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Overview of the Extrusion Process
Prior to Spheronization

A Brief Overview of the Various Types of Extruders, and Extruders Used Prior to the Spheronization of Pharmaceutical Products

example of extrudate

Example of Extrudate

In the pharmaceutical industry, extrusion is the necessary first step in the extrusion-spheronization process. However, extrusion is often used to eliminate dust in formulations even when spheronization is not the final objective. The choice between gear and screen extruders depends on the formulation characteristics and the required density of the extrudate. Therefore, the right equipment for you would depend on the specific needs of your application.



There are Three Main Types of Extruders (Although There are Other Variations on These Basic Types)

Screw Extruders

diagram of screw extruder



Screen, or Basket, Extruders

diagram of screw extruder




Gear Extruders

diagram of screw extruder




Other Types of Extruders

Cylinder Extruder

diagram of screw extruder

The cylinder type consists of two contra-rotating cylinders, one of which is solid. The second cylinder is hollow and has a series of holes drilled through it. The material to be extruded is fed into the area above the two cylinders and is extruded into the bore of the larger perforated cylinder where it is cut into lengths by an adjustable cutter blade.






Radial Extruder

diagram of screw extruder

The radial and axial type of extruders consist of one or two feed screws that force the material either through a circumferential screen in the radial type, or through a die head in the case of the axial type.






Table Summarizing the Different Types of Caleva Extruders
For Pharmaceutical Productin and Development

Types of Caleva Extruders

Main Uses
MTR extruder head MTR option Laboratory: small quantity (10g) development use
Extruder 20 Bench top screen extruder Laboratory
experimental / small scale production
(30 g 25 kg /hr)
Extruder 35 Production screen extruder Lab/Production
Low cost-high output
(2kg /min) of less dense extrudate
Extruder 40 Production gear extruder Quality Extrudate
40-100 kg/hr
Extruder 100 Production gear extruder Quality Extrudate
Output 100-500 kg/hr