Hydroxypropyl methyl cellulose acetate succinate

Hypromellose acetate succinate is a white to off-white powder or granules. It has a faint acetic acid-like odor and a barely detectable taste. Hypromellose acetate succinate is available in several grades, according to the pH at which the polymer dissolves (low, L; medium, M; and high, H) and its predominant particle size (cohesive fine powder, F; or free-flowing granules, G).

soluble in organic solvents, including acetone, methanol, aqueous ethanol

Hypromellose Acetate Succinate HPMCAS;is a pharmaceutical compound comprising enzalutamide.

Hypromellose acetate succinate is produced by the esterification of hypromellose with acetic anhydride and succinic anhydride, in a reaction medium of a carboxylic acid, such as acetic acid, and using an alkali carboxylate, such as sodium acetate, as catalyst. The fibrous reaction product is precipitated out by adding a large volume of water to the reaction medium. Purification is achieved by thorough washing with water. The granular grade of hypromellose acetate succinate that is so obtained can be pulverized to a fine powder if required.