Introduction: Drooling is a common problem in patients with chronic neuromuscular diseases. Several studies have proposed transdermal administration of scopolamine for alleviation of this problem. At present, no transdermal formulation of scopolamine has been approved in Japan, and an in-house ointment formulation is usually used to control drooling in patients with disabilities. However, there is insufficient evidence to support the clinical use. The aim of this study was to perform an exploratory assessment of the pharmacokinetics and pharmacodynamics of a single dose of scopolamine ointment applied to the postauricular area in healthy subjects.

Methods: In this randomized, placebo-controlled, double-blind, single-dose, two-way crossover study, scopolamine ointment spread on an adhesive plaster (0.1g/2.0 cm² ) was applied to the postauricular area for 24 h in 10 healthy subjects. Blood and urine samples were collected up to 48 h after the application. The concentration of scopolamine was measured by liquid chromatography-tandem mass spectrometry. The volume of saliva secreted, subjective salivary secretion assessed on a visual analog scale, and heart rate variability were measured to determine the pharmacodynamics of scopolamine.

Results: The plasma concentration of scopolamine increased slowly, reaching the maximum level (12.0±6.3 pg/mL) approximately 12 h after application of scopolamine ointment, and the level was maintained up to the last observation conducted 24 h after removal of the ointment. No apparent pharmacodynamic changes were observed.

Conclusions: The plasma concentration of scopolamine was maintained at low level, even after removal of the ointment. Pharmacological effects were not evident in healthy subjects. The current study indicates that further research is required to explore pharmacokinetics and the effects of multiple treatment doses in patients.

In Japan, the centralization of institutional review boards (IRBs) has been considered with the objectives to standardize the quality of the review process for multicenter studies and to facilitate efficient and speedy implementation of clinical trials and research. Therefore, we visited some core facilities in Taiwan to observe the IRB meetings for clinical studies, and to exchange ideas with staff of the IRB secretariats. Furthermore, we researched the pioneering review mechanisms for multicenter, sponsor-initiated clinical trials in Taiwan. In Taiwan, the Joint IRB (J-IRB: a type of centralized review system) was established in 1997. This review system contributed to improve the quality of ethical reviews in the country. However, because the J-IRB was not fully government-initiated, many co-operating sites gradually started to conduct their own reviews, and this tendency caused a decline in the efficacy of the J-IRB. Following this, the Taiwanese government enacted a law called the Human Subjects Research Act in 2011. Moreover, the government also started the Central IRB (C-IRB) system in 2013, which is a central-local hybrid type of ethical review system for multicenter clinical trials. The establishment of the C-IRB system increased the number of sponsor-initiated clinical trials. The new Human Subjects Research Act allowed each site to develop appropriate organizational structures, and thus maintained the high quality of clinical studies, regardless of whether they were sponsor-initiated or investigator-initiated studies. Considering the future Japanese goals to conduct ethical reviews and to organize the operational structures of medical facilities, we identified many constructive ideas based on the Taiwanese challenges in past decades.