ISSN : 1225-0112(Print)
ISSN : 2288-4505(Online)
ISSN : 2288-4505(Online)
Article : Characteristics of α-Tocopherol-loaded Nanostructured Lipid Carriers and their Stabilization Effect
Abstract
Loading of hydrophobic α-tocopherol into nanostructured lipid carrier (NLC) was performed for improving its oxidative stability. First, various NLCs with different constituents and mixing ratios were prepared and their characteristics were investigated. While the stable NLCs were made when cetyl palmitate (CP) or glyceryl monosterate (GMS) was used as a solid lipid, the phase separation occurred in the NLCs consisting of stearic acid. Particle sizes of the NLCs were several hundreds of nanometers and the size decreased with increasing the ratio of solvent to lipid. It was examined from DSC thermogram and anisotropy test that the degree of crystallinity of the lipid phase decreased and the lipid matrix became less ordered when octyldodecanol, a long chain fatty alcohol, was added into the solid lipid. The oxidative stability of α -tocopherol in NLC was remarkably improved compared to that in solution or emulsion under high temperature (45 ℃) and UV radiation, which was verified through DPPH test and peroxide value measurement.
α-Tocopherol을 함유한 Nanostructured Lipid Carriers의 특성과 안정화 효과
초록
지용성 토코페롤(α-tocopherol)의 산화 안정성을 높이기 위하여 nanostructured lipid carrier (NLC)에 봉입을 시도하였다. 먼저 구성 성분과 혼합 비율을 달리한 여러 NLC를 만들고 각각의 특성을 살펴보았다. 고체 지질로 세틸 팔미테이트또는 글리세릴 모노스테아레이트를 사용했을 때는 안정한 상태의 NLC 입자가 만들어지지만 스테아린 산으로 만든NLC에서는 상분리가 일어났다. NLC 입자는 수백 나노미터 크기로 만들어지는데 지질대비 용매의 비율이 높을수록입자크기가 작게 나타났다. 고급 지방알콜인 옥틸도데칸올을 고체 지질에 첨가하면 결정화도가 감소하면서 지질 매트릭스의 배열규칙성 이 약해짐을 DSC (Differential Scanning Calorimetry) 열차트와 anisotropy 측정을 통해서 확인하였다. 고온(45 ℃) 또는 UV 빛이 조사되는 조건에서 토코페롤이 NLC에 봉입되어 있으면 용액이나 에멀젼 상태로 있는 것에비해 산화 안정성이 크게 향상됨을 DPPH 테스트와 과산화물가 측정으로 확인하였다.