穿心莲有效部位Poloxamer188聚合物胶束的制备工艺

目的制备Poloxamer188穿心莲有效部位的聚合物胶束。方法薄膜水化法制备穿心莲有效部位聚合物胶束,正交设计优化处方工艺。HPLC法测定其载药量和包封率,激光粒度仪测定粒径。结果载药胶束包封率为(85.7+2.1)%,载药量为(1.11+0.09)%,粒径为(198.32+3.35)nm。结论载药Poloxamer188胶束制备工艺简便易行,为中药制剂提供了新剂型。     

Surfactant Copolymers Prevent Aggregation of Heat Denatured Lysozyme

We investigated the ability of certain triblock copolymer surfactant poloxamers of the form polyethylene oxide-polypropylene oxide-polyethylene oxide (PEO-PPO-PEO), to prevent formation of stable aggregates of heat denatured hen egg lysozyme. Differential scanning calorimetry (DSC) and synchrotron small angle x-ray scattering (SAXS) experiments were performed to study the thermodynamics and solution structures of lysozyme at temperatures between 20 and 90°C in the presence and absence of poloxamers with various molecular weights (8.4–14.3 kDa), but similar hydrophile/hydrophobe (PEO:PPO) ratio of 80%. Poloxmer 188 was found to be very effective in preventing aggregation of heat denatured lysozyme and those functioned as a synthetic surfactant, thus enabling them to refold when the conditions become optimal. For comparison, we measured the ability of 8 kDa polyethylene glycol (PEG) to prevent lysozyme aggregation under same conditions. The results of these studies suggest that poloxamers are more efficient than PEG in preventing aggregation of heat denaturated lysozyme, To achieve equivalence, more than an order of magnitude higher concentration of PEG concentration was needed. Apparently, the presence of a hydrophobic segment in the poloxamers increases their ability to target the hydrophobic region of the unfolded proteins and protect them from self association. Given their biocompatibility and the low concentrations at which they effectively facilitate refolding of denatured proteins, they may be useful in the treatment of burns and other conditions resulting in the denaturation of proteins.     

Protein adsorption patterns on poloxamer- and poloxamine-stabilized solid lipid nanoparticles (SLN)

Solid lipid nanoparticles (SLN) were produced using a full range of poloxamer polymers and poloxamine 908 for stabilization. The protein adsorption pattern acquired on the surface of these particles after intravenous injection is the key factor determining the organ distribution. Two-dimensional polyacrylamide gel electrophoresis (2-DE) was employed for determination of particle interactions with human plasma proteins. The objective of this study was to investigate changes in the plasma protein adsorption patterns in the course of variation of the polymers stabilizing the SLN. Considerable differences in the protein adsorption with regard to preferential adsorbed proteins were detected for the different stabilizers. Possible correlations between the polyethylene oxide (PEO) chain length and the adsorption of various proteins (first of all apolipoproteins) are shown and discussed. Besides the study of protein adsorption patterns, the total protein mass adsorbed to the SLN was also evaluated using the bicinchoninic acid (BCA)-protein assay. The knowledge concerning the interactions of proteins and nanoparticles can be used for a rational development of particulate drug carriers. Based on the findings presented in this paper, we anticipate that the in vivo well-tolerable SLN are a promising site-specific drug delivery system for intravenous injection.     

Evaluation of a novel oxiconazole nitrate formulation: The thermosensitive gel

Superficial fungal infections caused by Candida species are common skin diseases. Therefore, this study aimed to develop a new formulation containing oxiconazole nitrate, which is an azole group derivative for antifungal treatment, as a thermosensitive gel since there has been no literature study until now.MIC value of the novel thermosensitive formulation against three Candida species was calculated and time-dependent antifungal activity analysis was performed. Viscosity, transition temperature T_sol-gel (°C) and gelation time of the thermosensitive gel formulation were also determined in the viscometer. The measurements performed on the tensilometer device were analyzed for adhesion hardness and elongation percentages of the formulation. In the FT-IR spectrometer, the spectrum of solution and gel state was compared between 650 and 4000?cm^?1 and it was found that there is no difference between them.It was found that the temperature is reversible on the formulation and did not cause any disruption of its components. Characterization parameters of the thermosensitive gel formulation containing oxiconazole nitrate and time-dependent activity against Candida species was observed to be the same as those of the solution containing only oxiconazole nitrate. MIC, MFC and time-dependent antifungal analysis did not show any particular difference between formulation and oxiconazole nitrate itself. Thermosensitive gel formulation containing oxiconazole nitrate was found to be effective on superficial fungal infections. We believe it is also appropriate for in vivo usage, but it is necessary to perform animal and human research. It is also needed to evaluate the formulation against other etiologic agents of superficial fungal infections.     

Quantitation of poloxamers in pharmaceutical formulations using size exclusion chromatography and colorimetric methods

Poloxamers have been used as functional excipients in pharmaceutical products. They function as surfactants, emulsifying agents, solubilizing agents, dispersing agents, and in vivo absorbance enhancer. Despite their wide range of applications, limited analytical techniques have been reported in literature for characterizing poloxamers and few are targeted to quantify poloxamer contents in formulations with desired sensitivity and accuracy. In this paper, two distinct analytical methods for quantifying low levels of poloxamers in pharmaceutical formulations have been developed and optimized: a colorimetric method and a size exclusion chromatography method. The colorimetric method is based on the formation of a colored complex between poloxamers and cobalt(II) thiocyanate in aqueous medium, which has a maximum UV absorbance at 624 nm. The feasibility of this method is product specific. In this report, adequate specificity and sensitivity was demonstrated for only one of the several products tested. The size exclusion chromatography (SEC) method utilizes size exclusion columns with THF as mobile phase and refractive index detection. The SEC method provides a limit of quantitation (LOQ) of 0.005 mg/mL (0.0005%, w/w) and at least three orders of magnitudes of linear range. We applied the SEC method to pharmaceutical products containing 0.3–10% poloxamer 188 or poloxamer 407, such as Avapro, Neurontin, Sudafed and other developmental formulations. The results obtained with the SEC method agreed very well with literature and theoretical values with 97–102% recovery. The SEC method was proven to be widely applicable, accurate, precise and simple to use.     

RP-HPLC法测定姜黄素温敏凝胶的含量及体外释放度

目的:建立姜黄素温敏凝胶中姜黄素的含量测定方法并研究其体外释放行为。方法:以泊洛沙姆407、泊洛沙姆188为基质制备姜黄素温敏凝胶;采用反相高效液相色谱(RP-HPLC)法测定姜黄素温敏凝胶的含量和体外释放度,色谱柱为Kromasil C18(250mm×4.6mm,5μm),流动相为乙腈-2%冰醋酸溶液(58∶42),检测波长为430nm。结果:回归方程为A=113.2c+82.177(r=0.9993),姜黄素检测浓度在4～128μg·mL-1范围内与峰面积积分值线性关系良好,平均回收率为(100.23±0.75)%,低、中、高浓度标准品溶液日内精密度的RSD分别为1.99%、1.86%、1.96%,日间精密度的RSD分别为1.04%、1.74%、1.98%。样品于120h在释放介质中的累积释放率为(81.54±1.07)%,药物释放遵循Higuchi方程释放动力学模型。结论:本方法准确、可靠,可用于姜黄素温敏凝胶中姜黄素的含量测定。姜黄素温敏凝胶具有一定的缓释作用。     

壬二酸固体分散体的制备及其表征

目的:制备壬二酸固体分散体,改善壬二酸的溶出度,从而提高其生物利用度。方法:分别以聚乙二醇6000(PEG)、泊洛沙姆188为载体并选取药物与其不同比例(1:3、1:6、1:9),采用熔融法、溶剂-熔融法制备壬二酸固体分散体,并对其进行体外溶出度的考察及比较;采用差示扫描量热法、X射线粉末衍射法鉴别壬二酸在固体分散体中的存在状态。结果:以PEG为载体的固体分散体的药物溶出优于以泊洛沙姆188为载体的固体分散体(90min内溶出分别为100%和80%);且当药物与PEG的比例为1:9时,药物的溶出效果最好,与原料药比较药物溶出50%所需的时间大大缩短(12.65、45.65min)。壬二酸-PEG固体分散体中药物部分呈分子状态分散,部分呈微晶状态分散。结论:壬二酸与PEG(1:9)的固体分散体能显著提高药物的溶出度。     

Gene Transfer Mediated by Sphingosine/ Dioleoylphosphatidylethanolamine Liposomes in the Presence of Poloxamer 188

A cationic liposome system consisting of sphingosine (SP) and dioleoylphosphatidylethanolamine (DOPE) was developed for in vitro and in vivo gene transfer. A nonionic surface active agent of poloxamer 188 was incorporated in the formulations to stabilize the DNA/liposome complex. Comparison of the results obtained from systems with and without the effect of poloxamer 188 was made to investigate the efficiency of gene expression. In vitro transfection study of the DNA/liposome complex showed that with the effect of poloxamer 188, gene transfer into some cell lines was enhanced. In vivo systemic delivery of the DNA/liposome complex with poloxamer 188 demonstrated gene expression with improved luciferase activity in all major organs including lung, spleen, heart, liver, and kidney. High level transgene activity was found in lung and spleen with prolonged gene expression. This was attributed to poloxamer 188 that stabilized the liposome system and produced homogeneous DNA/liposome complex for enhancement of gene delivery.     

左氧氟沙星与曲安奈德双载药温敏泪道凝胶的制备及评价

摘 要 目的：制备左氧氟沙星和曲安奈德温敏型双载药泪道凝胶,以期用于泪道阻塞性疾病防治。 方法: 以泊洛沙姆407为基质,泊洛沙姆188为凝胶增强剂,以人工泪液稀释前后的胶凝温度为考察指标,确定合适的凝胶基质处方。再以盐酸左氧氟沙星和醋酸曲安奈德为主药,制备温敏型双载药泪道凝胶,测定凝胶的含药量,并考察凝胶体外溶蚀行为。建立泪道阻塞动物模型,进一步考察凝胶对泪道炎症的作用。 结果: 最佳凝胶基质组成为：泊洛沙姆188浓度为10%,泊洛沙姆407浓度为18%。所制得的温敏型双载药泪道凝胶中,盐酸左氧氟沙星的标示含量为（97.4±0.72）%,醋酸曲安奈德的标示含量为（92.98±0.85）%,体外溶蚀行为持续缓慢,在阻塞局部具有显著的抗炎作用。 结论: 成功制得温敏型双载药泪道凝胶。     

Determination of poloxamer 188 and poloxamer 407 using high-performance thin-layer chromatography in pharmaceutical formulations

Poloxamers (PXMs) are amphiphilic non-ionic block polymers commonly used in the cosmetic and pharmaceutical industries. In spite of the wide use of PXMs, few studies have dealt with the analysis of these polymers in pharmaceutical preparations. In this work, high-performance thin-layer chromatography (HPTLC) has been used to quantify both PXM-188 and PXM-407 in pharmaceutical preparations. The separation of these compounds was carried out using reverse phase HPTLC plates with a chloroform-methanol mixture as the mobile phase. Detection was performed densitometrically using the Dragendorff's reagent for the visualization of PXMs. Quality parameters were established, and the detection limits ranged from 24 to 47ng/spot. A good precision (day to day and run to run), with relative standard deviations <11.18%, was obtained. The proposed method was satisfactorily applied to the analysis of laboratory-made and commercial pharmaceutical products.