Preparation and evaluation of microparticles from thiolated polymers via air jet milling

Microparticles were formulated by incorporation of the model protein horseradish peroxidase in (thiolated) chitosan and (thiolated) poly(acrylic acid) via co-precipitation. Dried protein/polymer complexes were ground with an air jet mill and resulting particles were evaluated regarding size distribution, shape, zeta potential, drug load, protein activity, release pattern, swelling behaviour and cytotoxicity. The mean particle size distribution was 0.5-12 microm. Non-porous microparticles with a smooth surface were prepared. Microparticles from (thiolated) chitosan had a positive charge whereas microparticles from (thiolated) poly(acrylic acid) were negatively charged. The maximum protein load for microparticles based on chitosan, chitosan-glutathione (Ch-GSH), poly(acrylic acid) (PAA) and for poly(acrylic acid)-glutathione (PAA-GSH) was 7+/-1%, 11+/-2%, 4+/-0.2% and 7+/-2%, respectively. The release profile of all microparticles followed a first order release kinetic. Chitosan (0.5mg), Ch-GSH, PAA and PAA-GSH particles showed a 31.4-, 13.8-, 54.2- and a 42.2-fold increase in weight, respectively. No significant cytotoxicity could be found. Thiolated microparticles prepared by jet milling technique were shown to be stable and to have controlled drug release characteristics. After further optimizations the preparation method described here might be a useful tool for the production of protein loaded drug delivery systems.     

Surface modified kokum butter lipid nanoparticles for the brain targeted delivery of nevirapine

Abstract

Aim: The present work investigates the efficacy of Polysorbate 80(P80) coated Kokum butter (KB) solid lipid nanoparticles (P80NvKLNs) for the brain targeted delivery of Nevirapine (Nv).

Methods: Solid lipid nanoparticles (SLNs) were prepared by nanoprecipitation technique and evaluated for drug excipient compatibility studies, z- average particle size (nm), zeta potential (mv), percentage drug entrapment efficiency (%EE), surface morphology and in-vitro drug release properties. The in-vivo biodistribution and brain targeting efficiency of nanoparticles were studied in healthy male Wistar rat (150–200?g).

Results: P80NvKLNs were found to be smooth surfaced, spherical shaped having average particle size of 177.80?±?0.82?nm, zeta potential of ?8.91?±?4.36?mv and %EE of 31.32?±?0.42%. P80NvKLNs remained in blood circulation for 48?h maintaining a sustained release in brain for 24?h (p?<?0.05).

Conclusion: The study proves the efficacy of Polysorbate 80 coated Kokum butter nanoparticles for brain-targeted delivery of drugs providing ample opportunities for further study.     

2种方法制备银杏内酯长循环固体脂质纳米粒的比较

目的:研究银杏内酯AB长循环固体脂质纳米粒(GAB-LSLN)的制备方法,并探讨GAB-LSLN的主要理化性质。方法:分别采用超声法和高压乳匀法制备GAB-LSLN。在电镜下观察其形态,测定其粒径、Zeta电位和包封率,并在室温下放置4周,观察GAB-LSLN的稳定性。结果:超声法制备的GAB-LSLN在透射电镜下呈片状存在,形态不规则;高压乳匀法制备的GAB-LSLN呈球状,形态规则。超声法和高压乳匀法制备的GAB-LSLN粒径分别为(219.6±14.3)nm和(173.9±10.4)nm(P<0.001);Zeta电位分别为(—21.12±1.03)mv和(—27.43±2.14)mV(P<0.001),包封率分别为(85.05±0.67)%和(92.49±0.88)%(P<0.001)。高压乳匀法制备的GAB-LSLN室温放置4周后,粒径无显著增加(P>0.05)。结论:高压乳匀法制备GAB-LSLN具有粒径小、稳定性和包封率高的特点,优于超声法。     

Hydrophilic coating of mitotane-loaded lipid nanoparticles: Preliminary studies for mucosal adhesion

The aim of the present work was to load mitotane, an effective drug for adrenocortical carcinoma treatment, in solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC). The SLN and NLC were successfully prepared by high shear homogenization followed by hot high pressure homogenization. Formulations were composed of cetyl palmitate as the solid lipid for SLN, whereas for NLC PEGylated stearic acid was selected as solid lipid and medium chain triacylglycerols as the liquid lipid. Tween® 80 and Span® 85 were used as surfactants for all formulations. The particle size, zeta potential, polydispersity index (PI), encapsulation efficiency (EE), and loading capacity (LC) were evaluated. The SLN showed a mean particle size of 150?nm, PI of 0.20, and surface charge ?10 mV, and the EE and LC could reach up to 92.26% and 0.92%, respectively. The NLC were obtained with a mean particle size of 250?nm, PI of 0.30, zeta potential ?15 mV and 84.50% EE, and 0.84% LC, respectively. Hydrophilic coating of SLN with chitosan or benzalkonium chloride was effective in changing zeta potential from negative to positive values. The results suggest that mitotane was efficiently loaded in SLN and in NLC, being potential delivery systems for improving mitotane LC and controlled drug release.     

蓝萼甲素固体脂质纳米粒的制备及理化性质研究

目的:制备蓝萼甲素固体脂质纳米粒,并对其理化性质进行研究。方法:用乳化-溶剂挥发法制得蓝萼甲素固体脂质纳米粒,并对其粒径、形态、表面电位、包封率、体外释药性质等进行研究。结果:所得蓝萼甲素固体脂质纳米粒的粒径分布均匀,平均粒径为(190±10·3)nm,Zeta电位为—31·2mV,平均包封率为(50·45±0·804)%;药物体外释放符合Higuchi线性方程,具有显著缓释作用。结论:固体脂质纳米粒可作为蓝萼甲素新型缓释给药系统。     

复合碳酸钙空腔纳米粒的制备及性能评价

目的 制备甘草次酸/海藻酸钠修饰碳酸钙空腔纳米粒并进行体外评价。方法 以可溶性淀粉为模板剂制备中空球状碳酸钙纳米粒（CaCO3 Nps）;在非均相体系中合成了甘草次酸/海藻酸钠聚合物（GA-ALG）;并以聚合物（GA-ALG）为壳以中空结构的碳酸钙纳米粒为核,合成了壳核结构的GA-ALG-CaCO3 Nps。采用Malvern粒度分析仪测定纳米粒子的粒度分布和Zeta电位,并通过SEM对纳米粒的形态进行表征。应用荧光分光光度计评价载盐酸阿霉素（DOX）纳米粒的载药量、包封率及体外释放特征。结果 纳米粒分布均一,平均粒径为（425.4±31.1）nm,PDI为0.289,Zeta 电位为（-17.0±0.3）mV。药物的载药量为（13.06±0.51）%,包封率为（78.35±3.08）%。;体外释放结果显示,纳米粒具有一定的缓释作用。结论 GA-ALG-CaCO3 Nps作为新型的药物载体,具有良好的pH响应性,并能显著提高载药量,还具有明显的缓释效果,为新型的纳米给药系统的深入研究提供参考。     

芹菜素固体脂质纳米粒的制备

目的为芹菜素新型制剂的研究和开发提供实验基础。方法采用热熔超声法制备芹菜素固体脂质纳米粒;以包封率为指标,通过正交试验对处方进行优化。结果制备的纳米粒为类球形,包封率为63.11%,平均粒径为(135±18)nm,zeta电位为-18.90 mV,36 h体外累积释放95.74%。结论热熔超声法可用于制备芹菜素固体脂质纳米粒。     

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。     

Preparation,characterization, and in vivo study of rhein solid lipid nanoparticles for oral delivery

In this study, rhein‐SLN s were successfully produced by hot homogenization followed by ultrasonication. Precirol ATO 5 in which rhein exhibited higher partition coefficient was selected for preparation of SLN s. In the dynamic light scattering, the rhein‐SLN s showed a smaller size with a mean value of 120.8 ± 7.9 nm and with zeta potential of ?16.9 ± 2.3 mV. SLN s exhibited a good stability during the period of 2 months. The SLN s indicated faster drug release with a burst release within 2 hr and followed by a sustained release with a biphasic drug‐release pattern. Comparing with the same concentration (free drug), the cellular cytotoxicity of rhein‐loaded SLN s increased significantly at the same incubation condition. In vivo, the AUC _0‐t of rhein in the form of SLN s was significantly increased and was 2.06‐fold that of suspensions group. The results showed an increased oral absorption and improved the oral bioavailability of rhein by the formulation of SLN s.     

羟基喜树碱脂质体的制备及质量评价研究

目的:制备羟基喜树碱(HCPT)脂质体,并对其质量进行评价.方法:采用薄膜分散-高压乳匀法制备羟基喜树碱脂质体;用激光粒度分析仪测定其Zeta电位、粒径大小;考察其在0.9%NaCl溶液、水、5%葡萄糖溶液中8 h的稳定性;用凝胶柱层析法考察包封率;采用薄膜透析法考察体外释药性质.结果:羟基喜树碱脂质体Zeta电位为(-33.1±1.3) mV,平均粒径(182.5±5.6) nm,8 h内在水、5%葡萄糖溶液中稳定性良好;包封率(91.2±1.2)%;体外释药曲线符合Higuchi方程Q=1.291 6t1/2 0.309 8,r=0.980 3.结论:本试验制备的羟基喜树碱脂质体稳定性好,大小均匀, 包封率高,并具有延缓药物释放的性质.     

吡喹酮-硬脂酸固体脂质纳米粒的制备及性能评价

目的：制备吡喹酮-固体脂质纳米粒,考察其理化性质和体外释放度。方法：以硬脂酸为脂质材料,聚乙烯吡咯烷酮为乳化剂,利用热熔乳化超声法制备吡喹酮-固体脂质纳米粒,扫描电镜观察纳米粒形态和均匀度,纳米粒度仪测定其粒径、分散指数、Zeta电位、包封率和载药量,并进行体外释放试验。结果：制备的固体脂质纳米粒为类圆球状,粒径分布较均匀、表面光滑。纳米的平均粒径、分散指数、电位、包封率和载药量分别为（316.5±22.8）nm、0.23±0.05、（-25.3±0.7）mV,（92.64±5.12）%和（18.45±1.34）%。药物在制剂的过程中稳定性良好。体外释放表明吡喹酮-硬脂酸固体脂质纳米粒在生理盐水中具有一定程度的突释和显著的缓释效果。结论：本试验制备的吡喹酮-硬脂酸固体脂质纳米粒具有较好的均匀度和高载药量,并具有良好的缓释性能。     

Long circulating nanoparticles of etoposide using PLGA‐MPEG and PLGA‐pluronic block copolymers: characterization,drug‐release,blood‐clearance,and biodistribution studies

The anti‐leukemic drug, etoposide (ETO), has variable oral bioavailability ranging from 24–74% with a short terminal half‐life of 1.5 h i.v. necessitating continuous infusion for 24–34 h for the treatment of leukemia. In the present study, etoposide‐loaded PLGA‐based surface‐modified nanoparticles (NPs) with long circulation were designed as an alternative to continuous i.v. administration. PLGA‐mPEG and PLGA‐PLURONIC copolymers were synthesised and used to prepared ETO‐loaded NPs by high‐pressure homogenization. The mean particle size of ETO‐loaded PLGA‐MPEG nanoparticles was 94.02±3.4 nm, with an Entrapment Efficiency (EE) of 71.2% and zeta potential value of −6.9±1.3 mV. ETO‐loaded PLGA‐pluronic nanoparticles had a mean particle size of 148.0±2.1 nm, an EE of 73.12±2.7%, and zeta potential value of −21.5±1.6 mV. In vitro release of the pure drug was complete within 4 h, but was sustained up to 7 days from PLGA‐mPEG nanoparticles and for 5 days from PLGA‐pluronic nanoparticles. Release was first order and followed non‐Fickian diffusion kinetics in both instances. ETO and ETO‐loaded PLGA nanoparticles labeled with ^99mTc were used in blood clearance studies in rats where the two coated NPs, ^99mTc‐ ETO‐PLGA‐PLU NP and ^99mTc‐ ETO‐PLGA‐mPEG NP, were found to be available in higher concentrations in the circulation as compared to the pure drug. Biodistribution studies in mice showed that ETO‐loaded PLGA‐MPEG NP and PLGA‐PLURONIC NP had reduced uptake by the RES due to their steric barrier properties and were present in the circulation for a longer time. Moreover, the NPs had greater uptake in bone and brain where concentration of the free drug, ETO, was negligible. Drug delivered from these NPs could result in a single i.v. injection that would release the drug for a number of days, which would be potentially beneficial and in better control of leukemia therapy. Drug Dev Res 71: 228–239, 2010. © 2010 Wiley‐Liss, Inc.     

Poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles prepared by high pressure homogenization for paclitaxel chemotherapy

High pressure homogenization was employed in the current work to prepare poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles (NPs) for controlled release of paclitaxel. The prepared drug-loaded PLGA NPs were found of spherical shape with a size of 200-300 nm. The drug encapsulation efficiency ranged from 34.8+/-1.6 to 62.6+/-7.9% depending on the homogenization pressure and cycles. Paclitaxel was released from the nanoparticles in a biphasic profile with a fast release rate in the first 3 days followed by a slow first-order release. A higher or comparable cytotoxicity against glioma C6 cells was found for the drug formulated in the PLGA NPs in comparison with the free drug Taxol. Confocal laser scanning microscopy (CLSM) evidenced internalization of the fluorescent coumarin 6-loaded PLGA NPs by the C6 cells. The freeze-dried nanoparticles were found to possess excellent water redispersability. The high pressure homogenization could be applied for large industrial scale production of nanoparticles for drug delivery.     

壳聚糖负载肉桂挥发油纳米粒制备工艺响应面法优化及质量评价

目的:优化壳聚糖负载肉桂挥发油纳米粒的制备工艺和处方,并对其质量进行评价。方法:采用单因素考察壳聚糖纳米粒制备的处方和工艺,以粒径、包封率和载药量为评价指标,应用星点设计-响应面法优化负载肉桂挥发油的壳聚糖纳米颗粒的制备工艺,采用透射电镜观察肉桂挥发油壳聚糖纳米粒形态,并对其稳定性进行研究。结果:壳聚糖负载肉桂挥发油纳米粒优化后的工艺为壳聚糖浓度0.2%,均质压力为500 bar(1 bar=0.1 MPa),循环次数为20次,TPP含量0.2 mg·mL^-1,在该条件下平均包封率为(83.37±0.40)%、平均载药量为(26.42±0.65)%、平均粒径为(248.5±12.2) nm, Zeta电位为(52.3±1.1) mV。透射电镜结果显示其呈粒径均匀的类球形,且肉桂油外包裹着一层壳聚糖。稳定性结果显示壳聚糖负载肉桂挥发油纳米粒混悬液在低温条件下贮存最佳。结论:负载肉桂挥发油壳聚糖纳米粒,制备工艺简单,可重复性较好,物理稳定性较好。     

Preparation and characterization of Meta-bromo-thiolactone calcium alginate nanoparticles

Recently, the focus has been shifting toward Quorum sensing inhibitors which reduce Pseudomonas aeruginosa virulence factors, alleviating infections. In this work, me-ta-bromo-thiolactone (mBTL), a potent quorum and virulence inhibitor for the Pseudomonas aeruginosa strains, were formulated in calcium alginate nanoparticles (CANPs). Alginate is used as nutrients and as backbone virulence aspect for Pseudomonas and therefore was chosen. mBTL-loaded-CANPs were characterized for particle size, polydispersity index, zeta potential, morphology visualized by Transmission Electron Microscopy (TEM) and drug release profile. Chemical and physical analysis of formulated mBTL-loaded-CANPs were evaluated using Fourier transform infrared Spectroscopy (FTIR) and differential scanning calorimetry (DSC) and Physical stability of mBTL-loaded-CANPs assessed at various temperature 25 ± 1 °C, 4 ± 0.5 °C and ?30° ± 1 °C over a period of 4 and 9 months. Synthesized CANPs showed nano-size particles ranging from 140 to 200 nm with spherical particles for plain CANPS and irregular shape for mBTL-loaded-CANPs with a sustainable release profile over 48hrs. FTIR showed stable structure of loaded-mBTL and DSC displayed no interaction between mBTL and polymer. State of released mBTL from CANPs kept at 25 °C, 4 °C and ?30 °C over 4 and 9 months showed stable formula at room temperature which kept as a goal of nanoparticles storage. The findings of this study revealed successful preparation of mBTL-loaded-CANPs.     

艾塞那肽聚乳酸-羟基乙酸共聚物纳米粒的制备及其分析方法研究

目的 以聚乳酸-羟基乙酸共聚物（PLGA）为载体,用乳化复乳法制备包载艾塞那肽（EX）的PLGA纳米粒（EX-PLGA NPs）,并对其分析方法进行研究。方法 2018年10月至2019年8月,采用Box-Behnken Design(BBD)响应面分析法对纳米粒制备的处方工艺进行优化,动态光散射技术检测EX-PLGA NPs粒径和Zeta电位;通过高效液相色谱法（HPLC）测定EX-PLGA NPs中艾塞那肽含量并进行方法学验证。结果 制备的EX-PLGA NPs粒径为（157.2±3.1）nm,Zeta电位为（-19.5±2.6）mV;载药量和包封率分别为（4.41±0.28）%和（73.43±0.59）%,透射电镜图显示纳米粒外观圆整,分布均匀;EX-PLGA NPs体外稳定性良好,透析袋法释放结果显示其具有缓释效果。结论 制备的EX-PLGA NPs粒径分布均一,包封率和载药量高,稳定性好,艾塞那肽含量分析方法科学有效,为艾塞那肽抗糖尿病口服缓释制剂的分析和开发提供了实验基础。     

Novel Topical Ophthalmic Formulations for Management of Glaucoma

Purpose

Preparation of topical ophthalmic formulations containing brimonidine-loaded nanoparticles prepared from various biodegradable polymers—PCL, PLA and PLGA—for sustained release of brimonidine as a once daily regimen for management of glaucoma.

Methods

Nanoparticles were prepared using spontaneous emulsification solvent diffusion method then characterized regarding their particle size, zeta potential, morphology and drug contents. Brimonidine-loaded nanoparticles were incorporated into eye drops, temperature-triggered in situ gelling system and preformed gel and characterized regarding their pH, viscosity, uniformity of drug contents, in vitro release study, in vitro cytotoxicity and in vivo intraocular pressure (IOP) lowering effects.

Results

The results of optimized brimonidine-loaded PCL-, PLGA- and PLA-NPs respectively, are: particle sizes of 117.33?±?4.58 nm, 125.67?±?5.15 nm and 131.67?±?3.79 nm; zeta potentials of ?18.5?±?2.87 mV, ?21.82?±?2.7 mV and ?28.11?±?2.21 mV; and encapsulation efficiencies of 77.97?±?1.38%, 68.65?±?3.35% and 73.52?±?2.92%. TEM analyses revealed that all NPs have spherical shapes with dense core and distinct coat. In vitro release data showed a sustained release without any burst effect with Higuchi non-Fickian diffusion mechanism. Cytotoxicity studies revealed that all formulations are non-toxic. Also all formulations possessed a sustained IOP lowering effect compared to Alphagan® P eye drops.

Conclusions

Our formulations showed prolonged management of glaucoma that should meet with better patient compliance as a once-daily formulation.     

Development of gatifloxacin-loaded cationic polymeric nanoparticles for ocular drug delivery

The present investigation aimed at improving the ocular bioavailability of gatifloxacin by prolonging its residence time in the eye and reducing problems associated with the drug re-crystallization after application through incorporation into cationic polymeric nanoparticles. Gatifloxacin-loaded nanoparticles were prepared via the nanoprecipitation and double emulsion techniques. A 50:50 Eudragit® RL and RS mixture was used as cationic polymer with other formulation parameters varied. Prepared nanoparticles were evaluated for size, zeta potential, and drug loading. An optimized formulation was selected and further characterized for in vitro drug release, cytotoxicity, and antimicrobial activity. The double emulsion method produced larger nanoparticles than the nanoprecipitation method (410?nm and 68?nm, respectively). Surfactant choice also affected particle size and zeta potential with Tween 80 producing smaller-sized particles with higher zeta potential than PVA. However, the zeta potential was positive at all experimental conditions investigated. The optimal formulation produced by double emulsion technique and has achieved 46% drug loading. This formulation had optimal physicochemical properties with acceptable cytotoxicity results, and very prolonged release rate. The particles antimicrobial activities of the selected formulation have been tested against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus and showed prolonged antimicrobial effect for gatifloxacin.     

Exploring the potential of lecithin/chitosan nanoparticles in enhancement of antihypertensive efficacy of hydrochlorothiazide

The present study involves the preparation of lecithin/chitosan nanoparticles loaded with hydrochlorothiazide (HCT) (a poorly water soluble antihypertensive) and hydrochlorothiazide complexed with β-cyclodextrin (HCT-β-CD) with a view to improve its biopharmaceutical properties. Nanoparticles prepared using modified solvent evaporation method showed a particle size in the range of 126–139 and 152–181?nm (polydispersity index, PDI?=?0.2) for HCT and HCT-β-CD loaded nanoparticles respectively. TEM images revealed their spherical nature. The stable nature of the prepared formulations was evident from the high positive value of zeta potential (>20?mV). HCT and HCT-β-CD loaded nanoparticles with 150?mg of drug have shown a maximum entrapment efficiency of 81.8?±?1.7% and 91.1?±?1.5% respectively. In vitro studies have shown an improved and a sustained release pattern. In vivo activity in DOCA induced hypertensive rats demonstrates 1.5-fold percentage decrease in systolic blood pressure and a prolonged duration of action.     

尼莫地平PEG-PLGA纳米粒的制备及其处方优化

目的：负载尼莫地平的聚乙二醇修饰的聚乳酸-羟基乙酸共聚物[poly （ethylene glycol-poly （lactin-co-glycolic acid）,PEG-PLGA）]纳米粒,并对其进行制备工艺、质量评价以及体外释放等相关性研究。方法：以PEG-PLGA为药物载体,采用乳化溶剂挥发法成功制备尼莫地平载药纳米粒。单因素实验和响应面法设计优化处方工艺,透射电子显微镜观察纳米粒形态,激光粒度仪测定其粒径和Zeta电位,HPLC法测定其包封率及载药量并考察其体外释药特性。结果：制备的尼莫地平纳米粒外观呈实心球体,大小均匀且分散性良好;平均粒径为（183.2±3.30） nm,PDI为（0.115±0.049）,Zata电位为（-11.78±2.16） mV;平均包封率为84.99%,平均载药量为2.45%;尼莫地平原料药在4 h时基本释放完全（达到95%左右）,而尼莫地平纳米粒在4 h时释放仅为43.9%,在第24 h时累计释放度达到（83.66±2.57）%。与对照组相比,制剂组释放缓慢,符合实验设计缓释的要求。结论：本实验成功制备了尼莫地平PEG-PLGA纳米粒,其体外释药具有明显缓释特征,为心脑血管疾病的治疗奠定了基础。