Development of novel delivery system for nanoencapsulation of catalase: formulation, characterization, and in vivo evaluation using oxidative skin injury model.

One of the main challenges for successful pharmaceutical application of Catalase (CAT) is maintaining its stability. Physical immobilization of CAT through nano-encapsulation was proposed to resolve this challenge. CAT encapsulating niosomes (e-CAT) were prepared using Brij® 30, 52, 76, 92, and 97 in the presence of cholesterol (Ch) by thin film hydration method. Niosomes were characterized for encapsulation efficiency % (EE), size, poly-dispersity index (PI), and morphology. Kinetic parameters, pH optimum, thermal stability, and reusability of CAT were determined. The influence of optimized e-CAT dispersion onto thermally injured rat skin was evaluated. Results revealed that encapsulation enhanced CAT catalytic efficiency (Vmax /Km ). Free CAT and e-CAT had pH optimum at 7.0. e-CAT exhibited improved thermal stability where it retained 50% residual activity at 60 °C. Free CAT lost its activity after three consecutive operational cycles; however, e-CAT retained 60% of its initial activity following 12 cycles. After 24 h of topical application on thermal injury, a significant difference in lesion size was observed with e-CAT compared with the control group. Based on these encouraging results, CAT immobilization demonstrated a promising novel delivery system that enhances its operational stability. In addition, nano-encapsulated CAT can be anticipated to be beneficial in skin oxidative injury.