External addition, internal addition, internal and external addition.
(1) Mix with prescription powder to form granules (internal addition method). The disintegration effect starts from the inside of the particles, causing them to completely disintegrate. However, due to the fact that the disintegrant is encapsulated in the particles and comes into contact with water slowly, and starch and other substances have already come into contact with mild heat during the granulation process, the disintegration effect is weak.
(2) Mix with dried particles and press into tablets (external addition method). Although the disintegration rate of this method is relatively fast, its disintegration mainly occurs between particles, and after disintegration, it often appears in a granular state rather than a fine powder.
(3) Part of it is mixed with the prescription powder to form granules, while the other part is added to the dried granules, mixed evenly and compressed into tablets (internal and external addition methods). This method can overcome the shortcomings of the above two methods and is a more ideal approach. As for the amount of disintegrant added during granulation and tablet pressing, it can be determined according to the specific variety. Generally, the addition ratio is 3 parts inside and 1 part outside.