Development of sucrose stearate-based nanoemulsions and optimisation through γ-cyclodextrin

Area of Science:

• Colloid and Surface Science
• Pharmaceutical Nanotechnology
• Dermal Drug Delivery

Background:

• Nanoemulsions for skin drug delivery commonly use lecithin surfactants.
• Lecithin exhibits self-aggregation and chemical degradation issues, limiting nanoemulsion stability.
• Alternative surfactants are needed to improve nanoemulsion performance for dermal applications.

Purpose of the Study:

• To develop stable nanoemulsions using a sucrose ester mixture as a sole surfactant for dermal drug delivery.
• To compare the physicochemical stability and emulsifying efficiency of sucrose stearate nanoemulsions with lecithin-based systems.
• To evaluate the in vitro skin permeation of drugs from these novel nanoemulsions.

Main Methods:

• Development and characterization of nanoemulsions stabilized by sucrose stearate and lecithin.
• Cryogenic transmission electron microscopy (Cryo TEM) for structural analysis.
• In vitro skin permeation studies of lipophilic drugs and fludrocortisone acetate, with and without gamma-cyclodextrin.

Main Results:

• Sucrose stearate nanoemulsions demonstrated superior emulsifying efficiency, droplet formation, and physical/chemical stability over lecithin.
• Cryo TEM revealed a homogeneous structure in sucrose stearate systems, unlike the variable structure of lecithin systems.
• In vitro skin permeation of lipophilic drugs was comparable; however, gamma-cyclodextrin significantly enhanced fludrocortisone acetate permeation, especially in lecithin formulations.

Conclusions:

• Sucrose stearate is a promising surfactant for developing stable and structurally homogeneous nanoemulsions for dermal drug delivery.
• The combination of sucrose stearate or lecithin with gamma-cyclodextrin shows potential for enhancing steroidal drug permeation.
• Synergistic interactions between surfactants and cyclodextrins may play a role in improving drug delivery across the skin.