Inclusion of Tetracycline Hydrochloride within Supramolecular Gels and Its Controlled Release to Bovine Serum Albumin

Three amphiphilic 3,4,5-triliydroxybenzoic derivatives with alkyl chains of different lengths were designed and synthesized. A small amount of these compounds can trap a large quantity of the water-soluble drug tetracycline hydrochloride (TH) within a stable gel in aqueous ethanol. Release experiments were carried out with solutions of bovine serum albumin (BSA) and various concentrations Of L-isoleucine, L-phenylalanine, and L-tryptophan. The results indicate that the release rate of TH for a BSA solution (10 mg/mL) was faster than that with the other solutions because of the strong interaction between TH and BSA. Furthermore, to gain an insight into the release dynamics, we studied the release ratios as a function of the square root of time (t(1/2)). During the initial 1.75 h, diffusion is the dominant release process in water, whereas intermolecular interaction controls TH release in the BSA solution.