Screw Extruders in HME Services

 

Extrusion is the procedure involved in changing the physical properties of a substance by forcing it through a die or an orifice under controlled conditions. The equipment used in this process is classified into three major categories: screw extruders, radial screens, and ram. However, screw extruders are the most essential in the pharmaceutical industry. They are the most important because they constantly convert feed material to the finished form such as film, tube, or rod.

Continue reading this blog to learn more about screw extruders as one of the equipment used in the process of proprietary hot melt extrusion.

 

Screw Extruders

Pharmaceutical screw extruders are manufactured based on the desired extrudate. They are needed to meet the present regulatory standards for the production of dosage forms. They are categorized as:

* Single-screw extruders

* Twin-screw extruders

* Multi-screw extruders

Regardless of the type, process complexity, or function, the different extruders must be able to rotate the screw at a particular working speed while making up for the generated and torque shear rate from both the type of screw used and the material being extruded.

The Types of Extruders

Below are the types of Extruders:

1. Single-screw Extruder

The single-screw types are commonly used for conveying and melting polymers to extrude these polymers into incessant shapes. In comparison, twin-screw extruders are used to melt-mix polymers with extra materials and to devolatilize.

In manufacturing pharmaceutical formulations, which entail consistent and homogeneous mixing of several formulation ingredients, a twin-screw extruder is desired due to its rotation. The gyration of the inter-meshing screw delivers greater mixing to produce a homogeneous solid. This solid has finely dispersed active pharmaceutical ingredient particles or a solid solution of active pharmaceutical ingredients in the polymer.

2. Twin-screw Extruders

Constant melt-mixing through twin-screw extrusion can advance the bioavailability and dissolution rate of poorly water-soluble active pharmaceutical ingredient formulation. The evenly distributed active pharmaceutical ingredient is also a precondition to manufacturing drug-eluting devices with inter- and intra-batch reproducibility of drug-release kinetics.

Melting; a Process in HME

* Melting is achieved by heating frictionally in the barrel. In twin-screw extruders, on the other hand, the resources undergo shearing between the screws and the wall of the barrel and the rotating screws as they are conveyed. The barrel can be heated or cooled with water.

* The barrel section temperatures are commonly optimized so that the material viscosity isn’t high enough to allow proper conveyance down the barrel and mixing while also keeping temperatures low enough to avoid thermal degradation.

* In twin-screw extruders, the screws are commonly engineered to deliver varied types of conveying and mixing conditions at different zones in the barrel. During product manufacturing, modular screws with several elements fitted on a common shaft optimize and tailor the screw design for each product.

* Sections of the screw can be created to perform particle size mixing, reduction, and conveying functions. The length of the screw is chosen to optimize the number of zones and level of mixing required to achieve the final product characteristics.

AbbVie is the leading company in Hot Melt Extrusion. We offer the best HME services. Contact us today.