Formulation of Lavender oil loaded Self-Microemulsifying Drug Delivery System for Psoriasis management.

Introduction

Psoriasis is a chronic, immune-mediated inflammatory skin disorder that demands effective and sustained therapeutic strategies. Conventional topical treatments often suffer from poor drug solubility, limited skin permeability, and systemic side effects. This study aimed to develop a novel Self-Microemulsifying Drug Delivery System (SMEDDS) incorporating lavender oil to enhance drug delivery and therapeutic efficacy for psoriasis management.

Methods

Comprehensive preformulation studies identified ethyl oleate as the oil phase, Tween 80 as the surfactant, and PEG 300 as the co-surfactant. A pseudo-ternary phase diagram guided the selection of an optimized oil-to-Smix ratio. The formulation was characterized for droplet size, zeta potential, and transmittance, and incorporated into cream bases with varying stearic acid concentrations. Analytical techniques including UV spectrophotometry and GC-MS validated the identity and purity of the drug and excipients. In vitro diffusion studies using Franz diffusion cells and cell line assays were conducted to assess drug release and biological activity. The HET-CAM assay was used to evaluate irritation potential.

Results

The optimized SMEDDS exhibited a droplet size of 147.3 nm, zeta potential of -26.1 mV, and transmittance of 92.57%, indicating a stable microemulsion. Among the cream formulations, the one with 10% stearic acid showed the best drug content and release profile. In vitro studies demonstrated sustained drug release over 24 hours, outperforming conventional formulations. Cell line studies revealed a 56% reduction in TNF-α expression and ROS reduction at 1 μg/mL, indicating strong anti-inflammatory potential. The HET-CAM assay confirmed the formulation’s non-irritating nature.

Conclusion

The developed lavender oil-loaded SMEDDS formulation significantly improved solubility, skin permeability, and controlled drug release, while demonstrating anti-inflammatory efficacy and safety. These findings support its potential as a novel, patient-friendly topical treatment for psoriasis.