The effect of three solvents on the permeation of leflunomide in excised mouse skin
OBJECTIVE To study the effect of solvents on the permeation of leflunomide in excised mouse skin. METHODS Modified Franz-diffusion cell adopted as apparatus for in vitro skin permeation, excised mouse skin as permeation barrier and permeability as index, the concentration of leflunomide in the samples was measured by HPLC. RESULTS Ethanol has enhancement effect on the permeability of leflunomide, propylene glycol and lower concentration DMI have little effect on the permeability of leflunomide. CONCLUSIONS These solvents can be used in the skin local preparations of leflunomide.
In selecting the appropriate extraction conditions for a range of pesticides from soil, the nature of the soil-pesticide interaction is of fundamental importance. This paper reviews the work that has been undertaken with a view to understanding the role that soil-pesticide interactions have played in affecting the extraction process. Supercritical fluid extraction has been of particular interest to this work. It is noted that the majority of papers cited refer to the use of spiked soil samples. The experimental conditions required for extraction from native samples may well be different. In this situation, the use of mathematical models, both for soil-pesticide interactions and the extraction process may well be useful. The important factors affecting the recovery of analytes from soils are summarised.