Characterization and Penetration of Quercetin Spanlastic Gel with Span 60 as Vesicle Builder and Edge Activator of Brij 35 and Tween 60

Aging is a process in which the skin undergoes degenerative changes caused by intrinsic and extrinsic factors. Quercetin has characteristics that demonstrate antioxidant potential. This research aimed to determine the effects of edge activators (EAs), namely, Tween 60 and Brij 35, on the characteristics and penetration of quercetin spanlastic gel with Span 60 as a vesicle builder. Spanlastic was made using the thin-layer hydration method and then formulated in an HPMC 4000 gel; its composition consisted of Span 60–Brij 35 (B1) and Span 60–Tween 60 (T1) at a ratio of 9:1. Characterization included particle size, the polydispersity index, entrapment efficiency, and drug loading. A penetration test was carried out in vivo on male balb/c mice with six samples, namely, F1 (quercetin spanlastic with EA Tween 60), F2 (quercetin spanlastic with EA Brij 35), F3 (quercetin spanlastic gel with EA Tween 60), F4 (quercetin spanlastic gel with EA Brij 35), K (quercetin gel), and R (gel base). Quercetin spanlastic F1 and F2 had a high entrapment efficiency of 94.48-99.06%, a drug loading of 0.142-0.158%, and a size of 841.2-1443.0 nm. F1 and F2 penetrated better than K and R, and F2 penetrated better than F1. Although quercetin spanlastic gel F3 and F4 also showed a good penetration ability, it was not as good as that of quercetin spanlastic F1 and F2. Spanlastic and spanlastic gel demonstrate potential which may be beneficial as innovative delivery systems.