Liposome-Containing Hibiscus sabdariffa Calyx Extract Formulations with Increased Antioxidant Activity, Improved Dermal Penetration and Reduced Dermal Toxicity
Sirirat Pinsuwan PhD*, Thanaporn Amnuaikit PhD*, Suwipa Ungphaiboon PhD*, Arunporn Itharat PhD**
Affiliation : * Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Songkhla, Thailand ** Department of Applied Thai Traditional Medicine, Faculty of Medicine, Thammasat University, Rangsit Campus, Pathumthani, Thailand
Hibiscus sabdariffa Linn, or Roselle, is a medicinal plant used extensively in traditional Thai medicine since ancient times. The extracts of Roselle calyces possess antioxidant activity and have potential for development as active ingredients in cosmetic products. However, the limitations of using Roselle extracts in cosmetics are its low skin permeation and dermal irritation. Liposome technology is an obvious approach that might overcome these problems. Liposome formulations of standardized Roselle extracts were developed with various lipid components. The formulation showing the highest entrapment efficiency was selected for stability, skin permeation and dermal irritability studies. The liposome formulation with the highest entrapment efficiency (83%) and smallest particle size (332 mm) was formulated with phosphatidylcholine from soybean (SPC): Tween 80: deoxycholic acid (DA); 84:16:2.5 weight ratio, total lipid of 200 g/mL and 10% w/v Roselle extract in final liposomal preparation. This liposome formulation was found to be stable after storage at 4°C, protected from light, for 2 months. The in vitro skin permeation studies, using freshly excised pig skin and modified Franz-diffusion cells, showed that the liposome formulation was able to considerably increased the rate of permeation of active compounds in Roselle extracts compared to the Roselle extract solution. The in vivo dermal irritability testing on rabbit skin showed that the liposome formulation dramatically decreased skin irritability compared to the unformulated extract. These results showed that the liposomes containing Roselle extracts had good stability, high entrapment efficacy, increased skin permeation and low skin irritation.
Keywords : Liposome, Antioxidant, Skin irritation, Hibiscus sabdariffa, Roselle
