Formulation and characterization of Mirtazapine loaded mucoadhesive cubosomal in-situ gel for intranasal delivery

The goal of the present investigation was to formulate and characterize the Cubosomal in-situ gel of Mirtazapine for intranasal delivery. The cubosomal preparation ensures higher entrapment of drug and delivery through intranasal route improves brain targeting of drug by avoiding the Blood Brain Barrier. Cubosomes were prepared by bottom-up approach &amp; Central Composite Design was used for optimization. In-situ thermosensitive gel was formulated by cold method and optimization was done based on gelation temperature and time. The optimized cubosomal formulation was evaluated for various parameters like vesicular size, entrapment efficiency, TEM analysis, in-vitro drug release and ex-vivo permeation study. The cubosomal in-situ gel was evaluated for gelling time, temperature, mucoadhesive and gelling strength. The optimized formulation exhibited 90.33% drug release which confirms that it exhibited superior drug release characteristic as compared to pure drug suspension. The optimized formulation was evaluated for nasal toxicity studies which assure its safety to nasal mucosal membrane. The <i>in-vivo</i> brain biodistribution study showed the Mirtazapine cubosomal in situ gel achieved higher brain concentrations compared to the oral suspension. The cubosomal in-situ gel of Mirtazapine seems to be a promising and safe approach for treatment of depression.