RÉSUMÉ
ObjectiveTo investigate the long-term safety of triptolide ferulic acid ethosome gel in percutaneous administration. MethodWe mixed triptolide with ferulic acid to make liposomes gel in different doses and then administrated the gel to SD rats of both sexes with intact skin and damaged skin for 12 weeks. The daily dosages calculated based on triptolide for the low-， middle-， and high-dose groups were 63.75， 127.50， 255.00 μg·kg-1， respectively. The body weight of each rat was measured weekly. The rats were sacrificed in the last week for the determination of serum biochemical parameters and organ indexes as well as the observation of histopathology. The toxicity was assessed based on the body weight and all the parameters and indexes. ResultAfter long-term administration， the body weight and serum biochemical parameters did not show significant difference between the gel-treated groups and the blank group with intact skin， which indicated that the percutaneous administration of triptolide and ferulic acid ethosomes gel was relatively safe. However， the rats in the high-dose group showed sparse hair and were easy to die in the case of unhairing with chloral hydrate at the late stage of the study. Comprared with the female rats with intact skin in the blank control group， the female rats with damaged skin in the middle-dose group showed decreased heart index （P<0.05）， which indicated certain cardiotoxicity. Moreover， damage appeared in skin and lung， which may be influeneced by dosage， sex， and skin state. ConclusionFerulic acid in combination with triptolide is relatively safe for percutaneous administration， whereas there are some risks of skin and lung damage in the case of long-term administration. Individualized administration scheme should be developed according to liver and kidney function and skin conditons to ensure the safety of clinical medication.
RÉSUMÉ
The aim of this study was to prepare triptolide and ferulic acid ethosomes gel, investigate its transdermal permeation, and compare the results with ordinary gel and cream. Improved Franz diffusion cell method was used in the transdermal delivery experiment with rat abdominal skin as in vitro model. The receptor fluid at different time points was collected; ferulic acid concentration was determined by high performance liquid chromatography (HPLC) and triptolide concentration was determined by liquid chromatography-electrospray ionization mass spectrometry (LC-MS/MS). Then the penetration rate, transdermal volume and skin reserve of three dosage forms (hydroplasy gel, ordinary gel, and cream) to investigate the transdermal properties of ferulic acid and triptolide in vitro of triptolide and ferulic acid ethosomes gel. The results showed that the steady penetration rate of ferulic acid was 5.268 5, 8.990 9, 12.042 0 μg·cm⁻² ·h⁻¹ respectively in triptolide and ferulic acid ethosomes gel, ordinary gel and cream; the skin retention was (30.234 8±1.525 4), (20.402 6±0.402 6), (7.635 3±1.094 2) μg·cm⁻² . The steady-state permeation rate of triptolide was 67.238 0, 67.238 0 ng·cm⁻² ·h⁻¹ in triptolide and ferulic acid ethosomes gel, about 1.24 times of cream and 3.28 times of ordinary gel; the skin retention was (371.351 4±35.317 1) ng·cm⁻², about 3.35 times of cream and 5.25 times of ordinary gel. Therefore, the ethosomes gel showed good transdermal absorption property and it may be good for clinical safety administration.