CAS 9005-38-3 Sodium Alginate Bulk For Pharmaceutical Preparation Excipients

CAS No. 9005-38-3 Alginate Sodium For Food Additives With Powder

Sodium alginate is a by-product of the extraction of iodine and mannitol from kelp or Sargasso Uronic acid (α-L-guluronic, G) is connected by (1→4) bonds. It is a natural polysaccharide with the stability, solubility, viscosity and safety required for pharmaceutical preparation excipients. Sodium alginate has been widely used in the food industry and pharmaceutical fields.

Sodium alginate is white or light yellow powder, almost odorless and tasteless. Sodium alginate is soluble in water, but insoluble in organic solvents such as ethanol, chloroform, etc. Dissolved in water to form a viscous liquid, the pH value of 1% aqueous solution is 6-8. When pH=6-9, the viscosity is stable, and the viscosity decreases when heated to above 80℃. Sodium alginate is non-toxic, LD50>5000mg/kg. The effect of chelating agent on the properties of sodium alginate solution The chelating agent can complex the divalent ions in the system, so that the sodium alginate can be stabilized in the system.

1. Composition

Molecular formula of sodium alginate: C6H7NaO6, mainly composed of sodium salt of alginic acid, composed of β-D-mannuronic acid (M unit) and α-L-guluronic acid (G unit) relying on β-1,4 - Copolymers linked by glycosidic linkages and composed of GM, MM and GG fragments in different proportions. 

2. Molecular weight

The molecular weight of commercial sodium alginate is usually the same as that of polysaccharides, which is relatively dispersed. Therefore, the molecular weight of one sodium alginate generally represents the average of all molecules in that group. The most common ways of expressing molecular weight are number average molecular weight (Mn) and weight average molecular weight (Mw).

In polydisperse molecular populations, Mw>Mn is generally the case. The coefficient of Mw/Mn is the dispersibility index, and the classic range of the index of sodium alginate commodity is 1.5 to 2.5. The most common methods for determining molecular weight are calculations based on intrinsic viscosity and light scattering measurements.