A comprehensive study of the effect of elevated temperature on the extractability and rate of exaggerated and exhaustive extractions of medical devices

Abstract

The effectiveness of an elevated temperature on the thermodynamic and kinetic properties of the solvent extraction of medical devices is evaluated in this study. The main objective of the current work is to specifically address the question of how effective a temperature of 50 °C, relative to 37 °C, is in improving the extractability and rate of the exaggerated and exhaustive extractions of medical devices. The extractability at equilibrium is related to the extraction partition coefficient, while the extraction rate is related to the corresponding diffusion coefficient. The partition and diffusion coefficients (or the enthalpies of extraction and diffusional activation energies) of solid-liquid extractions for different polymeric materials, solvents, and types of extractables entities at different temperatures are compiled comprehensively from extensive publications in the literature. The collected partition and diffusion coefficients at different temperatures are used to derive the partition enthalpies and diffusional activation energies in this study. The combined 209 partition enthalpies and 262 diffusional activation energies are then used to calculate the ratios of the partition and diffusion coefficients, when the extraction temperature increases from 37 °C to 50 °C. It is concluded from the study that the maximum improvement in extracted chemical amount with this specific temperature increase is about 3-fold, but the median improvement is only 16%. The most probable improvement is 25%. The maximum improvement (or decrease) in extraction time is 3.2-fold by the change in the diffusional coefficient, but the median value is 1.9-fold. The most probable decrease in extraction time is 2.4-fold. The collected data also allow the calculation of the ratio of the diffusion coefficient for a 10 °C increase, and the results are compared with the “factor 10 rule” in the literature on the relationship between the diffusion coefficient and temperature. The explicit conclusions of the study certainly provide evidences (not assumptions) in designing practical and cost-effective exaggerated and exhaustive extractions in the chemical characterization of medical devices, taking into considerations of extraction cycle time, temperature-dependent chemical stability, and the number of repeated extractions.