Ex-vivo and in-vivo skin analysis has been extensively evaluated by confocal Raman spectroscopy (CRS). The off-line measurement with a CRS-suited skin-mounted device after Franz-cell incubations is the most popular choice. However, real-time monitoring of in-line measurement has clear advantages for obtaining dynamic and more timely results. In our study, a custom-built setup suitable for in-line measurements was implemented, which ensures constant skin incubation and in-situ skin detections. We aim to compare the differences between using in-line and off-line devices for monitoring skin drug penetrations. A well-assessed formulation gel with procaine-HCl as the active ingredient was used as reference. The PEG-23 lauryl ether was added to the formulation as a penetration enhancer to evaluate the enhancement effects of procaine on skin. After incubation times of 14, 20, and 24 h, skin penetration profiles were assessed. Comparable results between off-line and in-line measurements were obtained. Remarkable improvements in penetrated procaine amount and depth were observed. Based on the significant differences of their enhanced penetration amounts, fairly similar estimations were achieved from both methods. A slight difference of 14 h incubation between these two setups can still be found, which may be due to the different detection conditions and affected skin properties. Overall, in-line measurements could provide a more time- and labor-saving alternative for off-line measurements in ex-vivo study.

中文翻译：

---

使用共焦拉曼光谱在线和离线监测皮肤渗透曲线

共聚焦拉曼光谱（CRS）已广泛评估了离体和体内皮肤分析。弗朗兹细胞孵育后，使用适合CRS的皮肤安装设备进行离线测量是最受欢迎的选择。但是，实时监测在线测量具有获得动态和更及时结果的明显优势。在我们的研究中，实施了适合在线测量的定制设置，以确保持续的皮肤孵育和原位皮肤检测。我们旨在比较使用在线和离线设备监测皮肤药物渗透之间的差异。使用普鲁卡因-HCl作为有效成分的经过良好评估的制剂凝胶用作参考。将PEG-23月桂基醚作为渗透促进剂添加到制剂中，以评估普鲁卡因对皮肤的增强作用。在孵育14、20和24小时后，评估了皮肤渗透曲线。获得了离线测量和在线测量的可比结果。观察到普鲁卡因的渗透量和深度都有明显改善。基于它们增加的渗透量的显着差异，两种方法都获得了相当相似的估计。仍然可以发现这两种设置在14 h孵育中存在细微差异，这可能是由于不同的检测条件和受影响的皮肤特性所致。总体而言，在线测量可以为离体研究中的离线测量提供更多的时间和劳动力节省。观察到普鲁卡因的渗透量和深度都有明显改善。基于它们增加的渗透量的显着差异，两种方法都获得了相当相似的估计。仍然可以发现这两种设置在14 h孵育中存在细微差异，这可能是由于不同的检测条件和受影响的皮肤特性所致。总体而言，在线测量可为离体研究中的离线测量提供更多省时和省力的选择。观察到普鲁卡因的渗透量和深度都有明显改善。基于它们增加的渗透量的显着差异，两种方法都获得了相当相似的估计。仍然可以发现这两种设置在14 h孵育中存在细微差异，这可能是由于不同的检测条件和受影响的皮肤特性所致。总体而言，在线测量可为离体研究中的离线测量提供更多省时和省力的选择。这可能是由于不同的检测条件和受影响的皮肤特性所致。总体而言，在线测量可以为离体研究中的离线测量提供更多的时间和劳动力节省。这可能是由于不同的检测条件和受影响的皮肤特性所致。总体而言，在线测量可以为离体研究中的离线测量提供更多的时间和劳动力节省。