کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
600397 1454301 2013 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effects of surfactants and thermodynamic activity of model active ingredient on transport over plant leaf cuticle
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی شیمی کلوئیدی و سطحی
پیش نمایش صفحه اول مقاله
Effects of surfactants and thermodynamic activity of model active ingredient on transport over plant leaf cuticle
چکیده انگلیسی

The main objective of this study was to investigate the mechanism of molecular transport across the cuticle of Clivia leaves. In vitro diffusion methodology was used to investigate the transport of a systemic fungicide, tebuconazole, over a model silicone membrane, enzymatically isolated cuticle membranes, and dermatomed leaves. It was shown that dermatomed leaves may replace enzymatically isolated cuticles. Furthermore, the effects of two surfactants, C10EO7 and C8G1.6, on the fungicide transport were investigated.Tebuconazole cuticle permeation was described using Fick's first law of diffusion, expressed by the thermodynamic activity of the solute in the membrane. A new method for calculation of diffusion coefficients in the membrane is proposed. To access the thermodynamic activity of the fungicide in the membranes, sorption isotherms of tebuconazole in the membrane materials studied were recorded. The thermodynamic activity of the fungicide in aqueous solutions was calculated from solubility data. For that purpose, the effect of surfactants on tebuconazole solubility was studied. The results show that addition of surfactants allows for higher concentrations of tebuconazole available for penetration. Nonetheless, at a fixed fungicide thermodynamic activity, all formulations produced the same flux over the silicone membrane independently on the fungicide concentration. This shows that the driving force across non-responding membranes is the gradient of thermodynamic activity, rather than the gradient of the fungicide concentration. In case of leaves, surfactants induced the same quantitative increase in both flux and diffusion coefficient of solute in the cuticle, while the cuticle-water partition coefficient was unaffected.

Figure optionsDownload as PowerPoint slideHighlights
► Tebuconazole transcuticular uptake can be increased several times by adjuvants.
► Lag-time for permeation can be significantly shortened by specific adjuvants.
► The same quantitative increase in both flux and diffusion coefficient, while the cuticle-water partition coefficient remains unchanged by adjuvants.
► A novel algorithm for diffusion coefficient determination is developed, able to accommodate inevitable changes in boundary conditions.
► Permeability quantification without enzymatically isolated cuticles or radioactive tracers.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Colloids and Surfaces B: Biointerfaces - Volume 103, 1 March 2013, Pages 572–579
نویسندگان
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