用离子交联-匀化工艺制备乙肝疫苗壳聚糖纳米粒

目的：研究制备乙肝疫苗壳聚糖（chitosan，CS）纳米粒的适宜条件和影响因素。方法：以CS溶液和三聚磷酸钠溶液，采用离子交联-高压匀化工艺制备乙肝疫苗壳聚糖纳米粒，考察CS的浓度、CS与二聚磷酸钠的质量比及高压匀化对壳聚糖纳米粒粒径和多分散系数的影响，测定了载药纳米粒的包封率和载药量。结果：当CS与三聚磷酸钠的浓度都为2mg/mL，质量比为3：1～6：1，通过离子交联-高压匀化工艺可以得到稳定的纳米粒。纳米粒外观圆整，粒径分布均匀，包封率达到90％以上。结论：用离子交联－高压匀化工艺制备CS纳米粒不需要使用有机溶剂，包封率较高，可以满足给药系统应用要求。     

盐酸吉西他滨壳聚糖纳米粒的制备及其体外释药特性研究

目的:优化盐酸吉西他滨壳聚糖纳米粒的制备参数,考察纳米粒体外释药特性。方法:以壳聚糖为辅料,采用离子交联法制备盐酸吉西他滨壳聚糖纳米粒,以包封率、载药量、粒径为参考指标设计试验,确定优化制备参数,以透射电镜观察其表观特征,考察纳米粒体外释药程度。结果:以优化参数制备的盐酸吉西他滨壳聚糖纳米粒包封率为(78.93±1.52)%,载药量为(11.71±0.88)%,纳米粒的平均粒径为(169±24)nm,体外释放试验表明纳米粒中盐酸吉西他滨的释放过程符合Higuchi方程。结论:盐酸吉西他滨可以通过离子交联法制备壳聚糖纳米粒,其粒径、包封率、载药量可控,具有缓释效果。     

壳寡糖-水杨酸接枝物纳米粒用于释放阿霉素的研究

目的 考察壳寡糖/水杨酸纳米粒负载碱化阿霉素的可能性,评价制备而得的微粒给药系统理化性质及其体外释放行为。方法 以碳二亚胺为交联偶合剂合成壳寡糖/水杨酸接枝共聚物,三硝基苯磺酸法测定水杨酸接枝率。运用超声分散法制备壳寡糖/水杨酸空白纳米粒,芘荧光法测定纳米粒临界聚集浓度,动态光散射法测定微粒粒径和表面电位,MTT法考察空白纳米粒的细胞毒性。以碱化阿霉素为模型药物,透析法制备壳寡糖/水杨酸载药纳米粒,经透射电镜考察载药纳米粒的形态,对其体外释放行为进行了研究。结果 合成得到的壳寡糖分子量=9000/水杨酸理论投料量=50%的实际接枝率为16.92%,空白纳米粒的临界聚集浓度为867.0 μg/mL,空白纳米粒的粒径和表面Zeta电位分别为434.0 nm和48.6 mV,对人肝癌细胞Hep-G2的半数抑制浓度为1745μg/mL。在碱化阿霉素理论投药量为10%时壳寡糖/水杨酸载药纳米粒的实际载药量为8.52%,包封率为93.15%。;载药纳米粒的粒径和表面电位分别为214.2 nm和33.6 mV。体外释放结果表明药物的释放呈现pH敏感性;并主要以溶蚀的方式从载体内部释放出来。结论 壳寡糖/水杨酸接枝物可以有效包裹碱化阿霉素并成为粒径均一的纳米粒给药系统。载药纳米粒具有pH敏感和缓释作用。壳寡糖/水杨酸接枝物有望成为潜在的难溶性药物的载体材料。     

阿昔洛韦眼用壳聚糖纳米粒的制备及家兔生物利用度研究

目的:应用离子交联法制备阿昔洛韦壳聚糖纳米粒,考察其体外性质及其经家兔眼部给药后的生物利用度.方法:壳聚糖与三聚磷酸钠通过离子交联作用制备纳米粒,考察了纳米粒的粒径、Zeta电位、包封率以及体外释放性质,通过家兔眼部结膜囊内给药,考察眼房水中药物浓度的变化,并与市售阿昔洛韦滴眼液相比较.结果:阿昔洛韦壳聚糖纳米粒的平均粒径为235 nm,多分散系数为0.256,Zeta电位为43.9 mV;平均包封率为15.6%,平均载药量为1.9%;家兔眼部给药后,AUC0→6 h达到3.69μg·h-1·mL-1,是市售制剂的2.4倍.结论:实验初步证实制备的壳聚糖纳米粒可以促进阿昔洛韦的眼部吸收.     

三甲基化壳聚糖卵清蛋白纳米粒的制备

目的：以N-三甲基壳聚糖盐酸盐（N—trimethyl chitosan chloride，TMC）为材料制备新型纳米粒（nanoparticles，NPs），包裹卵清蛋白（ovalbumin，OVA），以提高卵清蛋白的包封率。方法：利用TMC与三聚磷酸钠（tripolyphosphatesodium，TPP）之间的离子胶凝作用制备纳米粒；用纳米粒度及表面电位分析仪测定纳米粒的粒径及zeta电位；探讨OVA溶液的pH值及浓度，TMC溶液的浓度，TPP溶液的浓度等因素对OVA包封率的影响；用十二烷基硫酸钠一聚丙烯酰胺明胶电泳（Soldium Dodeoyl Sulfate—Polyacrylamide，SDS-PAGE）检验OVA在纳米粒制备及体外释放过程中有无降解。结果：本研究制备的TMC／OVA纳米粒为紧密球形，分布均匀，粒径约为135．4nm，zeta电位约为＋20mV；OVA的pH值及制备工艺是影响包封率的主要因素；SDS-PAGE电泳证实在纳米粒的制备及释放过程中OVA没有降解。结论：用离子胶凝法制备载蛋白多肽类疫苗的纳米粒，操作简便，采用合适的制备方法，调整处方可将包封率提高到90％以。     

乙酰半胱氨酸纳米粒的制备及体外释放研究

目的制备乙酰半胱氨酸纳米粒,并对其进行体外释放的研究。方法溶剂扩散法制备乙酰半胱氨酸纳米粒,单因素考察了壳聚糖浓度、油相中乙醇浓度、油水相比例对乙酰半胱氨酸纳米粒形态、大小、包封率的影响,通过透析袋法研究乙酰半胱氨酸纳米粒体外释药过程。结果经筛选得到形成纳米粒的最佳工艺为壳聚糖浓度2mg.min-1、乙醇浓度25%、油水相比为10∶1。该工艺制备纳米粒大小圆整,粒径为163±12.8nm,包封率达81%。体外释放结果表明,乙酰半胱氨酸纳米粒具有一定的缓释作用,药物在24h累积释放74.5%。结论溶剂扩散法制备乙酰半胱氨酸纳米粒方法简便、药物包封率高,该纳米粒是一种比较理想的乙酰半胱氨酸新剂型。     

三甲基壳聚糖分子量对载胰岛素纳米粒的影响

目的 研究不同分子量的三甲基壳聚糖(TMC)对载胰岛素口服纳米粒性质的影响,以寻找更适于口服的TMC分子量.方法 选用高、中、低分子量(400、200、50 kDa)的TMC为载体材料,采用离子交联法制备载胰岛素的聚电解质纳米粒;以不同分子量的TMC、三聚磷酸钠(TPP)和胰岛素(Ins)的浓度为考察因素,以纳米粒表面形态、粒径、Zeta电位、包封率和载药量为考察指标,进行单因素筛选试验,对比不同分子量的TMC对纳米粒性质的影响.结果与结论 中分子量TMC载胰岛素纳米粒的载药量较高,包封率合适,且释药较平稳,为相对较优的载体材料.     

N-琥珀酰壳聚糖纳米粒的制备及体外评价

目的制备N-琥珀酰壳聚糖纳米粒并对其进行体外评价。方法采用乳化溶剂挥发法制备N-琥珀酰壳聚糖纳米粒;以包封率、载药量及粒径为指标,采用正交设计法对处方进行优化;考察其理化特征及体外释药行为。结果纳米粒包封率及载药量分别为62.36%和18.98%,平均粒径及zeta电位分别为(206.6±64.7)nm和(-27.2±0.2)mV;1 h药物释放达到45%,随后药物的释药行为是一个缓释过程。结论作者采用乳化溶剂挥发法成功制得N-琥珀酰壳聚糖纳米粒。该方法制得纳米粒包封率较高,制备工艺简单。     

超临界辅助喷雾法用于固体脂质纳米粒的制备

目的采用超临界辅助喷雾制粒法制备固体脂质纳米粒,并考察工艺与处方因素对纳米粒理化性质的影响。方法采用自制超临界喷雾制粒设备,制备硬脂酸脂质纳米粒,考察硬脂酸浓度、超临界流体CO2与载体溶液流量比、喷嘴孔径等对固体脂质纳米粒粒径的影响,筛选合适的处方工艺参数;以亲水性大分子药物胰岛素为模型药物,制备载药固体脂质纳米粒,评价纳米粒的粒径、电位、包封率、释放度等理化性质。结果制备得到的纳米粒粒径与载体浓度、超临界流体CO2与载体溶液流量比、喷嘴孔径有关,通过处方工艺的调节,可制得平均粒径〈300nm的固体脂质纳米粒;制得的胰岛素固体脂质纳米粒的平均粒径约300nm,包封率72．2％,载药量为3．44％,载药纳米粒在体外可实现12h缓慢释放;处方中加入泊洛沙姆可减小纳米粒粒径和粒度分布,但药物的包封率降低,并且突释现象更明显。结论超临界辅助喷雾制粒法可用于固体脂质纳米粒的制备,并能够对亲水性药物实现有效的包封和释放的调节。     

乳化蒸发法制备固体脂质纳米粒

目的：采用乳化蒸发法制备固体脂质纳米粒,并考察其载药性能。方法：对影响固体脂质纳米粒质量的工艺因素和处方因素进行考察和优化设计,得到最优处方。选用模型药物酮洛芬制备载药固体脂质纳米粒,考察其包封率和体外释放行为。结果：所得固体脂质纳米粒平均粒径为（228.2±18.1）nm,多分散系数为（0.217±0.022）,ξ电位为-（21.4±0.6）mV。载药固体脂质纳米粒最佳包封率为（64.1±3.3）%,体外释放行为符合Weibull模型。结论：采用乳化蒸发法制备固体脂质纳米粒是可行的。     

Chitosan drug binding by ionic interaction.

Three model drugs (insulin, diclofenac sodium, and salicylic acid) with different pI or pKa were used to prepare drug-chitosan micro/nanoparticles by ionic interaction. Physicochemical properties and entrapment efficiencies were determined. The amount of drug entrapped in the formulation influences zeta potential and surface charge of the micro/nanoparticles. A high entrapment efficiency of the micro/nanoparticles could be obtained by careful control of formulation pH. The maximum entrapment efficiency did not occur in the highest ionization range of the model drugs. The high burst release of drugs from chitosan micro/nanoparticles was observed regardless of the pH of dissolution media. It can be concluded that the ionic interaction between drug and chitosan is low and too weak to control the drug release.     

正交试验优选羧甲基壳聚糖-醋甲唑胺纳米微球的制备方案

目的：制备羧甲基壳聚糖载药纳米微球,醋甲唑胺为模型药物,测量药物的包封率和纳米微球形态.方法：采用乳化交联法,在微乳液的基础上制备载药纳米微球,对可能影响药物包封率的处方因素进行优化设计,筛选出最优配方.结果：羧甲基壳聚糖溶液的浓度对包封率有显著性影响,三聚磷酸钠溶液浓度和醋甲唑胺药量对包封率未见影响.优化方案的载药纳米微球包封率为49.36％,其电镜下为较规整的球型纳米微球,平均粒径386.0 nm.结论：采用乳化交联法,可形成较高包封率的羧甲基壳聚糖-醋甲唑胺纳米微球.     

Chitosan nanoparticles for controlled delivery of brimonidine tartrate to the ocular membrane

Various efforts have been made to improve the bioavailability and to prolong the residence time of eye drops. Drug loaded polymeric nanoparticles offer several favorable biological properties. Thus, brimonidine tartrate (BT) loaded chitosan (CS) nanoparticles were prepared by inducing the ionic gelation upon addition of sodium tripolyphosphate (TPP). Nanoparticles were characterized by TEM, SEM, particle size, polydispersity index (PI), DSC, IR, entrapment efficiency which gave an insight of physicochemical interaction that influenced the CS nanoparticle formation and entrapment of BT. In vitro release of BT nanoparticle showed sustained release over the period of 4 h in saline phosphate buffer pH 7.4. Both placebo and BT loaded nanoparticles had a mean particle size range of about 270-370 nm with PI less than 0.5. DSC studies demonstrated structural interactions between BT, TPP and CS matrix. Entrapment efficiency of the CS nanoparticles ranged from 36-49% depending on the CS:TPP weight ratio. In vivo studies confirmed a significant sustained effect of BT nanoparticles compared to conventional eye drops. These results suggest that BT loaded CS nanoparticles could help to reduce dosage frequency by sustained drug release in the treatment of glaucoma.     

Intranasal Delivery of Chitosan Nanoparticles for Migraine Therapy

Objective

The objective of the research was to formulate and evaluate sumatriptan succinate-loaded chitosan nanoparticles for migraine therapy in order to improve its therapeutic effect and reduce dosing frequency.

Material and Methods

The Taguchi method design of experiments (L9 orthogonal array) was applied to obtain the optimized formulation. The sumatriptan succinate-loaded chitosan nanoparticles (CNPs) were prepared by ionic gelation of chitosan with tripolyphosphate anions (TPP) and Tween 80 as surfactant.

Results

The CNPs had a mean size of 306.8 ± 3.9 nm, a zeta potential of +28.79 mV, and entrapment efficiency of 75.4 ± 1.1%. The in vitro drug release of chitosan nanoparticles was evaluated in phosphate buffer saline pH 5.5 using goat nasal mucosa and found to be 76.7 ± 1.3% within 28 hours.

Discussion

The release of the drug from the nanoparticles was anomalous, showing non-Fickian diffusion indicating that drug release is controlled by more than one process i.e. the superposition of both phenomena, a diffusion-controlled as well as a swelling-controlled release. This is clearly due to the characteristics of chitosan which easily dissolves at low pH, thus a nasal pH range of 5.5 ± 0.5 supports it very well. The mechanism of pH-sensitive swelling involves protonation of the amine groups of chitosan at low pH. This protonation leads to chain repulsion, diffusion of protons and counter ions together with water inside the gel, and the dissociation of secondary interactions.

Conclusion

The results suggest that sumatriptan succinate-loaded chitosan nanoparticles are the most suitable mode of drug delivery for promising therapeutic action.     

Brain targeted oral delivery of doxycycline hydrochloride encapsulated Tween 80 coated chitosan nanoparticles against ketamine induced psychosis: behavioral,biochemical, neurochemical and histological alterations in mice

To develop statistically optimized brain targeted Tween 80 coated chitosan nanoparticulate formulation for oral delivery of doxycycline hydrochloride for the treatment of psychosis and to evaluate its protective effect on ketamine induced behavioral, biochemical, neurochemical and histological alterations in mice. 3² full factorial design was used to optimize the nanoparticulate formulation to minimize particle size and maximize entrapment efficiency, while independent variables chosen were concentration of chitosan and Tween 80. The optimized formulation was characterized by particle size, drug entrapment efficiency, Fourier transform infrared, Transmission electron microscopy analysis and drug release behavior. Pure doxycycline hydrochloride (25 and 50?mg/kg, p.o.) and optimized doxycycline hydrochloride encapsulated Tween 80 coated chitosan nanoparticles (DCNP_opt) (equivalent to 25?mg/kg doxycycline hydrochloride, p.o.) were explored against ketamine induced psychosis in mice. The experimental studies for DCNP_opt, with mean particle size 237?nm and entrapment efficiency 78.16%, elucidated that the formulation successfully passed through blood brain barrier and exhibited significant antipsychotic activity. The underlying mechanism of action was further confirmed by behavioral, biochemical, neurochemical estimations and histopathological study. Significantly enhanced GABA and GSH level and diminished MDA, TNF-α and dopamine levels were observed after administration of DCNP_opt at just half the dose of pure doxycycline hydrochloride, showing better penetration of doxycyline hydrochloride in the form of Tween 80 coated nanoparticles through blood brain barrier. This study demonstrates the hydrophilic drug doxycycline hydrochloride, loaded in Tween 80 coated chitosan nanoparticles, can be effectively brain targeted through oral delivery and therefore represents a suitable approach for the treatment of psychotic symptoms.     

壳聚糖纳米粒表面游离氨基与纳米粒特性研究

为研究对三聚磷酸钠(TPP)交联的壳聚糖纳米粒的表面游离氨基与纳米粒的性质之间的关联性,采用胶体滴定法测定壳聚糖纳米粒表面氨基游离率，考察表面游离氨基的数量及离解程度对纳米粒粒径、电位、形态及对药物包封率和体外释药特性的影响，并阐述这种变化机制。结果表明，随TPP浓度增加，表面游离氨基逐步减少，在一定TPP浓度范围内，纳米粒粒径减小，表面zeta电位降低，稳定性也随之下降，粒子易聚集，释药速度和程度也随之降低，但药物包封率未受到影响；随着pH升高，表面游离氨基离解程度降低，纳米粒粒径亦随之减小，表面zeta电位降低。酸性介质提高纳米粒的释药速度和程度，在中性和碱性介质中纳米粒的释药速度和程度明显降低。交联程度和pH影响表面游离氨基的数量或离解程度，进而影响纳米粒的体积相转变(溶胀/收缩过程)等重要性质。表面游离氨基与纳米粒性质间有密切的联系。     

Effect of chitosan salts and molecular weight on a nanoparticulate carrier for therapeutic protein

The objective of this study was to investigate the potential of chitosan salts as a carrier in the preparation of protein-loaded nanoparticles. Glutamic and aspartic acids were used to prepare chitosan salts of 35, 100, and 800 KDa. Nanoparticles of chitosan base, chitosan glutamate, and chitosan aspartate were produced by ionotropic gelation with sodium tripolyphosphate (TPP). Bovine serum albumin (BSA) was applied as a model protein at loading concentrations ranging from 0.2 to 2 mg/mL. The size of the nanoparticles, as measured by photon correlation spectroscopy, was in the range of 195 to 3450 nm, depending on type and molecular weight of chitosan. Nanoparticles prepared with higher molecular weight chitosan showed larger sizes. The encapsulation was controlled by the competition of BSA in forming ionic cross-linking with chitosan and by the entrapment of BSA during the gelation process. Higher BSA encapsulation efficiency (EE) was obtained for nanoparticles prepared with chitosan salts compared to those prepared with the base. The higher EE was a result of a higher degree of ionization, causing more active sites to interact with BSA. In addition, a higher and faster release of BSA from the nanoparticles into pH 7.4 buffer medium was observed for nanoparticles of the chitosan salts than was observed for nanoparticles of the chitosan base. The higher and faster release was attributed to higher EE and lower entrapment of BSA within the matrix of the nanoparticle during the gelation process. The influence of molecular weight on the property of nanoparticles exhibited different effects. The difference was a result of different organic acids used to prepare nanoparticles leading to the difference in polymer conformation and viscosity of organic acid solution. Therefore, this study showed that the characteristics of chitosan nanoparticles loaded with a protein drug could be readily modulated by changing the salt form or the molecular weight of the chitosan carrier.     

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。     

Pharmacokinetic variables of medium molecular weight cross linked chitosan nanoparticles to enhance the bioavailability of 5-fluorouracil and reduce the acute oral toxicity

To prepare glutaraldehyde-based cross-linked medium molecular weight chitosan nanoparticles encapsulated with 5-Fluorouracil (5-FU), to overcome dosing frequency as well as reducing acute oral toxicity and poor bioavailability of the drug. Medium molecular weight chitosan nanoparticles (MMWCH-NPs) were prepared by reverse micelles method based on glutaraldehyde (GA) cross-linking and optimized by the process as well as formulation variables like a various drug to polymer ratio, cross-linker volumes, varying stirring speeds (rpm), different time of rotation/stirring, respectively and their effects on the mean particles size distribution and entrapment efficiency %EE and %LC of NPs. Characterization of formulations was done by FTIR studies, TEM, PXRD, TGA, Stability, and dissolution drug release studies were performed by dialysis bag technique at both pH (1.2 & 7.4) and acute oral toxicity studies in albino rabbits. The formulated nanoparticles showed a smooth morphology with smaller particle size distribution (230–550 nm), zeta potential (−15 to −18 mV) required to achieve enhanced permeation and retention effect (EPR), entrapment efficiency (%EE 12–59%). These NPs exhibited a controlled drug release profile with 84.36% of the drug over a period of 24 h. Drug release data were fitted to different kinetic models which predominantly followed Fickian diffusion mechanism (R² = 0.972–0.976, N = 0.326–0.256). The optimized formulation (5-FU6) was observed under DSC/TGA, TEM. PXRD curves, FTIR, which confirmed thermal stability, structural integrity, amorphous state, compatibility between drug and polymer of optimized (5-FU6) as well as reduced acute oral toxicity in albino rabbits. Cross-linked medium molecular weight chitosan nanoparticles are nontoxic, well-tolerated therefore could be the future candidate for therapeutic effects as novel drug delivery carrier for anticancer drug(s).     

Bile salt-reinforced alginate-chitosan beads

A polymeric delayed release protein delivery system was investigated with albumin as the model drug. The polysaccharide chitosan was reacted with sodium alginate in the presence of calcium chloride to form beads with a polyelectrolyte. In this study, attempts were made to extend albumin release in the phosphate buffer at pH 6.8 from the alginate-chitosan beads by reinforcing the matrix with bile salts. Sodium taurocholate was able to prevent albumin release at pH 1.2, protecting the protein from the acidic environment and extending the total albumin release at pH 6.8. This effect was explained by an interaction between the permanent negatively charged sulfonic acid of sodium taurocholate with the amino groups of chitosan. Mild formulation conditions, high bovine serum albumin (BSA) entrapment efficiency, and resistance to gastrointestinal release seem to be synergic and promising factors toward the development of an oral protein delivery form.