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 trama...