This site uses technical cookies and profiling third party cookies to offer a better user experience; third party cookies require your consent. By continuing to browse the site, clicking or tapping the screen, scrolling the web page or closing this banner, you are agreeing to our use of cookies. For further information or opt out options.
IMA is loading

How to preserve tablet integrity

Tablets require gentle treatment during the coating process, especially those with unsuitable technological characteristics. Machine design and adjustment of process parameters are key points to preserve the integrity of the cores. Case studies will explain how this should be handled.

June 08, 2016
Caterina Funaro
Massimo Malavolti

Live Webinar

Now on demand

The webinar has a total duration of about 30.
For a good visualization of the webinar:

check_circle Check your network connection
check_circle Refresh your page at the beginning of the webinar
check_circle Verify that Vimeo platform is not filtered by your company
check_circle Switch on the volume of your device

The answers of the coating experts

In the first case study, a formulation providing 28% solid concentration was used. Which technical solutions were implemented to be able to spray such a concentrated solution?
Read the answer
  • Mill and homogenize the insoluble powder very well.
  • Increase the nozzle diameter from 1.2 to 1.5 mm.
  • Adapt the dimension of the tube size due to the increased viscosity.
  • Control the pump flow rate with a flowmeter and a pressure sensor.
  • Increase the atomization pressure from 1.6 to 2 bar.
Can you explain better how to minimize the stress on the tablets during the loading in the pan?
Read the answer

The geometry of the drum with two conical parts and a cylindrical central sector with the perforated surface has been designed to guarantee right and gentle mixing of the tablets. During the cores’ loading, the front conical part of the drum can be used as a chute to reduce the impact between the tablets and the drum’s surface.

What is the meaning of pre-heat in jog mode?
Read the answer

The pre-heating phase is the first step of the coating process. It starts when the cores are uncoated and the mechanical stress can be dangerous. Before starting with the spray phase, the cores are pre-heated to reach the right temperature and the jog mode can be used. This means that the rotation of the drum can be ON or OFF according to the parameters set in the recipe.

Is the use of a deduster after tableting making worst the edges erosion problem?
Read the answer

The use of a deduster is not recommended because the tablet edges are very weak and can be damaged during this procedure. This affects final coating quality. In case the tablet edges are sharp due to the press tooling, the use of a deduster is useful to make the sharpness less evident (smoother) and avoid coating removal from the edges. For the same reason it is advisable to preheat the cores in a continuous way instead of using the jog-mode.

You spoke about optimal values for hardness and friability. Is there a recommended humidity value for tablets (LOD) suggested to ensure good coating performance and to avoid tablets damage?
Read the answer

There are no standard recommendations for LOD (Loss On Drying), common value is usually 2-3%. This strictly depends on formulation, both API and excipients, their hygroscopicity, etc. The suggestion is to maintain the LOD value of initial uncoated tablets equal to the final coated tablets. At the end, a proper final drying should be performed to avoid humidity addition to the tablets. In fact, humidity addition makes the cores’ softer and it has to be avoided.

Is the strategy of spraying high amount of coating at the beginning of the process feasible with both cosmetic and enteric polymers?
Read the answer

It is feasible, but the procedure is definitely more suitable and effective for enteric coatings due to the plastic nature of the acrylic polymers.

How do you scale up the pan speed when passing from a lab scale to an industrial coater? How this affect tablets response to stress?
Read the answer

A simple formula is used. It takes into account the diameter of the pan and converts any peripheral speed to a speed value in rpm (revolution per minute). When moving from a laboratory scale coater to production scale coater it is advisable to keep the peripheral speed the same value (rpm value is lower). Then it is necessary to observe the tablet movement and adjust the rpm value because the amount of tablets in a production coater can be 20-30 times higher. This means more mechanical resistance for the cores that should move freely on the pan surface and depth.

Meet our webinar speakers

Caterina Funaro
Process R&D Laboratory Manager
Caterina Funaro got her degree in Chemistry and Pharmaceutical Technology at the University of Bologna in 1998. She is actually employed at IMA Active Division as process laboratory manager and her main responsibilities are technical assistance to sales for all solid dose equipment, after sales process assistance, R&D, training and cleaning support for solid dose manufacturing equipment.
Massimo Malavolti
Product Manager for Coating Equipment
Massimo Malavolti got his degree in Technological Institute specialized for electronical and mechanical applications in 1990 in Bologna. He is employed at IMA since 1990. At the beginning he supported validation development and calibration strategy for coating equipment, actually he is Product Manager for coating equipment and his main responsibilities are sales technical support and projects management.
IMA launches #StayConnect
Remote FAT, virtual training and more. All on a single platform.