by Michael Gamlen and Dipankar Dey at Gamlen Tableting Limited
Tablets under pressure
The hardness of a tablet has traditionally been used as a measure of quality; however, tensile strength is more appropriate when comparing tablets of different composition, shape and size, and compressed on different pieces of equipment.
The modern tablet is a complex drug delivery system where the drug substance is combined with a number of excipients to aid formulation of the desired product. These include bulking agents, binders, disintegrants and coatings all of which have some function to aid the processing of the drug substance into the end product form. The excipients and drug substance are processed through a number of unit operations such as mixing, blending, granulation, tableting and often coating to form the final product.
The final tablet has to fulfil a number of characteristics including the ability to deliver the correct amount of drug substance into the patient’s system at the required rate, as well as possess physicochemical characteristics that make it easy to handle, administer and store. For dispensable products these include a suitable size, hardness, texture and stability, as well as taste and smell.
Process and formulation development of the desired tablet form is time consuming and complex because knowledge of excipient/ drug substance material properties, and their relationship to the processing parameters by which the final product is made is limited, preventing a priori prediction of quality.
This causes manufacturers particular problems in developing and producing the ideal tablet which satisfies both its therapeutic use and its requirement to be manufactured both efficiently and economically. Even small variations in material properties or process parameters can have profound effects on the final tablet quality.
Why use a Gamlen Tablet Press?
It can save you time, money and materials. People need help to study tablets under properly controlled conditions in a laboratory.
Michael Gamlen invented the Gamlen Tablet Press (GTP) to help you understand the relationship between the properties of your drug, formulation, and manufacturing process. When you do this you can develop better products more quickly, and improve productivity of your tablet manufacturing operations.
The GTP is the first machine designed to make tablets on a small scale at a user-specified compaction force. This force determines both the physical strength and the dissolution behaviour of the tablet. These are the key properties which ensure the tablet reaches the patient and delivers the drug.
The machine works by monitoring the force in real time using a PLC. The punch force and punch position are displayed in real time on a computer which is also used to input the compaction conditions. Using the GTP we make tablets of extraordinary reproducibility and consistency, within 1-2% force, and with no wastage. Batch yields are >99%.
For the measurement of tablet breaking load, the press records both force and displacement during both compression and fracture, and also provides the ejection force profile associated with tablet ejection
In the scale-up of tablet production, the press can be used to determine the relationship between tablets developed at the bench-top scale using a few grams of material (often at the early development stage) and the final tablet manufactured on a rotary tablet press. The latter uses hundreds of kilograms of material, making process development difficult because of practical difficulties in experimentation; smaller and different shaped tablets can, however, be scaled to the final desired tablet design if TFS is used as the basis for comparison.
If you want better tablet products and processes you need the Gamlen Tablet Press.
Have a question? Like a quotation?
Like to see a Gamlen Tablet Press demo or have batch tablet samples made?
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