**6.4 Other parenteral routes**

Delivering the drug directly into the brain is another way of treating brain disorders. This local drug delivery has been approved by the US FDA [66]. Intrathecal administration of nanopharmaceuticals delivers the nano-drugs in the CSF. However, this route of administration is most commonly used for anesthetics and neurotic pain [67]. This route is under experimental phases in humans. It includes two different ways of delivering the therapeutic moiety, either by infusion in the intralumbar region or intraventricularly using an Ommaya reservoir placed subcutaneously and connected to the brain with a catheter [68]. Thioflavin-T was delivered by intrahippocampal injection for targeting the β amyloid in the brain using the nanoparticles. The data reported localization of thioflavin-T in the intracellular and extracellular spaces of the brain, which prevented the formation of β-amyloid aggregates in the Alzheimer's disease. This same method can be adapted to deliver the anticancerous drugs as well as other analgesic peptides [69]. In an *in situ* perfusion study conducted on mice, Polysorbate 80 coated PBCA NPs loaded with the tubocurarine were able to cross the BBB after intraventricular drug administration. There was a marked effect on the EEG epileptiform spikes [70]. Intraarterial drug delivery has an advantage over the other conventional systems of drug delivery because of the increased dose delivery at the desired site of the brain. This route can also be exploited for the immun0-targeting. However, this route has some limitations like a dilution of the drug because of cerebral blood flow [71].
