Types of Airlock used in Pharmaceutical

In the pharmaceutical industry, maintaining strict contamination control is of paramount importance. Contaminants can compromise the quality and safety of pharmaceutical products, making it crucial to prevent their entry into critical areas such as cleanrooms. Airlocks play a vital role in ensuring the integrity of controlled environments by creating a barrier between different zones with varying cleanliness levels. In this article, we will explore the different types of airlocks commonly used in the pharmaceutical industry and their significance in maintaining aseptic conditions.

An airlock is a transitional space that typically has two doors in series to separate a controlled environment (such as a cleanroom, lab, operating room, or isolation room) from a corridor, or vice versa. The two doors should be interlocked to avoid being opened at the same time.

Types of Air Locks
There are three types of airlocks:

1. Cascade Airlock

• In a cascade air locking system, pressure increases or decreases in ascending or descending order respectively, (from 30 Pa to 20 Pa to 10 Pa \or\ 10 Pa to 20 Pa to 30 Pa). Thus, air moves from higher pressure to lower pressure, preventing cross-contamination. This type of airlock is commonly used in Tablet manufacturing facilities where higher pressure remains in the corridor to keep drugs inside the cubicle.

• These airlocks are very common having higher pressure on one side and lower pressure on another side. In this system, positive air pressure flows from the higher internal zone to the airlock and from the airlock to a lesser lower pressure grade area
• This prevents the entry of dust and contamination from outside to the airlock and from the airlock to the inner side.

Application

Any manufacturing facility where the product requires protection from particulate but the people outside the clean room does not need protection from the product in the clean room.

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2. Bubble Airlock

• In a bubble airlock, the pressure inside the airlock is high or positive and is low or negative on adjacent sides. Thus, air moves from the airlock to the primary manufacturing area, and in the same way from the airlock to the corridor. Higher air changes are produced in the airlock, thus producing a bubble as it pushes air outside from the airlock. 
• This type of airlock system is commonly used in Injectable manufacturing facilities so that air contaminants from outside do not contaminate the product.
• These types of airlocks have higher pressure inside the airlock and lower pressure both outside.
• It creates a barrier where contaminants within either area are pushed back into their own respective areas.

Application

Used in, areas where the product needs protection and the people external to the cleanrooms require protection from the product, to reduce the possibility of viable articulate from entering the lesser pressure clean-room. In areas such as higher potency, and compounding areas terminal sterilization is not an option.

3. Sink Airlock

• In sink airlocks, the pressure inside the airlock is negative and is positive in adjacent areas, such that the air moves from higher pressure to lower pressure areas.
• Higher pressure on both sides of the airlock prevents contaminants from escaping the primary manufacturing area. It is commonly used in the manufacturing of harmful substances such as poison.
• Airlocks have lower pressure inside the airlock and higher pressure on both sides of the airlock.
• This airlock pulls air from adjacent areas sore creating a low-pressure barrier and reducing the opportunity for contamination to pass to the internal zone.

Application

In many research facilities, substances that are experimented on are highly dangerous, and it is essential to keep them from being exposed. During a few types of production processes in a clean room, air from a contaminated area has to be contained in one place.

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4. Personnel Airlocks

• Personnel airlocks, also known as gowning airlocks, are designed to control the movement of personnel entering or exiting cleanroom environments. These airlocks typically consist of two or more interlocking doors separated by a small vestibule.
• The purpose of this design is to prevent the direct flow of contaminants into clean areas when personnel pass through.
• To ensure effective contamination control, personnel airlocks are equipped with air filtration systems that maintain positive pressure inside the cleanroom.

• These systems help in minimizing the ingress of airborne particles and ensure that any contaminants brought in are quickly removed from the air.

5. Material Airlocks

• Material airlocks also referred to as goods transfer airlocks, are designed to transfer materials, equipment, or samples between different cleanroom environments or between clean and non-clean areas.
• These airlocks provide a physical barrier that prevents cross-contamination and maintains the required cleanliness level.
• Material airlocks are typically equipped with airtight doors and interlocking mechanisms to ensure that only one door can be opened at a time.
• The doors are also equipped with sterilization mechanisms such as ultraviolet (UV) lights or hydrogen peroxide (H2O2) vapor systems to eliminate any microorganisms present on the surfaces of materials or equipment before they enter the clean area.

6. Equipment Airlocks

• Equipment airlocks, as the name suggests, are specifically designed for transferring large equipment or machinery into cleanroom environments. 
• These airlocks are typically larger in size compared to personnel or material airlocks to accommodate the size and weight of the equipment being transferred.
• Equipment airlocks are equipped with robust sealing mechanisms, such as inflatable gaskets or mechanical seals, to ensure a tight seal during equipment transfer.
• They also incorporate air shower systems that blow high-velocity, filtered air onto the equipment to remove any surface particles before it enters the clean area.

7. Pass-Through Airlocks

• Pass-through airlocks, also known as double-door airlocks or interlocking airlocks, are used for the transfer of materials or samples between adjacent cleanrooms with different cleanliness levels. 
• These airlocks consist of two doors that cannot be opened simultaneously, preventing cross-contamination between the two areas.
• Pass-through airlocks are commonly used in pharmaceutical manufacturing facilities to transfer materials from lower-grade cleanrooms, such as manufacturing areas, to higher-grade cleanrooms, such as sterile filling areas.
• By maintaining the pressure differentials between these areas, pass-through airlocks minimize the risk of contamination and ensure product integrity.

Conclusion

Airlocks play a vital role in maintaining the integrity and cleanliness of controlled environments in the pharmaceutical industry. Personnel airlocks, material airlocks, equipment airlocks, and pass-through airlocks each serve unique purposes in preventing contamination and ensuring the safety and quality of pharmaceutical products.

The proper selection and design of airlocks are crucial to meet regulatory requirements and industry standards. By implementing the appropriate airlock systems and associated technologies, pharmaceutical companies can safeguard their manufacturing processes and protect the health and well-being of patients who rely on their products.

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