Comprehensive Guide to Pharmaceutical Pumps: Peristaltic vs. Sealless Volumetric Pumps
Pumps play a vital role in pharmaceutical manufacturing, from transferring delicate fluids to ensuring precise dosing in filling systems. Two of the most widely used types of pumps in this field are peristaltic pumps and sealless volumetric pumps. This guide will explore the operating principles, advantages, disadvantages, major manufacturers, and current industry standards, with a focus on the leading products in the market such as Flexinol by Watson-Marlow and Colanar pumps, alongside volumetric options from Neoceram, MPA, Asepticon, and PSC.
1.1 Operating Principles
Peristaltic Pumps
Peristaltic pumps work by compressing a flexible tube with rotating rollers or shoes, creating a peristaltic motion that moves fluid through the tubing. This design ensures that the pumped liquid does not come into contact with the internal components of the pump, making them ideal for applications where sterility and contamination control are critical.
Construction: Comprised of a rotor with rollers or shoes, flexible tubing (often silicone or PTFE), and a housing. Most advanced configuration is 6 + 6 rollers on 2 lines, solution utilized by the top class world manufacturer that is technically proved to be the most precise and fast at the same time.
Operation: The rotating action of the rollers compresses the tubing, creating a series of small pockets that push the fluid forward. Once a roller moves past, the tubing returns to its original shape, drawing more fluid into the pump.
Figure 1 E-Lab Filler compact Engmotion solution of dispensing machine with peristaltic pump on board
Advantages:
Sterility and contamination prevention: The fluid only comes into contact with the inner surface of the tubing, which is especially beneficial for transferring sterile or sensitive pharmaceutical products [1].
Low shear handling: Peristaltic pumps generate a low-shear flow, making them suitable for shear-sensitive fluids such as cell cultures, proteins, and suspensions [2].
Simple maintenance: Tubing replacement is easy and can be done without disassembling the pump, making these pumps user-friendly in high-turnover environments [3].
Disadvantages:
Limited pressure and flow capabilities: These pumps are generally limited in their ability to handle high pressures and large flow rates, which can be a drawback for more demanding applications [4].
Tubing wear: The flexible tubing experiences wear over time, requiring regular replacement, which could result in downtime [5]. Usually manufacturers advice to change the sterile tube set after one shift use, anyway it depends on validation results.
1.2 Precision and Flow Rate
Precision and Flow Rate of Peristaltic Pumps
Precision in peristaltic pumps is largely influenced by factors such as tubing elasticity, compression force, and rotor speed control:
Tubing material: The elasticity and durability of the tubing affect accuracy. Over time, the tubing may stretch or wear, leading to variations in flow rate. For applications that require precision, frequent monitoring and replacement of the tubing are essential.
Compression force: The amount of compression on the tubing impacts flow precision. Inconsistent compression leads to variations in flow rates.
Rotor speed control: The flow rate can be controlled by adjusting the motor speed. Many modern peristaltic pumps, such as those in the Watson-Marlow Flexinol series, feature electronic controls to fine-tune the flow rate and ensure consistent dosing over time.
Typical precision for peristaltic pumps is around ±1% for dosing applications, making them suitable for sterile filling processes but less ideal for highly precise API dosing where tighter tolerances are required.
Flow Rate and Time Dependency:
Flow rate: Peristaltic pumps handle flow rates ranging from 0.01 ml/min to 4 L/min, depending on tubing size and pump configuration.
Time dependency: Over time, tubing degrades due to continuous compression, leading to variations in flow rate. For long-term use, recalibration or tubing replacement is necessary to maintain performance consistency, making peristaltic pumps better suited for short- to medium-duration processes.
1.3 Key Market Players:
Watson-Marlow Flexinol: Watson-Marlow's Flexinol peristaltic pumps are considered top-tier in the pharmaceutical market due to their precision, robustness, and ability to handle sterile fluids [6].
Colanar: Colanar offers a range of peristaltic pumps that are optimized for aseptic filling applications, emphasizing precision and clean operation [7].
2.1 Sealless Volumetric Pumps
Sealless volumetric pumps excel in precision due to their fixed displacement mechanism, which ensures a consistent volume of fluid with each piston stroke.
·Fixed displacement: This mechanism guarantees high precision, typically within ±0.1%, making these pumps perfect for applications requiring exact dosing [5].
·Flow control systems: Many sealless volumetric pumps, such as Neoceram’s ceramic pumps or MPA’s volumetric pumps, are equipped with precise electronic controls that allow fine adjustments to flow rates, ensuring minimal variation even in demanding tasks [6].
High precision: Volumetric pumps deliver exact, repeatable volumes, which is crucial for dosing active pharmaceutical ingredients (APIs) [8].
Leak-free operation: The sealless design eliminates the potential for fluid leakage, ensuring sterility and minimizing contamination risks [9].
Durability and longevity: Without seals to wear down, these pumps often require less frequent maintenance, resulting in higher uptime [10].
Disadvantages:
Higher cost: These pumps tend to be more expensive upfront, both in terms of equipment costs and maintenance due to their complexity [11].
Complex maintenance: Although durable, when issues arise, the pumps may require specialized service, which can be costly [12].
2.2 Flow Rate and Time Dependency:
Flow rate: Sealless volumetric pumps can handle flow rates ranging from a few milliliters per minute to several hundred liters per hour, depending on the design and application.
Stability over time: Due to the absence of elastomeric components, these pumps maintain consistent flow rates over extended use. Once calibrated, they deliver accurate dosing for long-term processes, making them ideal for continuous operations such as API synthesis or sterile filling lines.
2.3 Key Market Players:
Neoceram: Known for their ceramic and stainless steel pumps, Neoceram offers highly durable and corrosion-resistant solutions that are ideal for precise volumetric dosing [13]. Their ceramic pumps, in particular, are favored in applications where chemical resistance and high accuracy are required.
MPA: MPA’s volumetric pumps are widely used in pharma for both precision and reliability. Their design focuses on sterile dosing and contamination-free handling [14].
Asepticon: Specializes in sealless pumps that are engineered for high-precision applications, particularly where sterility is paramount [15].
PSC: PSC pumps are recognized for their advanced magnetically coupled designs, offering high performance in aseptic conditions [16].
2. Comparison of Peristaltic and Sealless Volumetric Pumps
Feature
Peristaltic Pump
Sealless Volumetric Pump
Fluid handling
No fluid contact (fluid stays in tube)
Direct contact with internal chamber
Sterility
Excellent (no contamination)
Excellent (no leakage)
Handling of shear-sensitive fluids
Excellent
Moderate
Pressure capabilities
Low
High
Flow rate precision
Moderate
High
Cost
Lower initial cost
Higher initial cost
Maintenance
Tubing replacement required
Complex but less frequent maintenance
3. Applications in Pharmaceutical Manufacturing
Peristaltic pumps: These pumps are ideal for handling sterile, shear-sensitive fluids such as vaccines, proteins, and suspensions. They are particularly effective in single-use systems for aseptic filling and transfer, where contamination must be avoided [17].
Sealless volumetric pumps: These pumps excel in dosing APIs and handling viscous liquids in high-precision applications. Their ability to deliver exact, repeatable volumes under high pressure makes them ideal for pharmaceutical environments where accuracy is critical [18].
4. Industry Standards and Regulations
Both peristaltic and sealless volumetric pumps must comply with various industry standards to ensure safety, sterility, and performance.
ISO 22519:2020: Specifies requirements for hygienic equipment in pharmaceutical manufacturing, including pumps used in sterile processing [19].
ASME BPE-2024: The Bioprocessing Equipment standard provides guidelines for the hygienic design of pumps and related equipment used in biopharmaceutical production [20].
FDA 21 CFR Part 11: This regulation addresses the use of electronic records and signatures in automated pharmaceutical manufacturing, including monitoring and data logging for pumps [21].
Conclusion
Choosing between peristaltic and sealless volumetric pumps depends on the specific requirements of the pharmaceutical process. Peristaltic pumps are highly effective for sterile, low-pressure applications involving shear-sensitive fluids, while sealless volumetric pumps offer the precision and sterility required for high-pressure dosing and exact volumetric control. By selecting the right pump, manufacturers can optimize their processes to meet the stringent demands of pharmaceutical production.
Bibliography
Herring, D. "Sterile Fluid Handling in Biopharma: The Role of Peristaltic Pumps." Journal of Bioprocess Engineering, 2021.