PRESCRIPTION DIVISION CROSSING THE BLOOD BRAIN BARRIER (BBB) WHICH ROUTE TO TAKE? An expert panel/roundtable hosted by Aptar Pharma Prescription Division

2 Aptar Pharma recently hosted an expert panel/roundtable on the various approaches to treating central nervous system (CNS) diseases. This international scientific forum was held in Paris, France on December 5th, 2014. The roundtable was organized to explore and exchange views on the challenges, approaches and opportunities that exist with regard to effectively crossing the blood brain barrier (BBB) and successfully treating a host of CNS diseases. A large number of therapeutic areas fall within the CNS drug delivery arena, including Alzheimer's disease, motor neuron disease, CNS trauma, Huntington's disease, Parkinson's disease and multiple sclerosis, Depression Schizophrenia, Sleep disorders etc. Currently it is estimated that drug delivery technologies used in applications for the CNS market total about 10Bn$ (2014) and this is predicted to grow to 22.5Bn$ by 2018 (1). During this one-day meeting the experts shared their knowledge and debated several key themes, structured around the following subject areas: Understand the background and unmet medical needs. Investigate the various routes by which drugs can cross the BBB. Explore the pros & cons of various approaches currently being undertaken to deliver drugs to the CNS. Invited guests came from a variety of backgrounds ranging from front-line neurosurgeon and clinicians to academic researchers as well as members of start-up companies in the CNS drug delivery field. The summary of some of the discussions held, detailed below, reflects the views of our invited experts. Every attempt has been made to express the overall consensus of views as accurately as possible. A large number of therapeutic areas fall within the CNS drug delivery arena, including Alzheimer's disease, motor neuron disease, CNS trauma, Huntington's disease, Parkinson's disease and multiple sclerosis. In order to improve existing CNS therapies and explore new ways of treating these disabling diseases, it is important to understand the role of the BBB and why it presents a particular problem for CNS drug delivery (2). The specific blood vessels that provide oxygen and nutrients to the human brain can reach up to a total length of 644 km, the distance between Paris and Munich (see Figure 1). It is said that every neuron is virtually perfused by its own blood vessel. They have an estimated surface area of around 20m2, almost half the size of a squash court and therefore, in theory, provide ample opportunity for drugs to cross from the systemic blood system to the CNS.