Chemical Properties
White or almost white, fine, free-flowing powder, very hygroscopic.
Uses
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 directcompression or wet-granulation processes.
Production Methods
Sodium starch glycolate is a substituted derivative of potato starch.
Typically, commercial products are also crosslinked using either
sodium trimetaphosphate (Types A and B) or dehydration (Type
C).
Starch is carboxymethylated by reacting it with sodium
chloroacetate in an alkaline, nonaqueous medium, typically
denatured ethanol or methanol, followed by neutralization with
citric acid, acetic acid, or some other acid. Vivastar P is
manufactured in methanolic medium, and Explotab in ethanolic
medium.
Pharmaceutical Applications
Sodium starch glycolate is widely used in oral pharmaceuticals as a
disintegrant in capsule and tablet formulations. It is
commonly used in tablets prepared by either direct-compression or wet-granulation processes. The usual concentration
employed in a formulation is between 2% and 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.
Although the effectiveness of many disintegrants is affected by
the presence of hydrophobic excipients such as lubricants, the
disintegrant efficiency of sodium starch glycolate is unimpaired.
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.
Safety
Sodium starch glycolate is widely used in oral pharmaceutical
formulations and is generally regarded as a nontoxic and
nonirritant material. However, oral ingestion of large quantities
may be harmful.
storage
Tablets prepared with sodium starch glycolate have good storage
properties. Sodium starch glycolate is stable although very
hygroscopic, and should be stored in a well-closed container in
order to protect it from wide variations of humidity and
temperature, which may cause caking.
The physical properties of sodium starch glycolate remain
unchanged for up to 3 years if it is stored at moderate temperatures
and humidity.
Incompatibilities
Sodium starch glycolate is incompatible with ascorbic acid.
Regulatory Status
Included in the FDA Inactive Ingredients Database (oral capsules
and tablets). Included in nonparenteral medicines licensed in the
UK. Included in the Canadian List of Acceptable Non-medicinal
Ingredients.
