Co-Delivery of Temozolomide and Quercetin via Nanoemulsion for Glioblastoma Therapy: From In-Silico to In-Vivo Evaluation

Glioblastoma (GBM) is a form of brain tumor, and the line of treatment includes the administration of temozolomide (TMZ). Due to the short life of TMZ, high doses are recommended, which leads to drug-induced adverse reactions. In this study, TMZ and Quercetin (QUE) loaded nanoemulsion was developed using a Quality by Design (QbD) approach for the treatment of GBM. The efficacy of TMZ and QUE was assessed through in silico studies, which revealed a synergistic effect of the drugs. Afterward, cellular assays using U87 MG cell lines demonstrated that the optimal ratio of TMZ to QUE (1:8 μg/mL) yielded a synergistic therapeutic effect. Thus, the ratio of TMZ to QUE was considered to design the formulation. The nanoemulsion was optimized by using a central composite rotatable design (CCRD). The prepared nanoemulsion was characterized by a droplet size of 84.91 ± 2.17 nm with a polydispersity index (PDI) value of 0.20 ± 0.01, zeta potential -7.7 ± 0.34 mV, % transmittance of 94.16 ± 8.05 %, etc. In vitro drug release and ex vivo permeation studies demonstrated that a dual drug-loaded nanoemulsion significantly improved drug permeation compared to the drug suspension. Furthermore, the pharmacokinetic studies also showed significant improvement in drug plasma concentrations for improved therapeutic efficacy. The nanoemulsion-treated groups also showed a significantly lower IC₅₀ value, indicating greater potency. Hence, the findings suggest that dual drug-loaded nanoemulsion could serve as an effective approach for treating GBM.

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