DESCRIPTION :
Sodium starch glycolate is the sodium salt of a carboxymethyl ether of starch. The molecular weight is typically 500 000-11 000 000.

Very fine, white or off white, free flowing powder; odourless or almost odourless. Practically insoluble in water, insoluble in most organic solvents

It consists of oval or spherical granules, 30-100 µm in diameter with some less-spherical granules ranging from 10-35 µm in diameter.

APPLICATIONS :
Sodium starch glycolate is widely used in oral pharmaceuticals as a disintegrant in capsule and tablet formulations. It is recommended to use in tablets prepared by either direct-compression or wet-granulation processes.

The recommended concentration in a formulation is 2-8%, with the optimum concentration about 4% although in many cases 2% is sufficient. Disintegration occurs by rapid uptake of water followed by rapid and enormous swelling.

The disintegrant efficiency of sodium starch glycolate is unimpaired in the presence of hydrophobic excipients, such as lubricants unlike many other disintegrants.

Increasing the tablet compression pressure also appears to have no effect on disintegration time.

Sodium starch glycolate has also been investigated for use as a suspending vehicle.

STABILITY AND STORAGE CONDITIONS :
Tablets prepared with sodium starch glycolate have good storage properties. Sodium starch glycolate is stable and should be stored in a well-closed container to protect it from wide variations in humidity and temperature that may cause caking. The physical properties of sodium starch glycolate remain unchanged for up to 4 years if stored at moderate temperatures and humidity.