Abstract: Synthesizing a drug-organic-acid-anhydride conjugate using docetaxel as a drug, including: mixing aconitic anhydride with a chlorinating reagent to produce a first mixture; dissolving the first mixture in an organic solvent to produce a dissolved mixture; stirring the dissolved mixture; evaporating the organic solvent from the dissolved mixture to produce a second mixture; washing the second mixture with an impurity remover to remove impurities and to produce an aconitic anhydride chloride solution; and mixing the docetaxel with the aconitic anhydride chloride solution to produce the drug-organic-acid-anhydride conjugate.