Preparation,in Vitro And In Vivo Preliminary Evaluation Of Salicylic Acid Pullulan Paint

The preparation of salicylic acid paint (SCP) is optimized by orthogonal design test while pullulan as main matrix and the film-forming time as evaluation index. The optimized SCP at body temperature can form film quickly. UV-vis method is used to determine the concentration of salicylic acid in SCP, the linear of salicylic acid in4～24μg/mL is good and the method is simple and reliable. The skin irritating test shows that no blisters, rash and swelling phenomena observed after24h during using SCP on mice. There is no difference between the SCP and blank matrix, indicating that the SCP does harmless to skin. To optimize the dosage of azone, the transdermal delivery experiment is carried out by Franz diffusion cell using the skin of KM mice. The result shows that1%azone is optimum and the increase of the concentration of azone is not increasing its penetration effect. The permeation release of SCP is investigated using the standing posture Franz’s type diffusion cell. The result indicates that the drug release from the SCP can be simulated by Higuchi equation. A HPLC mehod is used to determine the release salicylic acid of SCP in vitro, the method appears good precision and accuracy. The pharmacokinetic of salicylic acid after using SCP in rabbits is studied. The concentration of salicylic acid in blood with non-ultrasound reaches the peak at1h, Cmax at34.87μg/mL and AUC up to261.73μg-h/mL, whereas the Cmax of salicylic acid in rabbits with ultrasound is39.06μg/mL at0.5h and the AUC value is up to314.78μg·h/mL. Which indicates that ultrasound promotes the transdermal absorption of salicylic acid.Hence we draw a conclusion:pullulan can be used as the matrix of paint, the preparation process of SCP is good and simple. SCP is stability, easy using and harmless. SCP with low-frequency ultrasound can promote absorption of salicylic acid.