Paterson Daniel A, Hallier Jacqueline, Jenkins Elizabeth, Cordery Sarah F, Delgado-Charro M Begoña
Department of Pharmacy and Pharmacology, University of Bath, Bath BA2 7AY, UK.
Pharmaceutics. 2018 Jan 12;10(1):9. doi: 10.3390/pharmaceutics10010009.
Fingertip units have been proposed as a tool to standardize topical therapy with semisolid formulations. However, no studies to date have characterized the variability in dosing by patients using this concept and whether this variability ultimately affects the topical absorption of drugs. This work aimed to answer these two questions. A first study determined the dose measured, the area of spread and the area-normalized dose for a 1% hydrocortisone cream and ointment applied by members of the public using this dosing approach before and after brief counselling. Then, in vivo tape-stripping and in vitro permeation studies investigated whether the variability in the area-normalized dose altered the skin absorption of hydrocortisone. Participants applied greater doses and spread them over larger areas after a short counselling intervention leading to smaller area-normalized doses. In vivo hydrocortisone uptake by the stratum corneum was significantly greater for the higher normalized dose and the differences were further supported by the in vitro permeation studies. However, these differences were relatively small and not proportional to the increase in normalized dose. This work shows that, following brief advice, patients and carers can apply consistent and sufficient doses of corticosteroids whilst minimizing risks and variability in hydrocortisone absorption.
指尖单位已被提议作为一种标准化半固体制剂局部治疗的工具。然而，迄今为止尚无研究描述患者使用这一概念时剂量的变异性，以及这种变异性是否最终会影响药物的局部吸收。这项工作旨在回答这两个问题。第一项研究确定了公众使用这种给药方法在接受简短咨询前后，应用1%氢化可的松乳膏和软膏时测量的剂量、涂抹面积和面积标准化剂量。然后，体内胶带剥离和体外渗透研究调查了面积标准化剂量的变异性是否改变了氢化可的松的皮肤吸收。经过简短的咨询干预后，参与者使用了更大的剂量并将其涂抹在更大的面积上，导致面积标准化剂量更小。角质层对氢化可的松的体内摄取在较高标准化剂量时显著更高，体外渗透研究进一步支持了这些差异。然而，这些差异相对较小，且与标准化剂量的增加不成比例。这项工作表明，在接受简短建议后，患者和护理人员可以应用一致且足够剂量的皮质类固醇，同时将氢化可的松吸收的风险和变异性降至最低。
