Physicochemical study on microencapsulation of hydroxypropyl-β-cyclodextrin in dermal preparations

Objective: To investigate the effect of hydroxypropyl-β-cyclodextrin (HP-β-CD) concentration on the physicochemical properties of the sunscreen agents, namely oxybenzone (Oxy), octocrylene (Oct), and ethylhexyl-methoxy-cinnamate (Cin), in aqueous solution and cream formulations. Methods: The inclusion complexes of sunscreen agents with hydroxypropyl-β-cyclodextrin (HP-β-CD) in aqueous solution and solid phase were studied by UV-vis spectrophotmetery, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and 13C-NMR techniques. The photodegradation reaction of the sunscreen agents' molecules in lotion was explored using UV-vis spectrophotometry and high-performance liquid chromatography (HPLC). Results: The formation of the inclusion complexes was confirmed experimentally using DSC, SEM, and 13C-NMR. The results of spectrophotometric and HPLC studies have shown that the inclusion complexation with HP-β-CD has the potential to enhance the photostability of the selected sunscreen agents in lotion. HPLC results indicated that HP-β-CD has approximately increases the photostability of Oct by six- to eightfold. Moreover, the presence of HP-β-CD in lotion controlled the isomerization process of Cin to a certain degree, which was found to be a function of the amount of HP-β-CD added. Conclusions: It has been demonstrated that the photostability of the tested sunscreen agents has been enhanced upon forming inclusion complexes with HP-β-CD in lotion. The results of this study demonstrate that HP-β-CD can be utilized as photostabilizer additive for enhancing the photostability of the sunscreen agents' molecules.     

羟丙基-β-环糊精/玫瑰香精纳米胶囊制备工艺的优化

利用羟丙基-β-环糊精(HP-β-CD)内疏水外亲水的空腔结构对东方琥珀玫瑰香精进行包合,以平均粒径为主要指标,粒径分布系数(PDI)及ζ电位为辅助指标对胶囊进行考察.通过单因素实验找出对包合工艺影响较大的因素.在此基础上采用Box-Behnken响应面设计法优化包合工艺,得到最佳包合工艺条件:包合时间为4h,磁力搅拌转速为1 000 r/min,反应pH值为8,壁芯质量比为1.69,乳化剂为聚氧乙烯失水山梨醇单月桂酸酯(Tween-20),乳化剂香精质量比为3.13,固形物质量分数为1.5％.其平均粒径为72.8 nm,粒径分布系数为0.127,ζ电位为-12.6 mV.通过透射电镜观察发现纳米香精胶囊呈不规则的圆形.     

羟丙基-β-环糊精/格列本脲包结物的制备及其表征

研究了羟丙基-β-环糊精对格列本脲的包结作用,考察了包结物的性质。通过相溶解度法确定了羟丙基-β-环糊精与格列本脲二者的包结摩尔比和包结稳定常数,采用中和法制备了羟丙基-β-环糊精/格列本脲固体包结物,并通过傅立叶变换红外光谱、差式扫描量热分析、X射线粉末衍射光谱对羟丙基-β-环糊精/格列本脲固体包结物进行了表征。结果表明,格列本脲与羟丙基-β-环糊精的相溶解度图为典型的AL型,两者形成了1∶1的可溶性包结物,在25℃时包结物平衡常数(K1∶1)为303 L.mol-1。羟丙基-β-环糊精/格列本脲包结物的光谱研究结果表明,羟丙基-β-环糊精/格列本脲包结物是格列本脲以无定形状态分散到羟丙基-β-环糊精中。包结物的水溶性实验结果表明包结后格列本脲的溶解度增加了15倍。     

Pharmacokinetic analysis and optimization of hydroxycamptothecin-loaded nanoparticles for liver targeting

In this paper, a pharmacokinetic model to describe the tissue distribution process of nanoparticles was established. To test the possibility of the model, nanoparticles composed of poly(butylcyanoacrylate) and hydroxypropyl-β-cyclodextrins (HP-β-CD) was prepared with a poorly soluble anticancer drug, hydroxycamptothecin (HCPT). Characteristics were determined including particle’s size, morphology and in vitro release. The tissue distribution of nanoparticles was also studied. Further, mathematical equation was fitted to the curve of drug concentration-time in liver of hydroxycamptothecin-loaded nanoparticles and the pharmacokinetic parameters of liver were obtained. The effectiveness of hydroxycamptothecin-loaded nanoparticles for liver targeting was evaluated. The results showed that nanoparticles composed of poly(butylcyanoacrylate) and hydroxypropyl-β-cyclodextrins (HP-β-CD) exhibited enhanced liver targeting in rats after i.v. injection. More importantly, the pharmacokinetic parameters (transport constant from blood to target organ KT, drug release rate from nanoparticles Kr and drug elimination constant in target organ Ke) provided some quantitative measure of liver distribution and were useful guidelines for development of targeted drug delivery systems.     

Investigation into the Mechanism by Which Cyclodextrins Influence Transdermal Drug Delivery

The objective of this study was to investigate the mechanism by which hydroxypropyl-β-cyclodextrin (HPCD) increases transdermal permeation. Hairless mouse skin was pretreated with HPCD solutions for up to 4 h. After removing the HPCD, corticosteroid-containing suspensions were applied and the transdermal flux and skin accumulation of two model drugs were investigated. After pretreatment, changes to the stratum corneum endothermic melting transitions were determined as an indication of HPCD-induced lipid disorganization. Results demonstrated that HPCD pretreatment had no significant effect on the transdermal permeation or skin accumulation of the model corticosteroids. These findings suggest that HPCD functions to enhance the apparent solubility of the drug in the formulation, thus increasing transdermal permeation rather than extracting lipids from the skin.     

新型羟丙基-β-环糊精交联聚合物的合成及其对苯酚的吸附

以环氧氯丙烷为交联剂,合成了羟丙基-β-环糊精交联聚合物,考察了振荡时间、溶液pH、吸附温度以及苯酚初始浓度等吸附条件对聚合物吸附苯酚性能的影响,考察了吸附苯酚前后聚合物的IR及XRD谱。结果表明,聚合物对苯酚的吸附量随着苯酚初始浓度增加而提高,苯酚初始浓度为500 mg/L时,振荡10 min,吸附量能达到14.30 mg/g,在pH<7和温度为15℃时吸附效果好。IR及XRD研究表明,聚合物对苯酚的吸附是形成包合物。     

超声波辅助羟丙基-β-环糊精包埋椒目α-亚麻酸工艺优化

为优化超声波辅助羟丙基-β-环糊精(HP-β-CD)包埋椒目α-亚麻酸工艺,考察超声功率、超声时间、无水乙醇+混合脂肪酸:HP-β-CD质量比对包合率的影响。结果表明,最优工艺条件为超声功率300W、超声时间20min、无水乙醇+混合脂肪酸:HP-β-CD质量比1:8,此条件下包合率达90.26%,可实现α-亚麻酸的安全无毒分离。     

羟丙基-β-环糊精包合法提高防晒剂光稳定性的研究

制备了丁基甲氧基二苯甲酰甲烷、对甲氧基肉桂酸辛酯两种防晒剂的羟丙基-β-环糊精包合物,采用紫外分光光度法、红外光谱法、薄层色谱法对防晒剂包合物进行了表征,并对防晒剂和防晒剂包合物进行了光稳定性研究。结果表明,羟丙基-β-环糊精包合法能有效抑制防晒剂的光分解作用,提高防晒剂的光稳定性。     

Limited contribution of isoflavones to hepatocellular phase II enzyme-inducing activity of soybean (Glycine max) extracts

Soy flour was successively extracted with ethyl acetate, ethanol, and water and tested for quinone reductase (QR) induction in the Hepa 1c1c7 cell line. The ethanol extract was found to be the most potent, with a CD value (concentration required to double QR specific activity) of 460 μg/ml. Phase separation of the ethanol extract and a phospholipid removal procedure yielded a fraction that doubled QR at 80 μg/ml. Reverse phase medium pressure chromatography of the purified ethanol extract yielded 13 fractions. Constituents of selected fractions were identified using mass spectrometry and NMR analysis. Fractions 2, 8, and 10 contained 47% of the recovered mass and were the least active of the isolates. These three fractions contained isoflavone glycosides. The latest eluting fractions 11–13 were found to be the most potent, and contained the majority of recovered inducing units (IUs), a measure of potency.     

棉织物羟丙基-β-环糊精接枝整理工艺研究

以无甲醛树脂Arkofix NZF为交联剂,MgCl2·6H2O为催化剂,采用轧-烘-焙工艺,用羟丙基-β-环糊精(HP-β-CD)整理棉织物。研究了HP-β-CD的质量浓度、树脂质量浓度、MgCl2·6H2O质量浓度、pH值、焙烘温度和时间等因素对织物性能的影响,确定最佳接枝工艺为:HP-β-CD质量浓度50g/L,树脂质量浓度60g/L,MgCl2·6H2O质量浓度10g/L,pH值5.5,焙烘温度170℃,焙烘时间3min。结果表明,经HP-β-CD整理的织物折皱回复角和接枝率比经β-CD整理后的高。