Fractionated alkylated cyclodextrin compositions and processes for preparing and using the same

A fractionated alkylated cyclodextrin composition comprising 85% by weight or more alkylated cyclodextrin having a single degree of substitution relative to all alkylated cyclodextrin in the composition, and wherein the alkylated cyclodextrin is a sulfoalkyl ether cyclodextrin of Formula (II):

• wherein p is 4, 5, or 6, and R1 is independently selected at each occurrence from —OH or —O—(C2-C6 alkylene)-SO3−-T, wherein T is independently selected at each occurrence from pharmaceutically acceptable cations, provided that at least one R1 is —OH and at least one R1 is O—(C2-C6 alkylene)-SO3−-T;
• wherein the composition further comprises an active agent selected from bortezomib, disulfiram, epigallocatchin-3-gallate, salinosporamide A, and carfilzomib;
• and
• wherein the single degree of substitution is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12.