1. 안승준, 임윤택 Droplet-Size Dependent Solubilization and Crystallization of Lipids in Oil-in-Water Emulsion

2. 발표순서 Introduction Materials and Methods( Materials, Solubilization, Crystallization) Results and Discussion

3. Introduction Oil-in-water(O/W) : 수중유적형 ; 분산매인 물 속에 기름이 가는 입자모양으로 분산되어 있는 형태 Emulsion : 콜로이드 분산계 중에서 분산매와 분산상이 모두 액체인 것

4. Oil-in-water(O/W) emulsion and microemulsion have been investigated as an advanced delivery tool of pharmaceutical, cosmetic and food materials having water-insoluble and oil soluble properties. This is because the O/W emulsion droplets are expected to exhibit multiple functions such as controlled release and high bioavailability. In particular, much attention has been paid to highly solubilized lipophilic materials in the O/W emulsion droplets High solubilization is critically important for the oil droplets having diameters around 100nm, since such droplets are new tools of delivery systems in nanotechnology applicable to food, cosmetics and phamaceutical industries.

5. We measured the rate and extent of solubilization and crystallization of lipids(long-chain fatty acids; lauric, myristic, and palmitic acids) in oil-in-water emulsion with average oil droplet diameters of 120nm, 170nm, and 220nm.

6. Materials Three fatty acids : lauric, myristic, and palmitic acids Nanometer-sized emulsions Dispersed oil phase : Soybean oil + Canola oil mixture Continuous phase : Distilled water Emulsifier : Polyglycerine fatty acid ester, Decaglycerine monostearate Emulsion samples D~120±30nm(oil droplets); O-W-E = 20-70-10, 200MPa D~170±30nm; O-W-E = 20-75-5, 138MPa D~220±30nm; O-W-E = 20-77-3, 100MPa Emulsification : High-pressure homogenizer(DeBEE 2000) Droplet size : ELS 8000, Dynamic light-scattering methods

8. Scattering 빛의 파동이 원자에 가해지면 원자는 진동에너지를 얻음 생성된 진동에너지는 안정화되기 위해 모든 방향으로 진동을 전달 이러한 현상을 scattering 이라고 함 Dynamic Light Scattering(DLS) 분자 또는 입자의 크기를 측정하기 위한 기술 확산율은 입자 크기에 비례

9. Solubilization Fatty acid(2g) + Emulsion sample(40g) ↓ Stirring; 200rpm ↓ Weight up to 48hours Solubilization Quantity, % Weight of fatty acid( after Vaccum filtration) / Total weight of FA Solubilization Temperature 15 ℃, 25 ℃, 35 ℃ for Lauric acid(melting point, 35 ℃ ) 25 ℃, 35 ℃, 45 ℃ for Myristic acid(melting point, 54 ℃ ) 35 ℃, 45 ℃, 55 ℃ for Palmitic acid(melting point, 63 ℃ )

10. Crystallization DSC by synchrotron radiation X-ray diffraction(SR-XRD) DSC cooling and heating thermopeaks Thermoplus 8240(Rigaku, Tokyo) Cooling : 50 ℃ to 0 ℃ Heating : 0 ℃ to 50 ℃

11. Result & Discussion

12. Solubilization quantity in emulsion

13. Result - Oil concentration Purpose - Find out the optimum condition of oil concentration Basic condition - 35 ℃, 5 hours Oil droplet-size - 120nm, 170nm, 220nm Oil concentration - 1%, 2%, 3%, 4%, 5%

14. Result - Oil concentration ① Oil droplet-size decreased ② Oil concentration increased

15. Result - Time Purpose - Find out the optimum condition of oil solubilization time Basic condition - 35 ℃, oil concentration (5%) Oil droplet-size - 120nm, 170nm, 220nm Oil solubilization time - 0hr, 12hr, 24hr, 36hr, 48hr

16. Result - Time

19. Common properties The solubilized quantity ① rapidly increased at it started ② decreased 0hr to 12hr and it remained to 48hr ③ increased when drop-size decreased ④ decreased when melting point of fatty acid increased

20. Compare with emulsion and bulk oil

21. Thermodynamic solubility ① correspond to Bulk oil ② do not correspond to Emulsion Since, the O/W emulsion is not thermodynamically stable

22. Result - Thermodynamic solubility Purpose - Find out correlation of solubilized quantity for the case of emulsion Oil droplet-size in emulsion - 120nm, 170nm, 220nm Temperature - Lauric acid (15 ℃, 25 ℃, 35 ℃ ), myristic acid (25 ℃, 35 ℃, 45 ℃ ), Palmitic acid (35, 45, 55) Solvent - Bulk oil, Emusion

23. Result - Thermodynamic solubility When the droplet-size deceased ① fatty acid solubility increased in emulsion ② correspond to thermodynamic solubility

24. Result - Crystallization Purpose - Find out crystallization difference between bulk oil and emulsion Oil droplet-size - 120nm Temperature - 0 ℃ to 50 ℃ Solvent - Bulk oil, Emusion

25. Result - Crystallization Crystallization in Bulk oil - Crystallization of lauric acid appeared at 29.7 ℃ Emulsion - Crystallization of lauric acid appeared at 12.1 ℃ Crystallization of lauric acid was remarkbly retarded in emulsion

26. Result – The SR-XRD patterns - Crystallization occurred at 12 ℃ - Polymorphic form was C form - The WAXS pattern of 0.41 nm and SAXS pattern of 2.7 nm - Melted at 34 ℃

27. conclusion Nano-meter size emulsion droplets ① increased solubility ② thermodynamically stable ③ decreased crystallization rate

28. conclusion The reason why … ① In the oil phase ② At the emulsion membrane surface Droplet-size Droplet & micelle Solubility

29. Thank you for your attention!