Preparation And Characterization Of Shikonin-loaded Film

[Objective] To preparation and evaluation of shikonin-loaded film by penetration study through rat abdominal skin and therapeutic effect on the psoriasis in guinea pig model. [Method] In order to optimize the extraction method of shikonin, the L9(33)orthogonal design was used while applying cold-dip method, petroleum ether was used as extraction solvent. Formulation of shikonin-loaded film were studied by transdemal experiment through rat abdomen skin. Skin stimulation of shikonin was conducted using rabbits. Psoriasis models were established by repaint propranolole hydrochloride suspension on back ears of guinea pigs. Effects of shikonin on the psoriasis were also observed compared with OXAROL(r) ointment as positive control drug. [Result] In results, there are significant effects of the grind degree of Lithospermumerythrorhizon Sieb. et Zucc and cold-dip time in the solvent on the efficacy of extraction shikonin. The results of percutaneous absorption of shikonin through rat abdominal skin indicated that 10% propanediol has a more satisfied enhancing effect; the penetration rate of shikonin is 18.45±1.84μg/cm2·h. Thecumulated amount of shikonin permeated was 168.10±14.90 μg/cm2 in 12 hours and higher than control group two-fold. Beyond of our previous imagine, Azone has an inhibiting effect on percutaneous absorption of shikonin. In addition, the capacity of forming membranes of shikonin-loaded films were affected by oleic acid although has permeation enhancing effect. No significant irritable effect of shikonin on the rabbit skin was observed in this experiment. There is a significant difference between control group and experimental group on the histology observation while the back ears of guinea pigs were repaint with propranolole hydrochloride suspension, and the scores were 0.83±0.26 and 7.17±0.68 degree, respectively. A significant histological difference was also observed between before and after treat with shikonin (p<0.05). The histological scores of saline and shikonin group were 6.83±0.41, 2.67±0.41 degree, respectively. Similar therapeutic effect shikonin on psoriasis model in high, middle and low dosage, and the degree were 3.08±0.38, 2.92±0.58, 2.83±0.52 degrees after the period of treatment for 14days. But no dosage dependent therapeutic effect was found in this study. [Conclusion] It is a more effective method to extract shikonin from the Lithospermumerythrorhizon Sieb. et Zucc while petroleum ether is used as solvent, cold-dip five days and repeat immerse residue onetime. Propanediol has a significant enhancing effect on the percutaneous absorption of shikonin. No significant skin irritation of shikonin observed. Shikonin-loaded film has a significant therapeutic effect on psoriasis caused by propranolole hydrochloride suspension in guinea pig.