The integrity of the blood brain barrier (BBB) is one of the major obstacles to effective chemotherapy for malignant brain tumors. Previous research has focused on how to circumvent the BBB with direct delivery of chemotherapy to the tumor or by mechanically opening the BBB using focused ultrasound or intra-arterial mannitol [1–6]. These direct methods are often associated with comorbidities, hospitalization or added expenses. Very few systemic pharmacologic agents have been evaluated for effectiveness of transient BBB disruption [7–9]. Yet, there is a significant need to identify agents that can transiently disrupt the BBB to improve chemotherapy delivery for patients with such CNS malignancies.