With minor modifications, CM-β-CD was synthesized as described in the literature. A solution of 16.3 percent monochloroacetic acid (2.7 ml) was used to treat a mixture of β-CD (1 g) and NaOH (0.93 g) in water (3.7 ml) at 50 0 C for 5 h. The pH values were modified in the range of 6-7 after the temperature of the reaction mixture was decreased to 25 °C. The obtained neutral solution was mixed with 10 mL of methanol to create a white carboxymethylated-β-cyclodextrin precipitate, which was purified and dried in a 50 °C oven.