Molecular imprinted-polymer as a controlled release material for tramadol

Abstract

The free-radical polymerization method was used to prepare crosslinked polymers as tramadol carriers for the controlled release process. The polymers were based mainly on ethylene glycol dimethacrylate (EGDMA) and methacrylic acid (MAA) in two different molar levels: 15 and 13. These two polymers represented the non-imprinted polymers (NIPs). Other corresponding polymers were prepared by adding tramadol hydrochloride during the synthesis that was removed at the end of the preparation process to produce tramadol-imprinted polymers (TIPs). The four polymers were loaded with tramadol for testing their in vitro release at various parameters such as soaking times, pH, and temperatures. The effect of molar ratio and imprinting process on tramadol release was studied. FTIR, TGA, and UV –absorption techniques were used to investigate the prepared and loaded polymers and the releasing process. More physical interactions were observed between the loaded tramadol and the matrix in TIPs than in NIPs. TIP with a molar ratio of crosslinker to polymer equals 13 demonstrated the highest control of releasing tramadol over 12-hour.