Intranasal administration of nanostructured lipid carriers containing CNS acting drug: Pharmacodynamic studies and estimation in blood and brain

The present study was aimed to investigate and compare the efficacy of duloxetine (DLX) loaded nanostructured lipid carriers (NLC) with DLX solution pharmacodynamically following intranasal administration. The study was further conducted to estimate DLX concentration in brain and blood. DLX was administered to albino Wistar rats either intranasally or orally in solution form (DLX solution) or encapsulated in NLC (DLX–NLC). These were evaluated in-vivo for pharmacodynamic studies for depression by forced swimming test and locomotor activity test. Intranasal DLX–NLC treatment exhibited improved behavioural analysis results (swimming, climbing, and immobility) than the DLX solution after 24 h of study. Furthermore, DLX–NLC significantly increased the total swimming and climbing time when compared with control and significantly reduced the immobility period. The intranasal DLX–NLC demonstrated improved locomotor activity when compared with DLX solution. Amount of DLX was quantified in blood and brain after the forced swimming test. The intranasal DLX–NLC demonstrated higher concentration in brain compared with DLX solution. Thus, intranasal DLX–NLC was found to be a promising formulation for the treatment of depression.