Peristaltic Pump for the pharma applications

Fluid flow is an essential process in pharma manufacturing, where its controlled flow (direction and speed) is required according to the equipment and process requirement. The fluid flow is controlled through a driver, such as pumps and compressors. These drivers take various fluids as input and generate the required fluid characteristics. 

The main driver for the fluid in pharmaceutical industries is a pump, which generates the required pressure and flow characteristics. However, the pump must also adhere to strict pharma requirements such as sanitization, contamination control, and others to prevent the fluid in action from changing its properties and losing its purity level. In a conventional, it becomes difficult due to various mechanical parts such as gears and screws.

A peristaltic pump is one of many drivers used to pump critical liquids from one point to another. It helps to maintain a high level of purity through its unique design while providing all the functionalities of a conventional pump.

What is a Peristaltic Pump?

A peristaltic pump is a mechanical device to transfer pharma liquid from one point to another, by forced pressure of rollers or brushes against a tube. The liquid is contained in the tube without contacting the pump's part. As the roller or bushes rotate and press against the tube, liquid moves forward by the action of push and suck; due to stress imposed by these rollers or brushes.

The main advantage of this pump is that liquid does not come in direct contact with the product. Instead, the product only comes in direct contact with the tube.

In the pharmaceutical industry, they are used in processes where a high degree of purity is required. It is also easy to clean, and the pump's internal parts remain free from product traces. 

Principle of operation of peristaltic pump

Let's discuss the principle of operation of a peristaltic pump

The peristaltic pump works on the principle of peristalsis, which refers to muscle contraction of the human body's digestive tract, resulting in food movement. This resembles a peristaltic pump, where a pharma liquid tube is subjected to deformation and compression through rotating rollers.

Let's discuss the general principle of operation of a peristaltic pump.

1. Peristaltic pump consists of a roller attached to a motor, which rotates the roller in a fixed circular path

2. A product-compatible tube is passed through rollers in a way that the roller presses the tube

3. One end of the tube is placed in a container or vessel, containing liquid to be pumped

4. As the pump starts, the roller starts rotation and presses against the tube

5. Roller exerts force on the tube, causing it to compress and decompress. This phenomenon creates a vacuum in the tube

6. The liquid is sucked in through the effect of a vacuum each time compression and decompression occurs and moves forward throughout the entire length of the tube

7. The liquid moves forward every time the rollers rotate a complete cycle. This continues until the liquid reaches the end of the tube.

8. The pressure and speed of a liquid is directly proportional to the speed of rollers. The liquid speed and pressure can be increased or decreased by increasing or decreasing the speed of rollers.

9. Peristaltic pump can be manually operated or through automatic mechanism. In the manual method, pump speed, rotation, and other parameters are manually adjusted, typically through a control panel on the pump, which requires constant human presence.

In automatic mode, the pump takes input from a centralized controller or Programmable Logic Controller – PLC and controls parameters such as speed and rotation through signals from the controller without human involvement. 

Applications of Peristaltic Pump

As discussed previously, peristaltic pumps, pump liquid from one point to another with high purity and preciseness. In the pharmaceutical industry, it is used where fluid needs to be pumped as a part of process requirements.

Let's discuss applications of peristaltic pumps in the pharma industry

Tablet Coating

In tablet coating equipment, peristaltic pumps transfer liquid from a container or vessel to a spray gun, which sprays the liquid into a tablet bed inside a coating pan. A peristaltic pump controls parameters like speed and pressure, directly affecting the spray pattern and the resultant final product. 

The liquid is sprayed on the tablet, which forms a coating and becomes part of the tablet. Since patients directly consume tablets, they must be free from contamination. The advantage of using a peristaltic pump is that it prevents human interaction with the liquid. As a result, it provides an excellent option to transfer liquid when a high purity level is required.

Moreover, the peristaltic pump also provides precise liquid control and enables preciseness when a small dosage is required. 

Injectable Filling

A peristaltic pump is also used in filling injectables in ampoules or vials. The liquid to be filled into the containers (ampoule/vials) is pumped through the peristaltic pump to the filling nozzles. The volume of injectables to be filled is controllable through the peristaltic pump by increasing or decreasing the speed of rotation of rollers.

Peristaltic pumps are used because injectables are administered through the skin, and contamination or impurity can harm patients. Peristaltic pumps control pollutants and precise control over fluid flow. 

It is also effective in contamination and impurity control because its operation does not require human interaction.

Chemical Dosing

A peristaltic pump is also used in processes where chemical is used, and is effective in adding chemicals to the production process. Chemicals are added for process industries due to their formulation requirement and are common in the pharmaceutical industry. The addition of chemicals requires precise measurements due to their highly reactive nature. It must also prevent human interaction due to its hazards. 

Peristaltic pumps are ideal for this situation; it helps to dose chemicals with precise measurements. It is difficult for conventional pumps to make exact measurements because the step size of rollers in a peristaltic pump can be changed and adjusted according to various preciseness requirements.

Additionally, chemical dosing can be performed without human involvement due to its automatic control feature and minimum parts replacement and changeover. 

Peristaltic pumps are also used in Water Treatment Plant, to dose chemicals at various stages.

Laboratory applications

A pharma laboratory uses a peristaltic pump to pump liquid to various instruments, such as the dissolution unit, during testing. It is most commonly applied for vaccines or biologics, where it is used in a controlled manner due to its ability to make precise movements.

Interaction with humans is also prevented with the help of a Peristaltic pump, which significantly increases the reliability and efficiency of a test.

Advantages of peristaltic pump for pharma applications

Let's discuss some benefits of peristaltic pumps in the pharma industry

Easy Operation and Changeover

Operation of a peristaltic pump is easy and can be conveniently performed by personnel with basic machine knowledge. Whether manually controlled or automatic, operators using the pump find no difficulty in operating it. 

It consists of an easy and understandable operator console, which includes all the necessary buttons for regular operation. It does not require any specialized programming to use it. Every procedure, such as Start / Stop /Speed increase and Speed decrease, can be easily performed.

Changeover in the peristaltic pump is also very easy because it only requires the tube to change, which can be quickly done in less than five minutes. This is advantageous for pharma processes, where the tube must be changed multiple times during production in a day.

No Excessive Mechanical Parts

The peristaltic pump does not contain excessive parts such as valves and pistons. It only has a roller connected directly to a motor through appropriate couplings. This feature eliminates the danger of friction, parts degradation, and wear & tear related to mechanical structure.

Precise Flow rates

With the peristaltic pump, it is possible to precisely control a flow rate much smaller in value than conventional pumps. The main reason is that roller rotation can be directed into smaller steps due to the type of motor (servo or stepper) used to control roller rotation. These motors can increment in smaller steps, which is impossible with other motor types.

Contamination Control

The peristaltic pump provides excellent control of contamination in the liquid being pumped. The product does not come in contact with humans or other machine parts, which are a significant source of contamination. Since pump parts do not come in direct contact with liquid, cleaning problems are also prevented and corrected quickly.

The only part that comes in contact with the liquid is a tube. It is made up of product-compatible material that resists chemical reactions with the liquid. The tube material is easy to clean, and product traces do not remain on the tube.

Easy Maintenance

A peristaltic pump is easy to maintain because it does not contain extensive mechanical parts, and this feature eliminates the necessities of mechanical parts maintenance such as oiling, greasing, damaged part replacement, or inspection. The components used in peristaltic pumps are a durable plastic that performs well in stressed operating conditions. 

About the Author

Muhammad Asim Niazi has a vast experience of about 11 years in a Pharmaceutical company. During his tenure he worked in their different departments and had been part of many initiatives within the company. He now uses his experience and skill to write interested content for audiences at PharmaSources.com.