สำนักราชบัณฑิตยสภา

95 Jaruwan Krongsin, Roongkan Nuisin, Supaporn Noppakundilograt, Suda Kiatkamjornwong วารสารราชบัณฑิตยสถาน ปีที่ ๓๗ ฉบับที่ ๔ ต.ค.-ธ.ค. ๒๕๕๕ can be used to form microcapsules, prevent loss of volatile flavors, and enhance stability of the core flavoring materials. 4 The microcapsules are stable during the release time. Kiatkamjornwong et al. 6 successfully prepared the chitosan microcapsules having 0.5-40 µm in diameter by the conventional stirring method in which chitosan is the shell of microcapsules encapsulating the core material of menthol. The size distribution of the conventional method is rather polydisperse and thus a better technique of porous glass membrane emulsification can remedy the large size distribution to a narrow size distribution of microcapsules. 7-10 In this study, the SPG membrane emulsification method was applied to prepare sodium tripolyphosphate crosslinked chitosan shell encapsulating the core material of menthol. Rheological behaviors of the chitosan microcapsules were studied in order to apply them as an active ingredient for a leave-on hair conditioner. The hair treated with the hair conditioner was characterized and analyzed. MATERIALS AND METHODS Materials Chitosan (Sea Fresh Chitosan Lab Co., Ltd., Bangkok, Thailand) with a degree of deacetylation of 95% and a viscosity-average molecular weight ( V Μ ) of 100,000 g/mol was used as received. Sodium tripolyphosphate (TPP, Merck, Höhenbrunn, Germany) was used as a crosslinker. Light mineral oil (Hopewell International Co., Ltd., Bangkok, Thailand) was used as an oil phase. Menthol with a molecular weight of 156.27 g/mol (Hong Huat Co., Ltd., Bangkok, Thailand) was used as a core material during encapsulation. Poly(oxyethylene-2-stearyl ether) (Brij 72, Greensville Co., Ltd., Bangkok, Thailand) was used as an oil-soluble surfactant. Sodium dodecyl sulfate (SDS, Merck KGaA, Darmstadt, Germany) and cetyl stearyl alcohol (Kao Co., Ltd., Bangkok, Thailand) were used as a surfactant and a co-surfactant, respectively. Poly(vinyl alcohol) (PVA-220, Kuraray Co., Ltd., Tokyo, Japan) with 87-89% of hydrolysis degree and viscosity of 27.0-34.0 mPa s was used as a stabilizer. For the leave-on conditioner preparation, cetearyl alcohol (Kao Industrial, Bangkok, Thailand), and ceteareth-20 (Honghuat, Bangkok, Thailand) were used as a thickening agent. Dipalmitoylethyl hydroxyethylmonium methosulfate (Shanghai Green Leaf Perfumery Co., Ltd., Shanghai, China) was used as a softener. 1,3-Bis(hydroxymethyl)- 5,5-dimethylimidazolidine-2,4-dione or glydant (Honghuat, Bangkok, Thailand) was used as a preservative. OriginPro 8 (OriginLab Corporation, MA, USA) was used as a tool for estimating the flow area of each material: microcapsule emulsion, conditioner base and leave-on conditioner.