Formulation and Evaluation of Diclofenac Sodium-Loaded Solid Lipid Nanoparticles in Ceramide Cream for the Treatment of Atopic Dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterized by impaired skin barrier function and recurrent episodes of itching and inflammation. Conventional therapies often involve corticosteroids, which, although effective, pose long-term side effects such as skin thinning and immunosuppression. This study aimed to develop a novel, non- steroidal topical formulation by incorporating Diclofenac Sodium (DS), a non-steroidal anti- inflammatory drug (NSAID), into Solid Lipid Nanoparticles (SLNs) and embedding them in a ceramide- based cream to address both inflammation and barrier dysfunction in AD. DS-loaded SLNs were prepared using high-shear homogenization followed by ultrasonication, employing glyceryl monostearate as the lipid and Tween 80 as the surfactant. The optimized formulation demonstrated a nanoscale particle size (150–180 nm), low polydispersity index (PDI < 0.3), and high zeta potential (> −30 mV), indicating good stability. These SLNs were then incorporated into a ceramide-rich oil-in-water cream base, formulated to enhance skin Epidermal barrier commonly seen in AD patients. Physicochemical evaluations revealed that the final formulation had a skin-friendly pH (~5.6), suitable viscosity, excellent spreadability, and no signs of phase separation or aggregation. The formulation demonstrated sustained release behavior of DS in in vitro studies, suggesting prolonged anti- inflammatory action at the site of application. The combined approach of barrier restoration via ceramides and targeted drug delivery via SLNs presents a promising therapeutic alternative to corticosteroids for AD management. This study supports the potential of DS-loaded SLNs in ceramide cream as a safe, effective, and patient-compliant strategy for treating chronic inflammatory skin conditions.