Varieties and properties of accessories for tablet press machine

The choice of excipients in direct tablet pressing is very important. In addition to the performance of general tablet excipients, the most important one is that excipients should have good fluidity and compressibility, and also need appropriate bulk density and large drug capacity (that is, adding more drugs without significant adverse effects on fluidity and compressibility). The types of excipients commonly used for direct compression are as follows:

Microcrystalline cellulose is white or almost white powder, odorless, tasteless, insoluble in water, ethanol, acetone or toluene. It has very good compressibility, fluidity and disintegration. It is an excellent filling agent and effective drying adhesive for tablets. It has good hardness after pressing and does not affect disintegration. This variety has a large capacity for medicine, and its dosage can range from 5% to 65%. But this variety has hygroscopicity. Now there are products on the market in China.

Pre gelatinized starch is white powder, odorless, tasteless, good fluidity, angle of repose of domestic product is 36.6 degrees, good compressibility; it has lubricating effect, can reduce the force of tablet ejecting from the mold hole; it has good disintegration and dry adhesion, can increase the hardness of tablet, reduce the brittleness. This product is an ideal multi-functional excipient for direct powder compression. The dosage is generally 5% - 20%.

Lactose spray dried lactose is used as a supplementary material for direct compression of powder. It is white crystalline powder with no hygroscopicity. The tablets are smooth, beautiful, fast release, fluidity, and good adhesion. It is an ideal filler for tablets. When the dosage is more than 50%, the hydrophobicity of the drug can be improved.

Carboxymethyl starch sodium is an excellent disintegrating agent for tablets. It is a white or almost white powder, odorless, and has hygroscopicity in air. It disperses into a viscous colloidal solution in water. It has good hydrophilicity and water swelling. It also has good fluidity and compressibility. It can improve the formability of tablets and increase the hardness of tablets without affecting their disintegration. It can improve the disintegration of insoluble tablets. The general dosage is 1% ～ 8%.

Calcium hydrogen phosphate is a white powder, odorless, tasteless, insoluble in water or ethanol, with moisture resistance, good fluidity and stability, low price, and good hardness. When the tablet contains 50% dicalcium phosphate, it disintegrates very quickly.

Micropowder silica gel is a light white anhydrous powder, odorless, tasteless, with large specific surface area. It is a commonly used tablet flow aid and has great adhesion to drugs. When the dosage is more than 1%, it can accelerate the disintegration of the tablet, and the disintegration is very fine, which can improve the dissolution of the drug and facilitate the absorption of the drug. The general dosage is 0.15% ～ 3%.

Magnesium stearate is a white, easy and sand free fine powder. It has a greasy feeling when contacting with skin. It is insoluble in water and has good adhesion. This product is a commonly used hydrophobic lubricant, can effectively solve the phenomenon of sticking and punching, one-sided smooth and beautiful. The general dosage is 0.2% ～ 1%.

Others include low substituted hydroxypropyl cellulose, starch, talc magnesium stearate mixed powder, aluminum magnesium raw powder, etc.