Application of the intranasal road of administration for delivery of drugs to the central nervous system

BACKGROUND: The development of effective drug delivery to the central nervous system still remains an important problem in pharmacology despite the rapid development of a large number of new treatment strategies in recent years. Recently interest of the intranasal method as delivery route has greatly increased because this method of administration allows to bypass the blood-brain barrier. There is not a single fundamental study comparing intranasal, central and peripheral methods of administration in order to determine the feasibility of using the intranasal route for delivering substances to the brain by far.

AIM: Aim is to study the effect of 6-hydroxydopamine (6-OHDA), a neurotoxin that does not penetrate through the blood-brain barrier by various administrations on the behavior of mice.

MATERIALS AND METHODS: The experiments were performed on 40 outbred female mice weighing 20–25 g. The mice were divided into groups of 10 which were injected with intraventricular, intranasal, intraperitoneal, and intact 6-OHDA. After 21 days, behavioral responses were observed in the Rotarod test, Verticalization, Open Field, and Pole test.

RESULTS: 1. A significant difference was found between animals after intraventricular administration of 6-OHDA and the intact control group when studying the behavior of animals in the “open field” test. 2. The study of coordination activity in the Rotarod test (rotating rod) showed a similar decrease in the retention time on a rotating drum in animals after intranasal and intraventricular administration of 6-OHDA. 3. Only the descent time increased after intranasal administration of 6-OHDA. 4. A significant increase in the motor activity of mice was revealed after intranasal and intraventricular administration of apomorphine in the verticalization test.

CONCLUSIONS: It was concluded that a neurotoxin that does not pass through the blood-brain barrier into the central nervous system penetrates through after intranasal administration.