Possible problems and solutions of tablet press in tablet preparation1

1. Tablet debris The situation where the tablet splits is called splitting. If the split position occurs at the top (or bottom) of the tablet, it is generally called capping. This is a common way to spin off. Uneven pressure distribution and the resulting difference in elastic recovery rate are important causes of gaps. The key to dealing with the debris problem is to use auxiliary materials with low elasticity and high ductility to reduce the overall elastic recovery rate of the material. In addition, too much fine powder in the granules, too dry granules, weak cohesion or insufficient dosage, too thick tablets and too fast inhibition can also cause splitting. 2. Loose tablet The tablet is not hard enough and will crack when slightly touched, which is called loose tablet. 3. During the operation of the tablet press, the surface of the sticky punched tablet is stuck to the chromatography or a small part by the puncher, resulting in a rough, uneven or sunken surface. Typically, this is sticky. If the edge of the tablet is rough or has voids, it can be called stick mold. The main reasons for sticking or sticking are: the particles are not dry enough or the material is not easy to absorb water, the lubricant is not selected correctly or the amount is insufficient, the surface of the punch is rusted or the lettering is rough and not smooth. The reason should be determined and dealt with according to the actual situation. 4. The difference in tablet weight exceeds the limit, indicating that the weight of the tablet exceeds the allowable range of the difference in tablet weight stipulated in the Pharmacopoeia. The reasons and solutions are: (1) The circulation of the granules is not good. Sometimes the number of granules flowing into the die hole is small, resulting in a large difference in the net weight of the tablet. It should be granulated again, or a better flow aid, such as fine powder silica gel, should be added. , to improve the fluidity of particles. (2) There are too many fine powders in the particles or the size of the particles is very different, resulting in heavy and light materials flowing into the die holes. Excess fine powder should be removed or re-granulated; (3) The particles in the silo are generally too small, which will cause fluctuations in the weight of the feed and make the difference in tablet weight beyond the limit. Therefore, the particles in the silo should always exceed 1/3. (4) The consistency of the punch and the die hole is not good. For example, there is a large amount of powder leakage between the periphery of the lower punch and the wall of the die hole, which will cause the 'squeaky punch' condition of the lower punch, which will inevitably lead to insufficient material filling. Therefore, the punch should replace the head die ring.