Apremilast loaded lyotropic liquid crystalline nanoparticles embedded hydrogel for improved permeation and skin retention: An effective approach for psoriasis treatment

The present work aimed to prepare and evaluate Apremilast loaded lyotropic liquid crystalline nanoparticles (LCNPs) formulation for skin delivery to enhance the efficacy with reduced adverse effects of the oral therapy in psoriasis treatment. The LCNPs were prepared using the emulsification using a high shear homogenizer for size reduction and optimized with Box Behnken design to achieve desired particle size and entrapment efficiency. The selected LCNPs formulation was evaluated for in-vitro release, in-vitro psoriasis efficacy, skin retention, der-matokinetic, in-vivo skin retention, and skin irritation study. The selected formulation exhibited 173.25 +/- 2.192 nm (polydispersity 0.273 +/- 0.008) particle size and 75.028 +/- 0.235% entrapment efficiency. The in-vitro drug release showed the prolonged-release for 18 h. The ex-vivo studies revealed that LCNPs formulation exhibited drug retention up to 3.2 and 11.9-fold higher, in stratum corneum and viable epidermis compared to conven-tional gel preparation. In-vitro cell line studies performed on immortal keratinocyte cells (HaCaT cells) demonstrated non-toxicity of selected excipients used in designed LCNPs. The dermatokinetic study revealed the AUC0-24 of the LCNPs loaded gel was 8.4 fold higher in epidermis and 2.06 fold in dermis, respectively compared to plain gel. Further, in-vivo animal studies showed enhanced skin permeation and retention of Apremilast compared to conventional gel.