Used as a key intermediate in the synthesis of pH-sensitive and enzyme-responsive prodrugs, particularly in targeted drug delivery systems. Its carboxyl and hydroxyl functional groups allow for easy conjugation with active pharmaceutical ingredients, enabling controlled release in specific physiological environments. Commonly employed in the development of polymer-drug conjugates and biodegradable hydrogels for cancer therapy and anti-inflammatory treatments. Also utilized in the preparation of stimuli-responsive nanocarriers that degrade under acidic conditions, such as those found in tumor tissues or intracellular endosomes.