Cross-linked high amylose starch for use in controlled-release pharmaceutical formulations and processes for its manufacture

A form of cross-linked high amylase starch and a process for its manufacture is disclosed. The described cross-linked high amylase starch is useful as an excipient in a controlled-release pharmaceutical formulation when compressed with a pharmaceutical agent(s) in a tablet. Such cross-linked high amylase starch is prepared by a) cross-linking and chemical modification of high amylase starch, b) gelatinization, and c) drying to obtain a powder of said controlled release excipient. The cross-linked high amylase starch may be prepared in the following steps: 1) granular cross-linking and additionally chemical modification, such as hydroxypropylation, of high-amylose starch; 2) thermal gelatinization of the starch from step 1); and 3) drying the starch from step 2) to yield a powder capable of being used as a controlled release excipient.