The inclusion complexes of a new family of nonionic amphiphilic calix[4]arenes with the anti-inflammatory hydrophobic drugs naproxen (NAP) and ibuprofen (IBP) were investigated. The effects of the alkyl chain's length and the inner core of calix[4]arenes on the interaction of the two drugs with the calix[4]arenes were explored. The inclusion complexes of Amphiphiles 1a-c with NAP and IBP increased the solubility of these drugs in aqueous media. The interaction of 1a-c with the drugs in aqueous media was investigated through fluorescence, molecular modeling, and ¹H-NMR analysis. TEM studies further supported the formation of inclusion complexes. The length of lipophilic alkyl chains and the intrinsic cyclic nature of cailx[4]arene derivatives 1a-c were found to have a significant impact on the solubility of NAP and IBP in pure water.
Keywords: amphiphilic calix[4]arene; ibuprofen; inclusion complexes; naproxen; solubility.