Effect of hydroxypropyl-β-cyclodextrin on the bounding of salazosulfapyridine to human serum albumin

Abstract

The supramolecular interaction between salazosulfapyridine (SASP) and hydroxypropyl-β-cyclodextrin (HP-β-CD), as well as the influence of HP-β-CD on SASP⿿s binding to human serum albumin (HSA), were investigated. Phase-solubility studies indicate that the HP-β-CD/SASP inclusion complex was formed at a 1:1 host⿿guest stoichiometry with high stability constant. The HP-β-CD/SASP complex, which was characterized by various techniques, exhibited markedly improves aqueous solubility of SASP. The binding of SASP with HSA in the presence and absence of HP-β-CD were investigated. The Stern⿿Volmer quenching constant and binding constant of SASP with HSA were found to be smaller in the presence of HP-β-CD. The Förster distance between the donor and the acceptor is altered in the presence of HP-β-CD. These results exhibited that the HP-β-CD reduced the quenching and binding of SASP on HSA. Molecular modeling is used to optimize the sites and mode of binding of SASP with HSA.