| Acne is a chronic inflammatory disease of the hair follicles and sebaceous glands.It has a high incidence in adolescence and often occurs in areas with strong sebum secretion on the cheeks,chest and back.The pathogenesis of acne is complicated,but it is closely related to the microorganisms living in the sebaceous glands of the hair follicles on the skin.Propionibacterium acnes(P.acnes)is the pathogen of acne and plays an important role in the pathogenesis of acne;Staphylococcus epidermidis(S.epidermidis)can aggravate the inflammatory response of acne and participate in the pathogenesis of acne.At present,antibiotics and tretinoin are commonly used to treat acne,but long-term use has the disadvantages of drug resistance and strong side effects.This topic screened the natural plant essential oil formula with antibacterial effect on acne pathogenic bacteria through in vitro antibacterial test,and studied its anti-P.acnes action mechanism.On this basis,it is made into liposome gel.Glue,which overcomes the shortcomings of essential oils such as easy oxidation,instability,and low water solubility.In the selection of the formula,use the filter paper antibacterial method to determine 8 kinds of plant essential oils with antibacterial effect(clove essential oil,bergamot essential oil,eucalyptus essential oil,lavender essential oil,mugwort essential oil,citrus aurantium essential oil,turmeric essential oil,chuanxiong essential oil)Two kinds of pathogenic bacteria that cause acne: P.acnes and S.epidermidis were used to determine the antibacterial effect,and the two essential oils with the best antibacterial effect were screened out;the two essential oils were compounded in different proportions to determine the compound ratio;The test tube serial dilution method was used to determine the minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)of compound essential oil,bergamot essential oil,and clove essential oil on P.acnes and S.epidermidis.Results: Bergamot essential oil and clove essential oil have the best antibacterial effect.It is determined that the compound essential oil is mixed with(bergamot:clove = 1:3),the combination of essential oils has a synergistic effect;the compound essential oil has the best inhibitory effect on P.acnes and S.epidermidis.The combination of a variety of essential oils can enhance the antibacterial effect.In the study of the antibacterial mechanism of BCEO on P.acnes,the main pathogenic bacteria of acne that is selected to explore the dynamic antibacterial effect of BCEO on P.acnes.Scanning electron microscope(SEM)is used to observe the morphological change process of P.acnes.Determination of alkaline phosphatase(AKP)activity and determination of extracellular nucleic acid content.The effect of BCEO on the cell wall and cell membrane of P.acnes is judged,the growth of bacterial biofilm is judged by crystal violet staining,and the changes of bacterial protein are analyzed by SDS-PAGE.Results:Under the action of BCEO,the bacteria caused the increase of bacterial AKP enzyme activity,the increase of extracellular nucleic acid content,the decrease of bacterial biofilm formation,the decrease of total intracellular protein content,the rough surface of the bacteria,cell rupture and other phenomena observed by SEM,which significantly affected Growth and metabolism of P.acnes.In order to improve the stability of essential oils,BCEO is made into liposome gels.First,the thin film dispersion-high pressure homogenization method is used to prepare BCEO liposomes,and the encapsulation rate is used as the evaluation index.The preparation process is optimized by orthogonal experiment and the optimal preparation process was determined as follows: weigh 240 mg egg yolk lecithin,40 mg cholesterol and 80 mg Add appropriate amount of chloroform to dissolve the essential oil of Buddha,add 20 m L of PBS(p H 8.0)to form a thin film,add 20 m L of PBS(p H 8.0),rotate the thin film at 45° C for 20 min,ultrasonic in a water bath for 20 min,and then pass the resulting suspension through a high-pressure homogenizer 80 MPa cycle homogenization for 120 s,it is obtained.The appearance of the obtained BCEO liposomes is a creamy yellow suspension.Observed by transmission electron microscope(TEM),the liposomes are spherical and are not adhere on the surface;the encapsulation efficiency of the representative components D-limonene and eugenol The values are 64.22 ± 0.70% and 84.30 ±0.41% respectively;the particle size is 178±2.05 nm and presents a single peak state,the distribution is uniform,the PDI is 0.18±0.02,the system is stable,and the Zeta potential is-32±0.89 m V,showing a negative charge;Pharmacopoeia of the People’s Republic of China(2020 edition)carried out the detection of organic reagent residues,which showed that there are no chloroform residues in the liposomes;differential scanning calorimetry and infrared spectroscopy showed that the essential oils are encapsulated in the liposomes;The in vitro release rate showed that the 24 h cumulative release rate of eugenol in the essential oil liposome solution was lower than the 24 h cumulative release rate of eugenol in the essential oil solution,without sudden release,and its in vitro release behavior conformed to the first-order kinetic model;preliminary stability investigation,Which shows that the liposomes of Buddha’s fragrance oil have good short-term stability.The liposome is further prepared into a gel by the direct swelling method,and the comprehensive score of the appearance,p H,water loss,and stability of the gel is used as the index.The preparation process is optimized by the orthogonal test,and the optimal process is determined as: Weigh 0.375 g carbomer and add it to 20 g BCEO liposomes to swell overnight,then use a high-speed dispersing homogenizer3000r/min,homogenize for 2 minutes,add 3.75 g propylene glycol,and then add0.125 g triethanolamine,0.1g Methyl 4-hydroxybenzoate,add water to 30 g,stir evenly to obtain.The quality of liposome gel was evaluated,and the appearance,viscosity,p H value and particle size of the gel were all in line with the relevant regulations of Pharmacopoeia of the People’s Republic of China for the 2020 version of the gel;the in vitro transdermal and skin retention test results showed that The permeation rate of the essential oil liposome gel is lower than that of the BCEO gel,and the liposome gel exhibits a slow release.At the same time,the skin retention of the BCEO liposome gel is greater than that of the essential oil gel,which prolongs the essential oil.Retention time in the skin;establish a content determination method,stipulating that the BCEO gel contains not less than 0.256 mg of D-limonene and eugenol not less than 0.658 mg per 1g;preliminary stability test results show that the BCEO liposomes The gel is relatively stable and meets quality standards.This topic screens out the compound essential oil formula with better antibacterial effect,and conducts a preliminary study on its antibacterial mechanism.The preparation process and quality evaluation research show that the Buddhaxiang liposome gel process is feasible,the quality is controllable,and the improvement The stability of essential oils lays the foundation for the development of new anti-acne products. |
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