School of Pharmacy, International Medical University, 57000, IMU Bukit Jalil, Kuala Lumpur, Malaysia.
J Nanobiotechnology. 2013 Aug 1;11:27. doi: 10.1186/1477-3155-11-27.
Palm oil esters (POEs) are esters derived from palm oil and oleyl alcohol have great potential in the cosmetic and pharmaceutical industries due to the excellent wetting behavior of the esters without the oily feel. The role of oil-in-water nanoemulsions loaded with tocotrienol sedimentation behavior was studied. LUMiFuge® 116 particle separation analyzer was used to investigate the sedimentation behavior of POEs/tocotrienol/xanthan gum nanoemulsion system during centrifugation. Analyzing the sedimentation kinetics of dispersions in a centrifugal field also yields information about the rheological behavior and structural stability.
Experiments were performed in an analytical centrifuge at 11 × g to 1140 × g (LUMiFuge® 116 particle separation analyzer). The samples in the LUMiFuge® 116 particle separation analyzer were centrifuged at 3000 rpm for 15 h at 32°C. Sample volume of 2 cm3 was used. The rheological property of nanoemulsions was investigated using oscillatory measurements test. A rotational/oscillatory viscometer, Kinexus Rheometer (Malvern Instrument, UK) was used. All measurements were performed with a stainless steel cone-plate sensor at 25.0 ± 0.1°C with 4°/40 mm.
The stable nanoemulsions showed sedimentation rates at earth gravity of 5.2, 3.0 and 2.6 mm/month for 10%, 20% and 30% (w/w) oil phase, respectively. Rheological behavior is an important target during the design of palm oil esters-based nanocosmeceuticals. The presence of a network structure was indicated by measurements which showed G' to be greater than G". This result implied the predominant elastic response and high storage stability of the nanoemulsion. It was also observed that the increase in oil phase concentration led to the profile which strongly indicated that the solid like elastic property; where the values of phase angle, δ of these nanoemulsions was lower than 45°.
The nanoemulsions with higher oil phase concentration (30% (w/w)) showed greater elasticity which implied strong dynamic rigidity of the nanoemulsion. It was the most stable with longest shelf-life.
棕榈油酯（POEs）是由棕榈油和油醇衍生而来的酯，由于酯具有出色的润湿性能而没有油腻感，因此在化妆品和制药行业具有巨大的潜力。本文研究了负载生育三烯酚的油包水纳米乳液的沉降行为。采用 LUMiFuge® 116 颗粒分离分析仪研究了 POEs/生育三烯酚/黄原胶纳米乳液体系在离心过程中的沉降行为。分析分散在离心场中的沉降动力学还可以提供关于流变行为和结构稳定性的信息。
在 11×g 至 1140×g（LUMiFuge® 116 颗粒分离分析仪）的分析离心机中进行实验。在 LUMiFuge® 116 颗粒分离分析仪中，将样品在 32°C 下以 3000rpm 离心 15 小时。使用 2cm3 的样品体积。使用振荡测量试验研究纳米乳液的流变性质。使用 Kinexus Rheometer（Malvern Instrument，英国）旋转/振荡粘度计进行所有测量。所有测量均在 25.0±0.1°C 下使用不锈钢锥板传感器进行，锥板角度为 4°/40mm。
稳定的纳米乳液在地球重力下的沉降速率分别为 5.2、3.0 和 2.6mm/月，油相浓度分别为 10%、20%和 30%（w/w）。流变行为是设计基于棕榈油酯的纳米化妆品时的一个重要目标。测量结果表明 G'大于 G"，表明存在网络结构。这一结果暗示了纳米乳液具有主要的弹性响应和高储存稳定性。还观察到油相浓度的增加导致了图谱，强烈表明具有固体弹性性质；这些纳米乳液的相角δ值低于 45°。
油相浓度较高（30%（w/w））的纳米乳液表现出更大的弹性，这意味着纳米乳液具有较强的动态刚性。它是最稳定的，保质期最长。
