Abstract: A process for obtaining a spray-dried high amylose sodium carboxymethyl starch comprising a major fraction of amorphous form and optionally a minor fraction of crystalline V form, is provided. The process comprises providing an amorphous pregelatinized high amylose sodium carboxymethyl starch (HASCA); dispersing the amorphous pregelatinized HASCA in a solution comprising water and at least one first pharmaceutically acceptable organic solvent miscible with water and suitable for spray-drying; and spray-drying the dispersion to obtain the spray-dried HASCA comprising a major fraction of amorphous form and optionally a minor fraction of crystalline V form, in the form of a powder. Also provided is a spray-dried HASCA sustained-release excipient. This excipient is useful for preparing a tablet for the sustained-release of at least one drug.