Subcritical water degradation of drug active substance and the optimization of the experimental conditions

In recent years, drug active substances in the waste water of medical resources and the irmetabolic waste can couse a serious threat on the human and ecosystem. A lot of techniques have been used for removal of drug active substance from wastewaters. Subcritical water degradation are shown in these techniques. Water is named high temperature water or subcritical water which is under pressure and temperature between 100 ºC – 374 ºC which is critical point's water. Subcritical water (<374 °C and <221 bar) has unique characteristics such as dramatically decreased dielectric constant, surface tension, and viscosity with increasing temperature, allowing for dissolution and reaction of organics in high-temperature water to occur. In this study, degradation rates of drug active substances such as coumarin, sulfamethoxazole, and ibuprofen were investigated in the presence of hydrogen peroxide in high pressure reactor at different temperature and time. Degradation studies of the drug active substance were designed and optimized by using chemometric response surface methodology. The degradation rates were found maximum 99, 89 and 88 % for sulfamethoxazole, ibuprofen and coumarin, respectively under subcritical water medium. Final and intermediate products were analyzed by gas chromatography-mass spectrometry.