Weight variation beyond limits is a common and important problem in pharmaceutical tablet pressing. It affects dose accuracy and can create risks for patient safety. Companies need practical measures to control it.
Causes of Weight Variation Overruns
Equipment factors:
Tablet press precision is insufficient or wear is severe, so tablet weight becomes unstable.
Errors or wear in the feed mechanism, dies, and other parts affect weight uniformity.
Raw material factors:
Inconsistent particle size, density, and flowability lead to weight variation.
Changes in moisture or oil content can also affect tablet weight.
Process factors:
Improper pressure, speed, and dwell time settings cause weight variation.
The wrong type or amount of lubricant, binder, or other excipients can also affect tablet weight.
Solutions
Optimize the tablet press:
Maintain and service the press regularly to keep precision and stability.
Replace worn parts such as feed mechanisms and dies. Hansheng Automation can machine replacement feed mechanisms, dies, pressure rollers, and similar non-standard parts from customer drawings, in single pieces or small batches. This helps restore fit and reduce variation.
Introduce advanced tablet press equipment to improve production precision and efficiency.
Control raw material quality:
Screen and test raw materials strictly to keep particle size, density, and flowability consistent.
Monitor moisture and oil content, and adjust the process when they change.
Use high-quality raw materials to reduce weight variation from material quality.
Optimize the production process:
Set pressure, speed, and time according to the drug formulation and production requirements.
Choose suitable lubricants and binders, and control their amounts.
Use inline inspection, automated control, and other advanced process methods to improve precision and stability.
Add a tablet checkweigher:
Function: A tablet checkweigher is a high-speed automatic weighing device that can be connected to a tablet press. It checks tablet weight one by one and automatically rejects nonconforming tablets.
Advantages:
High speed and accuracy: a self-developed high-speed weighing module and checkweighing algorithm software give the weight value of each tablet in a short time.
Automatic rejection: nonconforming tablets are removed automatically.
Easy maintenance: the load cell and A/D conversion module are designed and installed separately, allowing remote monitoring and maintenance.
Multi-function: it can display weight trend curves for all channels at the same time, making it easier to observe tablet weight and press operation.
Application example: The Xitaike tablet checkweigher uses a sliding plate weighing invention patent. A vibrating corrugated plate feeds and queues tablets, so they slide one by one under gravity across inclined weighing channels. This provides efficient and accurate checkweighing. Several models are available with different inspection speeds.
We do not limit our precision parts customization to tablet press components. Hansheng Automation also machines non-standard parts for yacht precision components, RC racing car precision components, tobacco packaging machinery, filling machinery, and other equipment such as printing and food machinery. We work from customer drawings and focus on precision machined parts, not complete machines.
