Schott H
School of Pharmacy, Temple University, Philadelphia, PA 19140, USA.
J Pharm Sci. 1995 Oct;84(10):1215-22. doi: 10.1002/jps.2600841014.
The following three parameters describing the balance between the hydrophilicity of the polar moieties and the lipophilicity of the hydrocarbon moieties of nonionic surfactants are tabulated and examined: hydrophilic-lipophilic balance (HLB), oil-water partition coefficient (KWO), and a solubility parameter (delta O) modified to take into account hydrogen bonding between water and the ether and hydroxyl groups of the surfactants. The purpose of the study is to ascertain whether these parameters are universal properties applicable to different categories of nonionic surfactants. Included were the following five nonionic surfactant categories or homologous series, comprising a total of 51 surfactants for which KWO values are available: octoxynols, nonoxynols, polyoxyethylated linear alcohols and dodecylamines, and sorbitan monoesters. The HLB of each homologous surfactant series gave a nearly linear correlation with log KWO. However, the five lines were spread far apart rather than falling on a single master curve. Therefore, the HLB is not a universal property, because it is based exclusively on the weight-percent of polyoxyethylene or polyol in the surfactant molecule while disregarding its molecular weight, the chemical nature of its hydrophilic and lipophilic moieties, and the structural features of the latter. These characteristics are taken into account when computing delta O. The correlation between the 51 experimental log KWO values and their calculated delta O is linear, with a regression coefficient of 0.902. Moreover, it is possible to estimate the KWO value of a nonionic surfactant (which is difficult to determine experimentally) from its delta O value (which is readily calculated) within a 95% confidence limit. Our conclusion, subject to continuing reappraisal as additional KWO values become available, is that delta O is a universal property applicable to all categories of nonionic surfactants.
亲水亲油平衡（HLB）、油水分配系数（KWO）以及考虑到水与表面活性剂醚基和羟基之间氢键作用而修正的溶解度参数（δO）。本研究的目的是确定这些参数是否为适用于不同类非离子表面活性剂的通用性质。研究中包括以下五个非离子表面活性剂类别或同系物系列，共有51种可获得KWO值的表面活性剂：辛氧基醇、壬氧基醇、聚氧乙烯化直链醇和十二烷基胺，以及脱水山梨醇单酯。每个同系表面活性剂系列的HLB与log KWO呈现出近乎线性的相关性。然而，这五条线分布得很分散，而非落在一条主曲线上。因此，HLB不是一个通用性质，因为它仅基于表面活性剂分子中聚氧乙烯或多元醇的重量百分比，而忽略了其分子量、亲水和亲脂部分的化学性质以及后者的结构特征。在计算δO时考虑了这些特性。51个实验log KWO值与其计算得到的δO之间的相关性呈线性，回归系数为0.902。此外，在95%置信限内，可以从非离子表面活性剂的δO值（易于计算）估计其KWO值（实验测定困难）。我们的结论是，δO是适用于所有类非离子表面活性剂的通用性质，但随着更多KWO值的获得，仍需持续重新评估。
