How to select Ampoule/vial filling machine for your applications

What is Ampoule/vial filling machine?

Ampoule / Vial filling machines are used to fill ampoules and vials with the liquid, which is then sealed. After sealing, the containers are discharged from the output feed for further processing.

Ampoule / Vial filling machines are capable of catering to both ampoules and vials without significant change in their mechanical design. Only specific and few change parts are added to swap between ampoules and vials, without any significant design change and using specialized tools, just like other changeovers.

The filling volume of a container for a particular product is fixed. If the filled volume of the ampoule or Vial is different from the specifications, the container cannot be sent to market and is rejected.

The filling operation is carried out in different stages, where each stage has a specific function, including the following:

Infeed Station - Ampoules / Vials enter the machine through the infeed station, where they are aligned directionally. It consists of a hopper where containers are continuously fed. A star wheel captures individual containers and places them into the filing stage

Filling Station – The filling station consists of a number of needles that fill the specific volume of liquid in the containers. The volume is filled automatically and controlled through pumps. The number of needles depends on the machine's capacity.

Before filling liquid, the containers are blown by an inert gas, usually Nitrogen, for purity and quality enhancement purposes.

When filling is complete and if the container is ampoules, there is a sealing station. In case of vials, the next station is the capping station.

(Ampoule)Sealing Station – After filling, ampoules are advanced to the sealing station, where the flame is used to seal the ampoules. Sealing is performed in more than one stage. In the initial stage, the ampoule tip is warmed to increase the temperature and facilitate the sealing by the main burner. In the final stage, while flaming the tip, a scrapper scraps the ampoule tip from the top, effectively sealing the ampoule and making a curved tip.

(Vial) Capping Station – After filling, Vial is transferred to the capping station, where vials are capped and sealed.

Vials enter the station from the infeed, and caps from the hopper are adjusted on top of the vials. A capper rotates and tightens the cap on the vials. After capping, the seal is placed and sealed.

(Ampoule)Sealing Station – After ampoule sealing and vial capping, ampoules/vials are discharged into the outfeed station, where they are collected for further processing

What can go wrong if a suitable filling machine is not selected?

Let’s discuss some drawbacks of not selecting the appropriate filling machine.

Filled Volume

The strength of any drug product is critical for patients, and doctors prescribe medicine on the basis of strength. There are various ways of expressing the strength of drug products, and the liquid is in milliliters.

Among other functionalities, filling machines are designed for a specific fill volume, and the machine buyer has to specify its fill volume requirement during the purchasing process.

If the ampoule/vial filling machine is not carefully selected, it will fail to fill the container with the required volume. Additionally, it will also become challenging to maintain the volume-to-size ratio of containers.

Ampoule Size

The amount of volume in an ampoule or Vial determines the physical size of the container. Different machine parts, such as change parts and filling needles, are adjusted according to the physical size of the container.

The filling machine must be able to handle all the specified container sizes without any difficulty. Moreover, there must be, under any conditions, no physical damage, such as breakage and scratches to the container. Otherwise, it will be rejected by the quality department.

Satisfactory selecting filling machine is necessary for the production of the specified-sized containers to fail. Moreover, it can also damage the physical appearance and condition of the containers.

Make sure to achieve the desired production capacity.

Every pharma manufacturer has a specified market for a particular product, and the primary purpose of purchasing machines is to maintain the current market footprint or to increase the production rate. The increased machine capacity is the byproduct of various individual systems that contribute to an increased output.

There are different stages in the Ampoule / Vial filling machine, as described earlier in this article. Improper machine selection will fail the optimum functionality of each individual stage, specifically the filling and sealing process. If forcefully run at higher speeds to increase productivity, it will result in problems with the filled volumes. Problems will also occur during the sealing process, where tips or irregular shapes will increase the rejection burned and decrease the total productivity.

Container breakage

Ampoules and vials are made up of glass that require precise and careful movement in the machine. If not, the ampoules or vials will break during the process, damage machine parts and other containers, and contaminate the machine with the product (if filled).

There may be many reasons for it, the main reason being inaccurate machine parts dimensions hindering the smooth container flow from one stage to another.

Factors to consider when selecting an ampoule/vial filling machine

Some factors that are useful to consider include, but are not limited to

Accuracy of Filled Volume

As discussed above, the volume of product in an ampoule or Vial is critical for patients, and every product is prescribed according to its end-user requirements.

There are different mechanism to ensure accurate filling volume in the container.

Traditional systems, such as manual pump adjustments, have less accuracy, and more liquid goes into the container to fulfill product requirements.

Modern systems, such as servo-driven and electronically controlled, have higher accuracy, and it is also possible to narrowly adjust the filling range to prevent the product from being over-filled

Number of filling heads 

Head refers to the nozzle through which ampoules or vials are simultaneously filled with the liquid. An increased number of heads increases the probability of filling more containers and thus increases the total productivity.

When buying a filling machine, always consider the number of heads in a filling machine, which in turn is the function of the total capacity of the machine. Standard configurations include single, four, six, and eight-head machines.

Also higher number of heads requires more requirements, such as piping and utilities, than a lower number of heads.

Filling technique

Filling techniques refer to the method through which liquid is controlled into the nozzles, and its selection affects the filling process in a filling machine. If the liquid flow in the nozzles is smooth and without any obstruction, it will result in accurate filling. Additionally, critical flow parameters such as fill volume and speed also depend on the filling control method.

There are two common types of control methods: automatic and manual.

In automatic systems, the filling pump is automatically controlled. Pump filling and discharge are integrated

through the central controller, such as the Programmable Logic Controller – PLC. All the pump parameters are adjusted through the controller. It provides more accuracy in fill volume.  It does not require any change parts, and volume change can be done using central control.  

Examples of automatic control include servo-driven pumps and peristaltic pumps.

In the manual method, pumps are manually adjusted for a particular fill volume. This method has less accuracy and largely depends on the mechanical design of the pump. Different fill volumes are adjusted by changing different change parts.

Adopting an automatic filling mechanism is always best to optimize your filling operations. It saves personnel time in getting the machine ready for machine operations and also helps to produce quality products.

No bottle – No filling

No bottle – no filling is a safety feature that prevents wastage of the liquid when there is no ampoule or Vial below a filling nozzle.

When buying a filling machine, it is always beneficial to add this feature to your machine. Although it comes at an added cost, it saves the product from being wasted.

Utility requirements

Like other pharma production machines, filling machines also require utilities for efficient production and smooth operation. These utilities are needed as a part of individual sub-components operating requirements.

Before purchasing a filling machine, make sure that all the relevant utilities are available in your facility. If not, inform in advance to the machine manufacturer to work on a suitable replacement.

Some standard utilities required are as follows

• Electrical Power supply – 380VAC – 3 phase

• Compressed air supply – 6 bar

• Natural gas for flame – as per the requirement

Area requirements

Ampoule and Vial filling machine machines have different mechanical structures that can vary in size. The higher the capacity of the machine, the greater the space required for installing and running the machine. Additionally, the filling machine requires additional components such as a laminar and vessel to store the feeling liquid. 

Components like these and others require space for easy operator movement and machine operation. Manufacturers, in the initial stage, communicate the area requirement to the machine buyer, along with other requirements. The machine buyer is responsible for making the area available and working with the machine manufacturer to alter the machine design if the desired location cannot be made available.