Manufacture of cross-linked amylose useful as a excipient for control

Abstract

A process for the manufacture of a slow-release excipient consisting mainly of cross-linked amylose in the form of solid particles, for use in the preparation of tablets or pellets. A starch containing a high amount of amylose (high amylose starch) is first subjected to a gelatinization. The gelatinized high amylose starch is then cross-linked with 1 to 5 g of a cross-linking agent per 100 g of dry-based gelatinized high amylose starch in an alkali medium, thereby forming a reaction medium containing a reaction product consisting of a cross-linked high amylose starch slurry. The obtained reaction medium is neutralized, thereby forming by-products mainly consisting of salts, which are removed from the reaction medium. The recovered cross-linked high amylose starch slurry is then subjected to a thermal treatment at a temperature of at least 60.degree. C. and the thermally treated product is dried to obtain the requested slow release excipient. This process is economical and industrially advantageous since it is carried out in an aqueous medium.