Oral Liquid Dosage Line

Introduction

The oral Liquid dosage line is a set of equipment, machines, and instruments used in the manufacturing, material transfer, filling, and packaging of the liquid pharma dosage in finished form. Raw material enters from one side of the line and passes through different phases, processes, and equipment. It changes its product shape and property until it converts itself into the final finished form from the end of the line.

The entire operations, such as manufacturing, filling, and packing, are carried out in a single facility without transferring material from one facility or area to another. The utilities, power, and other necessities are provided at a single location.

Components of Oral Dosage Line

Following are some important components of oral dosage line

Vessels

Vessels are metallic, circular-shaped containers used for containing liquids. They are used in the manufacturing section to manufacture a liquid pharma product. Depending upon the product and process requirements, they can include additional accessories such as a temperature sensor, level sensor, mixer with motor, and nozzles for water or another liquid solvent.

Vessels are made up of stainless steel material to prevent corrosion and to affect the liquid product. There are two types of stainless steel used for manufacturing vessels – 304 & 316L

SS316L is used for manufacturing parts that come in direct contact with the product, such as internal parts and mixers. While 304 is used to manufacture parts of the vessel that do not come in direct contact with a product, such as a vessel exterior.

In a liquid section, there can be different types of vessels. Each type has a dedicated function that can be used for specific purposes and applications. There are two common types of vessels used in oral liquid manufacturing – Manufacturing and Storage vessels.

Manufacturing Vessel

Manufacturing vessels are used to manufacture the liquid product. They contain accessories, systems, and functions typically used during product manufacturing.  

 For example, they contain a mixer powered by a motor to mix the solution. Mixer is used to mixing the water/solvent with raw material. Other accessories can include 

· Temperature sensor to monitor the temperature of product

· Level sensor for mentoring the liquid level.

· Sight glass to manually observe the product condition

After manufacturing the product in manufacturing vessels, the liquid is transferred to storage vessels for storing liquid product for further processing.

Storage Vessel

Storage vessels are used to store liquid products after manufacturing from the manufacturing vessel. They are used as a transition before filling into the containers. Its purpose is to free the manufacturing vessel for further product manufacturing. Storage vessels are often superficial and commonly do not contain accessories other than the basic ones.

Transfer System

A transfer system directly transfers the liquid from the storage vessels into the filling machine. It consists of a network of pipes interconnected to different vessels and filling machines. A pump transfers liquid from vessels by connecting the appropriate piping network.

The transfer system is interconnected to the level monitor in the filling machine. If the tank in the filling machine is empty or below the threshold level, the pump is activated to fill the tank. When the level is enough at the threshold level, the pump stops. 

The main purpose of the transfer system is to facilitate liquid transfer into the filling machine without human involvement. It also helps to prevent contamination and liquid spill. 

Air blowing machine

Air-blowing machines blow empty bottles with air before filling liquid in them. Its purpose is to remove foreign particles or objects from the bottles using filtered compressed air. Every bottle receives a jet of compressed air at high pressure. Any foreign body or particles are displaced away by the action of forced air.

There are many configurations of the air-blowing machine, commonly the rotary type. This configuration consists of a rotating wheel, which contains air nozzles. Air at high pressure flows from these nozzles.

 Bottles enter the machine from the feeding section and are placed at each nozzle. Air from each nozzle starts to flow into the bottle, removing particles. The bottle enters the wheel from the infeed station and leaves the wheel when at the outfeed station. This way, bottles from infeed stations are transferred to the outfeed station.

Filling Machine

A filling machine is used to fill liquid into empty bottles.

 It consists of an infeed station, a filling station, and an outfeed station. The Infeed station receives bottles from the conveyor belt and transfers them to the filling station. It aligns the bottle with the filling nozzle for accuracy to prevent liquid wastage.

At the filing station, nozzles fill the liquid product into empty containers. The filling is activated when bottles come beneath the nozzles. Liquid fills into the container for the desired volume. The filling volume is adjustable and can be set according to the product requirement.

After filling, bottles are transferred to the outfeed station. It is the last section of the filling machine, and filled containers are moved out of the device for the capping process.

The filling machine can be automatically controlled by a main or programmable logic controller – PLC. Different sensors are used to monitor machine position and processes. Based on feedback from this sensor, the main controller progresses with the filling operation.

Filling machines can also be manual, which requires human involvement throughout the entire operation. Humans manually place the containers and give a signal to initiate the filling process. Humans also monitor the filling level and manually stop the filling operation when the required volume has been filled in the container.

Liquid to be filled is contained a filling machine tank, which automatically fills when its levels drop below the threshold level. The tank is connected to the storage vessel through a transfer system. A level sensor continuously monitors the filling tank level. It signals the main controller to either start or stop filling the tank.

No Container – No Fill

No container – no fill feature is used to prevent liquid spillage in case there is no container beneath the nozzle. The main controller calculates the position of the empty container and controls the nozzle's filling when that particular nozzle's position comes below it. This feature is only provided with an automatic filling machine. An encoder can detect position, calculating individual positions in a rotating cycle.

Position can detection can also be performed by a proximity sensor. When bottles are present, it signals the main controller and initiates filling. When there is no bottle, the main controller does not receive a signal, termed as no container, and filling is not initiated for that particular position.

Capping machine

A capping machine is used to seal the liquid container with caps. It consists of a rotating head, which holds a cap. The rotating head presses the container's head with force, and places tightens and seal the cap. After capping, the rotating head releases the container and passes it to the conveyor belt, which directs the container to the machine's outfeed. This procedure is repeated for the entire batch of containers.

The capping machine consists of a hopper in which caps are stored. A chute connects the hopper with the rotating head to transfer caps into it. When the head becomes empty, caps are automatically transferred into the head for smooth and continuous capping operation.

The capping machine can be separately installed or integrated into the filling machine. 

If it becomes part of the filling machine, bottles are transferred to the capping station immediately after the filling station. Here the capping is performed before leaving the machine. The capping machine works synchronously with the filing machine and is also controlled by the filling machine.

If the capping machine is separately installed, filled containers are transferred to the capping machine through a manual or automated system. The capping machine operates independently and is not synchronized with the filling operation. 

Labeling Machine

The labeling machine is used to paste labels on the filled and capped containers. It consists of an infeed station from where bottles are fed. A separate container or hopper contains the glue or adhesive for pasting labels to the bottles. The machine also consists of an assembly that includes labels. 

During labeling operation, a mechanical assembly picks labels from the label. It applies the glue or adhesive to the label and, in the final stage, pastes the label to the bottle. After pasting, a mechanical arm tightens the label to prevent the dropping or removal of labeling.

After labeling is complete, the filled container is transferred to the outfeed for further processing. 

Cartoner Machine

Cartoner machines are used to pack one or more than one blisters into cartons of various sizes. It automatically puts the blister into the carton and closes it without human involvement.

Empty cartons enter from one side of the machine and fill the bottle from another end. Empty cartons are first opened and stretched to their size. This allows easy insertion of filled containers into the cartons. Filled bottles enter into the open containers up to their range and size. After insertion, the carton is automatically closed by cams, guiding the catch cover into its closing position as it advances linearly. 

After packing, the filled catch cover moves out of the machine for further processing.

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.