Abstract
Tris (2-ethylhexyl) trimellitate (TOTM) and Di (2-ethylhexyl) phthalate (DEHP) are plasticizers of Polyvinyl Chloride (PVC). We compared PVC-TOTM tubes and PVC-DEHP tubes regarding the loss of isosorbide dinetrate (ISDN) during drip infusion. The ISDN concentration was determined using HPLC. When ISDN injection (0. 5mg/mL) was passed through. a PVC-TOTM tube or a PVC-DEHP tube 90cm in length and 0.21cm inside diameter at a flow rate of 5. OmL/hr at 24°C, the ISDN concentrations were reduced to about 33. 1 % or 33.6% after lhr respectively, and gradually returned to the initial level with time. A liner relation was observed between the amount of ISDN sorbed to the PVC-TOTM tube and the equilibrium concentration of the diluted solution within the10-40μg/mL range. The same relationship was also observed in a PVC-DEHP tube. The results suggest that the ISDN loss from the solution occur through the mechanism of partition and diffusion to the PVC-TOTM tube.