Incompatibilities : Powdered sucrose may be contaminated with traces of heavy metals, which can lead to incompatibility with active ingredients, e.g. ascorbic acid. Sucrose may also be contaminated with sulfite from the refining process. With high sulfite content, color changes can occur in sugar-coated tablets; for certain colors used in sugar-coating the maximum limit for sulfite content, calculated as sulfur, is 1 ppm. In the presence of dilute or concentrated acids, sucrose is hydrolyzed or inverted to dextrose and fructose (invert sugar). Sucrose may attack aluminum closures.

Characteristics of Sucrose or sugar

  • It requires high machine pressures, especially in cases with over wetted granulations.
  • It is water soluble.
  • It possesses good binding properties.
  • It is slightly hygroscopic.
  • It is inexpensive.
  • It produces gritty mouth feel (i.e., it is not free from grittiness).
  • Sucrose serves as a dry binder (2–20% w/w) or as a bulking agent and sweetener in chewable tablets and lozenges.
  • Tablets that contain large amounts of sucrose may harden to give poor disintegration.


It is water soluble, non-hygroscopic and produces a semi-sweet, smooth, cool taste. It can be advantageously combined with other direct compression excipients. Mannitol may be used in direct-compression tablet applications, for which the granular and spray-dried forms are available, or in wet granulations. Granulations containing mannitol have the advantage of being dried easily. Specific tablet applications include antacid preparations, glyceryl trinitrate tablets, and vitamin preparations.

Characteristics of Mannitol
  • Mannitol a sugar alcohol is an optical isomer of Sorbitol.
  • It exhibits poor flow properties.
  • It requires high lubricant content.
  • It is probably the most expensive sugar used as a tablet diluent and is water soluble.
  • It is widely used in chewable tablets because of its negative heat of solution, its slow solubility and its mild cooling sensation in mouth.
  • It is non hygroscopic and may be used with moisture-sensitive drug, e.g vitamin
  • It is free from grittiness.
  • It possesses low caloric value and is noncariogenic.
  • Trade name : Parteck, Pearlitol and Mannogem.


Sorbitol is used as a diluent in tablet formulations prepared by either wet granulation or direct compression.

Characteristics of Sorbitol

  • Sorbitol is often combined with mannitol formulations in order to reduce diluent cost.
  • It is highly compressible diluent and is water soluble.
  • It is hygroscopic in nature.
  • It useful in chewable tablets owing to its pleasant, sweet taste and cooling sensation.
  • It is free from grittiness.
  • It possesses low caloric value and is noncariogenic.
  • Trade name :  Sorbifin and Neosorb .

Poorly absorbed sugar alcohols such as Sorbitol and mannitol can decrease small intestinal transit time. Therefore absorption may be altered for the drugs that are preferentially absorbed from this region.