Slow-release tablets are made of special high-density material with a skeleton, and the drug is slowly released from the skeleton, so if it is crushed, the skeleton structure will be damaged and the efficacy will be affected. Therefore, they should not be crushed for consumption. ② Controlled-release tablets Controlled-release tablets are preparations with relatively high requirements for drug release, so they are mostly seen in cardiovascular preparations, which have a relatively constant release dose per unit time to maintain a constant blood concentration and longer-lasting efficacy. After the tablet is divided, the controlled-release film or controlled-release skeleton is destroyed, and the drug will be released rapidly, which will not achieve the purpose of controlled-release, and sometimes can cause a sudden increase of drug concentration in the body, resulting in drug poisoning. ③ Double-layer sugar-coated tablets such as multi-enzyme tablets are double-layer sugar-coated tablets containing 3 kinds of digestive enzymes (amylase, pepsin and pancreatic enzyme). The outer layer is general enteric coating, amylase and pepsin are in the outer layer of the tablet, which can play the role of digestive aid in the stomach. The pancreatic enzymes need to function in the alkaline intestine, so they are wrapped in the inner layer of the tablet. If the tablets are crushed, they will lose their protective effect, especially if the pancreatic enzyme powder remains in the mouth, it can damage the oral mucosa and even cause serious oral ulcers. (4) Enteric tablets i.e. a layer of outer coating is wrapped around the outside of ordinary tablets, and this layer is dissolved only when it reaches the intestine. Therefore, these tablets must be swallowed whole, if crushed and taken will not only reduce the efficacy of the drug, but also cause side effects. For example, if you want to take erythromycin enteric-coated tablets, you should take an appropriate amount of alkaline drug (such as sodium bicarbonate) 5 minutes before taking to neutralize the stomach acid, so as to ensure that erythromycin can pass through the acidic environment of the stomach and enter the alkaline environment of the intestine to function.