Abstract: Chemically modified cyclodextrins such as hydroxypropyl cyclodextrins are purified by treatment with an activated carbon made from either coal or coconut shells. The amount of activated carbon used is 50% to 300% by weight of modified cyclodextrin. The treatment removes organic impurities such as glycol introduced during the chemical modification process of the cyclodextrin. The treatment step is conducted by passing an aqueous solution of the unpurified modified cyclodextrin through a column packed with the activated carbon or by adding the activated carbon to a container of the unpruified modified cyclodextrin and mildly agitating the contents of the container to remove the impurities.