogyo (Kanazawa, Japan) was selected to design, build, and install a state-of-the-art vial processing line at E.R. Squibb (New Brunswick, NJ). This vial production line embodied what were a number of automated features that are now rather common but were quite unusual two decades ago. One of us (Izumi) was directly involved in this project and the other (Akers) was fortunate enough to visit the facility not long after validation was completed and eventually became a technical consultant to Shibuya Kogyo. This facility not only had a fully automated vial-washing and depyrogenation system but also included automated weight checking, vial-handling advancements designed to prevent misfeeds, automated clean-in-place and steam-in-place systems to eliminate aseptic connections in set-up, and automated lyophilizer loading of three large production lyophilizers. Although the data processing and acquisition systems available at that time were far less sophisticated than what is available today, this filling line was arguably the most sophisticated aseptic production line in use in the pharmaceutical industry at the time of its installation. Automation had eliminated even the highly risk intensive aseptic set-up and lyophilization loading activities.  

The ability of this system to run with minimal line stoppages and infrequent interventions pointed the way to the future in another way. It seemed that a marriage of automation and isolator technology, which was also an emerging and exciting new concept in pharmaceutical aseptic processing, would be a logical way forward. This has proved to be the case and the remainder of this article will be devoted to an overview of a few projects undertaken over the past decade and a half and will explain the role played by automation in solving sometimes difficult production challenges. 

 defines automation as "The technique, method, or system of operating or controlling a process by highly automatic means, as by electronic devices, reducing human intervention to a minimum." This is obviously and appropriately a very broad definition that includes what might be called machine automation as well as the field of robotics. Over the years, we have been involved in several projects that use automation and robotics, usually within the same process with the objective of as 

 says, "reducing human intervention to a minimum." However, the objectives in these pharmaceutical manufacturing projects are not merely to relieve human operators of repetitive and often boring tasks undertaken in difficult or uncomfortable environments but also to reduce end user or patient risk from contamination. Experience has shown that automation and robotics can achieve both of these goals. In cases of high pharmacological activity and allergenic, cytotoxic, and radiological products, the benefit of increased operator safety also can be added (5).  

Combination products, automation, and separative technologies

The first project began in 1994, when Shibuya Kogyo designed several filling lines for Nipro Corporation (Osaka, Japan) (6). These aseptic fill lines were for beta-lactam antibiotics and involved both automatic parts feeding and assembly. The first filling line involved no less than 13 isolators, a blow–fill–seal bag filling process, terminal sterilization with automatic feed and unload, and two semicontinuous vapor-phase hydrogen peroxide (VPHP) surface decontamination systems for component in feed. The finished product consisted of a terminally sterilized bag aseptically assembled to a double-ended linkage into which a prefilled standard glass vial was fit. The user activated the product and initiated reconstitution by simply twisting the linkage that contained a device with double-ended needles.  

A fully safe liquid pathway was then created to mitigate risk that inevitably arises from product admixture. Nipro designed and built the main assembly system that incorporated robotic assembly stations. Shibuya was responsible for the isolators, the VPHP tunnels, the parts feeders, and total system integration. The largest isolator was the autoclave interface, which contained the conveying apparatus for loading specially designed bag positioning pallets into the autoclave. This isolator had an enclosed volume of more than 1800 ft

, in fact the both the number and total enclosed isolator volume of this project still exceed that of any aseptic processing line build anywhere in the world. 

Given the size, scope, and complexity of this system, success would simply not have been possible without an extensive use of automation. In some cases, the materials supply requirements were such that undertaking them by human intervention would have been impossible in isolator technology.  

Shibuya Kogyo and Nipro have collaborated on several other filling lines for dual-container products in which two separate bags are assembled together and reconstitution occurs by the opening of a pealable seal between the two bags. These products require both a highly automated liquid fill line and a powder fill line as well as an assembly station. Restricted access barrier systems (RABS), isolators, automation, and terminal sterilization are used to achieve the most reliable outcome in terms of sterility assurance while retaining desired production reliability and therefore consistent throughput (4) 

Radiopharmaceuticals are not only aseptically filled but also have human exposure considerations. For this application, an isolator was the most effective choice for the filling environment, while robots were used for product packaging, labeling, and inspection. This system produces radiopharmaceuticals in both vials and syringes, which underscores another important feature of robotics: positive container handling with easy adaptability without the change parts normally associated with format changes.  

Robotics has the further advantage of avoiding the need for extensive lead shielding because the system is designed to operate without intervention. This design saves both equipment and facility costs and makes access simpler when the facility is undergoing periodic maintenance. The flexibility of the robots also facilitated the incorporation of visual systems for the inspection of each syringe and vial and the verification of proper labeling information. The system has automatic alarm and rejection should a problem be detected. This production system proved again that a variety of advanced technologies, including isolators, automatic inspection systems, automated filling systems, and robotics could be brought together to ensure a high level of aseptic process control with enhanced overall production reliability. 

A few years ago, Shibuya Kogyo undertook the design and manufacture of a high-speed vial line for vaccines that was delivered to Handai-Biken (Kagawa, Japan) (7). Commercial production from this facility commenced in 2005. All product filling, lyophilization, and stoppering are performed in unidirectional airflow isolators that comply with ISO 14644 Class 5 requirements. The system consists of five isolator sections:  

Depyrogenation tunnel and filler interface

The total enclosed volume for this isolator network is 47.3 m

, with the lyophilizer loading and unloading and rubber stopper feed isolators each comprising about 17 m

Both machine automation and robotics play central roles in the operation of this production line. The depyrogenation tunnel has push-button setup and fully automatic sterilization of the cooling zone. It also has an automatic vial-counting system to ensure that each row of glass entering the tunnel is carefully arranged and introduced without crashing the vials into the previously loaded row. This automated feature reduces the likelihood of vial breakage.  

The filling system has two weight-control features. The first is an automated mass flowmeter filling system in which all fill data are digitized and electronically stored. The second system is a gravimetric weight-check system that uses load cells to take empty and filled vial weights. The gravimetric weight-check data are also digitized and stored electronically. Both systems automatically alarm and reject out-of-specification containers. Actual fill-weight accuracies attained with the mass flow system are measured within ± 0.5% of the target. 

The rubber-stopper supply system is fully automatic and uses the first VPHP-compatible robots installed and validated in the world. One such robot unloads sterilized containers of rubber stoppers from the autoclave, while a second robot lifts these cans and replenishes the load of stoppers in the feed hopper when signaled to do so by a level sensor. Thus, human operators are not involved in transporting containers of stoppers nor do they play any role in the feeding of stoppers into the feed hoppers. 

Like the previously described vial line installed in the United States, the Handai-Biken system has fully automated lyophilizer loading and unloading. In this case however, the loading system is not only fully automatic, it is also VPHP decontaminated and operates within an isolator enclosure. This filling line is an excellent example of the marriage of machine automation and robotics with modern isolator technology. The use of isolators and VPHP decontamination requires that all components be resistant to long-term exposure to H

This article provides only a glimpse into the history of automation in aseptic processing and its development during the past three decades (8). Although our experience is extensive, we realize that there are many other examples of the use of automation in aseptic processing and the marriage of automation with modern separative environments such as isolators. We do not see the evolution in aseptic technology described in this article coming to an end; rather we believe it will follow an accelerating trajectory onward and upward. The future of aseptic technology lies in the continued implementation of automation with the ultimate goal being the complete elimination of interventions altogether. We have glimpsed this future with the design and installation of high speed "interventionless" aseptic processing systems operating at throughputs as high as 1200 containers/min.  

Robotics continue to evolve as well, and VPHP-compatible six-axis robots are being designed for cytotherapy products among other potential production, research, and testing applications. These robots can be operated either under full electronic programmed control, or by humans controlling them by remote control devices called "Manipens." Current software allows the operator to quite literally train the robot to perform a specific task. These robots can interface well with single-use technologies (disposables) and are well-suited for aseptic compounding operations as well.  

The future of automation and robotics in aseptic processing is an exciting one. Thousands of industrial robots are undertaking a wide range of manufacturing tasks in facilities throughout the world. Our industry has actually been relatively slow to adopt robots, but we believe change is underway and that the future of aseptic processing is one in which human contamination is no longer a risk (9). 

 is executive vice-president at Shibuya Hoppmann Co., a subsidiary of Shibuya Kogyo, Co. Ltd. 

 is president of Akers Kennedy Associates and technical consultant to Shibuya Kogyo, Co. Ltd., 

*To whom all correspondence should be addressed. 

 1. J. Akers et al., "A Review of Current Technology in Parenteral Manufacturing," 

Guidance for Industry: Sterile Drug Products Produced by Aseptic Processing

 3. J. Akers and J. Agalloco, "Aseptic Processing: A Current Perspective," in 

, R. Morrisey and G.B. Phillips, Ed. (Van Nostrand Reinhold, New York, NY, 1993). 

 4. J. Agalloco, J. Akers, and R. Madsen, "Current Practices in the Validation of Aseptic Processing–2001," 

PDA Technical Report #36, PDA J. Pharm. Sci. Technol. 

 5. J. Agalloco and J. Akers, "Risk Analysis for Aseptic Processing: The Akers-Agalloco Method," 

 6. J. Akers et al., "Manufacture of a Dual Chamber 'Kit' Product Utilizing a Combination of Aseptic Fill in Isolators and Terminal Sterilization," 

Proceedings of the ISPE Barrier Isolator Technology Conference, 

 7. J.E. Akers, M. Kokubo, and Y. Oshima, "The Next Generation of Aseptic Processing Equipment," Aseptic Processing Supplement to 

 8. J. Akers, K. Tanimoto, and M. Kawata, "Aseptic Processing the Japanese Way," 

 9. W. Morris and E. Hough, "Risky Business-Aseptic Processing," 

The authors review the role of automation in aseptic processing and describe their experience in implementing advanced technologies, including the use of isolators and robotics.

The Impact of Automation on Aseptic Processing

Robotic sampling can be applied to the surface sampling of isolators, restricted access barrier systems (RABS), and other critical environments where sampling by human operators results in a potentially risky intervention near sterile surfaces and components or is ergonomically difficult to achieve. Although this robotic environmental monitoring system has previously been reported upon in several public lectures, this article for the first time provides data regarding the performance of this system in surface sampling (1). This automated approach to environmental monitoring—aimed at reducing interventions—was developed in response to the US Food and Drug Administration's 2004 

Guideline on Sterile Drug Products Produced by Aseptic Processing

Pharmaceutical CGMPs for the 21st Century: A Risk-Based Approach

. The ultimate objective is to eliminate human interventions in critical aseptic space and to collect process control data in real time as much as current technology allows (2). This article presents a study of an aseptic environmental monitoring system for surface contamination at critical areas using a robot that can be programmed according to predetermined sampling parameters.  

The robotic system described conducts active-air and settle-plate monitoring as well as surface monitoring using swabs. However, this article reports only on studies done on the surface-sampling capabilities of this robotic system. It is anticipated that in production operations, this system would handle surface and air sampling and that nonviable or total particulate sampling would be automated as well, using currently available technology. The authors hypothesized that a robot that can be programmed in terms of pressure applied to a swab, and also can be programmed to sample a given surface in a highly reproducible manner in terms of area sampled, might actually yield better recovery than a human sampler.  

In the near future, an automatic environmental monitoring system could also include rapid microbiological methods, which would allow the direct, and nearly real-time enumeration of contamination. The authors understand, however, that because those technologies would enumerate cells rather than colony forming units (CFU), some reconsideration of monitoring levels or contamination incidence rates would be required. 

Isolators were introduced for aseptic processing in the 1980s, and for the most part, conducting environmental monitoring has been logistically difficult. In some projects, microbiological monitoring could not be easily accommodated, and modifications to the system's design were required after the fact. At present, the reliability of gloves and half-suits is widely considered a weak point in isolator or RABS operations. The authors believe that the automation of environmental monitoring to avoid direct human intervention will be a requirement in the evolution of gloveless aseptic processing systems. In addition, the automation of environmental monitoring and consideration of locations and sampling points during the construction of the filling system will obviate planning and logistics issues concerning environment monitoring (3,4).  

A corollary benefit of an automated approach to microbiological monitoring will be near elimination of false positives (2). The system reported in this article requires no manipulation by human operators either in preparing samples or in handling them. Also, because the sampling materials can be identified automatically by barcode, the control system can correlate the sample identification with location and time that are then stored electronically (1). All sample materials are vapor-phase-hydrogen-peroxide-decontaminated before use. 

, a vegetative Gram-positive coccus, and 

, a spore, were selected as test organisms. These microorganisms were selected because they are representative of common human associated organisms, which are often Gram-positive cocci, and also of spore-bearing organisms that may enter on supplies or apparatus that might not have been properly decontaminated. Small stainless-steel coupons were used as carriers of the test microorganisms. The carrier surface was polished to 320 grit and a predetermined number of CFU was inoculated on the polished surface of the carrier. A metal surface finish of 320 grit was chosen because it is broadly representative of a level of polish applied to critical surfaces of the filing and component feed machinery. In general, the surfaces of isolator enclosures are given a similar surface finish. The inoculated carriers were air-dried under HEPA-filtered uni-directional airflow. 

After some preliminary experimentation with commercial swabs (Becton, Dickinson and Company in Franklin Lakes, NJ, and ITW Texwipe in Mahwah, NJ), the authors developed specifications for a swab apparatus that was then custom made. After test operation, all swab rods were incubated in Soya Bean Casein Digest broth at 30° C for two weeks and then inspected for the presence of colonies indicative of microbial growth. The relatively long incubation time was chosen to ensure maximal recovery. 

The swab sampling experiments were conducted using the test parameters listed in Table I. The authors hypothesized that when the wet-swab method was used, the microbial recovery rate might vary as a function of moisture content in the swab tip. Therefore, two moisture levels were evaluated in this study. To ensure a very moist swab in one study, the tip was moistened immediately before use. To achieve a higher moisture level, swabs were soaked one day before use to ensure the full saturation of the swab tip. 

Table III: Wet swab efficiency with distilled water as wetting agent (robot).			

When the dry-swab method was used, the observed recovery (CFU) correlated well with the inoculation level for 

 colonies were observed after incubation. A high swabbing force resulted in better recovery of spores (see Table II). In addition, the wet method, in which distilled water was used as the wetting agent, gave much better recovery efficiency than was observed using dry swabs. Sufficient time for absorption of water into the swab tip resulted in more efficient recovery. In addition, recovery efficiency was significantly affected by the speed at which the swab moved across the surface being sampled (see Table III).  

Table IV:Wet swab efficiency with distilled water 10.1%Tween80 as wetting agent (robot) .			

When the wetting agent was changed from distilled water to mixture 0.1%Tween 80 in distilled water, the rate of recovery of 

 improved, but complete recovery could not be achieved. Increasing the number of back-and-forth swabbing motions actually resulted in a decrease in recovery rates (see Table IV). A comparison of manual sampling to robotic sampling under the same test conditions showed a lower recovery rate associated with manual swabbing. The recovery efficiency observed with manual swabbing was approximately 20%. Additionally, far more variability in recovery was observed with manual swabbing as compared with robotic swabbing (see Table V). 

Table V: Wet swab efficiency (manual).			

Wet-swab sampling often is avoided in aseptic operations because of concerns about residual moisture that might encourage microbial proliferation. However, the experimental data clearly confirm that moistened swabs are much more effective in terms of contamination recovery. We observed that using surfactant Tween 80 resulted in improved recovery as compared with using plain distilled water. It has been reported that dry, agglomerated microorganisms can strongly adhere to surfaces; therefore, it is logical that moistened swabs, particularly with the addition of a surfactant, can recover this contamination from surfaces. Given the benefits of using moistened swabs, surface monitoring could best be executed just after the completion of an aseptic production operation or in advance of breaking the aseptic condition of the isolator or RABS. As demonstrated in Table IV, even when using the robot for sampling, better efficiency of recovery was observed with 

The most significant difference between these two test organisms is that 

is a spore. The sizes are also different. The size of the former is ~0.7–0.8 Âµm, and the latter has a diameter of ~1 × 2–3 Âµm, although it is unknown to what degree the size of the organism plays a role in recovery efficiency. Consequently, the authors believe the primary considerations in recovery efficiency differences between these two organisms are: spores as compared with vegetative cells, and the agglomeration and adherence to the test coupon. The authors also believe the physical composition of the swab tip may play a role in recovery efficiency. Additional investigation is needed to determine which factors have the greatest influence on recovery rates. 

Recovery efficiency was influenced by the time allowed for soaking the swab tip with the wetting agent. Wetting the swab immediately before use does not appear to allow sufficient time for saturation to occur. The authors believe that wetting immediately before use results in a swab that is completely dry before the completion of the swabbing action and therefore less efficient. In this case, the full benefits of wet swabbing are not realized. When the swab tip is allowed to soak overnight before use, however, the swab retains moisture from beginning to end of the swabbing action. The fully saturated swab gave a superior recovery efficiency of microorganisms. Therefore, the degree of wetness of the swabs plays a critical role in recovery efficiency. 

could not be achieved in these experiments, which is not surprising. However, the robotic sampling operation could achieve much better recovery of 

 than could manual sampling. This better result could be attributed to the robot's more precise control over sampling speed, pressure, and area (5) (see Figures 3–7). 

The experimental data suggest that the operating parameters of robotic surface sampling shown in Figure 7 result in the best rates of recovery. However, further investigation will be required to determine whether higher recovery rates can be obtained with other robotic sampling parameters. The authors will investigate both the influence of robotic sampling parameters as well as other variables such as swab-tip composition, flexibility of the swab's rod, and recovery media. It is significant that the recovery rates observed with the robotic swab method were in many cases three to fourfold higher than those that resulted from manual swabbing under otherwise identical experimental conditions. These results indicate that robotic sampling has the potential to improve the limit of detection of surface monitoring and also to reduce variability. 			

The authors believe the automated approach to monitoring reduces the likelihood of false-positive results, although they did not attempt to quantify this benefit. Of course, because the robotic sampling parameters are variable and user-selectable, it will be possible for users to define sampling conditions that are optimal for their particular application (6). The authors are also aware that the robotic surface-sampling method may afford advantages in terms of chemical recovery. This means that a robot installed in an isolator for microbiological sampling could be used to assess cleaning effectiveness as well. This, of course, would depend upon the location of the robot within an enclosure or RABS environment.  

 work in the Microbial Control Department at Shibuya Kogyo Co., Ltd. in Kanazawa, Japan. 

 is the president of Akers Kennedy & Associates, PO Box 22562, Kansas City, MO 64113, 

*To whom all correspondence should be addressed.

 1. J.E. Akers and Y. Oshima, "PAsepT, Aseptic Vial Filling Processing Based on Principles of PAT," in 

Presentation at the ISPE Annual Conference

 2. M. Deguchi, et al, "Development of an Advanced High Speed Aseptic Filling System," in P

roceedings of the PDA International Congress

 3. B. Ljungvist, B. Reinmüller, and R. Nydahl, "Microbiological Assessment in Clean Rooms for Aseptic Processing," 

 4. J.E. Akers, "Environmental Monitoring and Control: Proposed Standards, Current Practices and Future Directions," 

 5. NASA, NASA Handbook for Biological Engineers (National Aeronautics and Space Administration, Washington, DC, 1971).  

 6. J. Levchuk, "FDA's Perspectives on Aseptic Process Validation," in 

Proceedings of the Third Annual GMP by the Sea Conference

 (University of Rhode Island School of Pharmacy, Kingston, RI, 2003). 

This article presents a study of an aseptic environmental monitoring system for surface contamination at critical areas using a robot.

The Application of Robotics to Aseptic Environmental Surface Monitoring

I am honored to have been asked to contribute an essay on the occasion of 

's 30th anniversary. I became a regular reader of this fine publication in 1981, only four years after PharmTech's beginning. So, I can honestly say that I've grown up in this industry alongside 

. It has been a distinct pleasure to read the magazine and to make the occasional contribution to its contents over the years.  

My primary field of interest has been well-covered in this periodical during its 30 years of service to the industry and has developed in ways that neither I nor, I suspect, those responsible for the technical content of 

 could have envisioned fully back in 1977. Incredible as it may seem, media-fill tests were not a universal requirement. In fact, these process-simulation tests were not extended to all types of aseptically produced dosage forms until several years later. The first international standard that mentioned an acceptance criterion for media-fill tests, to the best of my knowledge, is the 

 that suggested a 0.3% contamination rate (1). When I started in this business, many firms considered 9 positives out of 3000 units filled to be a successful media-fill test. Just writing the previous sentence today leaves me shaking my head in amazement at how far capability and expectations have evolved in the past 30 years. 

Milestone. 30 years of Pharmaceutical Technology			

Not only was the media-fill test only starting on the pathway to becoming a mandatory requirement, in 1977 the word 

 was only starting to enter our lexicon. At that point, firms were validating autoclaves, and that was by and large the full extent of process validation. The appropriate approach for validation of moist-heat sterilization processes would have been a topic of considerable debate in 1977, although Irving Pflug, PhD, Carl Bruch, PhD, and other sterilization scientists were hard at work attempting to educate what was already an audience eager for knowledge. The seminal industry document about moist-heat sterilization, 

 began publication. It is with some disappointment that I must report that in some ways the art and science of sterilization validation has actually regressed over these three long decades. The clear thinking and analytical approach of Dr. Pflug has been replaced by a mishmash of requirements, some of which seem to have been borne out of worst-case thinking run amok or by efforts to force parochial approaches on industry, ironically enough in the alleged interest of harmonization. What has not changed is that sterilization, in 2007 as in 1977, is still a process best measured by microbiological analysis. The statement that will forever be associated with Dr. Pflug still rings true today: "The bugs don't lie." It is important to remind ourselves that those spores are just as honest and reliable  evaluators of sterilization now as they were in 1977. None of the foregoing is intended to diminish the importance of thermometric and pressure data; it is to remind the reader that the purpose of sterilization is to destroy microbial contamination. Thankfully, there are ample data on the destruction of microorganisms by moist heat, heat, radiation of various types, and chemicals, so let us not reinvent the wheel. 

I am sure that many readers under 40 years of age will find it astonishing that prefilled syringes were a real rarity in 1977, and ampuls were still a widely manufactured dosage form. Today, as prefilled syringes gain market share in most of the world, the ampul is as extinct as the Tyrannosaurus. Most significantly, though, many aseptic processing lines in those days lacked the now-common depyrogenation tunnel. Instead, gowned operators, who typically wore nothing more than undergarments or street clothes under their gowns and were never required to "double glove" manually scraped vials off of the trays that had been depyrogenated in an oven that might or might not have contained a high-efficiency particulate air filter so that the oven could be operated at a positive pressure relative to the surrounding environment. The complete elimination of manual glassware transfer is very close to being a reality today, although I cannot honestly say how close with absolute certainty. In my opinion, the introduction of in-line glassware washing and depyrogenation would rank very near the top of the list of developments most responsible for increased aseptic-product safety during the last 30 years. Of course, it has proven difficult to implement the direct sterilization in conjunction with some product types, notably plastic containers with volumes of 100–1000 mL. Cold sterilization technology, however, has evolved tremendously during the last 30 years, and the means of achieving direct in-line sterilization of most products appears be within our grasp. 

There is one year that stands out in my mind in the 30 years that 

 has been published. That year is 1984, and it is memorable to me because in that year the pharmaceutical industry was made aware that the US Food and Drug Administration was working on a draft guideline, which was eventually published in 1987 as the 

Guideline on Sterile Drug Products Produced by Aseptic Processing 

(3). Word began to spread that this guideline would force industry to do some things very differently. The nature of one important change emerged when the pharmaceutical industry learned through podium presentations by key FDA personnel and inspectional activity that the industry practice of automatic sterility test "retests" was no longer considered acceptable.  

Before that time, the formal sterility-test failure investigation did not exist; rather, sterility-test positives were considered more like a minor glitch on the road to release than as a potential processing failure. Actually, my firm did take the occurrence of a sterility positive seriously, and we performed a limited version of the investigation required today. My firm also immediately did a retest while conducting the investigation. Some firms, however, skipped most of the steps involved in today's investigation and just went right to the retest and, if it passed, released the product.  

Industry was forced to face rather quickly that this change really meant that the 0.25–0.5% retest rates that were common in sterility testing operations were no longer acceptable. The industry needed a more reliable sterility test. At the same time, the industry needed to improve the contamination control in aseptic processing. Out of this situation came word that a new technology had been used for sterility testing in Europe and that it seemed to effectively eliminate microbial contamination. This technology was, of course, the isolator. Later in 1984, I saw a flexible wall isolator for the first time at a trade show, and as I walked away from that exhibit, I mentioned to a colleague that we had just seen not only the future of sterility testing, but also the future of aseptic processing.  

Having been involved in aseptic processing for three years by 1984, and having spent over a decade before that engaged in cell culture and virology, I knew very well that microbial contamination was almost exclusively a problem associated with humans performing interventions. Our firm had already considered using robots to reduce reliance on personnel, and we had a robotics laboratory to evaluate concepts. In the isolator, we saw a system that could separate the human from the operation and, that when used in concert with machine automation and robotics, would enable us to achieve levels of control over microbial contamination that would never be attainable in conventional cleanrooms.  

				This year at the International Society for Pharmaceutical Engineering's Barrier Isolation Technology Forum, Rick Friedman, director of the division of manufacturing and product quality in FDA's Center for Drug Evaluation and Research,  commented that nearly all submissions for new facilities at the agency are isolators or restricted access barrier systems (4).			

So, the revolution that started in 1984 is now in the end game. Although the end of the manned-cleanroom era in aseptic processing has not come, the industry can certainly see it from here. Look for machine automation and robotic applications to provide the next phase of this contamination-control revolution as the industry  moves from the isolator era to the gloveless-isolator era.  

If I am still around to write an essay on the occasion of 

's 50th anniversary, I predict the human cleanroom will be gone forever, and it will be possible to run plants with the lights turned off, which will be very good for the carbon footprint and for contamination control.   

The improvements in aseptic processing equipment and facilities during the last three decades have resulted in a circumstance that is still not widely recognized. Although microbiological assays remain the way to best analyze moist-heat sterilization processes, the industry has reached a point in the evolution of aseptic processing where the utility of microbiological assays is now questionable in many ways. Two or three decades ago, the pharmaceutical industry did a lot less environmental monitoring in support of aseptic processing than is the current norm. Back then, the industry actually recovered organisms with some frequency, and media fills were still something of a cross-your-fingers adventure. Today, in ISO 5 environments, microbial recoveries are rare, and in isolators they are so rare that some operations have reported having nothing but zero recovery rates for years. I believe what this should mean to any pragmatic microbiologist is that we may have reached the limits of growth and recovery microbiology as a means of evaluating process control. Really, this has been an issue in the cleanest environments longer than the industry might imagine.   

Now the reader might quite reasonably ask why it is that I can endorse the value of microbiological analysis in the validation of moist heat while at the same time asserting that microbiological analysis may no longer be particularly useful when applied to contamination assessment of the cleanest environments. The answer is simple. Sterilization processes begin with a very large population of microorganisms and use the well-known thermal-death kinetics of spores to determine the effectiveness of the sterilization cycle. The statistics of starting with large populations of biological indicators with known resistance properties allows operators to work in a quantitative range that is suitable for growth and recovery assays. This is to say that the biological variation that might be as much as ±0.5 log in the worst case is actually of only limited significance when we have a starting spore population of >10

 . The biological effectiveness of the sterilization process can be estimated well enough to establish correlations with what would be expected from thermometric data.  

Contrast this with attempting to evaluate sterility in more or less the opposite manner by recovering the miniscule residual bioburden within a very clean environment. This is a task made all the more daunting by the fact that this miniscule bioburden is not homogeneously distributed. Making the situation more difficult still is that those organisms that may be present can be or are likely to be under significant nutritional and environmental stress. It is not without reason that the compendial growth promotion tests suggest a challenge population of 10–100 colony-forming units to support the fertility of microbiological media. This process is done because it is very difficult to achieve growth at low inoculum levels, even when working with healthy stock cultures. Of course, the same logic applies to the media-fill test for precisely the same reasons.  

I have heard some regulators suggest that if the environmental-monitoring test results are all zeros, then there is not enough testing. The problem, however, is if the results are below the limit of detection of the assay testing, more testing will not help. Even if the possible problem was simply that there were microbes in the environment that could not be found at current sampling intensities at modern air flow rates, it is very hard to imagine how large the sample size would have to be. The answer may well be that there just is not a practical way to sample enough.  

Late last year at the Parenteral Drug Association's Asian Symposium in Tokyo, Katayama 

 reported that they had used two risk-analysis models for aseptic processing to evaluate three different aseptic processing production lines spanning more human intervention-intensive technology to modern separative technology with a high level of line automation (5). They compared these quantitative risk analysis models (including one Jim Agalloco and I published in 

) (6, 7) and microbiological methods and found that in the higher technology lines, risk- analysis may be a more effective way to evaluate process control than microbiological monitoring.  

This finding means that less reliance on traditional microbiological monitoring and process-simulation testing and more reliance on risk analysis may be the way forward. With this in mind, I list the move toward risk- and science-based regulation and the greater emphasis on quality systems as major innovations of the last 30 years.  

The pharmaceutical industry needs to be inspired enough to ask whether what it is doing makes sense, and if it does not, the industry needs to be on the lookout for better ways. Albert Einstein thought that in the case of creativity, inspiration was more important than knowledge. He just may have been right. It may also be true that if we are going to insist upon trying to measure something, we need to know how capable we are of measuring that something.   

 will continue to inspire us in the future as it has it has in its first 30 years.  I'll bet that it will. I also hope that as the industry moves forward, it keeps an open mind and is inspired enough not only  to embrace the inevitability of change but to facilitate that change through its own creativity. The industry should demand that its standards and its harmonization efforts always be driven by evidentiary science rather than merely by someone's opinion. That is where 

 comes in, as it will continue to enhance our understanding during the next 30 years. 

"In 1977, I was a post-doctoral fellow and instructor at East Carolina School of Medicine, Department of Microbiology. I took my first position in the pharmaceutical industry in 1981 at Burroughs Wellcome, Co. (now part of GlaxoSmithKline) in 1981." 

2. Parenteral Drug Association, "Validation of Steam Sterilization Cycles," PDA Technical Monograph No. 1, (PDA, Bethesda, MD), 1978. 

4. R. Friedman, Presented at the 16th Annual Barrier Isolation Technology Forum, Arlington, VA, June. 5, 2007. 

5. H. Katayama and A.Toda, "Risk Categorization of Aseptic Processing Facilities Based Upon Risk Assessment Scores," in 

Proceedings of  the Parenteral Drug Association's Asian Symposium

6. J. Akers and J. Agalloco, "Risk Analysis for Aseptic Processing: The Akers–Agalloco Method," 

 7. J.Akers and J. Agalloco, The Simplified Akers–Agalloco Method for Aseptic Processing Risk Analysis," 

Sterile product manufacturing and related testing have evolved significantly during the last 30 years. From requirements for acceptance criteria for media-fill tests, to developing validated approaches for moist-heat sterilization, to the introduction of formalized sterility-testing practices, the pharmaceutical industry has made significant advances in testing and in key technology such as isolators, prefilled syringes, automation, and robotics. The author outlines the key regulatory and technical changes to sterile product manufacturing and takes a visionary look for the next era of sterile manufacturing marked by a greater emphasis on risk analysis.

Charting Process Improvement in Sterile Product Manufacturing

Aseptic processing is widely used for preparing sterile products. Although regulatory authorities and industry experts emphasize the sterility-assurance advantages of terminal sterilization, the fact remains that most products being introduced today must be manufactured aseptically (1). Implicit in aseptic processing is the notion that items are first sterilized and then processed under aseptic conditions into the final product. More often than not, that assembly involves the labor of one or more appropriately gowned individuals in a pristine environment. The operators' typical activities will include the set-up, filling or assembly process, and environment monitoring of the processing area. 

During the past 50 years, aseptic processing has evolved. Before the advent of the high-efficiency particulate air (HEPA) filter and cleanroom, aseptic processing was performed by operators working in gloveboxes that separated them from the sterilized materials. This approach afforded a degree of isolation between the operator and the sterilized items they were charged with handling and assembling, which helped ensure the sterility (or perhaps more accurately the safety) of the final product.  

In the mid-1950s, HEPA filters became available to industry and were quickly adopted to provide large areas in which equipment could perform the majority of the aseptic processing activities. The operators, now garbed in sterilized garments, were still present to initially set up the equipment, perform any needed equipment adjustments, address component malfunctions, and collect environmental samples. Over the years, many improvements to cleanroom operations occurred. Equipment reliability improved, and air changes were increased. Sterilization processes were validated, and gowning materials became more comfortable and robust. And barriers were introduced. 

. The most evolved cleanroom-based designs today are restricted access barrier systems (RABS) in which operator access to the aseptic environment is severely limited (2). RABS and all of the prior technological advances in aseptic processing were implemented because there was a clear understanding that personnel were the only significant source of microbial contamination in conventional cleanroom aseptic processing. 

 Some 20 years ago, before the advent of RABS technology, the original gloveboxes of aseptic processing antiquity were reincarnated as isolators. Isolators were a substantial improvement over gloveboxes. The isolators were supplied with HEPA-filtered air that enabled these enclosures to be maintained at a positive pressure relative to the surrounding environment, mitigating issues with leaks and with finished-product out-feed isolators. The isolators could be reproducibly decontaminated and could be connected to other isolators and process equipment in a way that maintained separation between the internal environment and operating personnel (3, 4). These advancements were a technological breakthrough of substantial magnitude, and some two decades after their introduction, isolators continue to represent the pinnacle of aseptic processing technology. 

Although that might be the end of an interesting story, present-day operations use all of these aseptic technologies, and new cleanrooms for aseptic processing still are in the planning stages. All present-day aseptic processing systems require to some extent the direct participation of operators with sterilized materials just as they always have. Using the word 

is not a compliance hedge. It is the recognition that once any material is placed in a manned cleanroom and handled by personnel, it legitimately cannot be considered sterile no matter how much overkill was applied in its validation. Cleanroom operators use utensils in their gloved hands, and RABS and isolator operators use the equipment's gloves in much the same manner. There are truly refined aseptic processing concepts available that perform without operators. As with any new technology in the extremely conservative pharmaceutical industry, however, the implementation of these concepts, although certainly desirable, is by no means imminent and is unlikely to be universal for many years. (It should be noted that high levels of automation already are widely used in other clean and aseptic industries). Although  we hope that in two decades aseptic processing in the pharmaceutical industry will have taken advantage of the numerous technological advancements that are available even today, their adoption is by no means a sure thing. 

. Aseptic processing performance certainly has improved over the years, yet at the same time, the pharmaceutical industry  has accepted its limitations. The operator is still allowed to interact with materials using a flexible glove system to perform many tasks as outlined below:  									

 Very few pieces of aseptic processing equipment, regardless of the background environmental technology, are able to begin operation at the push of a button. An operator is typically required to adjust fill weights, conveyor rails, and closure-feed systems before the process can begin.

The operator serves as a support to the equipment by clearing jams, wiping up spills, replenishing components, and other supportive activities during the process.

 Operators take environmental and product samples, check and adjust fill weights, and generally oversee the process.

Each of these activities requires some intervention with the sterilized equipment and components. The pharmaceutical industry has become largely tolerant of interventions. The current practice is to ensure routine (process-inherent) and nonroutine (process-corrective) interventions are closely aligned between routine operation and aseptic process simulation. This situation may seem reasonable in the interim; however, it is wholly unsatisfactory in the long term. The pharmaceutical industry's tendency to believe that gowned people can work in sterile environments often leads it to misidentify risks. HEPA-filtered air, for example, recently was advanced as a source of contamination as significant as personnel, which is not only absolutely wrong, but essentially precludes aseptic processing in its entirety. 

. In developing our recent position on aseptic processing risk assessment, we were influenced by things we learned from experienced professionals when we began working in this industry at the dawn of the validation era. The simple message we learned is that people spread contamination, and that all interventions are risky. The following quote from Hank Avallone, a former US Food and Drug Administration inspector and long-time industry authority dates to 1988: 

It is useful to assume that the operator is always contaminated while operating in the aseptic area. If the procedures are viewed from this perspective, those practices which are exposing the product to contamination are more easily identified (5). 

It is universally acknowledged that personnel are 

 source of microbial contamination in cleanrooms (1). Our concerns for the capability of RABS and isolators center on glove sterility and integrity because the failure of glove sterility and integrity  is the greatest weakness of these very capable systems. A recent communication highlighted the limitations of a variety of glove-integrity test methods and ultimately acknowledged that glove integrity cannot be ensured by any current means. This effort focused on gloves for RABS and isolators, and these gloves are substantially more robust than those relied upon in cleanroom operations (6). The integrity of aseptic gowning systems is superior in every way to what existed 40 years ago, but it is still orders of magnitude away from what is necessary to consider aseptically gowned operators as anything close to sterile. 

Aseptic processing has advanced over the past several decades, yet the pharmaceutical industry is still accepting of its limitations, particularly as it relates to human intervention as a source of contamination. The authors explain the importance of further diminishing the role of operators in aseptic processing and the approaches and technologies needed to achieve that goal.