Extrusion & Spheronization

Use this table to link to the appropriate section of this website relating to extrusion-spheronization

Extruders	Spheronizers	Mixer Torque Rheometer (MTR)	Datastor Data Acquisition System
This link will take you to the Extruders section of this website for a brief overview of extruders commonly used in the pharmaceutical industry, with links to the extruders being offered.	This like will take you to the section of our page describing the spheronization process along with links to the various Caleva extruders.	The MTR provides a quick and easy way to consistently and quantitatively measure a wet mass prior to extrusion and spheronization.	The Caleva Datastor is used to automatically record extrusion and spheronization and parameters.

Spheronization - A General Overview of the Manufacture of Pharmaceutical Pellets by Spheronization (or, as Sometimes Written, Spheronisation or Marumerization)

Why Spheronize?

Definition of Spheronization: The formation of small spheres of material.

Spheronization, or Marumerization, is a rapid and flexible process where pharmaceutical products are made into small spheres, or spheroids. These products are often also referred to as micro-spheres, pellets, micro-pellets, beads or pharmaceutical pellets. Spheronized products are relatively dense, of a uniform in size and shape and have defined surface characteristics.

Granulation, which is a different process, normally refers to less dense, irregularly shaped particles with a large size distribution within a batch.

The flow characteristics of spheres makes them suitable for transportation by most systems found in the pharmaceutical industry. Spheres provide the lowest surface area to volume ratio and thus pharmaceutical compounds can be coated with a minimum of coating material.

The advantages of spheronization (pelletization) are:

• Manufacture of modified, or controlled release formulations.
• Mixing of otherwise incompatible formulations.
• To enable uniform coating and accurate free flow filling into capsules. This application requires consistent smooth surface particles, with a narrow size distribution.
• Esthetics. Small spheres can be an important marketing and product feature for pharmaceutical, food and cosmetic products.
• Elimination of dust. Spheroids can reduce risks due to toxic, environmental, and explosive hazards.
• To improve processing consistency and productivity by using consistent free-flowing spheres.
• To reduce product settlement in transport and handling.

Typical Spheronization Process:

Spheronization is a rapid, economical and well understood method for making pharmaceutical spheroids. Since extrusion is a necessary first step, this process is often referred to as the "extrusion & spheronization" process. The usual steps in the extrusion-spheronization process are described as follows:

1. The powdered pharmaceutical ingredients are mixed and blended.
2. Liquid binders are added to the mix to create a semi-wet plastic mass with the proper consistency for extrusion. The venerable "hand squeeze test" can be used to gauge the consistency of the wet mass, however, the Caleva Mixer Torque Rheometer (MTR) can be used to more accurately and consistently quantify the properties of the mix.
3. The wet mass is extruded to form a "spaghetti-like" extrudate. The diameter of the extrudate will be the approximate size of the final spheres.
4. The extrudate is put into a spheronizer which converts the extrudate into small spheres.
5. The spheres are dried and, if necessary, coated.

 

There is also a very good website, http://www.spheronization.com/ which provides a more detailed explanation of the extrusion-spheronization process than is given here.