Excess white adipose tissue (WAT), or obesity, is the leading cause of many diseases. Combating obesity is, however, challenging due to the fact that laboratory-proven anti-obesity compounds lose effectiveness or/and cause severe side-effects while being delivered via conventional routes. Here, a new strategy is reported using disposable transdermal patches equipped with detachable polymeric microneedle (MN) arrays for painless and bloodless drug delivery to subcutaneous WAT. In contrast to the current methods to reduce energy intake, MN-patches are used to deliver anti-obesity compounds to increase energy expenditure by transforming calorie-storing white fat into calorie-burning brown fat. Specifically, prominent WAT browning and reduction effects are demonstrated by β3-adrenoceptor agonist and thyroid hormone T3 transdermally delivered from rapidly dissolving MNs on mice. Furthermore, using a diet-induced obese mouse model, it is shown that β3-adrenoceptor agonist released by slowly dissolving MNs can effectively promote WAT browning and suppress gaining of body fat and weight, without the need of daily administration. Such an MN approach can achieve a much lower effective dose as compared to systemic administration and enables long-term home-based treatment. Drug Delivery

BackgroundHyperpigmentation is a skin disorder characterized by elevated production of melanin. Current treatment approaches mainly rely on the application of skin lightening chemicals, most of which have safety issues. Efficacy of delivery of the active ingredients to the target organ has also been a challenge. Transdermal based drug delivery platform has been shown to improve drug bioavailability, avoiding the hepatic first pass metabolism, decrease gastrointestinal side effects, and eventually enhance patient compliance.ResultsThis article explores the utilization of micellar transdermal delivery technology to improve skin penetration and efficacy of arbutin, a hyperpigmentation agent. The suppression efficacy of cellular melanin production versus cell viability of four active ingredients commonly used in skin lightening products, namely allantoin, arbutin, glycolic acid, and hyaluronic acid were first compared. Arbutin was selected for the micellar delivery studies base on its comparatively low cytotoxicity and better performance in reducing melanin production. Micellar Arbutin cream was formulated using Urah® proprietary micellar technology and was assessed for its cellular melanin suppression efficacy and skin penetration capacity.ConclusionThe results show that micellar arbutin cream improved both the delivery and cellular melanin suppression, suggesting that micellar transdermal delivery may have potential application in addressing hyperpigmentation skin disorders.Graphical abstractTransdermal delivery of arbutin with micelles for melanin production suppression.Electronic supplementary materialThe online version of this article (doi:10.1186/s13104-016-2047-x) contains supplementary material, which is available to authorized users.