Agranulocytosis-Protective Olanzapine-Loaded Nanostructured Lipid Carriers Engineered for CNS Delivery: Optimization...

Potential risk of agranulocytosis is one of the drug-induced adverse effects of the second-generation antipsychotic agents. The present investigation aimed to formulate and investigate olanzapine (OLZ)-loaded nanostructured lipid carriers (OLZ-NLCs) via intranasal (i.n.) route. The NLC was prepared by melt emulsification method and optimized by Box-Behnken design. Mucoadhesive NLC was prepared by using 0.4% Carbopol 974P (OLZ-MNLC (C)) and the combination of 17% poloxamer 407 and 0.3% of HPMC K4M (OLZ-MNLC (P+H)). The particle size, zeta potential, and entrapment efficiency were found to be 88.95 nm ± 1.7 nm, - 22.62 mV ± 1.9 mV, and 88.94% ± 3.9%, respectively. Ex vivo permeation of OLZ-NLC, OLZ-MNLC (P+H), and OLZ-MNLC (C) was found to be 545.12 μg/cm² ± 12.8 μg/cm², 940.02 μg/cm² ± 15.5 μg/cm², and 820.10 μg/cm² ± 11.3 μg/cm², respectively, whereas the OLZ-MNLC (P+H) formulation showed rapid drug permeation than the OLZ-NLC and OLZ-MNLC (C) formulations. The OLZ-MNLC (P+H) formulation was shown to have 13.57- and 27.64-fold more J_ss than the OLZ-MNLC (C) and OLZ-NLC formulations. The OLZ nanoformulations showed sustained release of up to 8 h. Finally, the brain C_max of technetium-99m (^99mTc)-OLZ-MNLC (i.n.) and ^99mTc-OLZ-NLC (i.v.) was found to be 936 ng and 235 ng, respectively, whereas the C_max of i.n. administration was increased 3.98-fold more than the C_max of i.v. administration. The in vivo hematological study of OLZ-MNLC (P+H) confirmed that the i.n. formulation did not reflect any variation in leukocyte, RBC and platelet counts. Hence, it can be concluded that the nose-to-brain delivery of OLZ-MNLC (P+H) can be considered as an effective and safe delivery for CNS disorders.