Which of the following is not permeable through the Blood Brain Barrier?

Large molecules do not pass through the BBB easily. Low lipid (fat) soluble molecules do not penetrate into the brain. However, lipid soluble molecules, such as barbituate drugs, rapidly cross through into the brain. Molecules that have a high electrical charge are slowed. Ref: guyton and hall textbook of medical physiology 12 edition page number:672,673,674