L-carnosine-loaded hya-ascorposomes Attenuate UVB-induced skin Photoaging: Formulation, in vitro andin vivoevaluation.

Skin photoaging induced by ultraviolet B (UVB) radiation involves oxidative stress, inflammation, and extracellular matrix degradation. L-Carnosine (CAR) possesses potent anti-inflammatory, antioxidant, and anti-wrinkling characteristics, but its topical delivery is limited by poor skin penetration. Development and evaluation of CAR-loaded hya-ascorposomes (CAR-HA-ASP) for enhanced efficacy against UVB-induced photoaging was the main aim of the study. CAR-HA-ASP were prepared using the phospholipid hydration method. The optimized formulation exhibited favorable colloidal properties: a particle size of 192.6 ± 0.56 nm, a negative zeta potential of -16 ± 1.34 mV confirming HA coating, and a high encapsulation efficiency of 85.23 ± 1.89 %. TEM micrographs revealed spherical vesicles with a distinct HA layer. A sustained drug release over 24 h was observed. Ex vivo permeation study revealed that CAR-HA-ASP could significantly enhance CAR flux and permeation coefficient compared with CAR gel. In a rat model of UVB-induced photoaging, topical application of CAR-HA-ASP (0.2 % CAR) significantly reduced skin damage compared to untreated UVB-irradiated and the conventional CAR gel group. Biochemical analysis showed CAR-HA-ASP treatment significantly increased skin superoxide dismutase levels (62.35 ± 1.09 U/g tissue) compared to the positive control (12.3 ± 0.87 U/g) and CAR gel (32.4 ± 1.09 U/g). Furthermore, levels of interleukin-6 and matrix metalloproteinase-9 in the CAR-HA-ASP group were comparable to the negative control group. Histopathological examination revealed normal epidermal and dermal structures in the CAR-HA-ASP-treated group.These results demonstrate that CAR-HA-ASP effectively delivers CAR into the skin, providing enhanced protection against UVB-induced photoaging, highlighting its potential as a novel advanced topical anti-aging formulation.