Citicoline loaded nanoemulsion enriched with D-alpha-Tocopherol acetate and protein: Formulation and in-silico study

Nanoemulsion, a nanostructured and colloidal dosage form, have emerged as a promising drug delivery system. Crossing the blood-brain barrier (BBB), effectively targeting the brain, and treating Alzheimer's disease (AD) are still formidable challenge. Citicoline (CL) nanoemulsion was developed utilizing D-alpha-Tocopherol acetate (DAT) as the emulsifier and BBB permeability enhancer, Bovine serum albumin (BSA) as the protein, and Poly lactide-co-glycolic acid (PLGA) as the release retardant. The binding affinity and suitability of DAT towards acetylcholinesterase was determined using molecular docking, which revealed a drug score of 0.88 and pi-alkyl linkages dominating the structure. A total of nine formulations were developed and characterized using the emulsification principle. Fluorescence spectra demonstrated complexation and interaction between CL and cationic BSA, which is highlighted by a decrease in fluorescence intensity. The drug loading of nanoemulsions ranged from 48.35 to 74.63%, and DAT displayed lesser CL entrapment than BSA formulations. The formulation "F1" containing a suitable amount of BSA, DAT, PLGA and MCC 200 found to be the optimum development with a mean globular size of 611.3 nm. An in-vitro investigation was performed for "F1"utilizing the Franz diffusion cell, which prolonged CL release while preserving the minimum effective concentration. Nanoemulsion "F1" was examined using a scanning electron microscope, zeta potentialvalue, attenuated total reflectance, differential scanning colorimetry, and X-ray diffraction. Using the Morris Water Maze (MWM) model, learning and memory ability of Alzheimer's disease (AD)-induced Long-Evans rats were observed, with significant satisfactory results for the selected formulation; which is validated by analysis of variance (ANOVA). Based on the findings, the present study concludes that, a suitable combination of CL-DAT-BSA and PLGA could be used to effectively deliver and enhance the therapeutic benefit in AD patients.