尼莫地平自微乳化释药系统处方优化

目的:制备尼莫地平的自微乳化释药系统.方法:通过溶解度实验筛选各种辅料,按照处方设计制得系列自微乳化液,并通过体外评价以确定最优处方.结果:最优处方为尼莫地平、聚氧乙烯氢化蓖麻油-35、油酸乙酯和单辛酸甘油酯的质量百分数分别为3.5%、40%、40%和16.5%.在0.1 mo1 oL-1稀盐酸中轻微搅拌,该优化处方能够在1 min内迅速乳化,得到粒径均值58.6 nm的乳滴,1 min时的溶出率为84.3%.结论:按优化处方制得的尼莫地平自微乳化释药系统显著提高了尼莫地平的溶出.     

龙葵生物碱自微乳化制剂配方研究

通过考查自微乳化给药系统(SMEDDS)配方中吐温-20、OP乳化剂、油酸、1,2-二丙醇、龙葵生物总碱提取物等各组分对其粒径和透光率的影响,最终找出龙葵生物碱自微乳化制剂最优的配方,为今后通过正交试验、星点设计等方式进一步探索龙葵生物碱自微乳化制剂最佳配方和研究龙葵生物碱自微乳化制剂的药效研究提供参考。     

辛伐他汀自微乳化胶囊的体内评价

目的:研究辛伐他汀(SV)自微乳化胶囊在比格犬体内的药代动力学。方法:采用HPLC法测定比格犬血浆药物浓度,与市售片比较,考察SV自微乳化胶囊的体内药代动力学。结果:药代动力学测定结果表明:与市售片比较,自微乳化胶囊血药浓度达峰时间提前、最高血药浓度增大,Tmax=1.41h,Cmax=46.22ng.mL-1,而市售片的Tmax=2.65h,Cmax=12.43ng.mL-1;AUC0-∞为市售片剂的227.5%。结论:自微乳化胶囊可以显著提高SV的体内吸收。     

肉桂油纳米微乳的制备

本研究采用转相乳化法,结合伪三元相图制备肉桂油纳米微乳,对其外观、类型、理化性质、粒径及微观形态进行考察。最终得到肉桂油纳米微乳由EL-40/Tween80/无水乙醇/IPP/肉桂油/水组成,所制备的肉桂油微乳为O/W型微乳,淡黄色、澄清透明、流动性好,透射电镜下微乳颗粒大小均匀,平均粒径32 nm,电导率111.0μs/cm,折光率1.415,黏度105 mpa.s,pH值5.24。     

HPLC法分析油菜种子油中维生素E的组成与含量

利用HPLC法分析了50份遗传背景丰富的白菜型油菜、甘蓝型油菜、芥菜型油菜和芸芥种子油中维生素E的组成与含量.研究结果显示,油菜种子油中主要含α-生育酚和γ -生育酚,且a-生育酚、γ-生育酚和维生素E总量均存在明显的基因型差异,甘蓝型油菜种子油中维生素E含量总体水平最高,平均总量较高,为123.11 mg/100g油,维生素E含量最高的Omega,总量为144.73 mg/100g油,α/γ-生育酚比值最高可达0.77.α-生育酚、γ-生育酚和维生素E总量与类胡萝卜素含量均呈现显著负相关,种子油中α-生育酚与含油量呈现显著正相关,α-生育酚、γ -生育酚和维生素E总量与生育期均呈现显著或极显著正相关,α-生育酚和维生素E总量与株高均呈现显著正相关,维生素E总量与千粒重呈显著正相关,而α-生育酚、γ-生育酚和维生素E总量与全株角果数和每角粒数相关不显著.     

运用HPLC-MS对鸦胆子油自微乳给药系统肠吸收的研究

目的:建立高效液相色谱-串联质谱法检测油酸和亚油酸含量的方法,从而对鸦胆子油自微乳给药系统中鸦胆子油的肠吸收进行研究.方法:以甲醇-水(95∶5 v/v)为流动相,流速为0.4 mL/min,柱温为35℃作为高效液相色谱的检测条件.利用大鼠小肠膜建立体外药物扩散体系研究鸦胆子油的肠吸收特性.结果:油酸和亚油酸的保留时间分别为10.46± 0.02和8.55±0.01 min,线性范围分别为0.50～50.0 ng/mL和5.06～101.2 ng/mL,平均绝对回收率分别为97.49±3.11％和105.76± 3.13％.日间和日内精密度都小于5％.在肠吸收实验中,鸦胆子油自微乳体系中测得油酸和亚油酸含量是单独给予鸦胆子油测得量的2.8和4.1倍.结论:该方法高效、灵敏、选择性高,可以用于鸦胆子油及鸦胆子油自微乳肠吸收中油酸和亚油酸的质量测定.     

反胶束体系中维生素E的胆甾醇酯酶催化水解

目的 :探索反胶束体系中维生素E醋酸酯的酶促水解规律。方法 :以维生素E醋酸酯的水解产物α -生育酚的生成量为检测指标 ,考察温度、pH值、离子强度、酶浓度、表面活性剂浓度、体系含水量等反应条件对胆甾醇酯酶催化活性的影响。结果 :在卵磷脂 胆固醇 环己烷反胶束体系中 ,胆甾醇酯酶对维生素E醋酸酯具有催化活性。结论 :胆甾醇酯酶发挥水解活性的最佳反应条件如下 :温度为 38℃ ,体系pH值为 8.0 ,胆甾醇酯酶浓度为 1IU·mL- 1 ,牛磺胆酸钠浓度为 5 0mmol·L- 1 ,表面活性剂浓度为 0 .0 2mol·L- 1 ,含水量W0 为 10 .5。     

壳聚糖和帕米膦酸双修饰的固体脂质纳米粒的制备

目的:制备壳聚糖和帕米膦酸双修饰的固体脂质纳米粒。方法:首先利用课题组发表的专利合成帕米膦酸修饰Brij78的新型非离子表面活性剂(Pa-Brij78),然后以壳聚糖(CS)溶液为水相,Pa-Brij78为乳化剂,E-Wax为油相,采用微乳法,利用修饰的帕米膦酸基团与壳聚糖分子链中质子化的氨基交联反应原理,通过一系列实验条件的探索,确定了最佳实验工艺条件,成功制备了壳聚糖和帕米膦酸双修饰的固体脂质纳米粒。通过动态光散射(DLS)粒径仪测定了纳米粒的粒径大小和Zeta电位;透射电子显微镜(TEM)对CS-Pa-Brij78-SLNs的形貌结构进行了表征。结果:实验结果显示,制备壳聚糖和帕米膦酸双修饰的固体脂质纳米粒的最佳条件为:p H=6.0,壳聚糖浓度分别为0.1%,0.2%;反应温度65℃,反应时间40 min,在该条件下,制备的壳聚糖和帕米膦酸双修饰的固体脂质纳米粒(CS-Pa-Brij78-SLNs)粒径分别为97.9±6.6 nm和182.4±62.2 nm,表面电位分别为(+5.21±1.4m V);(+7.94±0.80 m V),装载姜黄素时,载药量为10%,包封率在90%以上,透射电镜下观察其形态圆整,清晰可见壳聚糖包裹的电晕。结论:本文以壳聚糖(CS)溶液为水相,合成的新型非离子表面活性剂Pa-Brij78为乳化剂,E-Wax为油相,采用微乳化法,经过最佳实验条件的探索,通过一步法成功制备了稳定的壳聚糖和帕米膦酸双修饰的固体脂质纳米粒(CS-Pa-Brij78-SLNs)。     

玉米须天然维生素E的提取工艺研究

目的:为充分利用玉米须植物资源,探讨玉米须维生素E的工艺流程、最佳提取方法和影响因素。方法:采用索氏回流提取法和甲酯化法对玉米须维生素E进行提取,用紫外分光光度法测定含量。结果:由单因素实验和正交实验得出的最佳提取工艺条件是:提取时间2h,料液比为1∶10,甲酯化温度70℃,甲酯化时间1h,得率为0.056%。影响因素依次为:甲酯化时间甲酯化温度料液比提取时间。结论:试验方法简单易操作,且提取效率高、污染少,是提取玉米须维生素E的有效途径,该试验得出玉米须维生素E的含量为0.056%。     

维生素E琥珀酸酯的合成及表征

目的:合成维生素E琥珀酸酯并对其进行表征.方法:以d,1-α-生育酚和丁二酸酐为原料,吡啶为溶媒,合成了维生素E琥珀酸酯.采用紫外光谱法、红外光谱法、核磁共振氢谱和差示扫描量热分析对产物进行表征.结果:经验证,成功合成了维生素E琥珀酸酯.结论:成功合成了维生素E琥珀酸酯.     

Exemestane Loaded Self-Microemulsifying Drug Delivery System (SMEDDS): Development and Optimization

The purpose of this research work was to formulate and characterize self-micro emulsifying drug delivery system containing exemestane. The solubility of exemestane was determined in various vehicles. Pseudo ternary phase diagram was used to evaluate the micro-emulsification existence area. SMEDDS formulations were tested for micro-emulsifying properties, and the resultant formulations loaded with exemestane (ME1, ME2, ME3, ME4 and ME5) were investigated for clarity, phase separation, globule size and shape, zeta potential, effect of various diluents and dilutions, thermodynamic and thermal stability. From the results it is concluded that increase in droplet size is proportional to the concentration of oil in SMEDDS formulation. Minor difference in the droplet size and zeta potential was observed by varying the diluents (deionized water and 0.1 N HCl) and dilutions (1:10, 1:50 and 1:100). Formulations, which were found to be thermodynamically stable (ME1, ME2, ME3 and ME4), were subjected to stability studies as per International Conference on Harmonization (ICH) guidelines. No significant variations were observed in the formulations over a period of 3 months at accelerated and long-term conditions. TEM photographs of microemulsions formulations further conformed the spherical shape of globules. Among the various SMEDDS formulations, ME4 offer the advantages of good clarity systems at high oil content and thus offer good solubilization of exemestane. Thus this study indicates that the SMEDDS can be used as a potential drug carrier for dissolution enhancement of exemestane and other lipophilic drug(s).     

SMEDDS of Glyburide: Formulation, In Vitro Evaluation, and Stability Studies

The objective of the present investigation was to develop and evaluate self-microemulsifying drug delivery system (SMEDDS) for improving the delivery of a BCS class II antidiabetic agent, glyburide (GLY). The solubility of GLY in oils, cosurfactants, and surfactants was evaluated to identify the components of the microemulsion. The ternary diagram was plotted to identify the area of microemulsion existence. The in vitro dissolution profile of GLY SMEDDS was evaluated in comparison to the marketed GLY tablet and pure drug in pH 1.2 and pH 7.4 buffers. The chemical stability of GLY in SMEDDS was determined as per the International Conference on Harmonisation guidelines. The area of microemulsion existence increased with the increase in the cosurfactant (Transcutol P) concentration. The GLY microemulsion exhibited globule size of 133.5 nm and polydispersity index of 0.94. The stability studies indicated that GLY undergoes significant degradation in the developed SMEDDS. This observation was totally unexpected and has been noticed for the first time. Further investigations indicated that the rate of GLY degradation was highest in Transcutol P.     

柚皮素自微乳不对称膜渗透泵胶囊的制备及体外评价

制备柚皮素自微乳不对称膜渗透泵胶囊并考察其体外释药行为。实验利用球晶技术进行自微乳的固化研究,以醋酸纤维素浓度、栓模浸入聚合物溶液中时间、栓模浸入淬火液中时间为自变量,采用星点设计-效应面优化法,以囊壳厚度和24h药物累积释放度为因变量,确定不对称膜渗透泵胶囊壳的最佳制备工艺。其最佳制备工艺为:醋酸纤维素浓度9.44%,栓模浸入聚合物溶液中时间3.77min,栓模浸入淬火液中时间15.86min,按最佳工艺得到的药物累积释放度为96.27%,囊壳厚度为0.275mm。体外释药行为符合零级释药方程(R=0.9997)。柚皮素自微乳不对称膜渗透泵胶囊可有效控制药物缓慢释放,解决难溶性药物制成渗透泵制剂释药不完全的问题。     

Omega-3 fatty acid-based self-microemulsifying drug delivery system (SMEDDS) of pioglitazone: Optimization,in vitro and in vivo studies

Pioglitazone (PGL) is an effective insulin sensitizer, however, side effects such as accumulation of subcutaneous fat, edema, and weight gain as well as poor oral bioavailability limit its therapeutic potential for oral delivery. Recent studies have shown that combination of both, PGL and fish oil significantly reduce fasting plasma glucose, improve insulin resistance, and mitigate pioglitazone-induced subcutaneous fat accumulation and weight gain. Nevertheless, developing an effective oral drug delivery system for administration of both medications have not been explored yet. Thus, this study aimed to develop a self-micro emulsifying drug delivery system (SMEDDS) for the simultaneous oral administration of PGL and fish oil. SMEDDS was developed using concentrated fish oil,Tween® 80, and Transcutol HP and optimized by central composite design (CCD). The reconstituted, optimized PGL-SMEDDS exhibited a globule size of 142 nm, a PDI of 0.232, and a zeta potential of −20.9 mV. The in-vitro drug release study of the PGL-SMEDDS showed a first-order model kinetic release and demonstrated remarkable 15-fold enhancement compared to PGL suspension. Additionally, following oral administration in fasting albino Wistar rats, PGL-SMEDDS exhibited 3.4-fold and 1.4-fold enhancements in the AUC_0–24h compared to PGL suspension and PGL marketed product. The accelerated stability testing showed that the optimized SMEDDS formulation was stable over a three-month storage period. Taken together, our findings demonstrate that the developed fish oil-based SMEDDS for PGL could serve as effective nanoplatforms for the oral delivery of PGL, warranting future studies to explore its synergistic therapeutic potential in rats.     

Development of Silymarin Self-Microemulsifying Drug Delivery System with Enhanced Oral Bioavailability

The objective of this work was to develop a self-microemulsifying drug delivery system (SMEDDS) for improving oral absorption of poorly water-soluble drug, silymarin. The pseudo-ternary phase diagrams were constructed using ethyl linoleate, Cremophor EL, ethyl alcohol, and normal saline to identify the efficient self-microemulsification region. The particle size and its distribution of the resultant microemulsions were determined using dynamic light scattering. The optimal formulation with the best self-microemulsifying and solubilization ability consisted of 10% (w/w) of ethyl linoleate, 30% of Cremophor EL, and 60% of ethyl alcohol. The release of silymarin from SMEDDS was significantly faster than that from the commercial silymarin preparation hard capsule (Legalon®). The bioavailability results indicated that the oral absorption of silymarin SMEDDS was enhanced about 2.2-fold compared with the hard capsule in fasted dogs. It could be concluded that SMEDDS would be a promising drug delivery system for poorly water-soluble drugs by the oral route.     

A Self-microemulsifying Drug Delivery System (SMEDDS) for a Novel Medicative Compound Against Depression: a Preparation and Bioavailability Study in Rats

AJS is the code name of an untitled novel medicative compound synthesized by the Tasly Holding Group Company (Tianjin, China) based on the structure of cinnamamide, which is one of the Biopharmaceutics Classification System (BCS) class II drugs. The drug has better antidepressant effect, achieved by acting on the 5-hydroxytryptamine receptor. However, the therapeutic effects of the drug are compromised due to its poor water solubility and lower bioavailability. Herein, a self-microemulsifying drug delivery system (SMEDDS) was developed to improve its solubility and oral bioavailability. AJS-SMEDDS formulation was optimized in terms of drug solubility in the excipients, droplet size, stability, and drug precipitation using a pseudo-ternary diagram. The pharmacokinetic study was performed in rats, and the drug concentration in plasma samples was assayed using the high-performance liquid chromatography-electrospray tandem mass spectrometry (HPLC-MS/MS) method. The optimized formulation for SMEDDS has a composition of castor oil 24.5%, Labrasol 28.6%, Cremphor EL 40.8%, and Transcutol HP 2.7% (co-surfactant). No drug precipitation or phase separation was observed from the optimized formulation after 3 months of storing at 25°C. The droplet size of microemulsion formed by the optimized formulation was 26.08 ± 1.68 nm, and the zeta potential was −2.76 mV. The oral bioavailability of AJS-SMEDDS was increased by 3.4- and 35.9-fold, respectively, compared with the solid dispersion and cyclodextrin inclusion; meanwhile, the C_max of AJS-SMEDDS was about 2- and 40-fold as great as the two controls, respectively. In summary, the present SMEDDS enhanced oral bioavailability of AJS and was a promising strategy to orally deliver the drug.KEY WORDS: bioavailability, HPLC-MS/MS, self-microemulsifying drug delivery system, solubilization, stability     

Porous Magnesium Aluminometasilicate Tablets as Carrier of a Cyclosporine Self-Emulsifying Formulation

The aim of this study was to investigate the ability of liquid loadable tablets (LLT) to be loaded with a self-microemulsifying drug delivery system (SMEDDS) containing cyclosporine (CyA). LLT were prepared by direct compression of the porous carrier magnesium aluminometasilicate and subsequently loaded with SMEDDS by a simple absorption method. SMEDDS was evaluated regarding visual appearance and droplet size distribution after dispersion in aqueous media. The developed SMEDDS was found to be similar to Neoral®. LLT were characterized before and after loading regarding weight variation, tablet hardness, disintegration time, and in vitro drug release. It was found that LLT with high porosities suitable for liquid loading and further processing could be prepared. Adding a tablet disintegrant was found to improve in vitro drug release. Additionally, the volume-based loading capacity of LLT was evaluated and found to be comparable to soft gelatin and hard two-piece capsules. Furthermore, the pharmacokinetic performance of CyA from loaded LLT was tested in two PK-studies in dogs. Absorption of CyA from SMEDDS loaded into LLT was found in the first study to be significantly lower than the absorption of CyA from SMEDDS filled into a capsule. However, addition of a superdisintegrant improved the absorption markedly. The bioavailability of CyA from SMEDDS loaded into disintegrating LLT was found in the second study to be at the same level as from capsule formulation. In conclusion, the LLT technology is therefore seen as a promising alternative way of achieving a solid dosage form from liquid drug delivery systems.     

Solid Self-Microemulsifying Formulation for Candesartan Cilexetil

Sparingly, water-soluble drugs such as candesartan cilexetil offer challenges in developing a drug product with adequate bioavailability. The objective of the present study was to develop and characterize self-microemulsifying drug delivery system (SMEDDS) of candesartan cilexetil for filling into hard gelatin capsules. Solubility of candesartan cilexetil was evaluated in various nonaqueous careers that included oils, surfactants, and cosurfactants. Pseudoternary phase diagrams were constructed to identify the self-microemulsification region. Four self-microemulsifying formulations were prepared using mixtures of oils, surfactants, and cosurfactants in various proportions. The self-microemulsification properties, droplet size, and zeta potential of these formulations were studied upon dilution with water. The optimized liquid SMEDDS formulation was converted into free flowing powder by adsorbing onto a solid carrier for encapsulation. The dissolution characteristics of solid intermediates of SMEDDS filled into hard gelatin capsules was investigated and compared with liquid formulation and commercial formulation to ascertain the impact on self-emulsifying properties following conversion. The results indicated that solid intermediates showed comparable rate and extent of drug dissolution in a discriminating dissolution medium as liquid SMEDDS indicating that the self-emulsifying properties of SMEDDS were unaffected following conversion. Also, the rate and extent of drug dissolution for solid intermediates was significantly higher than commercial tablet formulation. The results from this study demonstrate the potential use of SMEDDS as a means of improving solubility, dissolution, and concomitantly the bioavailability.     

Preparation and Bioavailability Assessment of SMEDDS Containing Valsartan

A self-microemulsifying drug delivery system (SMEDDS) has been developed to enhance diffusion rate and oral bioavailability of valsartan. The solubility of valsartan was checked in different oils, surfactants, and cosurfactants and ternary phase diagrams were constructed to evaluate the microemulsion domain. The valsartan SMEDDS was prepared using Capmul MCM (oil), Tween 80 (surfactant), and polyethylene glycol 400 (cosurfactant). The particle size distribution, zeta potential, and polydispersity index were determined and were found to be 12.3 nm, −0.746, and 0.138, respectively. Diffusion rate of valsartan was measured by in vitro dialysis bag method using phosphate buffer pH 6.8 as diffusion media. Developed high-performance liquid chromatography method was used to determine drug content in diffusion media. Oral bioavailability of valsartan SMEDDS was checked by using rabbit model. Results of diffusion rate and oral bioavailability of valsartan SMEDDS were compared with those of pure drug solution and of marketed formulation. Diffusion of valsartan SMEDDS showed maximum drug release when compared to pure drug solution and marketed formulation. The area under curve and time showed significant improvement as the values obtained were 607 ng h/mL and 1 h for SMEDDS in comparison to 445.36 and 1.36 h for market formulation suggesting significant increase (p < 0.01) in oral bioavailability of valsartan SMEDDS.     

Oral Bioavailability Enhancement of Exemestane from Self-Microemulsifying Drug Delivery System (SMEDDS)

Limited aqueous solubility of exemestane leads to high variability in absorption after oral administration. To improve the solubility and bioavailability of exemestane, the self-microemulsifying drug delivery system (SMEDDS) was developed. SMEDDS comprises of isotropic mixture of natural or synthetic oil, surfactant, and cosurfactant, which, upon dilution with aqueous media, spontaneously form fine o/w microemulsion with less than 100 nm in droplet size. Solubility of exemestane were determined in various vehicles. Ternary phase diagrams were plotted to identify the efficient self-emulsification region. Dilution studies, droplet size, and zeta potential of the formulations were investigated. The release of exemestane from SMEDDS capsules was studied using USP dissolution apparatus in different dissolution media and compared the release of exemestane from a conventional tablet. Oral pharmacokinetic study was performed in female Wistar rats (n = 8) at the dose of 30 mg kg⁻¹. The absorption of exemestane from SMEDDS form resulted in about 2.9-fold increase in bioavailability compared with the suspension. Our studies illustrated the potential use of SMEDDS for the delivery of hydrophobic compounds, such as exemestane by the oral route.Key words: bioavailability enhancement, exemestane, microemulsion, SMEDDS