Category: Formulation and Quality
Purpose: Glioblastoma (GBM) is extremely lethal and poorly treated primary brain tumors. Using of multimodality treatments such as surgical resection followed by radiation therapy and temozolomide based chemotherapy; the life expectancy remains poor (1). The treatment is challenging due to the blood-brain barrier (BBB) which prevent the entry of the drug into the brain (2). One of the well-known route of drug administration to the brain which bypasses BBB is by delivering the drugs through the olfactory lobe pathway (). Hence, drugs with poor bioavailability can be effectively delivered through intranasal in-situ gels with drugs loaded in ethosomes. This system in total will not only bypass the BBB but also will act as the permeation enhancer to transfer the drugs across the intranasal membrane. The present investigation was to develop resveratrol loaded ethosomal in situ nasal gel and its evaluation for in-vitro antitumor activity against glioma cells. Further, in-vivo biodistribution of the optimized formulation was also evaluated.
Methods: Resveratrol loaded ethosomes (RE) was formulated by thin film hydration method by using lipoid S75, sodium deoxycholate (SDC) and ethanol 40% respectively (4). The effect of independent variable (X1- lipid and X2- SDC) on quality attributes of RE i.e., dependent variable (Y1- particle size, Y2- zeta potential and Y2- % encapsulation efficiency (%EE)) were investigated by using 32 factorial design. Formulated ethosomes were evaluated for preliminary microscopic examination followed by percent drug entrapment efﬁciency, vesicle size analysis, zeta potential, polydispersibility index and Transmission electron microscopy (TEM). Thermoreversible gel of RE was formulated by using poloxamer407 as Thermoreversible polymer and carbapol 934 as mucoadhesive polymer. Ethosomal thermoreversible gel was evaluated for gelation temperature, gel strength, mucoadhesive strength, in-vitro drug release and ex-vivo permeation study using sheep nasal mucosa
Results: The Optimized RE formulation has a spherical morphology with narrow size distribution (PDI- 0. 286), particle size 207.9 nm and 82.5 percent of EE (Fig.1) . A total nine formulations were prepared according to factorial design and the observed response surface plot shown in fig.2. The developed and characterized formulations were used to comparatively assess in vitro cellular uptake, invitro cytocompatibility against mouse fibroblast, invitro cytotoxicity against U-87MG glioma cell line using standard MTT (3-(4, 5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide) assay and in-vivo bio-distribution. Our results showed greater cellular uptake, nontoxic nature of RE to normal fibroblast cells and invitro cytotoxicity at lowest IC50 with better invivo bioavailability and tumor targeting efficiency with minimum secondary organ drug distribution. Histopathology results showed intact epithelial cells neither internal damage, nor cell necrosis conforming the non-toxic nature of thermoreversible gel of RE.
In conclusion, thermoreversible gel of RE showed promising results and warrants to explore the development of therapeutic interventions for Glioblastoma.