Possible problems and solutions of tablet press in tablet preparation
1. Sticking and punching during tablet press operation
The surface of the tablet is stuck to a thin layer or a small part by the perforator, resulting in a rough, uneven or concave surface. Usually, it is adhesive. If the edge of the tablet is rough or notched, it can be called adhesive molding.
The main reasons for adhesion or adhesion 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 rusty or the lettering is rough and not smooth. The cause shall be determined and solved according to the actual situation.
2. Exceeding the dissolution limit
The tablets cannot dissolve the specified amount of drugs within the specified time, that is, the dissolution exceeds the limit or is called unqualified dissolution, which will make it difficult for the tablets to play their due role. After taking the tablet orally, it must go through multiple processes, such as disintegration, dissolution and absorption. Any problems in these processes will affect the actual efficacy of the drug.
3. Tablet fragments
The phenomenon of tablet splitting is called splitting. If the split position occurs at the top (or bottom) of the tablet, it is usually called capping. This is a common form of splitting. Uneven pressure distribution and the resulting difference in elastic recovery rate are the main causes of cracks.
The key to solve the fragmentation problem is to use auxiliary materials with low elasticity and large plasticity to reduce the overall elastic recovery rate of materials. In addition, there are too many fine powders in the granules, the granules are too dry, the adhesive force is weak or the dosage is insufficient, and the tablets are too thick and pressed too fast, which will also cause splitting.
4. Tablets Loose tablets
The phenomenon that the tablets are not hard enough and will crack with a little touch is called tablet looseness.
5. The difference in tablet weight exceeds the limit
Indicates that the tablet weight exceeds the allowable range of tablet weight difference specified in the pharmacopoeia. Reasons and solutions for exceeding the limit of tablet weight difference of tablet press:
(1) The fluidity of particles is poor. Sometimes, the number of particles flowing into the mold hole is small, resulting in a large weight difference of the tablets. It is necessary to re granulate, or add better flow aids, such as fine silica gel, to improve the fluidity of particles.
(2) Too much fine powder in the particles or large difference in particle size lead to heavy and light materials flowing into the mold hole. Excess fine powder shall be removed or re granulated;
(3) The particles in the hopper are usually too small, which will cause fluctuations in the feed weight and cause the difference in tablet weight to exceed the limit. Therefore, the particles in the hopper should always exceed 1/3.
(4) The consistency between punch and die hole is not good. For example, there is a large amount of powder leakage between the outer circumference of the punch and the die hole wall, which will lead to the "astringent punch" phenomenon of the lower punch, inevitably leading to insufficient material filling. Therefore, the die ring of the tablet press should be replaced.
Contact Person: Ms. Wei