Innovative Aqueous Nanoemulsion Prepared by Phase Inversion Emulsification with Exceptional Homogeneity

Area of Science:

• Pharmaceutical Sciences
• Drug Delivery Systems
• Nanotechnology

Background:

• Formulating drugs with low solubility or permeability for intranasal delivery is difficult due to small administration volumes.
• Nanoemulsions (NE) can address these challenges but face production and stability issues, especially with high lipid content.

Purpose of the Study:

• To develop a nanoemulsion (NE) with high solubilization capacity for lipophilic drugs (e.g., simvastatin) and enhanced absorption for low-permeability drugs (e.g., fosphenytoin) via intranasal administration.
• To investigate formulation factors influencing NE homogeneity and explore low-energy production methods.

Main Methods:

• Screening and characterization of NE compositions with high lipid proportions.
• Evaluation of formulation factors affecting droplet size homogeneity and cytotoxicity screening.
• Development and optimization of NE using a low-energy phase inversion method.

Main Results:

• A novel NE formulation using propylene glycol monocaprylate NF achieved high homogeneity without high-energy methods.
• The optimized NE demonstrated excellent solubilization of simvastatin and promoted faster intranasal absorption of fosphenytoin.
• Screening identified formulations with good homogeneity and acceptable cytotoxicity profiles.

Conclusions:

• A highly homogeneous NE was successfully developed using a simple, low-energy phase inversion method.
• This NE formulation is a promising alternative for industrial applications, enabling solubilization and protection of lipophilic drugs and co-administration of hydrophilic molecules.
• The findings highlight the potential of NE for overcoming formulation barriers in intranasal drug delivery.