Basics of tableting and coating techniques
a brief overview of processes and machines
Which machine do I need for which process?
The right choice of process and machine is crucial for your tablet compression and coating, as it has a direct influence on production quality, efficiency and cost-effectiveness.
The challenge in the
tableting process: Which tableting process do I use? Can my active ingredient be pressed directly or do I need to pre-treat it? Do I need a single-layer or multi-layer tablet?
Coating process: Does my tablet need a coating to give it more stability, to mask odors or tastes, to maintain a certain release profile or to add more color?
1. Tableting process
Powder preparation
Sometimes it is necessary to pre-treat the still powdery tablet mass. For example, if the powder is difficult to compress or has poor flow properties. The following methods can be used to improve this:
Dry Compression
Used for active ingredients that are very sensitive to moisture (hygroscopicity) or heat (thermolability). They can disintegrate or lose their effectiveness during wet granulation. Dry compression avoids the use of liquids and thus protects the active ingredients from moisture; highly hygroscopic substances (water-attracting) can clump together during wet granulation and make tablet production more difficult. Dry compression reduces this risk.
Wet Compression
This common process is used to improve the flowability of fine particulate powders. Or for low compressibility. Wet granulation can improve compressibility by changing the particle structure and increasing the surface area. The resulting granules have better cohesion and are easier to compress into tablets.
Compression method
Direct Compression
In this process, the powder of the active ingredient and excipients is pressed directly in a tablet press without prior granulation or compression.
The production process is quick, cost-effective and simple.
Multilayer Pressing
In this process, tablets are pressed in several layers. Each layer can contain different active ingredients, release profiles or colors.
Machine types
Single Punch Press
A single punch press, also known as an eccentric press, is a simple and compact machine for producing tablets in small batches or for research and development purposes. Its mode of operation is based on a single pair of punches and a die.
Rotary Press
The powder is produced in a machine with several rotating stations. Machines for large-scale production can be equipped with over 100 punches and can press well over 1 million tablets per hour. Ideal for mass production due to high production speed.
Tableting machine overview
BIOGRUND works with tableting machines from the following manufacturers:
2. coating process
Coating process
Filmcoating
Film coating is a process in which tablets are coated with a thin, even layer of one or more polymers. This layer, also known as a film, can fulfill different functions and improve the properties of the tablet. Compared to coating, the process times for film coating are significantly faster.
Sugar Coating
Traditional coating method in which numerous layers of a sugar solution are applied. The end product, a coated tablet, has a smooth, shiny and well-insulating surface. Aesthetically pleasing (colorful, shiny dragee), protects the active ingredient from light & moisture while maintaining a neutral odor and sweet taste. The disadvantage is extremely long processing times.
Hot Melt Coating
Here, one or more active ingredients are dispersed in a molten matrix of polymers or other materials (waxes) and then applied as a thin layer to tablets or other solid dosage forms (particles, pellets). The matrix solidifies on cooling and forms a coating that can fulfill various functions. It can be applied solvent-free and offers good barrier properties against moisture.
Machine types
Trommel-Coater
Anwendung: Filmcoating von pharmazeutischen & Nahrungsergänzungsmittel-Tabletten. Hier unterscheidet man zwischen perforierten und Glattwand-Trommeln. Eine Trommel mit Perforation ermöglicht eine effiziente Luftführung & schnellere Trocknungszeiten, was die Prozesszeit positiv beeinflusst.
Wirbelschicht-Coater
Anwendung: für den Überzug von Pellets, Granulaten, Partikeln, Mini-Tabletten. Die Wirbelschicht-Technologie ermöglicht eine gleichmäßige Beschichtung. Ebenso für die Verkapselung von Aromen und Duftstoffen geeignet oder zur Granulierung. Findet auch Anwendung in der Herstellung von Instant-Produkten (z. B. Kaffeepulver).
Dragierkessel
Anwendung: für den Auftrag einer Zuckerdragierung, Schokoladen-Überzüge in der Süßwarenindustrie sowie Schutz- und Glanzüberzüge für pharmazeutische Produkte (Dragees). Schicht für Schicht Methode: Auftragen/Verteilen/Trocknen. Trocknung erfolgt durch Warmluft oder ein offenes System. Dragierkessel kommen aber auch im Labormaßstab (F&E) als Filmcoater zum Einsatz.
Coating machine overview
BIOGRUND works with film coating machines from the following manufacturers:
Questions?
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