Nanoemulsions for topical delivery: formulation, applications and recent advances

Area of Science:

• Pharmaceutical Sciences
• Materials Science
• Nanotechnology

Background:

• Nanoemulsions (NE) are kinetically stable dispersions of oil and water (20-200 nm droplets) stabilized by emulsifiers.
• NE formulations enhance drug solubility, permeability, and bioavailability for both lipophilic and hydrophilic compounds.
• They are crucial for topical drug delivery, addressing various skin ailments.

Purpose of the Study:

• To review the development and application of nanoemulsions.
• To compare different nanoemulsion preparation methods regarding droplet size and stability.
• To highlight advancements in nanoemulsion formulations and address toxicity concerns.

Main Methods:

• Comparison of high-energy (e.g., phase inversion) and low-energy (e.g., solvent diffusion, membrane emulsification) methods for NE development.
• Review of literature on topical nanoemulsion applications for skin diseases.
• Analysis of novel NE formulations including ionic liquids, nanoparticles, stimuli-responsive, and Pickering NE.

Main Results:

• Nanoemulsions offer improved drug delivery for various skin conditions like psoriasis, infections, cancer, and wound healing.
• Advanced formulations like stimuli-responsive and Pickering NE show promise.
• Methods for mitigating NE and surfactant toxicity are discussed.

Conclusions:

• Nanoemulsions are versatile drug delivery systems with significant potential for topical applications.
• Ongoing research focuses on advanced formulations and safety profiles of nanoemulsions.
• Optimized formulation and preparation methods are key to successful nanoemulsion-based therapies.