title: The research about microscopic structure of emulsion membrane in O/W emulsion by NMR and its influence to emulsion stability.
abstract: OBJECTIVE
  This paper discussed the influence of microstructure of emulsion membrane on O/W emulsion stability.
  
  
  METHODS
  O/W emulsions were emulsified with equal dosage of egg yolk lecithin and increasing dosage of co-emulsifier (oleic acid or HS15). The average particle size and centrifugal stability constant of emulsion, as well as interfacial tension between oil and water phase were determined. The microstructure of emulsion membrane had been studied by (1)H/(13)C NMR, meanwhile the emulsion droplets were visually presented with TEM and IFM.
  
  
  RESULTS
  With increasing dosage of co-emulsifier, emulsions showed two stable states, under which the signal intensity of characteristic group (orient to lipophilic core) of egg yolk lecithin disappeared in NMR of emulsions, but that (orient to aqueous phase) of co-emulsifiers only had some reduction at the second stable state. At the two stable states, the emulsion membranes were neater in TEM and emulsion droplets were rounder in IFM. Furthermore, the average particle size of emulsions at the second stable state was bigger than that at the first stable state.
  
  
  CONCLUSIONS
  Egg yolk lecithin and co-emulsifier respectively arranged into monolayer and bilayer emulsion membrane at the two stable states. The microstructure of emulsion membrane was related to the stability of emulsion.
authors.affiliation: Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China. Electronic address: 15002013083@163.com.
authors.forename: Yiqiao
authors.initials: Y
authors.lastname: Xie
authors.affiliation: Department of Pharmacy, First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China. Electronic address: cjslym@163.com.
authors.forename: Jisheng
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China. Electronic address: zzss_97@163.com.
authors.forename: Shu
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China. Electronic address: 412787243@qq.com.
authors.forename: Kaiyan
authors.initials: K
authors.lastname: Fan
authors.affiliation: Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China. Electronic address: cg753@126.com.
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
authors.affiliation: Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China. Electronic address: 1091318015@qq.com.
authors.forename: Zerong
authors.initials: Z
authors.lastname: Zhuang
authors.affiliation: Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China. Electronic address: 378156445@qq.com.
authors.forename: Mingying
authors.initials: M
authors.lastname: Zeng
authors.affiliation: Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China. Electronic address: 496806331@qq.com.
authors.forename: De
authors.initials: D
authors.lastname: Chen
authors.affiliation: Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China. Electronic address: 215496932@qq.com.
authors.forename: Longgui
authors.initials: L
authors.lastname: Lu
authors.affiliation: Guangdong Province Maternity and Child Care Hospital, Guangzhou, Guangdong 510006, China. Electronic address: Fy_yanglinlinlin@126.com.
authors.forename: Linlin
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China. Electronic address: gzyangfan@hotmail.com.
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
mesh_terms: D001896:Boron Compounds / Q000737:chemistry; D066241:Carbon-13 Magnetic Resonance Spectroscopy; D045703:Emulsifying Agents / Q000737:chemistry; D004655:Emulsions / Q000737:chemistry*; D006575:Heterocyclic Compounds, 3-Ring / Q000737:chemistry; D054709:Lecithins / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D019301:Oleic Acid / Q000737:chemistry; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry; D066244:Proton Magnetic Resonance Spectroscopy; D013024:Soybean Oil / Q000737:chemistry; D013229:Stearic Acids / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: C560998:BODIPY-PC; D001896:Boron Compounds; D045703:Emulsifying Agents; D004655:Emulsions; D006575:Heterocyclic Compounds, 3-Ring; D054709:Lecithins; D013229:Stearic Acids; D014867:Water; D019301:Oleic Acid; D011092:Polyethylene Glycols; C067028:Solutol HS 15; D013024:Soybean Oil
keywords: (1)H NMR/(13)C NMR spectroscopy; Emulsion membrane; Microscopic structure; O/W emulsion; Stability