Development, optimization, and characterization of a novel tea tree oil nanogel using response surface methodology

Area of Science:

• Pharmaceutical Sciences
• Materials Science

Background:

• Topical drug delivery faces challenges with poorly soluble compounds like tea tree oil (TTO).
• Nanoemulsions (NEs) offer enhanced solubility and bioavailability for active ingredients.
• Emulgels (EGs) combine the benefits of NEs with the cosmetic advantages of gels for topical application.

Purpose of the Study:

• To formulate and optimize a nanoemulsion-based emulgel (NE-EG) for effective topical delivery of tea tree oil (TTO).
• To evaluate the physicochemical, permeation, and antimicrobial properties of the developed TTO-loaded emulgel.

Main Methods:

• Nanoemulsions were optimized using a central composite design for high-energy emulsification.
• The optimized NEs were formulated into emulgels using Carbopol 940 and triethanolamine.
• Evaluations included particle size, zeta potential, TEM, pH, viscosity, texture analysis, ex vivo skin permeation, stability, and antimicrobial assays.

Main Results:

• Optimized NEs exhibited a particle size of 16.23 nm and zeta potential of 36.11 mV.
• The TTO-emulgel (EG) showed a skin-compatible pH (5.57), significant ex vivo skin permeation (79.58 μL/cm²), and enhanced antimicrobial activity.
• The formulation demonstrated favorable viscosity, texture, and stability over 90 days, with no observed irritation.

Conclusions:

• The optimized TTO-loaded emulgel is a promising vehicle for topical delivery.
• This formulation enhances the therapeutic efficacy of tea tree oil for dermatological applications.