Another problem with tablet production is variation in the hardness of the tablet. A soft tablet can cause a multitude of problems not only with the press but also with product consistency, film coating process and packaging which can sometimes lead to product recall.
The first step in addressing issues of tablet hardness is to check the press before investigating the upstream processes
1.Weight Control. Maintaining the weight of the tablet is the key to controlling its hardness; fluctuations in the weight cause changes in the hardness of the tablet. Accuracy in the control of tablet weight with respect to a target weight is therefore especially important. A tablet that is lighter than the target tends to be soft tablet whereas a heavier tablet tends to be harder. If there are variations in the bulk density, then the die filling will not be consistent, resulting in wide variations in tablet weight.
2.Scraper blade and die fill. The scraper blade is often overlooked as a item that wears, and should be replaced regularly. If the product is very abrasive it may be that the scraper blade should be changed on a daily basis. For other regular products, the blade may last for several months. Blade lifetime is therefore dependent on the product type and how well the blade is maintained…