| Psoralen compounds are widely present in Umbrella,Compositae,and Rutaceae plants.They are a class of natural plant photosensitizers with strong photochemical effects.Psoralen compounds play an important role in the clinical treatment of vitiligo due to their photosensitivity.Bergapten is one of the important representatives of psoralen drugs.However,bergapten is poorly water-soluble,not easily absorbed through the skin,and has low bioavailability,which greatly limits its application in topical skin medicine.Liposome gel is a new type of carrier gel,which can remarkably improve the insoluble drugs’solubility and transdermal absorption velocity,aggrandize the skin retention of drugs,the drug bioavailability can be improved,too.This study evaluated the effect of bergapten in treating vitiligo through animal experiments,and prepared bergapten into liposomes and gels,laying the foundation for the development and application of bergapten.The specific research results are as follows:1.The effect of bergapten on mice model of vitiligoUsing hydroquinone-induced vitiligo mouse model and confirming that the model is successfully prepared,the pharmacodynamic evaluation is carried out from the three aspects of apparent index,pathological index and biochemical index with the method of model building and drug delivery:bergamot Compared with the model group,the white hair area of the lesion area in each group of ester administration was reduced to different degrees.The melanin particles in the hair follicles of mice in each group of bergamot lactone administration had significant changes compared with the model group.The positive drug group,The average thickness of the spine and stratum corneum of the low,medium and high bergamot lactone groups were 24.02μm,24.21μm,34.29μm,31.75μm,24.65μm,23.67μm,20.82μm,19.42μm（P<0.01）,positive drugs The average concentration of tyrosinase in the serum of mice in the bergamot lactone low,medium and high groups were 13.73μmol·L-1,12.67μmol·L-1,13.64μmol·L-1,and 13.78μmol·L-1（P<0.01）,the average concentration of tumor necrosis factor-ɑwas 106.00μmol·L-1,107.11μmol·L-1,107.75μmol·L-1,104.22μmol·L-1（P<0.05）,The average concentrations of interleukin-6were 18.60μmol·L-1,19.14μmol·L-1,17.70μmol·L-1,and 17.75μmol·L-1（P<0.05）.The results show that bergamot lactone has a therapeutic effect on mouse models of vitiligo.2.Process optimization and quality research of bergapten liposomesThe thin-film dispersion-probe ultrasonic method was used to prepare bergapten liposomes,and the particle size and encapsulation efficiency were selected as the response values to optimize the liposome prescription by Box-Behnken method,The final preparation process was determined as follows:weigh lecithin 300 mg,Cholesterol 75 mg,bergapten 10 mg add appropriate amount of chloroform to dissolve,rotary evaporation to form a thin film,continue to vacuum for 10 minutes to remove the organic reagents,add 3 m L 1.59%Tween-80 PBS（p H 6.5）The solution was hydrated for 0.5 h,and the probe was sonicated for 10 min under ice-water bath conditions to obtain liposomes with a particle size of（169.69±0.23）nm and an encapsulation efficiency of（83.75%±1.60）.The quality of bergapten liposomes was studied:the appearance of bergapten liposomes was milky white and there was no obvious particles;transmission electron microscopy confirmed that the liposomes were spherical shape and there was no adhesion on the surface;The DSC results verified that bergapten could be encapsulated by the liposomes;Chinese Pharmacopoeia’s 2020 edition carried out the organic reagent residue test,and finally showed that the liposomes had no chloroform residues;the in vitro release test results showed that the bergapten liposomes had no burst of release in the first 0.25 h.The12h cumulative release amount is 56.72%;compared to the bergapten suspension,bergapten liposomes showed higher results of 24 h cumulative permeation and skin retention in the vitro transdermal experiments;bergapten liposomes are initially stable The results of the performance evaluation show that the bergapten liposomes have good short-term stability.3.Preparation and quality evaluation of bergapten liposome gelThe bergapten liposome gel was prepared by the direct swelling method.the24-hour skin retention was used as the evaluation index,and the orthogonal design experiment was used to optimize gel formulation,and the best preparation method was finally obtained.:Weigh out 1 g carbomer 940,10 g propylene glycol,1 g mixed essential oil of frankincense and myrrh,and 40 g bergapten liposomes and swell for24 h,stir well and add an appropriate amount of PBS buffer（p H 6.5）To 100 g,and finally add an appropriate amount of triethanolamine to adjust the p H to 5.5-6.5 to obtain a milky white gel with a content of 0.12%.The appearance,particle size,potential,PDI,viscosity coefficient,p H,etc.of the prepared bergapten liposome gel were checked,and they all met the requirements of external preparations;the stability results showed that temperature and light had an effect on bergapten.Liposome gel has a certain degree of influence,suggesting that it should be stored in a low temperature and dark environment;the in vitro release results of the preparation show that bergapten gel and bergamot liposome gel are 12 h The cumulative release amounts were 47.09%and 54.48%,respectively,indicating that liposomes can increase the solubility of bergapten. |
PDF Full Text Request