核磁共振法测定非离子表面活性剂HLB值的研究 1.Span和Tween类及其混合物

本文用核磁共振法研究了制剂中常用的 Span 类与 Tween 类以及混合时 HLB 值的测定,建立了求算 HLB 值的方程式:HLB=18.24R+1.80,式中 R=(ΣH_((W))/(ΣH_((W))+ΣH_((0))),该式对此类单一的和混合的非离子表面活性剂都适用。此方法快速,无破坏性,需样品量少。     

无患子皂苷HLB值的化学计算

本文通过无患子皂苷化学结构的表面活性分析,采用Davies法计算了无患子皂苷A的亲水亲油平衡值（Hydrophile-Lipophile Balance Number。HLB值）．首次提出了无患子皂苷A的HLB值为1．6,为无患子皂苷的研究与开发提供了可靠的理论依据。     

乳化剂HLB值对莪术油亚微乳理化性质的影响

目的制备莪术油亚微乳,并考察乳化剂的HLB值对亚微乳理化性质的影响。方法使用高压微射流纳米分散仪制备含不同HLB值乳化剂的莪术油亚微乳;激光粒度及电泳分析仪测定其粒径和表面电位;离心法测定其稳定常数;测定药物在不同HLB值乳化剂的水相中的溶解度,并采用透析法测定亚微乳的体外释放。结果制备得到的莪术油亚微乳粒径在123～154nm之间,粒子带负电。几种乳化剂对药物均有明显的增溶作用,增溶倍数从5.5～8.2倍不等,载药亚微乳的体外释放符合Higuchi方程,且能持续释放48h。结论乳化剂的HLB值不同,制备得到的亚微乳的性质如粒径和稳定性有所不同;随着HLB值增加,乳化剂对药物的增溶作用增强,药物从亚微乳中释放略有加快。     

应用交叉法计算乳化剂 HLB 值

在乳剂生产中,为得到所需的HLB 值,通常用药剂学中的方法进行计算。即:     

HLB值与有机概念图理论在乳膏剂处方设计中的互补应用

依ＨＬＢ值理论设计肤轻松霜处方Ⅰ，结合有机概念图理论对处方Ⅰ中的相组分进行量比调整后，改良为处方Ⅱ。经物理稳定性比较实验，结果显示，处方Ⅱ显著优于处方Ⅰ。     

精制蛋黄卵磷脂亲水-亲油平衡值测定及其在鸦胆子油乳注射液中的应用

目的以亲水-亲脂平衡值为指标考察精制蛋黄卵磷脂在水中和油中的分散特性并研究其在鸦胆子油乳注射液中的应用。方法采用核磁共振波谱(NMR)法,根据其化学位移值及亲水基团与亲油基团质子数相对比值(R)计算亲水-亲脂平衡值。结果精制蛋黄卵磷脂在水中具有良好的分散性。结论可用精制蛋黄卵磷脂代替豆磷脂作乳化剂制备鸦胆子油乳注射液。     

应用双叉法计算两种乳化剂的合用量及HLB值

凡具有乳浊分散系统的制剂必须添加乳化剂,但是乳化剂的选用必须与乳剂的使用目的、要求、类型和药物的性质相适应,并应选择无配伍禁忌的混合乳化剂(两种以上)的效果较用一种为好。虽然文献对混合乳化剂的合用量及其HLB 值的计     

系数倍率导数光谱法和等导数值导数光谱法测定息热痛注射液中盐酸异丙嗪和对乙酰氨基酚

本文提出了系数倍率导数光谱法和等导数值导数光谱法用于混合组分体系测定的基本原理和实验方法。并试用本法消除盐酸异丙嗪、对乙酰氨基酚,维生素C及附加剂之间的相互干扰,从而分别测定了息热痛注射液中的盐酸异丙嗪、对乙酰氨基酚的含量,其平均回收率分别为:99.99±0.53%(CV)和99.84±0.91%(CV)。其精密度、准确度均较满意。     

血浆纤维蛋白原检测测定值与计算值的比较分析

目的探讨纤维蛋白原测定值与计算值的差异。纤维蛋白原的测定方法有多种,大体分为3种,即①凝血酶作用形成纤维蛋白法;②物理化学法;③免疫学测定法。在全自动血凝分析仪中,我们为了简单、快速、经济,又经常在测定PT值的同时经过演算导出FBG值作为FBG的检测值。在实际工作中FBG实测值与演算值是不完全相符合的,应当引起重视。方法随机抽取FBG值正常人群50例,纤维蛋白原值FBG<2mg/L人群23例,纤维蛋白原值FBG>4mg/L人群67例;分别配对作PT、FBG测定,并通过PT曲线演算出FBG值,然后统计分析之间的差异性得出统计学结论。结果 PT值与FBG值无关,P<0.01;FBG值在正常参考区间2~4mg/L组,FBG计算值与测定值无显著性差异,P>0.05;FBG<2mg/L组,有显著性差异,P<0.01;计算值偏低;FBG>4mg/L组,有显著性差异,P<0.01;计算值偏高。结论血凝自动分析仪纤维蛋白原Clauss法检测值在2~4mg/L范围内,计算值与实测值无差异,可以用此方法计算出FBG值;当FBG<2或FBG>4mg/L时,有显著性差异,P<0.01;不能用计算方法得出FBG值,必须实测方能真实准确反应纤维蛋白原水平。     

密切值法在水质变化趋势评价中的应用

水质动态变化趋势综合评价的方法很多 ,但目前还没有一种很成熟的标准方法。为此 ,笔者参考文献 [1]的方法原理 ,试用密切值法对某水厂水源水质动态变化趋势进行了综合评价探讨 ,现介绍如下。1　原理与方法密切值法是系统工程的一种优选方法。它适用于正向指标体系 ,对负向指标则要求将其转化为正向指标。应用时先确定各评介指标的“最优点”与“最劣点”,然后计算各评价单元与“最优点”、“最劣点”的距离 ,根据密切值大小确定各评价单元综合质量的优劣顺序。1.1　原理数据处理1.1.1　计算统计值 Cij　按姚志麒水质指数法中的 Cij=Xmax.…     

The influence of HLB on the encapsulation of oils by complex coacervation

Abstract

Microcapsules are used for the formulation of drug controlled release and drug targeting dosage forms. Encapsulated hydrophobic drugs are often applied as their solutions in plant oils. The uptake of the oils in the complex coacervate microcapsules can be improved by the addition of surfactants. In this study, soybean, olive and peanut oils were chosen as the representatives of plant oils. The well characterized complex coacervation of gelatin and acacia has been used to produce the microcapsules. The amount of encapsulated oil has been determined gravimetrically. The encapsulation of the oils was high (75–80%). When the surfactants with HLB values from 1.8 to 6.7 were used, the amount of encapsulated oil was high (65–85%). A significant decrease of the oil content in the microcapsules was found when Tween 61 with HLB = 9.6 had been added into the mixture. No oil was found inside the microcapsules from the coacervate emulsion mixture containing Tween 81 (HLB = 10) and Tween 80 (HLB = 15), respectively. The results of the experiment confirm the dependence of hydrophobic substance encapsulation on the HLB published recently for Squalan     

Assessment of the percutaneous penetration of indomethacin from soybean oil microemulsion: effects of the HLB value of mixed surfactants

The objective of this study was to evaluate the influence of the ratios or the hydrophile-lipophile balance (HLB) values of Cremophor EL and Span 80 on the phase behavior of the O/W microemulsions and the percutaneous absorption and penetration of indomethacin microemulsions. The existence of microemulsion regions is investigated in quaternary systems composed of soybean oil/Cremophor EL and Span 80 (mixed surfactants)/diethylene glycol monoethyl ether (cosurfactant)/water by constructing pseudo-ternary phase diagrams at various Cremophor EL/Span 80 ratios. In addition, five microemulsion formulations with various mixed surfactants HLB values were evaluated by in vitro penetration experiments using mouse skin and Franz diffusion cells. The flux and amount of indomethacin penetration from 5 microemulsion formulations were significantly different from the control, and the enhance ratios ranged from 2.38 to 4.68 and 2.11 to 4.23, respectively. The HLB value of mixed surfactants in the formulations was a principal factor in determining the percutaneous penetration of the drug. The flux and amount of drug penetration increased gradually with increasing content of the lipophilic surfactant Span 80 and skin retention was highest for mixed surfactants with a HLB value of 7.6. Therefore, it is suggested that the presence of mixed surfactants was beneficial in the formation of O/W microemulsions and enhanced percutaneous penetration of indomethacin.     

Determination of the required HLB values of some essential oils

The required HLB values of eucalyptus, lippia and peppermint essential oils were determined using droplet size analysis and turbidimetric method on emulsions prepared with emulsifier blends of varying HLB values. The percentage increase in mean droplet diameter and the degree of dispersion of droplet sizes were determined before and after centrifugation of the emulsions. The HLB value of the emulsion with the least dispersion ratio or the least percentage increase in mean droplet diameter was taken as the required HLB of the respective essential oil. The turbidimetric method was validated by the existence of correlation (r=-0.958) between the mean droplet diameter and the turbidity of the emulsions. The turbidity curve went through a maximum at the HLB value where the mean droplet diameter was least. Based on these methods, the required HLB values of eucalyptus, lippia and peppermint oils were determined as 9.8, 12.1 and 12.3, respectively (P<0.05). Liquid paraffin was used as a reference standard and its required HLB fell within literature value.     

Chemoprevention of skin cancer using low HLB surfactant nanoemulsion of 5-fluorouracil: a preliminary study

Abstract

Oral delivery of 5-fluorouracil (5-FU) is difficult due to its serious adverse effects and extremely low bioavailability. Therefore, the aim of present investigation was to develop and evaluate low HLB surfactant nanoemulsion of 5-FU for topical chemoprevention of skin cancer. Low HLB surfactant nanoemulsions were prepared by oil phase titration method. Thermodynamically stable nanoemulsions were characterized in terms of droplet size distribution, zeta potential, viscosity and refractive index. Selected formulations and control were subjected to in vitro skin permeation studies through rat skin using Franz diffusion cells. Optimized formulation F9 was subjected to stability and in vitro cytotoxic studies on melanoma cell lines. Enhancement ratio was found to be 22.33 in formulation F9 compared with control and other formulations. The values of steady state flux and permeability coefficient for formulation F9 were found to be 206.40?±?14.56?µg?cm^?2?h^?1 and 2.064?×?10^?2?±?0.050?×?10^?2?cm?h^?1, respectively. Optimized formulation F9 was found to be physical stable. In vitro cytotoxicity studies on SK-MEL-5 cancer cells indicated that 5-FU in optimized nanoemulsion is much more efficacious than free 5-FU. From these results, it can be concluded that the developed nanoemulsion might be a promising vehicle for chemoprevention of skin cancer.     

Effect of surfactant HLB and different formulation variables on the properties of poly-D,L-lactide microspheres of naltrexone prepared by double emulsion technique

The aim of this work was to investigate the role of HLB of emulsifier as well as volume of the internal aqueous phase (W(1)) and presence of salt in the external aqueous phase (W(2)) on the morphology, size and encapsulation efficiency of poly(D,L-lactide) microspheres containing naltrexone HCl. PLA microparticles containing naltrexone HCl, an effective opiate antagonist, were prepared by a water-in-oil-in-water emulsification-solvent evaporation procedure. One of the five different emulsifiers: span 80, span 20, tween 85, tween 80 and tween 20, with HLB values from 4-17 were added to W(1). Presence of emulsifier in W(1) resulted in smaller particles with a more dense and uniform internal structure. Incorporation of span 80 (HLB 4.3, suitable for W/O emulsions) yield the highest encapsulation efficiency. Increasing the HLB value to 8 or 11 (span 20 or tween 85) decreased the efficiency of naltrexone HCl-loading. HLB values higher than 15 (tween 80 or tween 20) increased encapsulation efficiency unexpectedly, which could be attributed to migration of these emulsifiers to the O/W(2) interface and modifying the surface properties of microparticles. Increasing the internal water phase volume from 0.2-1.8 ml resulted in larger particle size with poor encapsulation efficiency. Addition of 10% w/w NaCl to the W(2) changed the surface morphology of microspheres from a porous form to a smooth surface. It was shown that, by selecting the appropriate HLB value of emulsifier in W(1), addition of salt to W(2) and controlling the volume of W(1), one can control the encapsulation efficiency, size and morphology of microspheres.     

抗癌药物FT-207脂肪乳剂物理性质的研究

本文对抗癌药物FT-207脂肪乳剂的制备及物理性质进行了研究。建立了乳剂物理稳定性新的评价方法。考查了乳化剂浓度、HLB值、FT-207浓度对乳剂稳定性的影响。测定了乳剂的粒度分布及乳剂的电位等物理性质。研究得到精制豆油乳化所需最佳HLB值为15.4,乳剂中分散液滴的平均粒径为1.0μm.     

Some considerations about the hydrophilic-lipophilic balance system

The methods and results obtained by Griffin et al. in the determination of the hydrophilic-lipophilic balance (HLB) values of non-ionic surfactants and of required HLB values of oil mixtures are reviewed in the present work. HLB values published by Griffin were compared with those obtained by calculations from theoretic chemical formulas. Griffin HLB values of polyoxyethylene alkyl ethers, polyoxyethylene monoesters and propylene glycol monoesters coincide with those obtained from such theoretical chemical formulations. These results demonstrate that, for these surfactants, Griffin did not experimentally obtain their HLB values, but instead calculated them from theoretic formulae. For the calculation of the HLB values of glycerol monostearate, sorbitan fatty acid esters and polyoxyethylene sorbitan fatty acid esters, Griffin's assumptions were possibly based upon the mean saponification values of the ester and the acid of the fatty acid. It is concluded that the HLB values of non-ionic surfactants were not rigorously defined. Moreover, Griffin could not demonstrate the validity of the assumption that individual required HLB values can be added up to obtain the overall required HLB value of an oil mixture. The HLB and required HLB values published by Griffin should only be taken as approximate guidelines.