Box-Behnken设计-效应面法优化甘草黄酮纳米混悬处方

目的:制备甘草黄酮纳米混悬剂,优化其制备工艺及处方。方法:采用沉淀法-高压均质法联合制备甘草黄酮混悬剂。以平均粒径为响应值,单因素试验和Box-Behnken设计-效应面法优化甘草黄酮纳米混悬剂处方,并对处方进行验证。结果:对试验结果进行模型拟合,采用Box-Behnken设计-效应面法优化甘草黄酮纳米混悬处方,按最优处方制得带乳光的棕黄色溶液,其粒径为(179.7±0.907)nm,PDI为0.274±0.012。结论:Box-Behnken设计-效应面法适用于甘草黄酮纳米混悬剂的处方优化,优化得的处方具良好的预测性。     

盐酸环丙沙星-聚氰基丙烯酸正丁酯纳米溶胶的制备

目的:制备盐酸环丙沙星-聚氰基丙烯酸正丁酯纳米溶胶,并对其处方因素进行考察。方法:以氰基丙烯酸正丁酯为载体材料,采用乳化聚合法制备盐酸环丙沙星-聚氰基丙烯酸正丁酯纳米溶胶,以粒径、外观为主要指标,用单因素方法优化处方,得到二步法制备纳米溶胶的条件和工艺。结果:制备的纳米溶胶的平均粒径为(82.6±15)nm,包封率为61.9%,载药量为34.2%(g/g),平均Zeta电位为(-25.1±9.92)mV。结论:本实验制备的盐酸环丙沙星-聚氰基丙烯酸正丁酯纳米溶胶的粒径小,分布窄,稳定性好。     

负载胰岛素壳聚糖接枝醋酸乙烯酯纳米粒的制备和性能

目的:制备负载胰岛素壳聚糖-醋酸乙烯酯共聚物纳米粒并研究其性能。方法:用自由基聚合法合成壳聚糖-醋酸乙烯酯共聚物,该聚合物在水中形成具有疏水核心、亲水表面的纳米粒。采用正交设计试验研究了投料比、引发剂浓度和反应时间对纳米粒粒径的影响。结果:对纳米粒进行了热重分析和红外表征。测定纳米粒的形态、粒径和表面电位(Zeta电位),以胰岛素为模型药物,研究纳米粒的包封和释药性能。结论:纳米粒呈球形,粒径均匀,表面荷正电。胰岛素的包封率可达90%以上。pH6.8的磷酸盐缓冲液中胰岛素释放较慢。结论:该纳米制剂具有较好的物理性能和体外缓释特性。     

阿苯达唑纳米混悬液的冻干工艺优化

目的:优化阿苯达唑纳米混悬液的冻干工艺,制备阿苯达唑纳米微粉。方法:采用冷冻干燥法,以粒径、Zeta电位为指标,对预冻温度和冻干保护剂的种类、配比及质量分散进行单因素试验考察及验证,将液相沉淀法制备的阿苯达唑纳米混悬液,制备成阿苯达唑纳米微粉。结果:预冻温度为-20℃、冻干保护剂为4%葡萄糖-甘露醇(3∶7)时,所制纳米微粉的平均粒径为(208.03±2.13)nm,平均Zeta电位为(-15.53±0.18)m V。结论:该冻干工艺可制得粒径、电位较优的阿苯达唑纳米微粉。     

离子型温敏纳米凝胶的制备及其载药性能评价

目的:制备离子型N-异丙基丙烯酰胺(NIPAM)类温敏纳米凝胶用于静电吸附载药。方法:分别采用乳液聚合(EP)、种子乳液聚合(SEP)和无皂乳液聚合(SFEP)法将NIPAM与丙烯酸(AA)或甲基丙烯酸β-硫酸乙基酯(SEMA)共聚制成纳米凝胶,通过TEM、PCS、电位滴定等方法表征各凝胶颗粒的形貌尺寸、温敏行为及单体含量。以阿霉素为模型药物,考察纳米凝胶通过静电吸附载药的能力。结果:EP或SEP法制备的AA凝胶(PNA)单分散性和温敏性良好,单体能完全参与聚合,当温度从20 ℃升至45 ℃时,粒径约从100 nm降至50 nm。EP法制备的SEMA凝胶(PNS)单分散性较差,改用SFEP法能提高凝胶的单分散性,但是约40%单体没有参与共聚。PNS凝胶的温敏性仍得到保留,20~45 ℃下粒径约为200~140 nm。核-壳型纳米凝胶的载药量和包封率最低,随着交联密度的增大,PNA纳米凝胶的载药量也相应提高。PNS纳米凝胶的载药量和包封率分别为14.6%和85.3%,载药能力最强,约为PNA纳米凝胶的2~3倍。PNS纳米凝胶负载的药物在纯水中24 h不释放,在生理盐水中约2 h释放完全。结论:PNS纳米凝胶粒径均一,具有温敏性,载药性能好,有望成为一个智能响应性纳米药物载体。     

β-环糊精-聚乙二醇-7-乙基-10-羟基喜树碱纳米胶束的制备及其质量评价

目的制备两亲性聚合物β-环糊精-聚乙二醇-7-乙基-10-羟基喜树碱(β-CD-PEG-SN38)纳米胶束并进行质量评价。方法采用自组装法制备β-CD-PEG-SN38纳米胶束,采用单因素变量法对影响纳米胶束粒径的因素进行了考察,并对β-CD-PEG-SN38纳米胶束的粒径、Zeta电位、形态和稳定性进行评价。结果胶束制备的最佳条件为丙酮作有机溶剂,β-CD-PEG-SN38在丙酮中的质量浓度为1 mg/mL,有机相和水相的体积比为1∶8。该纳米胶束大小适中、粒径分布均匀,为均匀的球形结构。β-CD-PEG-SN38纳米胶束的临界胶束质量浓度为7μg/mL,在模拟的生理条件下具有良好的胶体稳定性,在4℃条件下储存6个月的粒径未发生明显变化。结论β-CD-PEG-SN38在水中能自发形成纳米胶束,粒径均匀、稳定性好,具有良好的胶体稳定性和长期储存稳定性。     

胰岛素纳米粒温敏凝胶的制备及体外释药性能

目的:制备胰岛素壳聚糖温度敏感型原位凝胶(INS-CS-NP-TISG)并进行体外释药动学考察。方法:采用离子凝胶化法制备胰岛素壳聚糖纳米粒;均匀设计法优化其处方及制备工艺,观察形态,测定粒径、表面电位、包封率和载药量;冷法配液的方法制备温度敏感型原位凝胶,改进透析袋-恒温水浴法研究胰岛素壳聚糖纳米粒温度敏感型原位凝胶溶液的体外释药动学。结果:优化制得的纳米粒呈类球形,均匀圆整,分散性好;平均粒径为(255.3±143.5)nm,在175.2~349.6nm范围内的纳米粒子达99.4%,大小均匀,分布较窄;高效液相色谱法(HPLC)测定胰岛素壳聚糖纳米粒平均包封率和载药量分别为75.84%与58.52%;表面电位(ζ)为+32.67;在人工鼻黏液中,胰岛素壳聚糖纳米粒温度敏感型原位凝胶的体外释药符合双相动力学方程,且持续释药24h。结论:选用合适的处方制备胰岛素壳聚糖纳米粒温度敏感型原位凝胶,方法简便,药物载药量高,具有较好的生物黏附性,并有一定的缓释作用。     

漆黄素纳米混悬剂和冻干粉末的制备及体外评价

目的:制备漆黄素纳米混悬剂及其冻干粉末,提高药物溶解度及溶出度.方法:高压均质法制备漆黄素纳米混悬剂.以粒径为评价指标,单因素考察聚乙烯吡咯烷酮K30 (PVP K30)用量、有机相与水相体积比、均质压力和次数的影响.采用Box-Behnken响应面法优化漆黄素纳米混悬剂的处方工艺,并制备成冻干粉.扫描电镜观察纳米混悬...     

紫杉醇纳米金刚石递药系统的构建及其体外评价

目的制备羧化纳米金刚石紫杉醇载药体系,单因素试验优化制备工艺,并进行体外评价。方法在混酸油浴下制备羧化纳米金刚石,以红外光谱进行结构确证。采用超声法包载紫杉醇,并以粒径大小为指标对制备工艺进行单因素考察,对优化后的纳米复合物进行制剂学和细胞毒性研究。结果通过红外图谱验证了羧化纳米金刚石的成功合成,优化纳米复合物呈均匀分散,平均粒径为(145.92±63.91)nm,Zeta电位为(-10.49±3.24)mV,体外释放具有更明显的缓释效果,细胞毒研究显示,羧化纳米金刚石紫杉醇载药系统对MCF-7肿瘤细胞的增殖具有更强的抑制作用,10μg·m L~(-1)可将细胞存活率控制在50%。结论羧化纳米金刚石具有更优的载药性质,减缓了药物的释放,用此载体载药可以提高紫杉醇的抗癌活性,羧化纳米金刚石是极具应用前景的抗肿瘤递药载体。     

柠檬苦素纳米混悬剂和冻干粉的制备及体外评价

目的:制备柠檬苦素纳米混悬剂及其冻干粉末，并进行体外评价。方法:以纳米混悬剂粒径为指标，单因素考察投药量、稳定剂用量、大豆磷脂(SPC)占稳定剂的比例等影响。采用Box-Behnken响应面法优化柠檬苦素纳米混悬剂的处方工艺，测定粒径及Zeta电位，并采用扫描电镜法观察纳米粒子形貌。冷冻干燥法制备柠檬苦素纳米混悬剂冻干粉，X射线粉末衍射法分析存在状态，平衡法测定溶解度，透析袋法评价其体外溶出度。结果:柠檬苦素纳米混悬剂最佳处方为：投药量为30 mg,稳定剂用量为88 mg,大豆磷脂占稳定剂比例为60%。平均粒径为(187.29±6.46)nm,与Box-Behnken响应面法预测值接近。Zeta电位值为(-31.58±1.77)mV,柠檬苦素纳米粒子外貌为球形或类球形。X射线粉末衍射法结果显示柠檬苦素纳米混悬剂冻干粉中以无定型状态存在，溶解度提高至95.63倍，纳米混悬剂在240 min累积溶出度达到96.11%。结论:将柠檬苦素制备成纳米混悬剂冻干粉可以提高其溶解度和溶出度，为进一步临床开发奠定了基础。     

羧甲基壳聚糖-聚乙二醇作为胰岛素载体的研究

目的：制备胰岛素-羧甲基壳聚糖-聚乙二醇纳米粒。方法：利用红外光谱（FTIR）和核磁共振氢谱（¹H-NMR）对羧甲基壳聚糖-聚乙二醇的结构进行表征,用粒度分析仪测定纳米粒的粒径分布及电位,采用动态透析法考察纳米粒的释药性能,用CCK-8试剂盒检测纳米粒细胞毒性,以糖尿病小鼠为模型,研究纳米粒的降血糖作用。结果：聚乙二醇成功接枝到羧甲基壳聚糖上,包埋胰岛素的纳米粒的平均粒径为（257.5±12.1）nm,Zeta电位为（-15.2±0.3）mV,负载胰岛素的羧甲基壳聚糖-聚乙二醇纳米粒在中性释放介质中,5 h内胰岛素的释放速度较快,之后8 h趋于平稳,胰岛素的累计释放量可达到80%,CCK-8试剂盒显示纳米粒对L929细胞基本无细胞毒性,50 U·kg^-1的纳米粒溶液经灌胃给药后,血糖浓度明显降低。结论：胰岛素-羧甲基壳聚糖-聚乙二醇纳米粒基本无毒性,具有良好的生物相容性,对糖尿病小鼠有效发挥降血糖作用。     

Development and in-vivo evaluation of insulin-loaded chitosan phthalate microspheres for oral delivery

Novel chitosan phthalate microspheres containing insulin were prepared by emulsion cross-linking technique. The feasibility of these microspheres as oral insulin delivery carriers was evaluated. The pH-responsive release behaviour of insulin from microspheres was analysed. The ability of chitosan phthalate-insulin microspheres to enhance intestinal absorption and improve the relative pharmacological availability of insulin was investigated by monitoring the plasma glucose and insulin level of streptozotocin-induced diabetic rats after oral administration of microspheres at insulin dose of 20 IU kg(-1). In simulated gastric fluid (pH 2.0), insulin release from the microspheres was very slow. However, as the pH of the medium was changed to simulated intestinal fluid (pH 7.4), a rapid release of insulin occurred. The relative pharmacological efficacy for chitosan phthalate microspheres (18.66 +/- 3.84%) was almost four-fold higher than the efficacy of the chitosan phthalate-insulin solution administration (4.08 +/- 1.52%). Chitosan phthalate microspheres sustained the plasma glucose at pre-diabetic level for at least 16 h. These findings suggest that the microsphere is a promising carrier as oral insulin delivery system.     

Acute and chronic treatment of L-isoleucine ameliorates glucose metabolism in glucose-intolerant and diabetic mice

The administration of L-isoleucine (isoleucine) has been shown to induce hypoglycemia in normal rats. However, it remains to be elucidated whether isoleucine can improve the blood glucose level in glucose-intolerant or diabetic animals. In the present study, oral isoleucine significantly reduced the blood glucose level after an oral glucose challenge in normal mice, as well as in glucose-intolerant mice fed a high-fat diet (HFD) and db/db mice, a model of severe type 2 diabetes. Isoleucine treatment significantly augmented the blood insulin level after an oral glucose load in HFD mice, but not in normal or db/db mice, suggesting that its hypoglycemic activity was attributable to both insulinotropic and non-insulinotropic mechanisms. Chronic supplementation of isoleucine in mice on a high-fat/high-sucrose diet significantly reduced insulin release after an oral glucose challenge without any change in glucose tolerance curve, suggesting that isoleucine might have an insulin-sensitizing effect along with its acute hypoglycemic effect. These results indicate that both acute and chronic treatment with isoleucine is beneficial for glucose metabolism in glucose-intolerant and diabetic animals.     

西红柿凝集素修饰脂质体对小鼠口服吸收胰岛素的促进作用西红柿凝集素修饰脂质体对小鼠口服吸收胰岛素的促进作用

目的研究西红柿凝集素修饰的胰岛素脂质体在小鼠胃肠道吸收作用。方法采用碳二亚胺交联法制备西红柿凝集素(TL)修饰的磷脂酰乙醇胺(PE),将TL-PE掺入胰岛素脂质体中制成凝集素修饰脂质体并证实TL凝集活性不受影响。分别对正常小鼠及糖尿病模型小鼠灌胃给予350 u·kg^-1胰岛素的修饰脂质体溶液,用葡萄糖酶试剂盒测定小鼠血糖,并与同剂量普通胰岛素脂质体比较。结果正常小鼠中,西红柿凝集素修饰脂质体在4 h血糖降至初始水平的(85±5)%,8 h降至(54±11)%,12 h为(57±6)%。胰岛素普通脂质体几乎没有降糖作用,与生理盐水对照组相当。糖尿病模型小鼠中,西红柿凝集素修饰脂质体在4 h血糖降至初始水平的(38±13)%,8 h降至(50±15)%,12 h为(50±16)%。结论西红柿凝集素修饰的脂质体可能通过与细胞表面特异性受体的结合作用促进大分子药物的胃肠吸收。     

Influence of magnesium stearate on the physicochemical and pharmacodynamic characteristics of insulin-loaded Eudragit entrapped mucoadhesive microspheres

Abstract

Effective oral insulin delivery has remained a challenge to the pharmaceutical industry. This study was designed to evaluate the effect of magnesium stearate on the properties of insulin-loaded Eudragit® RL 100 entrapped mucoadhesive microspheres. Microspheres containing Eudragit® RL 100, insulin, and varying concentrations of magnesium stearate (agglomeration-preventing agent) were prepared by emulsification-coacervation method and characterized with respect to differential scanning calorimetry (DSC), morphology, particle size, loading efficiency, mucoadhesive and micromeritics properties. The in vitro release of insulin from the microspheres was performed in simulated intestinal fluid (SIF, pH 7.2) while the in vivo hypoglycemic effect was investigated by monitoring the plasma glucose level of the alloxan-induced diabetic rats after oral administration. Stable, spherical, brownish, mucoadhesive, discrete and free flowing insulin-loaded microspheres were formed. While the average particle size and mucoadhesiveness of the microspheres increased with an increase in the proportion of magnesium stearate, loading efficiency generally decreased. After 12?h, microspheres prepared with Eudragit® RL 100: magnesium stearate ratios of 15:1, 15:2, 15:3 and 15:4 released 68.20?±?1.57, 79.40?±?1.52, 76.60?±?1.93 and 70.00?±?1.00 (%) of insulin, respectively. Reduction in the blood glucose level for the subcutaneously (sc) administered insulin was significantly (p?≤?0.05) higher than for most of the formulations. However, the blood glucose reduction effect produced by the orally administered insulin-loaded microspheres prepared with four parts of magnesium stearate and fifteen parts of Eudragit® RL 100 after 12?h was equal to that produced by subcutaneously administered insulin solution. The results of this study can suggest that this carrier system could be an alternative for the delivery of insulin.     

Hypoglycemic efficacy of chitosan-coated insulin liposomes after oral administration in mice

INTRODUCTION In the past two decades the potential usefulnessof liposomes as drug carriers for improving enteral ab-sorption of poorly absorbed drugs including peptidedrugs such as insulin has attracted considerable interest.These phospholipid vesicles are capable of encapsulat-ing both hydrophobic and hydrophilic drugs; they arebiodegradable and are not toxic in vivo. The drugsencapsulated in liposomes are sufficiently protectedfrom enzymatic attack and immune recognition[1]. Li-po…     

Enteric-coated insulin microparticles delivered by lipopeptides of iturin and surfactin

Surfactin, a lipopeptide produced by Bacillus species, has been used for the oral delivery of insulin. In this study, another lipopeptide of iturin was tested for its ability to orally delivery insulin alone or plus surfactin. Iturin could form co-precipitate with insulin at acidic pH values. After treatment by ultrasonification, the structure of coprecipitate was destroyed that led to a significant decrease in hypoglycemic effect after oral administration. Iturin weakly binds to (Kd?=?257?μM) and induce insulin structure more compact that is favorable for insulin uptake by the intestine. After being coated with Acryl-Eze by lyophilization, the coprecipitate formed the spherical enteric-coated insulin microparticles delivered by iturin with a relative oral bioavailability of 6.84% in diabetic mice. For further improving oral hypoglycemic effect, surfactin was added to form the spherical enteric-coated insulin microparticles in a formulation containing insulin, Acryl-Eze, iturin and surfactin at a ratio of 1:1:0.5: 0.5 (w/w), with an insulin encapsulation efficiency of 66.22%. The enteric-coated insulin microparticles delivered by iturin plus surfactin showed a classical profile for controlled release in the intestine with a relative bioavailability of 7.67% after oral administration, which could effectively control the postprandial blood glucose at a level about 50% of the initial one just like the subcutaneous injection. Collectively, iturin plus surfactin is more efficient for oral delivering insulin than the sole one, and the resultant enteric-coated insulin microparticles are potential for the development of oral insulin to control postprandial blood glucose in diabetic patients.     

Calcium phosphate-PEG-insulin-casein (CAPIC) particles as oral delivery systems for insulin

An oral delivery system for insulin was developed and functional activity was tested in a non-obese diabetic (NOD) mice model. Calcium phosphate particles containing insulin was synthesized in the presence of PEG-3350 and modified by aggregating the particles with caseins to obtain the calcium phosphate-PEG-insulin-casein (CAPIC) oral insulin delivery system. Single doses of CAPIC formulation were tested in NOD mice under fasting or fed conditions to evaluate the glycemic activity. The blood glucose levels were monitored every 1-2h for 12h following the treatments using an ACCU CHECK blood glucose monitoring system. Orally administered and subcutaneously injected free insulin solution served as controls in the study. Based on the results obtained we propose that: (1). the biological activity of insulin is preserved in CAPIC formulation; (2). insulin in CAPIC formulations, but not the free insulin, displays a prolonged hypoglycemic effect after oral administration to diabetic mice; (3). CAPIC formulation protects insulin from degradation while passing through the acidic environment of the GI track until it is released in the less acidic environment of the intestines where it can be absorbed in its biologically active form; (4). CAPIC formulation represents a new and unique oral delivery system for insulin and other macromolecules.     

Preparation,characterization, and evaluation in vivo of Ins-SiO2-HP55 (insulin-loaded silica coating HP55) for oral delivery of insulin

Insulin is the most effective and durable drug in the treatment of advanced stage diabetes. However, oral delivering insulin was a tough task for rapid enzymatic degradation. In this work, we designed and developed a delivery system composed of enteric nanosphere for oral delivery of insulin. The silica was selected for loading insulin, which surface has a lot of pores with a powerful adsorption capacity, advantages for permeability and slow-release. The insulin-loaded silica (Ins-SiO₂) was prepared by adsorption in HCl solution. The Ins-SiO₂ obtained was coated with the hydroxypropyl methylcellulose phthalate (HP55) by desolvation method, which is a good enteric coating material. The Ins-SiO₂-HP55, an enteric nanosphere of insulin obtained were characterized by transmission electron microscope (TEM), surface area, Fourier-transform infrared (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The results showed that insulin was loaded most in the pores of silica, while the HP55 coated on the extent of Ins-SiO_2. In vitro drug release results revealed that the release of insulin from Ins-SiO₂-HP55 was markedly reduced in simulated gastric fluid (SGF). By contrast, the release amount of insulin from Ins-SiO₂-HP55 was increased significantly in simulated intestinal fluid (SIF). In vivo evaluation on diabetic animals showed the blood glucose level of diabetic rats could be effectively reduced after oral administration Ins-SiO₂-HP55. There is marked hypoglycemic effect after 1 h of taking the Ins-SiO₂-HP55. After 3 h, the GLU of rats of the Ins-SiO₂-HP55 stably kept from 4.85 to 2.67 mmol/L that was significantly less than the normal level (6.7 mmol/L). However, that of rats taking raw insulin kept from 8.03 to 6.56 mmol/L that is higher than the normal level. These results suggested that Ins-SiO₂-HP55 could have potential value in oral administration systems of diabetes chemotherapy.     

Development of novel gastroretentive floating particulate drug delivery system of gliclazide

The objective of present project was to improve the dissolution profile of gliclazide by developing floating alginate beads using various biodegradable polymers like gelatin, pectin and hydroxypropylmethylcellulose (HPMC). The floating beads were prepared by a simple ionotropic gelatin method using calcium carbonate as gas generating agent. The developed beads were characterized by Fourier transform infrared spectroscopy analysis, differential scanning calorimetry, X-ray diffraction analysis and scanning electron microscopy (SEM). The prepared beads showed good in vitro floatation, which was dependent on the concentration of gas-forming agent. SEM photomicrographs confirmed that the developed beads were spherical in shape and had particle size in the range of 730 to 890 μm. The incorporation efficiency was found to be in the range of 59.96 to 85.1%. The cumulative percent drug release from the beads after 10 h dissolution study at pH 1.2 and pH 5.8 was in the range of 33 to 46% and 82 to 95% respectively. The concentration of the gas generating agent was found to influence the release rate. The mechanism of drug release was Fickian diffusion with swelling. The in vivo sub-acute hypoglycemic study in high fat diet induced diabetic C57BL/6J mice demonstrated significant (p < 0.05) hypoglycemic effect over a period of 12 h and 24 h, respectively, with HPMC and pectin beads. A significant (p & 0.05) reduction in fasting and non-fasting blood glucose levels, reduction in fasting plasma insulin level and a significant improvement in glucose tolerance were observed in animals treated with formulations. The developed beads were suitable carriers for improving the systemic absorption of gliclazide and maintaining reduced blood glucose levels.