Influence of Electrolytes on the Micellar Growth of Amphiphilic Drug Chlorpromazine Hydrochloride

The effect of electrolytes on the micellar behavior of an amphiphilic drug, chlorpromazine (CPZ) hydrochloride, was studied using cloud point (CP) and dye solubilization techniques. In the presence of KBr, increase in pH led to decrease in the CP of 50 mmol·L_-1 drug solution (prepared in 10 mmol·L_-1 sodium phosphate (SP) buffer) because of deprotonation of drug molecules at high pH. The visible absorbance increased (due to dye solubilization) with the increase in pH from 6.5 to 6.9, which indicated micellar growth. At fixed pH (6.7), addition of inorganic salts (KF, KCl, and KBr) to drug solutions (50 mmol·L_-1) caused an increase in the CP as well as in the visible absorbance, with effectiveness being in the order: F_- < Cl_- < Br_-. The results were discussed on the basis of counter-ion binding and their effect toward micellar growth. Cations (co-ions) also led to an increase in the CP (and also the visible absorbance), with their effectiveness order being Li₊ > Na₊ > K₊, which was explained by considering cognizance of their hydrated radii. Compared with anions, their effect was small. Increase in [CPZ] caused micellar growth and hence the CP as well as the visible absorbance increased. The overall behavior was discussed in terms of electrostatic interactions and micellar growth.     

电解质对两性药物分子盐酸氯丙嗪的胶团生长的影响

The effect of electrolytes on the micellar behavior of an amphiphilic drug,chlorpromazine(CPZ)hydroehloride,was studied using cloud point(CP)and dye solubilization techniques.In the presence of KBr,increase because of deprotonation of drug molecules at high pH. The visible absorbance increased(due to dye solubilization)with the increase in pH from 6.5 to 6.9,which indicated micellar growth.At fixed pH(6.7),addition of inorganic salts(KF,KC1,effecfiveness being in the order:F-Na >K ,which Was explained by considering cognizance of their hydrated radii.Compared with anions,their effect was small.Increase in[CPZ]caused micellar growth and hence the CP as well as the visible absorbance increased.The overall behavior Was discussed in terms of electrostatic interactions and micellar growth.     

Interaction of the Amphiphilic Drug Amitriptyline Hydrochloride with Gemini and Conventional Surfactants: A Physicochemical Approach

Pyrene fluorescence measurements were carried out on various binary mixtures of the antidepressant amphiphilic drug amitriptyline hydrochloride (AMT) with conventional (TTAB and CTAB) and gemini surfactants (14-4-14 and 16-4-16). In all cases mixed micellar aggregates were formed and the mixed critical micelle concentration (cmc) of various mixtures was computed from the I ₁/I ₃ versus total surfactant concentration plots. In the region where mixed micelles are formed, the interaction of the amphiphlic drug and four surfactants showed synergistic behavior. The results were analyzed using an interaction parameter, β, which characterize the interaction in the mixed micelle and is introduced by a regular solution theory. The β values are negative in all binary mixtures, and their magnitudes increase with increasing hydrophobicity of the amphiphile. The micellar mole fraction of AMT in the mixed micelle (x ₁) and in the ideal sate (x _ideal) were evaluated and their values (x ₁ > x _ideal) suggest that the contribution of the AMT component is greater in binary mixtures as compared to that in the ideal state. Activity coefficients (f ₁ and f ₂) and excess Gibbs energy (G _ex) were also calculated. The values of micelle aggregation numbers (N _agg) and various other parameters like the Stern–Volmer constant (K _sv), micropolarity and dielectric constant of mixed systems have also been evaluated from the ratios of respective peak intensities (I ₁/I ₃ or I ₀/I ₁).     

Cloud Point Phenomenon in Amphiphilic Drug Promethazine Hydrochloride+Electrolyte Systems

Herein we report clouding phenomenon occurring in amphiphilic drug promethazine hydrochloride (PMT) in the presence of electrolytes. The CP of 50 mM drug solution, prepared in 10 mM sodium phosphate buffer, was found to decrease with increasing pH due to deprotonation of drug molecules at high pH. Addition of inorganic salts (KF, KCl and KBr) to drug solutions at fixed pH (6.7) and drug concentration (50 mM) caused an increase in CP. The results have been discussed on the desorption/adsorption of counterions to the headgroups. Cations also increased the CP by affecting the water structure with their effectiveness being in the order: Li⁺<Na⁺<K⁺<NH₄ ⁺. In the presence of NaCl, increase in drug concentration increased the CP while increase in pH showed an opposite trend.     

Phase Separation Phenomenon in Non-ionic Surfactant TX-114 Micellar Solutions: Effect of Added Surfactants and Polymers

Clouding (or phase separation) in non-ionic surfactants is a well-known phenomenon. Clouding is to be avoided in some applications whereas in others it is preferred. Herein the results of CP (cloud point—the temperature at which solution separates into two phases) measurements of the non-ionic surfactant Triton X-114 (TX-114) in the presence of surfactants and polymers are presented. Cationic and nonionic surfactants, in the absence and presence of the quaternary salt tetrabutylammonium bromide (TBAB), increase the CP of TX-114. Anionic surfactants, in the absence of TBAB, increase the CP; in the presence of TBAB, these surfactants decrease the CP. Polymers of PEG and PVP series have been found to decrease the CP. The results are discussed by taking into consideration the nature of the added surfactants and polymers.     

Mixing Behavior of Cationic Hydrotropes with Anionic Surfactant Sodium Dodecyl Sulfate

Mixing behavior of anionic surfactant sodium dodecyl sulfate (SDS) with cationic hydrotropes aniline hydrochloride (AH), o-toluidine hydrochloride (o-TH), and p-toluidine hydrochloride (p-TH) have been studied using conductivity at different temperatures. Critical micelle concentration for different mixing mole fractions, their ideal values, and different interaction parameters have been estimated. All the parameters show nonideal behavior with synergistic interactions. Thermodynamic parameters are also calculated for these systems.     

用SEC柱和胶束流动相分离小分子的模型

 使用体积排阻色谱 (SEC)柱和胶束流动相成功地分离了一些小分子化合物 ,给出了分离模型。这种分离方式是基于胶束和水相在色谱过程中的不同迁移以及溶质在胶束和水相间的不同分配而实现的 ,其分离的机制与胶束电动色谱 (micellar electrokinetic chromatography,MEKC)十分相似。理论处理的结果表明 ,溶质的保留体积与胶束浓度有关 ;通过溶质的保留体积可得到溶质在胶束和水相间的分配系数。还采用了两种不同的 SEC柱分离了一些脂肪醇 ,验证了这一理论模型 ,测定了它们的分配系数 ,结果表明两种柱测得的小分子醇在胶束和水相中的分配系数具有较好的一致。     

Self-assembly of Amphiphilic Diblock Copolymers Induced by Liquid-Liquid Phase Separation

The liquid-liquid phase separation(LLPS) widely exists in biology, synthetic chemistry, crystallization kinetics and other fields, and it is very important to realize the related functions. The research on the competition between LLPS and micellization/vesiculation has made considerable progress. However, the way to effectively control the formation paths from homogeneous state to aggregates has not been completely solved, which is vital to determine its structure and properties and even its fut...     

盐对C8-卵磷脂胶团溶液相分离的作用

借助描述胶团溶液相变过程的唯象理论，结合有关电解质作用的理论模型，分析了盐对Ｃ８－卵磷脂胶团相分离的作用，导出加盐后Ｃ８－卵磷脂胶团溶液的吉布斯自由能，并据此推导出该溶液相谱临界温度随盐度类型和离子强度变化的规律，以及溶液中盐离子与卵磷肥分子相互作用的机制。     

CMC and Phase Separation Studies of RAFT Mediated Amphiphilic Diblock Glycopolymers with Methyl Acrylate and Styrene

Summary: Interesting new CMC and phase separation data of carbohydrate-based self-assembling core-shell nanoparticles which were synthesized via the Reversible Addition-Fragmentation Transfer (RAFT) process. The macro-RAFT agent, poly(3-O- Methacryloyl-1,2:5,6-di-O-isopropylidene-D-glucofuranose) (PMAlpGlc), was prepared by RAFT polymerization of the glycomonomer with cumyl phenyl dithioacetate as the chain transfer agent. Chain extension with styrene and methyl acrylate afforded the diblock copolymers (PMAlpGlc-b-styrene and PMAlpGlc-b-methyl acrylate) having predetermined molecular weight and narrow molecular weight distributions. Acidolysis of these diblock copolymers were undertaken and confirmed by NMR. Core-shell nanoparticles were observed by TEM.     

两亲性嵌段共聚物PAA-b-PS的合成及胶束形态

通过丙烯酸叔丁酯的自由基调聚和苯乙烯的原子转移自由基聚合（ATRP）法合成了聚丙烯酸叔丁酯-聚苯乙烯（PtBA-b-PS）嵌段共聚物,然后在三氟乙酸作用下进行选择性水解得到了两亲性聚丙烯酸-聚苯乙烯（PAA-b-PS）嵌段共聚物。利用1H-NMR、FT-IR和GPC对产物的结构进行了表征。采用透析法制备了PAA-b-P...     

Design and Application of Amphiphilic Polymeric Supports for Micellar Catalysis

In this contribution, the synthesis and application of amphiphilic poly(2-oxazoline)s with covalently bound transition metal catalysts for reactions in aqueous media is described. In the first example, bipyridine moieties were introduced via living ring-opening polymerization of functionalized oxazoline monomers and the resulting block copolymers were used as macroligands for ATRP (atom transfer radical polymerization) using Cu(I)Br as active metal species. Furthermore, the fixation of a chiral biphosphane and its use for enantioselective hydrogenation of enamides is presented as well as the fixation of a ruthenium catalyst. The latter one is used for polymerization of diethyl dipropargylmalonate (DEDPM), and represents the first example of an alkyne polymerization using a ruthenium catalyst. In the case of the polymers stable latex particles were obtained     

Micellization and Clouding Phenomenon of Phenothiazine Drug Promethazine Hydrochloride: Effect of NaCl and Urea Addition

Herein we report the micellization and clouding behavior of promethazine hydrochloride (PMT) in absence and presence of NaCl/ureas. The critical micelle concentration (CMC) of PMT is measured by conductivity method and the values decrease with increasing the NaCl concentration. With increasing the temperature, the CMC first increases then decreases. At 25°C, the maximum CMC values were obtained (with or without NaCl). The thermodynamic parameters are evaluated which indicate more stability of the PMT solution in presence of NaCl. PMT shows phase separation also. The cloud point (CP) of PMT decreases with increase in pH due to deprotonation of the drug molecules. Ureas decreased the CP and the behavior is explained on the basis of removal of water from the head group region.     

胶束电动毛细管色谱法分离酮康唑手性异构体

1引言胶束电动毛细管色谱法（MECC）综合了反相高效液相色谱的分配机理和毛细管区带电泳的电渗及电泳机理,实现了对电中性物的分离。由于环糊精（CD）外表面具有亲水性,当其与胶束共存时,不能进入胶束,所以溶液存在三相即：胶束相、水相和CD相。异构体通过与CD形成不同稳定常数的主-客体络合物而达到手性识别,由于十二烷基硫酸钠（SDS）的高疏水性,该方法对分离电中性和疏水性化合物具有突出的优越性。酮康华（ketoconazole）属口服咪唑类抗真菌合成药物,到目前为止,人们对其它手性药物拆分进行了较多的研究,但对酮康唑的研…     

Synthesis and Hydrodynamic Behavior of Stoichiometric Complexes of Cationic Polyelectrolytes with Amphiphilic Anions

Complexation of poly(N,N-dimethyl-N-benzyl-N-methacryloyloxyethyl)ammonium chloride with oppositely charged amphiphilic compounds was studied. The solubility and hydrodynamic properties of the resulting complexes in chloroform, methanol, and chloroform-hexane and chloroform-toluene mixtures were determined.     

对微环境敏感的系列双亲卟啉的光谱研究

研究了系列双亲卟啉(四苯酚基卟啉P₀及其烷氧基衍生物P₁,P₂,P₃)在不同微环境下的电子吸收光谱和荧光发射及荧光激发光谱.研究发现,卟啉在THF溶液中以单体形式存在,并且其侧链取代基对卟啉电子态的影响很小;然而卟啉在CTAB胶束溶液中的光谱特性却表现出很大差异,由此分析了不同侧链取代基对卟啉分子聚集行为和定位性质的影响,初步解释了卟啉在CTAB胶束溶液中随体系pH值改变而发生的荧光猝灭现象.     

两亲性壳聚糖衍生物的合成及其自聚集现象

以壳聚糖为主链, 聚乙二醇单甲醚为亲水性链段, 癸二酸为疏水链段, 合成了一系列两亲性壳聚糖衍生物. 通过FTIR, 1H NMR和X射线粉末衍射等手段对壳聚糖衍生物进行了结构表征, 由元素分析方法计算出衍生物的取代度. 采用直接溶解法制备了壳聚糖衍生物的空白胶束, 通过透射电子显微镜(TEM)观察了胶束的形态. 由动态光散射(DLS)测定了胶束的粒径及分布, 并以芘为分子探针, 通过荧光光谱法测定了壳聚糖衍生物的临界聚集浓度(CAC). 研究结果表明, 壳聚糖主链上疏水链段的取代度越大, 其衍生物的临界聚集浓度越低, 相同浓度下的胶束的粒径也越小.     

Synthesis and Micellar Behavior of DL-lactide-gelatin Copolymers as Amphiphilic and Biodegradable Materials

A series of novel biodegradable polymers, graft copolymers of D,L-lactide on gelatin, were designed and synthesized to overcome the shortcomings of gelatin and polylactide(PLA) biomaterials. The copolymers were characterized by nitrogen analysis, IR, 1H-NMR and thermal analysis. The amphiphilic properties of these copolymers were also investigated.     

Validated LC Method, with a Chiral Mobile Phase, for Separation of the Isomers of Fexofenadine Hydrochloride

A rapid, simple and sensitive high-performance liquid chromatographic method (HPLC) has been developed to assay atomoxetine HCl in capsules. The HPLC analysis used a reversed phase C18 (150 × 4.6 mm i.d. 5 μm particle size) analytical column and a mobile phase consisting of monobasic potassium dihydrogen orthophosphate and acetonitrile (95:5 v/v), with UV detection at 269 nm. The validation data showed that the assay is sensitive, specific and reproducible for determination of atomoxetine HCl in this dosage form. Calibration curves were linear from 1 to 10 μg mL⁻¹ (R ² > 0.997). The accuracy of the method ranged from 98.13 to 101.5%. Mean inter- and intra-assay relative standard deviations (RSD) were less than 1.0%. The proposed method provided an accurate and precise analysis of atomoxetine HCl in its pharmaceutical dosage form.