National Institute of Metrology, Quality and Technology (Inmetro), Postgraduate Program in Biotechnology, Av. Nossa Senhora das Graças, 50, Xerém, CEP 25250-020 Duque de Caxias, RJ, Brazil.
National Institute of Metrology, Quality and Technology (Inmetro), Postgraduate Program in Biotechnology, Av. Nossa Senhora das Graças, 50, Xerém, CEP 25250-020 Duque de Caxias, RJ, Brazil; National Institute of Metrology, Quality and Technology (Inmetro), Training Center, Av. Nossa Senhora das Graças, 50, Xerém, CEP 25250-020 Duque de Caxias, RJ, Brazil.
Toxicol In Vitro. 2022 Oct;84:105425. doi: 10.1016/j.tiv.2022.105425. Epub 2022 Jun 25.
Usually, if percutaneous absorption tests are conducted in accordance with OECD Guideline 428, in vitro determination is accepted by mainly regulatory agencies. In this paper, we focus on the lack of comparability of the results regarding the permeation parameter/flow rate, although it is widely discussed in the literature. This work sought to evaluate the absorption of caffeine using Franz-type diffusion cell with porcine ear skin samples, varying the storage duration and the way to handle them. Metrological tools were used for caffeine quantification such as certified reference material candidate, calibrated instruments, and validated methodology. Our results corroborate with the recommendation that membranes should be freshly prepared or frozen for short periods. Samples frozen for approximately one year should not be used because they present high cutaneous absorption. The results obtained for the absorption rate (J) are comparable to the results obtained by previous studies using similar experimental conditions. The evidence of the barrier characteristic promoted by the stratum corneum and the effect promoted by the storage time is shown through J = 6.25 ± 0.48 μg/cm/h. We demonstrated the importance of metrological tools to guarantee reproducibility and comparability of the results between different laboratories.
通常，如果按照 OECD 指南 428 进行经皮吸收测试，体外测定结果将被主要监管机构所接受。本文主要关注的是，尽管文献中对此进行了广泛讨论，但关于渗透参数/流速的结果缺乏可比性。本工作旨在使用 Franz 型扩散池和猪耳朵皮肤样本评估咖啡因的吸收情况，同时改变储存时间和处理方式。使用了计量工具来对咖啡因进行定量，例如候选有证参考物质、校准仪器和经过验证的方法。我们的结果证实了以下建议，即应使用新鲜制备或短期冷冻的膜。不应使用冷冻约一年的样本，因为它们表现出较高的皮肤吸收。所获得的吸收速率（J）与使用类似实验条件的先前研究获得的结果具有可比性。通过 J = 6.25 ± 0.48 μg/cm/h 证明了角质层的屏障特性和储存时间的影响。我们证明了计量工具对于保证不同实验室之间结果的可重复性和可比性的重要性。
