Application of Microcrystalline Cellulose—Avicel in Medicine
Avicel is the foreign trade name, composed by mixing the product with sodium carboxymethyl cellulose in different proportions. For example, Avicel -RC-591 contains 11%（±1）CMC; while Avicel -RC-581 contains 8.5%（±1）CMC. These models are used in the food industry.
Products of Avicel PH models are used for the pharmaceutical industry, including Avicel PH101, PH102, PH103, PH 105, PH301, PH302 and so on. And the differences of Avicel PH101, PH102, PH103, PH 105, etc. are the particle size and the moisture content level. Of them, PH 102 has the largest particle, with an average particle diameter of 62μm; while PH 105 has the smallest particle, with an average particle size of 25μm. And PH103 has a less moisture content.
Widely used as the excipient of tablets are two specifications—PH 101 and PH 102, with good compressibility as well as adhesion, flow aid, disintegration and other effects. They are especially suitable for the direct compression process. The compressed tablets have good hardness and are easy to disintegrate.
The coefficient of friction of microcrystalline cellulose is small, but when the content of drug or other excipients does not exceed 20%, the lubricant is generally not required to add during tableting. For the alkaline salt lubricants, if the amount is higher (0.75%) and the mixing time is longer, then the softening phenomenon will occur in tablets. However, the situation is better by using PH102 than PH101. The disadvantage is that the price is higher than more commonly used starch, dextrin, powdered sugar, etc.. Therefore, if not for special needs, it is generally not used alone.