Introduction:
Squamous cell carcinoma (SCC), the second most common non-melanoma skin cancer globally, is attributed to ultraviolet radiation exposure. Current therapeutic approaches including surgery, radiotherapy, and chemotherapy present limitations in patient compliance and systemic toxicity. Curcumin, a natural bioactive compound with anticancer properties, faces challenges in topical delivery due to poor aqueous solubility and limited bioavailability. This study aimed to develop a curcumin-loaded nanoemulsion gel for SCC treatment.
Methods:
Curcumin nanoemulsions were prepared using spontaneous emulsification technique following preformulation studies. Solubility screening identified the optimal oil phase, while surfactant and co-surfactant combinations were evaluated. Various oil-to-surfactant/co-surfactant (SCOS) ratios were investigated. Selected formulations underwent stability testing, particle size analysis using dynamic light scattering, zeta potential measurement, and polydispersity index determination. Optimized nanoemulsions were incorporated into the carbopol gel matrix and evaluated for physicochemical characteristics, entrapment efficiency, pH, viscosity, and spreadability. Drug release studies were conducted using Franz diffusion cells. Cytotoxicity evaluation was performed using MTT assay.
Results:
Capmul CMC demonstrated superior curcumin solubility (90±0.18 mg/mL) and was selected as the optimal oil phase. Tween 20 and PEG 400 served as surfactant and co-surfactant, respectively. Two formulations were developed: F6 (oil:SCOS 1:6) and F8 (oil:SCOS 1:8). F8 formulation exhibited superior characteristics with globule size of 125.3 nm, zeta potential of -18.3 mV, and polydispersity index of 0.310, indicating enhanced stability. The nanoemulsion gel demonstrated 99% entrapment efficiency. Release studies revealed sustained drug release, with F8 releasing 59.41% compared to F6's 66.11%. Cytotoxicity studies demonstrated anticancer activity with IC₅₀ values of 59.63 µg/mL.
Conclusions:
The curcumin nanoemulsion gel system enhanced drug solubilization and provided controlled, sustained release characteristics for SCC treatment. This delivery system offers improved bioavailability, patient compliance, and reduced systemic toxicity, representing advancement in topical cancer chemotherapy.
