Powdered cellulose

Powdered cellulose has acceptable compression properties, although the flow properties of most brands are poor. However, low-crystallinity powdered cellulose has exhibited properties that are different from standard powdered cellulose materials, and has shown potential as a direct-compression excipient. Powdered cellulose also acts as a bulking agent to increase the physical size of the dosage form for formulations containing a small amount of active substance. Powdered cellulose incompatible with strong oxidizing agents, bromine pentafluoride, sodium nitrite and fluorine.

Characteristics of Powdered cellulose

  • Powdered cellulose products consist of finely divided amorphous and crystalline a-cellulose particles.
  • Powdered cellulose may be used alone or together with other fillers such as lactose, calcium phosphates, dextrans and others.
  • It possesses poor compressibility and exhibits poor flow properties.
  • It has poor binding properties and low dilution potential.
  • It is water insoluble.
  • It possesses some degree of inherent lubricity.
  • It is inexpensive.
  • Trade name :  Elcema G-250, Arbocel; Microcel 3E-150

Microcrystalline cellulose (MCC)

Microcrystalline cellulose (MCC) is purified partially depolymerized cellulose, prepared by treating a-cellulose with mineral acids. It is a white, crystalline powder composed of agglomerated porous microfibers. After purification by filtration and spray-drying, porous microcrystal are obtained. Microcrystalline cellulose occurs as a white odourless, tasteless crystalline powder composed of porous particles of an agglomerated product. Apart from its use in direct compression, microcrystalline cellulose is used as a diluent in tablets prepared by wet granulation, as filler in capsules and for the production of spheres.

Characteristics of Microcrystalline cellulose

  • Microcrystalline cellulose (MCC) is highly compressible and is perhaps the most widely used direct-compression tablet diluent.
  • Hard tablets, at low compression pressures, are usually obtained when MCC is used as tablet diluent.
  • It undergoes plastic deformation on compression and hence it is more sensitive to lubricants.
  • It exhibits fair flowability and binding properties.
  • MCC also has some lubricant and disintegrant properties that make it useful in tableting.
  • It is water insoluble.
  • MCC is expensive.
  • Trade name : Emcocel, Ethispheres, Fibrocel