TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The SAE-CD composition has absorption of less than 0.2 A.U. due to a color-forming agent or drug-degrading agent, as determined by UV/visible spectrophotometry at a wavelength of 320-350 nm or 245-270 nm for an aqueous solution containing 500 mg of the SAE-CD composition per ml of solution in a cell having a 1 cm path length. The composition further comprises phosphate (less than 50, preferably less than 10, especially less than 5) ppm; sulfoalkylating agent (less than 20, preferably less than 10, especially less than 2) ppm; underivatized cyclodextrin (less than 0.5, preferably less than 0.2, especially less than 0.1) wt.%; alkali metal halide salt (less than 1, preferably less than 0.5, especially less than 0.2) wt.%; and hydrolyzed sulfoalkylating agent (less than 0.25, preferably less than 0.1, more preferably less than 0.08, especially less than 0.05) wt.%. The SAE-CD composition comprises a sulfobutyl ether cyclodextrin having an average degree of substitution of 7 and less than 100 ppm of a phosphate, where the composition has an absorption of less than 0.2 A.U. due to a drug-degrading agent, as determined by UV/visible spectrophotometry at a wavelength of 245-270 nm for an aqueous solution containing 300 mg of the SAE-CD composition per ml of solution in a cell having a 1 cm path length. Preferred Compound: The sulfoalkyl ether cyclodextrin is a compound of formula (I).p=1-3;R1=-OH or -O-(2-6C alkylene)-SO3--T;T=cations.Preferred Method: In the process, the SAE-CD composition has absorption of less than 0.5 A.U. due to the drug-degrading agent. In the process, the treatment involves: adding a phosphate-free particulate or powdered activated carbon to the partially purified aqueous solution while mixing, separating the activated carbon from the solution, and repeating the adding and the separating at least once until the amount of drug-degrading agent in the solution is reduced to a target level; or passing and recycling the partially purified aqueous solution through a mass of phosphate-free activated carbon in a flow-through apparatus until the amount of drug-degrading agent in the solution is reduced to a target level. The conducting involves passing and recycling at least two times, where each passing is with a different mass of activated carbon. The activated carbon present during the conducting is sulfoalkyl ether cyclodextrin (12 wt.%), and the conducting is performed for at least 2 hours. ADMINISTRATION - The composition is administered topically, orally, by injection, infusion, or by inhalation. No dosage details given.    EXAMPLE - A disulfobutyl ether cyclodextrin (SBE2- beta -CD) composition was prepared by the following procedure: an underivatized beta -CD starting material present in an alkaline aqueous medium was derivatized with an SBE precursor to form a SBE- beta -CD having an average degree of substitution of 2. The underivatized beta -CD was dissolved in 6.5 equivalents of 3.6 N sodium hydroxide (NaOH) aqueous solution, heated to 50 degrees C and stirred until complete dissolution. The reaction temperature was then increased to 70-75 degrees C. Two (2) equivalents of a sulfoalkylating agent (1,4-butanesultone) was then added for 20 minutes. The total equivalent of sulfoalkylating agent added was proportional to the degree of substitution of the SAE-CD product. The pH was monitored for 4 hours and never dropped below 12. A second portion of 2.7 equivalents of 3.5 M NaOH was charged and the reaction was allowed to continue at 70 degrees C for at least an addition 16 hours. The reaction mixture was cooled and diluted with water (roughly one half the total reaction volumes). The solution was neutralized with 7 M hydrochloric acid (HCl) to pH 6.5-7.5 and filtered through a 0.45 mu m filter. The solution was purified by ultrafiltration using a 1000 MWCO membrane. The ultrafiltration end point was determined by capillary electrophoresis where the filtrate showed no or substantially no presence of 4-hydroxybutane-1-sulfonic acid and/or disodium bis(4-sulfobutyl)ether, and by osmolarity, where the permeate samples had little to no ion present. The solution was further treated with activated carbon (0.12 g activated carbon/gram of cyclodextrin), filtered through a 0.22 mu m filter and neutralized (pH 6.5-7). The resulting solution was concentrated to roughly a 50% solution by rotary evaporation at 50-60 degrees C under less than 30 mmHg vacuum. The solution was freeze-dried to yield the SBE2.0- beta -CD as a white solid.