A potential new therapeutic system for glaucoma: solid lipid nanoparticles containing methazolamide

Methazolamide (MTA) is an antiglaucoma drug; however, there are many side effects of its systemic administration with insufficient ocular therapeutic concentrations. The aim of this study was to formulate MTA-loaded solid lipid nanoparticles (SLNs) and evaluate the potential of SLNs as a new therapeutic system for glaucoma. SLNs were prepared by a modified emulsion-solvent evaporation method and their physicochemical characteristics were evaluated. The pharmacodynamics was investigated by determining the percentage decrease in intraocular pressure. The ocular irritation was studied by Draize test. Despite a burst release of SLNs, the pharmacodynamic experiment indicated that MTA-SLNs had higher therapeutic efficacy, later occurrence of maximum action, and more prolonged effect than drug solution and commercial product. Formulation of MTA-SLNs would be a potential delivery carrier for ocular delivery, with the advantages of a more intensive treatment for glaucoma, lower in doses and better patient compliance compared to the conventional eye drops.     

吡喹酮固体脂质纳米粒的研制

目的采用超声分散法制备吡喹酮固体脂质纳米粒,并考察制备过程中的主要影响因素。方法首先通过试验确定制备工艺参数,然后考察各处方因素对粒径大小和稳定性的影响,最后以包封率为评价指标,采用正交实验设计法确定最优处方。结果透射电镜测得纳米粒为类圆球状,粒径分布较均匀。动态光散射法测得样品的粒径为(100±21)nm,包封率为(79.3±0.69)%,平均zeta电位值为-66.3 mV。结论以山嵛酸甘油酯和乙酸丁酯为脂质材料,豆磷脂、泊洛沙姆188和硬脂酸钠为复配乳化剂,采用超声分散法可以简便、快速制得吡喹酮固体脂质纳米粒。     

Skin permeation of buprenorphine and its ester prodrugs from lipid nanoparticles: lipid emulsion,nanostructured lipid carriers and solid lipid nanoparticles

The aim of this study was to develop and characterize lipid nanoparticle systems for the transdermal delivery of buprenorphine and its prodrugs. A panel of three buprenorphine prodrugs with ester chains of various lengths was synthesized and characterized by solubility, capacity factor (log K′), partitioning between lipids and water and the ability to penetrate nude mouse skin. Colloidal systems made of squalene (lipid emulsion, LE), squalene + Precirol (nanostructured lipid carriers, NLC) and Precirol (solid lipid nanoparticles, SLN) as the lipid core material were prepared. Differential scanning calorimetry showed that the SLN had a more-ordered crystalline lattice in the inner matrix compared to the NLC. The particle size ranged from 220–300 nm, with NLC showing the smallest size. All prodrugs were highly lipophilic and chemically stable, but enzymatically unstable in skin homogenate and plasma. The in vitro permeation results exhibited a lower skin delivery of drug/prodrug with an increase in the alkyl chain length. SLN produced the highest drug/prodrug permeation, followed by the NLC and LE. A small inter-subject variation was also observed with SLN carriers. SLN with soybean phosphatidylcholine (SLN-PC) as the lipophilic emulsifier showed a higher drug/prodrug delivery across the skin compared to SLN with Myverol, a palmitinic acid monoglyceride. The in vitro permeation of the prodrugs occurred in a sustained manner for SLN-PC. The skin permeation of buprenorphine could be adjusted within a wide range by combining a prodrug strategy and lipid nanoparticles.     

溶剂扩散法制备丙酸倍氯米松固体脂质纳米粒溶剂扩散法制备丙酸倍氯米松固体脂质纳米粒

目的 建立一种高效的固体脂质纳米粒制备与分离方法。方法 用水性溶剂扩散法,制备得到甘油单硬脂酸酯固体脂质纳米粒。通过调节纳米粒表面Zeta电位,提高纳米粒的回收率。结果 用水性溶剂扩散法可以简便、快速制备得到含药固体脂质纳米粒,低转速离心(4 000 r·min^-1)即可达到纳米粒与分散体系之间的分离,回收率明显高于未调节纳米粒表面Zeta电位条件下的高速离心分离方法。用本法制备得到的纳米粒在最初3 h有药物的突释现象,随后4 d药物的释放明显缓慢,每天释放约药物总量的6%。结论 水性溶剂扩散法适用于固体脂质纳米粒的制备,得到的固体脂质纳米粒可实现药物的控制释放。     

溶剂扩散法制备丙酸倍氯米松固体脂质纳米粒

目的　建立一种高效的固体脂质纳米粒制备与分离方法。方法　用水性溶剂扩散法 ,制备得到甘油单硬脂酸酯固体脂质纳米粒。通过调节纳米粒表面Zeta电位 ,提高纳米粒的回收率。结果　用水性溶剂扩散法可以简便、快速制备得到含药固体脂质纳米粒 ,低转速离心 (40 0 0r·min- 1 )即可达到纳米粒与分散体系之间的分离 ,回收率明显高于未调节纳米粒表面Zeta电位条件下的高速离心分离方法。用本法制备得到的纳米粒在最初 3h有药物的突释现象 ,随后 4d药物的释放明显缓慢 ,每天释放约药物总量的 6%。结论　水性溶剂扩散法适用于固体脂质纳米粒的制备 ,得到的固体脂质纳米粒可实现药物的控制释放     

非洛地平-硬脂酸固体脂质纳米粒的制备及其体外透皮吸收研究

目的:以固体脂质纳米粒为栽体,通过透皮给药达到提高非洛地平透皮吸收及缓释长效的目的.方法:采用溶剂挥发-超声法制备非洛地平固体脂质纳米粒水分散体,以大鼠皮肤为渗透屏障对非洛地平固体脂质纳米粒的经皮渗透进行研究.结果:非洛地平-硬脂酸固体脂质纳米粒为类球形实体粒子,平均粒径范围在50～150 nm,包封率大于85%,栽药量大于7%,药物体外释放符合一级动力学过程.体外经皮渗透速率显著高于空白对照组.结论:非洛地平固体脂质纳米粒处方设计合理,制备工艺可靠,以纳米粒作为透皮给药载体具有广阔的发展前景.     

Nanostructured lipid carriers (NLCs) versus solid lipid nanoparticles (SLNs) for topical delivery of meloxicam

Abstract

Objective: The aim of this study was to develop nanostructured lipid carriers (NLCs) as well as solid lipid nanoparticles (SLNs) and evaluate their potential in the topical delivery of meloxicam (MLX).

Materials and methods: The effect of various compositional variations on their physicochemical properties was investigated. Furthermore, MLX-loaded lipid nanoparticles-based hydrogels were formulated and the gels were evaluated as vehicles for topical application.

Results and discussion: The results showed that NLC and SLN dispersions had spherical shapes with an average size between 215 and 430?nm. High entrapment efficiency was obtained ranging from 61.94 to 90.38% with negatively charged zeta potential in the range of ?19.1 to ?25.7?mV. The release profiles of all formulations exhibited sustained release characteristics over 48?h and the release rates increased as the amount of liquid lipid in lipid core increased. Finally, Precirol NLC with 50% Miglyol® 812 and its corresponding SLN were incorporated in hydrogels. The gels showed adequate pH, non-Newtonian flow with shear-thinning behavior and controlled release profiles. The biological evaluation revealed that MLX-loaded NLC gel showed more pronounced effect compared to MLX-loaded SLN gel.

Conclusion: It can be concluded that lipid nanoparticles represent promising particulate carriers for topical application.     

人参皂苷Rd固体脂质纳米粒的制备

目的:制备人参皂苷Rd固体脂质纳米粒,并考察其理化性质。方法:从旋转薄膜-超声分散法、乳化蒸发-低温固化法、高剪切乳化超声法和高压乳匀法中优选出制备方法;在脂质、表面活性剂等辅料和主药用量的单因素考察基础上,采用正交试验设计,确定最佳处方组成和制备工艺条件;用凝胶柱色谱和HPLC法测定包封率,透射电镜观察形态,激光粒径分析仪测定粒径和Zeta电位。结果:脂质、表面活性剂、助表面活性剂和主药的用量对Rd固体脂质纳米粒的粒径、Zeta电位和包封率均有不同程度的影响。高压乳匀法适合制备Rd固体脂质纳米粒。纳米粒表面呈圆整的球状,大小相近,分散均匀;平均粒径为(102.7±27.0)nm,Zeta电位为(-44.9±9.5)mV,包封率和载药量分别为(81.8±2.6)%和(6.37±0.21)%(n=3)。纳米粒稳定性良好,在4℃下保存4周后,粒径和包封率变化不明显。结论:高压乳匀法适合制备人参皂苷Rd固体脂质纳米粒,工艺稳定可行。     

Lactoferrin bioconjugated solid lipid nanoparticles: a new drug delivery system for potential brain targeting

Background: Delivery of drugs to brain is a subtle task in the therapy of many severe neurological disorders. Solid lipid nanoparticles (SLN) easily diffuse the blood–brain barrier (BBB) due to their lipophilic nature. Furthermore, ligand conjugation on SLN surface enhances the targeting efficiency. Lactoferin (Lf) conjugated SLN system is first time attempted for effective brain targeting in this study.

Purpose: Preparation of Lf-modified docetaxel (DTX)-loaded SLN for proficient delivery of DTX to brain.

Methods: DTX-loaded SLN were prepared using emulsification and solvent evaporation method and conjugation of Lf on SLN surface (C-SLN) was attained through carbodiimide chemistry. These lipidic nanoparticles were evaluated by DLS, AFM, FTIR, XRD techniques and in vitro release studies. Colloidal stability study was performed in biologically simulated environment (normal saline and serum). These lipidic nanoparticles were further evaluated for its targeting mechanism for uptake in brain tumour cells and brain via receptor saturation studies and distribution studies in brain, respectively.

Results: Particle size of lipidic nanoparticles was found to be optimum. Surface morphology (zeta potential, AFM) and surface chemistry (FTIR) confirmed conjugation of Lf on SLN surface. Cytotoxicity studies revealed augmented apoptotic activity of C-SLN than SLN and DTX. Enhanced cytotoxicity was demonstrated by receptor saturation and uptake studies. Brain concentration of DTX was elevated significantly with C-SLN than marketed formulation.

Conclusions: It is evident from the cytotoxicity, uptake that SLN has potential to deliver drug to brain than marketed formulation but conjugating Lf on SLN surface (C-SLN) further increased the targeting potential for brain tumour. Moreover, brain distribution studies corroborated the use of C-SLN as a viable vehicle to target drug to brain. Hence, C-SLN was demonstrated to be a promising DTX delivery system to brain as it possessed remarkable biocompatibility, stability and efficacy than other reported delivery systems.     

Targeted delivery of hyaluronic acid-coated solid lipid nanoparticles for rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disease. Long-term, high-dose glucocorticoid therapy can be used to treat the disease, but the fact that the drug distributes systemically can give rise to severe adverse effects. Here we develop a targeted system for treating RA in which the glucocorticoid prednisolone (PD) is encapsulated within solid lipid nanoparticles (SLNs) coated with hyaluronic acid (HA), giving rise to HA-SLNs/PD. HA binds to hyaluronic receptor CD44, which is over-expressed on the surface of synovial lymphocytes, macrophages and fibroblasts in inflamed joints in RA. As predicted, HA-SLNs/PD particles accumulated in affected joint tissue after intravenous injection into mice with collagen-induced arthritis (CIA), and HA-SLNs/PD persisted longer in circulation and preserved bone and cartilage better than free drug or drug encapsulated in SLNs without HA. HA-SLNs/PD reduced joint swelling, bone erosion and levels of inflammatory cytokines in serum. These results suggest that encapsulating glucocorticoids such as PD in HA-coated SLNs may render them safe and effective for treating inflammatory disorders.     

In vitro cytotoxicity and bioavailability of solid lipid nanoparticles containing tamoxifen citrate

Abstract

The objective of this study was to evaluate the influence of solid lipid nanoparticles (SLN) loaded with the poorly water-soluble drug tamoxifen citrate (TC) on the in vitro antitumor activity and bioavailability of the drug. TC-loaded SLN were prepared by solvent injection method using glycerol monostearate (GMS) or stearic acid (SA) as lipid matrix. Poloxamer 188 or tween 80 were used as stabilizers. TC-loaded SLN (F3 and F4) prepared using GMS and stabilized by poloxamer 188 showed highest entrapment efficiency % (86.07?±?1.74 and 90.40?±?1.22%) and reasonable mean particle sizes (130.40?±?9.45 and 243.80?±?12.33?nm), respectively. The in vitro release of TC from F3 and F4 exhibited an initial burst effect followed by a sustained drug release. In vitro cytotoxicity of F3 against human breast cancer cell line MCF-7 showed comparable antitumor activity to free drug. Moreover, the results of bioavailability evaluation of TC-loaded SLN in rats compared to free TC indicated that 160.61% increase in the oral bioavailability of TC. The obtained results suggest that incorporation of the poorly water-soluble drug TC in SLN preserves the in vitro antitumor activity and significantly enhance oral bioavailability of TC in rats.     

莪术油固体脂质纳米粒的制备

目的研究影响莪术油固体脂质纳米粒制备的主要因素。方法采用高压均质法制备莪术油固体脂质纳米粒混悬液,以单因素考察和正交设计法筛选出比较理想的处方和工艺,并考察其形态、粒径、载药量及包封率。结果所制得的固体脂质纳米粒为圆整的类球形实体粒子,表面光滑,平均粒径为80.3nm,载药量为11.82%,包封率为81.75%。结论高压均质法可用于莪术油类液体药物固体脂质纳米粒的制备。     

米托蒽醌固体脂质纳米粒的制备与处方优化

目的：制备米托蒽醌固体脂质纳米粒并优化其处方组成。方法：采用薄膜蒸发-超声分散法制备米托蒽醌固体脂质纳米粒。以包封产率、载药量和体外释药为考察指标，中心组合设计优化处方中米托蒽醌、磷脂、山嵛酸甘油酯和硬脂酸聚烃氧酯（S-40）的组成。结果：米托蒽醌固体脂质纳米粒的最优处方组成为米托蒽醌0．2％，磷脂3．0％，山嵛酸甘油酯1．0%，S-400．5％，注射用水加至10mL；优化处方的各指标值依次为包封产率（87．2±2．2）％，载药量（4．2±0．1）％，Q2h为（7．6±0．2）%，Q24h为（25．9±0．8）％，t50为（5．3±1．1）d和t90为（28．4±4．5）d。结论：薄膜蒸发-超声分散法适于制备米托蒽醌固体脂质纳米粒，优化后的各指标值均接近预测值。     

Methazolamide-loaded solid lipid nanoparticles modified with low-molecular weight chitosan for the treatment of glaucoma: vitro and vivo study

Abstract

The aims of this study were to design and characterize methazolamide (MTZ)-loaded solid lipid nanoparticles (SLN) with and without modification of low molecular weight chitosan (CS) and compare their potentials for ocular drug delivery. Low molecular weight CS was obtained via a modified chemical oxidative degradation method. SLN with CS (CS-SLN-MTZ) and without CS (SLN-MTZ) were prepared according to a modified emulsion-solvent evaporation method. SLN-MTZ and CS-SLN-MTZ were 199.4?±?2.8?nm and 252.8?±?4.0?nm in particle size, ?21.3?±?1.9?mV and +31.3?±?1.7?mV in zeta potential, respectively. Physical stability studies demonstrated that CS-SLN-MTZ remained stable for at least 4 months at 4?°C, while SLN-MTZ no more than 2 months. A prolonged in vitro release profile of MTZ from CS-SLN-MTZ was obtained compared with SLN-MTZ. Furthermore, CS-SLN-MTZ presented a better permeation property in excised rabbit cornea. In vivo studies indicated that the intraocular pressure lowering effect of CS-SLN-MTZ (245.75?±?18.31?mmHg?×?h) was significantly better than both SLN-MTZ (126.74?±?17.73?mmHg?×?h) and commercial product Brinzolamide Eye Drops AZOPT® (171.17?±?16.45?mmHg?×?h). The maximum percentage decrease in IOP of CS-SLN-MTZ (42.78?±?7.71%) was higher than SLN-MTZ (27.82?±?4.15%) and was comparable to AZOPT (38.06?±?1.25%). CS-SLN-MTZ showed no sign of ocular irritancy according to the Draize method and the histological examination.     

Isotretinoin-loaded solid lipid nanoparticles with skin targeting for topical delivery

The purpose of this study was to construct isotretinoin-loaded SLN (IT-SLN) formulation with skin targeting for topical delivery of isotretinoin. PRECIROL ATO 5 was selected as the lipid of SLN. Tween 80 and soybean lecithin were used as the surfactants to stabilize SLN. The hot homogenization method was performed to prepare the drug-loaded SLN. The various formulations were characterized by photon correlation spectroscopy and all the SLN formulations had low average size between 30 and 50 nm. Transmission electron microscopy studies showed that the IT-SLN formulation had a spherical shape. All the formulations had high entrapment efficiency ranging from 80% to 100%. The penetration of isotretinoin from the IT-SLN formulations through skins and into skins were evaluated in vitro using Franz diffusion cells fitted with rat skins. The in vitro permeation data showed that all the IT-SLN formulations can avoid the systemic uptake of isotretinoin in skins, however the control tincture had a permeation rate of 0.76+/-0.30 microg cm(-2)h(-1) through skins. The IT-SLN consisting of 3.0% PRECIROL ATO 5, 4.0% soybean lecithin and 4.5% Tween 80 could significantly increased the accumulative uptake of isotretinoin in skin and showed a significantly enhanced skin targeting effect. The studied IT-SLN showed a good stability. These results indicate that the studied IT-SLN formulation with skin targeting may be a promising carrier for topical delivery of isotretinoin.     

正交设计优化伊曲康唑固体脂质纳米粒的处方组成与制备工艺

目的:制备伊曲康唑固体脂质纳米粒(itraconazole solid lipid nanoparticles,ITZ-SLNs)并对其进行物相分析以确定纳米粒的形成。方法:以伊曲康唑(ITZ)为模型药物,硬脂酸为载体材料,采用乳化-低温固化法制备伊曲康唑固体脂质纳米粒(ITZ-SLN),正交试验设计优化处方组成和制备工艺,并对纳米粒的结构形态、粒径、表面电位、包封率、体外释药特性等进行了研究。结果:以优化处方制备的伊曲康唑固体脂质纳米粒为类球形实体,粒径分布比较均匀,平均粒径为dav=(118.2±15.00)nm,Zeta电位为-(37.06±0.53)mV,包封率为(92.11±1.60)%,药物体外释放符合Higuchi方程,经DSC分析证明纳米粒确已形成。结论:伊曲康唑固体脂质纳米粒有望成为新型缓释纳米给药系统。     

Development and characterization of 5-FU bearing ferritin appended solid lipid nanoparticles for tumour targeting

Ferritin coupled solid lipid nanoparticles were investigated for tumour targeting. Solid lipid nanoparticles were prepared using HSPC, cholesterol, DSPE and triolien. The SLNs without ferritin which has similar lipid composition were used for comparison. SLNs preparations were characterized for shape, size and percentage entrapment. The average size of SLNs was found to be in the range 110–152 nm and maximum drug entrapment was found to be 34.6–39.1%. In vitro drug release from the formulations is obeying fickian release kinetics. Cellular uptake and IC₅₀ values of the formulation were determined in vitro in MDA-MB-468 breast cancer cells. In vitro cell binding of Fr-SLN exhibits 7.7-folds higher binding to MDA-MB-468 breast cancer cells in comparison to plain SLNs. Ex-vivo cytotoxicity assay on targeted nanoparticles gave IC₅₀ of 1.28 µM and non-targeted nanoparticles gave IC₅₀ of 3.56 µM. In therapeutic experiments, 5-FU, SLNs and Fr-SLNs were administered at the dose of 10 mg 5-FU/kg body weight to MDA-MB-468 tumour bearing Balb/c mice. Administration of Fr-SLNs formulation results in effective reduction in tumour growth as compared with free 5-FU and plain SLNs. The result demonstrates that this delivery system possessed an enhanced anti-tumour activity. The results warrant further evaluation of this delivery system.     

Trehalose is not a universal solution for solid lipid nanoparticles freeze-drying

Abstract

Objective: To prepare stable and easy to handle formulation of solid lipid nanoparticles (SLNs) by freeze-drying with or without cryoprotectants, as appropriate.

Materials and methods: SLNs were freeze-dried without cryoprotectants or with cryoprotectants in quantities selected by freeze–thaw test (sucrose, glucose) or literature search (trehalose, maltose). Appearance, re-dispersability and size distribution of re-dispersed samples were evaluated.

Results: SLN could be freeze-dried using 10% sucrose, trehalose or maltose. Trehalose was effective in protecting one of presented formulations that was already very stable on its own; its efficiency in protecting other two formulations was limited.

Discussion: Our results are in line with various reports of successful freeze-drying of SLN, but considering the stability of original dispersions, no improvement was achieved.

Conclusion: We confirmed that trehalose is among the most suitable cryoprotectant for SLN, however it did not improve shelf-life of the most stable formulation.     

Fluconazole-loaded solid lipid nanoparticles topical gel for treatment of pityriasis versicolor: formulation and clinical study

Solid lipid nanoparticles (SLNs) are very potential formulations for topical delivery of antifungal drugs. Hence, the purpose of this research was to formulate the well-known antifungal agent Fluconazole (FLZ)-loaded SLNs topical gel to improve its efficiency for treatment of Pityriasis Versicolor (PV). FLZ-SLNs were prepared by modified high shear homogenization and ultrasonication method using different concentration of solid lipid (Compritol 888 ATO, Precirol ATO5) and surfactant (Cremophor RH40, Poloxamer 407). The physicochemical properties and the in vitro release study for all FLZ-SLNs were investigated. Furthermore, the optimized FLZ-SLN formula was incorporated into gel using Carpobol 934. A randomized controlled clinical trial (RCT) of potential batches was carried out on 30 well diagnosed PV patients comparing to market product Candistan^® 1% cream. Follow up was done for 4?weeks by clinical and KOH examinations. The results showed that FlZ-SLNs were almost spherical shape having colloidal sizes with no aggregation. The drug entrapment efficiency ranged from 55.49% to 83.04%. The zeta potential values lie between ?21 and ?33?mV presenting good stability. FLZ showed prolonged in vitro release from SLNs dispersion and its Carbapol gel following Higuchi order equation. Clinical studies registered significant improvement (p?® cream.