RESUMEN
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.
RESUMEN
Objective In order to optimize the preparation technology of triptolide and ferulic acid ethosomes and evaluate its characteristics of the in vitro transdermal penetration and the preparations performance using ethosome as carrier. Methods The compatibility ratio between triptolide and ferulic acid was determined by MTT. The triptolide and ferulic acid ethosomes were prepared with injection method based on the results of single factor experiments, Box-Behnken design was used to optimize the particle size, electric potential, and encapsulation efficiency (EE) of the ethosomes, and the in vitro release behavior prepared by the optimal formulation were studied. The in vitro transdermal absorption experiment was carried out in optimized Franz diffusion cells. Results The ratio of triptolide to ferulic acid was 1:100. The optimized prescription of the ethosomes was 20% ethanol, 2.2% phospholipid, 90 s ultrasonic time. The results showed that the appearance of the triptolide and ferulic acid ethosomes was clear liquid with blue opalescence in an average diameter of (46.75 ± 2.39) nm at potential of (-46.32 ± 3.76) mV, and the EE was (67.72 ± 1.10)%. The in vitro transdermal behaviors of ferulic acid and triptolide in the ethosomes were in line with the Higuchi equation. Conclusion The ethosomes has the advantages of small particle size, uniform distribution, good stability, and good transdermal absorption property, so as to provide the basis for the development of the transdermal preparation of the effective components of Tripterygium wilfordii.