Evaluation of the surfactant/phillipsite composites as carriers for diclofenac sodium

Incorporation of diclofenac sodium into phillipsite modified with cetylpyridinium chloride (CP-Cl) or hexadecyltrimethyl ammonium bromide (HDTMA-Br) was followed by batch equilibrium adsorption studies in buffer solution at pH = 7.4. Characteristics of the drug/surfactant/zeolite complexes were investigated by UV/VIS, FTIR spectroscopy, thermal (DTA/TG) analysis and ζ-potential measurements. The obtained data confirmed that organic cations at phillipsite surface were responsible for incorporation of diclofenac sodium. Diclofenac sodium incorporated amounts increased with increasing the amount of each surfactant as well as with increasing the initial drug concentration. Langmuir model was the best model for fitting the experimental data of diclofenac adsorption on surfactant/phillipsite composites, suggesting complex adsorption mechanism. The physico-chemical properties of surfactant/phillipsite composites and enhanced incorporation of diclofenac sodium suggests that it might be possible to use these materials as drug carriers.