Study On The Inhibitory Effect Of Salicylic Acid Microcapsule On Malassezia

Dandruff is a scalp condition that afflicts most people,and Malassezia is one of the main factors that cause dandruff production.Antifungal agents are commonly used to treat dandruff.However,the commonly used antifungal agents,including zinc pyrylium,pyrrolidone ethanolamine salt,etc.,are chemically synthesized,and are highly irritating,and even cause environmental pollution.Therefore,Salicylic acid(SA),as a natural antifungal agent,is increasingly popular.But using SA in water-soluble products directly will cause problems such as solubility,poor stability and precipitation.The microencapsulation of SA can solve this problem well,through the hydrophilic wall material(β-cyclodextrin)wrapping,not only can improve the solubility in water-soluble products,but also reducing the irritation.However,it is unknown whether the antibacterial properties of SA have changed as it is encapsulated in microcapsules.Therefore,in this thesis,the microencapsulated salicylic acid(SAM)was used as the subject of study,and Malassezia furfur was used as the test strain to study the inhibitory effect of SAM on Malassezia furfur,and SAM was used as an anti-dandruff agent to formulate a clear shampoo to study the basic physicochemical properties and actual bactericidal effect of the shampoo.The basic physicochemical properties and the actual bactericidal effect of the shampoo were investigated.The main findings of this thesis are as follows.1.Analysis of the encapsulation rate of SAM and the release effect in water.According to the standard curves of SA in anhydrous ethanol and deionized water obtained by UV method,the encapsulation rates of the prepared microcapsules with the core to wall ratio(SA:β-cyclodextrin)of 1:2.7 and 1:1 were 24.8% and 47.5%(i.e.SAM25 and SAM48),respectively.all reached more than 98%,and there was no significant difference among the three throughout the release time,indicating that microencapsulation would not affect the dissolution efficiency of SA.2.Changes in the antibacterial properties of SA and SAM.The results were investigated by commonly used in vitro antibacterial indicators,including minimum inhibitory concentration,minimum bactericidal concentration exposure time and bactericidal curve,etc.The results showed that: a)There was no significant difference in the antibacterial effect effect of SA and SAM25 and SAM48.The MICs of SAM25 and SAM48 against M.furfur were 2.5mg/m L and5.0mg/m L,respectively,and the MBC values were 2.5 mg/m L and 5.0 mg/m L,respectively.The SA content of the inner core material of the microcapsules was all 1.0 mg/m L,which was the same as the MIC value of SA.b)The growth curve trends of SA,SAM25 and SAM48 on M.furfur were basically the same.c)The dynamic bactericidal effect was positively correlated with the concentration of SAM25 and SAM48.3.The effects of SAM25 and SAM48 on the physiological characteristics of Malassezia furfur.The effects of SAM25 and SAM48 on the physiological characteristics of Malassezia were studied using cell membrane,cell wall and biofilm as indicators.The results showed that: a)After SAM25 and SAM48 treatment,a large amount of intracellular alkaline phosphatase,nucleic acid and protein leaked,indicating that the integrity of Malassezia cell wall and cell membrane permeability were damaged.b)Biofilm experiments showed that after SAM25 and SAM48 treatment,the biofilm formation of Malassezia was inhibited,and it was positively correlated with the concentration.4.Application of SAM48 in shampoo.A transparent shampoo was prepared with SAM48 as an anti-dandruff agent according to the basic formulation of transparent shampoo,and physicochemical property testing and microbiological experiments were conducted.The results indicated that: a)the physicochemical properties of the experimentally configured shampoo were all in accordance with national standards,and there was no significant difference with the commercially available shampoo.b)The dynamic sterilization experiment and the in vitro biological model experiment both indicated that the shampoo had good antidandruff effect and the microbial indexes were in accordance with the requirements.