Acrylate copolymer: a rate-controlling membrane in the transdermal drug delivery system

A film-like copolymer composed of 2-hydroxy-3-phenoxypropylacrylate, 4-hydroxybutyl acrylate and cyclohexyl methacrylate was synthesized and exploited as a rate-controlling membrane in the transdermal drug delivery systems (TDDs). A series of acrylate copolymers with different formulations were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry and tensile strength, and then evaluated by clonidine hydrochloride transporting through the films. It was found that the formulation M2 composed of three monomers at a ratio of 4:4:2 (w/w/w) showed excellent mechanical and permeation properties. The optimal formulation M2 was further characterized by scanning electron microscopy, contact angles and swelling ratio, and then the permeation behaviors of five different physicochemical drugs transporting through the M2 were evaluated. The results showed that the permeation behaviors were influenced by many factors including the thickness of the membrane, the physicochemical properties of the drugs, the dose of the drugs and the interactions between the drugs and the membrane. This type of copolymer membrane might open new applications in the field of TDDs.