Gel-Dispersed Nanostructured Lipid Carriers Loading Thymol Designed for Dermal Pathologies

Area of Science:

• Dermatology and Nanotechnology
• Pharmacology and Drug Delivery

Background:

• Acne vulgaris is a common skin condition with no definitive cure.
• Current treatments often disrupt the skin's natural microbiome.
• There is a need for targeted acne therapies that preserve healthy skin flora.

Purpose of the Study:

• To develop and optimize thymol-loaded nanostructured lipid carriers (NLC) for topical acne treatment.
• To evaluate the physicochemical properties, stability, and skin retention of the NLC formulation.
• To assess the antimicrobial efficacy against acne-causing bacteria while sparing beneficial skin microbes.

Main Methods:

• Nanostructured lipid carriers (NLC) encapsulating thymol were prepared using ultrasonication or high-pressure homogenization.
• Formulations were optimized using a 2^2 star factorial design and characterized by various physicochemical techniques.
• Stability, cell viability (HaCat cells), and antimicrobial activity (in vitro and ex vivo) were assessed.
• Thymol-loaded NLC were dispersed in various gels, with carbomer selected for optimal skin retention.

Main Results:

• Optimized NLC demonstrated prolonged thymol release and good physicochemical properties.
• Carbomer-based gels showed high skin retention, particularly in the epidermis and dermis.
• Thymol-loaded NLC gels exhibited significant antimicrobial efficacy against *C. acnes*.
• The NLC formulation showed reduced activity against *S. epidermidis* compared to free thymol, suggesting microbiome preservation.

Conclusions:

• Thymol-loaded NLC successfully encapsulated and delivered thymol for topical application.
• The developed gelling system is a promising candidate for acne vulgaris treatment.
• The formulation effectively targets pathogenic bacteria while potentially preserving the healthy skin microbiome.