Frogs have permeable skin, so transdermal delivery provides a practical alternative to traditional dosing routes. However, little is known about how frog skin permeability differs interspecifically, and there are different reported clinical outcomes following topical application of the same chemical in different frog species. This study collated in vitro absorption kinetic data previously reported for two frog species: the green tree frog (Litoria caerulea) and the cane toad (Rhinella marina), and used linear mixed-effects modelling to produce a model of absorption. Histology of skin samples from each species was performed to observe morphological differences that may affect absorption. Absorption kinetics differed significantly between species, with the logP of the applied chemical a better predictor of permeability than molecular weight. Application site also influenced permeability, with dorsal permeability consistently higher in cane toads. Ventral permeability was more consistent between species. Skin thickness differed between species and skin regions, and this may explain the differences in absorption kinetics. Guidelines for selecting chemicals and dosing site when treating frogs are presented. The permeability differences identified may explain the poor reproducibility reported in the treatment of disease across frog species, and reinforces the importance of considering interspecies differences when designing therapeutic treatments for frogs.

中文翻译：

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青蛙物种之间的经皮吸收：皮肤中的变异性可能会影响治疗剂的递送。

青蛙的皮肤具有渗透性，因此透皮递送是传统给药途径的一种实用替代方法。但是，人们对青蛙皮肤渗透性之间的种种差异知之甚少，并且在不同的青蛙物种中局部使用相同的化学药品后，临床结果有所不同。这项研究整理了先前报道的两种青蛙物种的体外吸收动力学数据：绿树蛙（Litoria caerulea）和甘蔗蟾蜍（Rhinella marina），并使用线性混合效应模型来产生吸收模型。进行每个物种的皮肤样品的组织学研究以观察可能影响吸收的形态学差异。物种之间的吸收动力学差异显着，所用化学物质的logP比分子量更好地预测渗透率。施用部位还影响渗透性，甘蔗蟾蜍的背侧渗透性始终较高。种间的腹透性更一致。物种和皮肤区域之间的皮肤厚度不同，这可以解释吸收动力学的差异。介绍了在治疗青蛙时选择化学药品和给药部位的指南。所确定的通透性差异可以解释在青蛙物种间疾病治疗中报道的可重复性差，并强调在设计青蛙的治疗方法时考虑种间差异的重要性。这可以解释吸收动力学的差异。介绍了在治疗青蛙时选择化学药品和给药部位的指南。所确定的通透性差异可以解释在青蛙物种间疾病治疗中报道的可重复性差，并强调在设计青蛙的治疗方法时考虑种间差异的重要性。这可以解释吸收动力学的差异。介绍了在治疗青蛙时选择化学药品和给药部位的指南。所确定的通透性差异可以解释在青蛙物种间疾病治疗中报道的可重复性差，并强调在设计青蛙的治疗方法时考虑种间差异的重要性。