Nanosized Intranasal Delivery of Novel Self-Assembled Cubic Liquid Crystals: Formulation and Evaluation

Purpose The focus of this research was to develop Almotriptan malate (ALM)-loaded cubosomal in situ gel to improve its permeation through the blood–brain barrier (BBB) with an efficient and quick action when administered through the intranasal route. Method Cubosomes were developed by emulsifying and homogenizing various proportions and concentrations of pluronics F127 (PF127) and glyceryl monooleate (GMO) along with polyvinyl alcohol (PVA) as suggested by the Box–Behnken design (BBD). The desirability function was used to select the optimum cubosomal formula. The developed cubosomes morphology was validated by high resolution transmission electron microscopy (HR-TEM) analysis. Differential scanning calorimetry (DSC) peaks served as proof that the drug was enclosed within the nanocarrier system. A range of concentrations of PF127 (15–21% w/v) were used to formulate and optimize the in situ gel. Ex vivo permeation experiments followed by histopathology studies were also conducted. Results It was observed that particle size (PS) of 177.15 ± 7.85 nm, polydispersity index (PDI) of 0.36 ± 2.55, zeta potential (ZP) of − 21.26 ± 0.19 mV, and entrapment efficiency percentage (EE%) of 72.58 ± 8.82% was obtained with a percent deviation of less than 5. G4 batch consisting of 18% w/v of PF127 demonstrated satisfactory results. Furthermore, the results were in accordance with the phase transition and the formulation displayed a pseudoplastic rheological behavior confirmed by the rheogram. The optimized formulation’s in vitro drug permeation measurements demonstrated 90.69% release after 5 h. The ex vivo permeation also revealed a 2.52 enhancement ratio when compared to plain in situ gel. Histopathology analyses showed a non-toxic effect of the optimized composition on the cellular structure of sheep’s nasal mucosa. A short-term stability analysis revealed that the formulation was stable at room temperature for 3 months. Conclusion ALM-loaded intranasal cubosomal in situ gel is likely to promote patient compliance by delivering immediate relief from migraine pain due to its rapid onset of action and safe dosage form. Graphical Abstract