Patent ID: 6153746
Filing Date: 2000-11-28
Classification: C08B

Abstract:
A process of making an aqueous sulfoalkyl ether cyclodextrin solution having a predetermnined degree of substitution, comprising the steps ofcombining in an aqueous reaction medium an unsubstituted cyclodextrin starting material and an alkyl sultone in an amount sufficient to effect said pre-determnined degree of substitution, in the presence of a base to effect sulfoalkylation of said cyclodextrin;maintaining the pH of the reaction medium basic but at a level less than about 11 during said sulfoalkylation for a time sufficient to consume said cyclodextrin such that residual unreacted cyclodextrin reaches a level of less than 0.5% by weight based on the original weight of unsubstituted cyclodextrin starting material;adding base in an amount sufficient to effect completion of said sulfoalkylation; andadding, additional base following said completion, said base being added in an amount and under conditions sufficient to effect destruction of residual alkylsultone to a level less than 20 ppm based on the weight of said solution.