Abstract
Carbamazepine (CBZ) is an antiepileptic orally administered drug, but due to its low solubility in water, its gastrointestinal absorption is slow and irregular, leading to delayed brain uptake with consequent peripheral side actions. The objective of this study was the brain targeting of CBZ via the olfactory mucosa in form of an intranasal mucoadhesive o/w nanoemulgel (MNEG). CBZ was formulated in a nanoemulgel system containing oleic acid/labrasol in a ratio of 1:5 as oil/surfactant and 0.1% xanthan gum as anionic mucoadhesive polymer. The prepared MNEG was characterized with respect to oil droplet size, mucoadhesion, in-vitro release of the drug and CBZ uptake by phosphatidylcoline liposomes as an in-vitro model for olfactory cells. The anticonvulsant action of nasal MNEG was studied on chemically and electrically induced convulsive Swiss Albino mice. The in-vitro release of CBZ from MNEG was very low, however CBZ uptake via liposomal membrane reached 65% within 1 hr. Treatment of animals with MNEG significantly prolonged the onset times for convulsion of chemically convulsive mice and protected the animals from two electric shocks. One can thus spire and hope for the emergence of a new intranasal treatment of epilepsy with consequent decrease in the peripheral side actions of CBZ.