Infrastructure Considerations for Containment Choices
Whether designing a new facility, retrofitting an existing dedicated facility, or even bringing potent and sensitizing drugs into a shared facility, the capital cost will be a serious consideration. Before identifying either the design and construction budget, or the operating cost burden, the needs of several interested parties need to be identified. The demands of handling such compounds extend beyond the battery limits of the building under consideration. Chemical compounds do not change their identity regardless of the building they are in. How they will be delivered to, and received, within the facility as well as the condition in which they leave the facility has impact on all associated services. Product final destination may also be of concern. Company liability once product is outside the manufacturers domain is a serious concern.
Some of the considerations include:
A) Footprint requirements
B) Headroom requirements and availability
C) Utilities - electrical (phase and voltage), purified water, solvents supply, pressurized air supply, liquid waste drainage, and solids waste handling
D) Zoned pressure controls
E) Computer or controller automation
F) Performance commissioning or validation
Installed Containment Facilities
The most burdensome are the commonly used down flow booths for materials transfer. They are capable of meeting 100 microgram/cu.m release levels with appropriate work practices. They need supplemental devices such as flexible drop curtains to protect the workers and minimize materials migration for lower release levels. They are immobile and require a large footprint and investment of time to set up, commission, and maintain, since items A through F above are all part of the functional requirements.
In Research and Development (R & D) laboratories the conventional bench-top and walk-in hoods create the same dilemma A – specifically for dedicated spaces, and B - F above.
The traditional approach to tableting, parenteral, and bulk materials handling involves layouts using different entry and exit pathways with controlled pressure cascades to isolate the processing room from the outer public areas. This requires a large footprint with automated pressure control requiring validation. Once installed, it is costly, both to maintain and modify, their usage since all items A–F are fundamental to the design.
Decontamination booths can be of both the misting wet-down or the deluge type of shower, both of which need a constant regulated water supply and drainage for collecting contaminated water, i.e. A - E above. Without a constant water pressure supply the decontamination efficiency is questionable.
By contrast R & D facilities tend to use a simple disrobe and bag-out approach allowing for secure contaminated waste disposal, i.e. C and E above.
Custom Containment Capabilities
Equipment manufacturers for finishing machines have taken to integrating rigid containment enclosures around their installations. There is a major cost for such provisions (B – F) even when installed within the footprint of the operating equipment. Designs place much of the operating assembly beyond reach of the operator requiring the enclosure to be opened for adjustment.
Rigid glovebox assemblies were adopted throughout the pharmaceutical industry based primarily on their claimed performance in the nuclear industry. They display many advantages because of their evolved capability over the years. While installation places less demands on the infrastructure there are still specific needs in all categories A – F above. Gloveboxes have a special place in facilities where a newly launched drug having a long patent life is to be handled. In such cases the investment offers a large payback.
Internal lighting must be provided inside rigid gloveboxes unless fabricated using clear or translucent rigid plastic materials.
A primary concern is the question of dedication to a single product due to the impact of cleaning cycles on efficiency and cycle times. All contract and third party manufacturers have a need for fast turnaround. Since most of the industry relies on batch processing for regulatory purposes, i.e. product trace-ability, cleaning cycles and waste volumes place constraints on operational design.
The internal finish of a glovebox is critical to cleaning performance, yet is one of the most overlooked design requirements. One company routinely passivates their steel surfaces with acid etching, which vastly improves cleaning performance.
Rigid gloveboxes can be installed on mobile frames using MilSpec approved quick disconnects for utilities.
Flexible Containment Enclosures
As its name suggests, flexible containment is the most adaptable selection for batch type operations that prevail within the pharmaceutical industry from discovery through final product storage and shipping. It is often used as a low cost and rapidly installed solution to supplement rigid containment performance in permanent installations.
Space requirements (A) for flexible containment are minimized to the temporary, or permanent, space allocated to the project. Flexible containment support frames can be assembled within hours at the user location to adapt to existing space constraints (B). Utility demands can be met using simple pass-through and clean make-and-break connectors, while outside lighting is provided through the enclosing film (C).
Complete suites with full entry, decontamination, and exit capabilities having fully functioning pressure gradients are readily installed using low cost blowers, baffles, and HEPA filtration. Installation, set-up, and performance testing can be accomplished within 1-2 days (C, D, and E).
Regardless of size, the cost is minimal compared with the alternatives.
Removal and waste cleanup is a simple matter of collapsing, bagging, and safe disposal by incineration (C). Laboratory and dispensing operations rely on this feature to optimize costs, minimizeturnaround time, and simplify waste handling. Removal and replacement is readily accomplished allowing for improved operational efficiency within a single day.
A typical dispensing suite may use an external collapsible frame to support a collapsed dispensing enclosure for storage between repeat uses.
Pressure requirements of -20” to +20” of water gauge (w.g.) are readily handled using rigid framing and attachments (D). This provides containment in the event of a pressure surge although at +20” w.g. the enclosure will be stretched taught and swollen making it impossible for an operator to enter the glovesleeves. By contrast, rigid gloveboxes lose their integrity at lower and higher pressures, and the glovesleeves swell at positive pressure conditions, so they are not recommended for safety reasons.
Depending on the selected film, temperatures can be safely accommodated within -20° to +150° Fahrenheit.
Select films are capable of withstanding common solvent vapors and liquids. Acetone and methylene chloride liquid and vapor are known problems for sustained contact. A specialty film is available for methylene chloride but requires long lead-time.
The ability of the supplier to provide pre-treated flexible containment for sterile operations eliminates costly investments in sterilization equipment.
Consult your Architectural and Engineering design resources for help in selecting the right solution for your project. You may find it necessary to provide guidance when flexible containment solutions arise. FabOhio Inc. can to provide additional assistance when considering specific project needs.
We would be pleased to discuss your needs.
You can contact our main office at: (740) 922-4233
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Technical support (317) 797-4540
International: 001 317 797 4540