Adsorption of acetylsalicylic acid drug on surfactant synthetic zeolite A and Y

Abstract

Synthetic zeolites NaA and NaY synthesized from rice husk ash were used as support system for acetylsalicylic acid (ASA) drug by attaching the drug on zeolites via adsorption technique with the assistance of cationic surfactant. Two cationic surfactants quaternary ammoniums were used in this study namely hexadecyltrimethyl ammonium (HDTMA) and benzalkonium chloride (BKC). The physicochemical properties of these zeolites related to their use as adsorbents were investigated and showed that zeolite A has higher cation exchange capacity (CEC) than zeolite Y. The unmodified zeolites do not have an affinity towards ASA since ASA was in the anionic forms due to the deprotonated condition of the ASA molecules in the suspension containing zeolites. Zeolites A and Y can adsorb ASA in the presence of cationic surfactants. The maximum uptake of ASA on zeolites is mainly depending on the types of surfactants, the initial concentration of surfactants and the experimental techniques used. The higher adsorption capacity of ASA on zeolites can be obtained by contacting zeolites with a mixture of ASA and surfactants rather than the adsorption of ASA on the surfactant modified zeolites. In order to uptake the maximum amount of ASA on zeolites, the initial concentrations of HDTMA and BKC should be 1.0 m M and 2.0 mM, respectively. The results from this study are beneficial towards the development of drug support system based on surfactant-synthetic zeolites complex.