The European Medicines Agency and the Japanese Ministry of Health, Labour and Welfare (MHLW) have launched a public consultation on a joint reflection paper on the development of block copolymer micelle medicinal products.


Nanotechnology, or the use of tiny structures, is an emerging field in science which can be used in a wide range of applications, from consumer goods to health products.


Block copolymer micelles are structures of nano-scale size which can be utilised to encapsulate medicinal products and allow improved delivery of poorly soluble or instable products. Importantly, these structures may also enable a preferential distribution of the medicine in the human body and then contribute to an improved benefit risk balance of the encapsulated product. In particular, block copolymer micelles have been shown to preferentially accumulate in solid tumours.


Several block copolymer micelles medicinal products are currently in preclinical or clinical development. This reflection paper, which intends to support innovation in the emergent field of nanotechnology-based medicines by providing guidance at very early stage of development, discusses the general principles for assessing block copolymer micelle products. It provides basic information for the pharmaceutical development, and non-clinical and early clinical studies of such products designed to modify the pharmacokinetics, stability and distribution or incorporated or conjugated active substances in vivo.


This reflection paper was initiated in late 2011 in the context of regular international regulators’ meetings on nanomedicines chaired by the Agency. It was progressed within the framework of the confidentiality arrangement between the Agency and Japanese authorities. The reflection paper is open for comments until 1 July 2013. Comments should be sent to


Posted on the EMA website on 1 February 2013