Loading and Sustained Release of 2,4-Dinitrophenol from Microporous Starch

In this paper,in order to reduce the toxic side effects of 2,4-dinitrophenol(DNP)and prolong its efficacy time,corn microporous starch was prepared by α-amylase catalyzed hydrolysis of corn starch,and used as a carrier for DNP-loaded sustained release agent preparation,the release performance in vitro was also investigated. The experimental results showed that the adsorption equilibrium of DNP onto microporous starch was reached at 1 h in the loading process. Increasing the initial concentration of DNP and decreasing the temperature were beneficial to increase the adsorption capacity. With the condition of initial DNP concentration of 500 mg/L,the adsorption temperature at 25℃ and adsorption for 1 h,the adsorption amount of DNP onto microporous starch could reach 3.4369 mg/g. The fitting results of kinetic and thermodynamic model showed it was a surface physical adsorption by Van der Waals force and hydrogen bonding force,and it was also a spontaneous exothermic process. In the release experiment in vitro,the gastric juice and intestinal fluid release medium were simulated,the complete release time of 0.5 g DNP-microporous starch sustained release agent(1.6543 mg DNP was loaded)was up to 12 h,the release amount was 91.18% and 89.29%,respectively;However,the complete release time of raw material medicine in simulated gastric juice and simulated intestinal fluid was 4 and 3 h,and the cumulative release of DNP was 91.01% and 92.23%,respectively. The release kinetics of DNP-microporous starch sustained release agent analysis showed that,the DNP released form microporous starch in simulated gastric juice was the synergistic result of diffusion and dissolution,the process was consistent with Peppas kinetic equation;the release process followed Fickian diffusion in intestinal juice,which was consistent with the first-order kinetic model. The microporous starch had good adsorption and sustained release properties for DNP. This study would provide a basis for the development and application of DNP sustained-release preparations.