Nanostructured lipid carriers system: Recent advances in drug delivery

Nanostructured lipid carrier (NLC) is second generation smarter drug carrier system having solid matrix at room temperature. This carrier system is made up of physiological, biodegradable and biocompatible lipid materials and surfactants and is accepted by regulatory authorities for application in different drug delivery systems. The availability of many products in the market in short span of time reveals the success story of this delivery system. Since the introduction of the first product, around 30 NLC preparations are commercially available. NLC exhibit superior advantages over other colloidal carriers viz., nanoemulsions, polymeric nanoparticles, liposomes, SLN etc. and thus, have been explored to more extent in pharmaceutical technology. The whole set of unique advantages such as enhanced drug loading capacity, prevention of drug expulsion, leads to more flexibility for modulation of drug release and makes NLC versatile delivery system for various routes of administration. The present review gives insights on the definitions and characterization of NLC as colloidal carriers including the production techniques and suitable formulations. This review paper also highlights the importance of NLC in pharmaceutical applications for the various routes of drug delivery viz., topical, oral, pulmonary, ocular and parenteral administration and its future perspective as a pharmaceutical carrier.     

Box-Behnken效应面法优化石杉碱甲纳米结构脂质载体处方

目的采用Box-Behnken效应面法筛选石杉碱甲纳米结构脂质载体最佳处方。方法采用熔融超声-高压匀质法制备石杉碱甲纳米结构脂质载体,分别以混合脂质(X1)、混合乳化剂(X2)和脂药比(X3)为考察对象,以粒径(Y1)、包封率(Y2)和载药量(Y3)为评价指标,利用三因素三水平Box-Behnken效应面设计法筛选石杉碱甲纳米结构脂质载体的最佳处方。结果按最优处方制备的纳米粒粒径为(121.67±3.21)nm、包封率为(89.18±0.28)%、载药量为(1.46±0.05)%,与预测值偏差均小于5%。结论采用Box-Behnken效应面法优化石杉碱甲纳米结构脂质载体处方是有效、可行的。     

固体脂质纳米粒和纳米结构脂质载体在经皮给药系统中的研究进展

目的介绍固体脂质纳米粒和纳米结构脂质载体在经皮给药系统中的应用与优势,为其开发利用提供参考。方法查阅国内外相关文献共30余篇,从固体脂质纳米粒和纳米结构脂质载体用于经皮给药系统的优势、药物在固体脂质纳米粒和纳米结构脂质载体中的分布形式及固体脂质纳米粒和纳米结构脂质载体在经皮给药领域中的应用等方面进行综述。结果固体脂质纳米粒和纳米结构脂质载体可以增强药物稳定性,能在皮肤表面产生包封效应,增加皮肤水合作用,具有药物靶向性。结论固体脂质纳米粒和纳米结构脂质载体是极有发展前景的新型经皮给药系统。     

Box-Behnken效应面法优化姜黄素纳米结构脂质载体处方

目的采用Box-Behnken效应面法优化处方,制备姜黄素纳米结构脂质载体,并考察其理化性质。方法采用薄膜超声法制备载药纳米结构脂质载体,分别以药物质量浓度(X1)、总脂质质量浓度(X2)和混合乳化剂质量浓度(X3)为考察对象,以包封率(Y1)、粒径(Y2)为评价指标,利用三因素三水平Box-Behnken效应面设计法筛选载药纳米结构脂质载体的最佳处方。采用微柱离心法测定制剂的包封率,透射电镜观察其外观形态,动态光衍射法测定其粒径及Zeta,差示扫描量热法确证姜黄素在载体中的分散状态。结果最优处方制备的载药纳米结构脂质载体外形呈圆形或椭球形,粒径分布均匀,平均粒径为(58.37±2.60)nm,Zeta电位为-(22.6±0.88)mV,包封率为(93.48±0.86)%,DSC结果表明药物以非结晶状分散于纳米结构脂质载体中。结论采用Box-Behnken效应面法优化姜黄素纳米结构脂质载体处方是可行的。     

Nanostructured lipid carriers: A potential use for skin drug delivery systems

Skin application of pharmaceutical products is one of the methods used for drug administration. The problem of limited drug penetration via topical application makes searching for safe drug carriers that will provide an expected therapeutic effect of utmost importance. Research into safe drug carriers began with liposome structures, paving the way for work with nanocarriers, which currently play a large role as drug vehicles. Nanostructured lipid carriers (NLC) consist of blended solid and liquid lipids (oils) dispersed in an aqueous solution containing a surfactant. These carriers have many advantages: good biocompatibility, low cytotoxicity, high drug content; they enhance a drug’s stability and have many possibilities of application (oral, intravenous, pulmonary, ocular, dermal). The following article presents properties, methods of preparation and tests to assess the quality and toxicity of NLC. This analysis indicates the possibility of using NLC for dermal and transdermal drug application.     

Nanostructured lipid carriers for intraocular brimonidine localisation: development,in-vitro and in-vivo evaluation

Brimonidine ocular hypotensive effect can be enhanced by increasing residence time and corneal penetration. The current work aimed to formulate, evaluate and compare nanostructured lipid carriers (NLCs) to solid lipid nanoparticles (SLNs) and commercial eye drops for controlled brimonidine delivery. NLCs prepared by modified high shear homogenisation were spherical with a mean size of 151.97?±?1.98?nm, negative zeta potential (ZP) of ?44.2?±?7.81?mV, % entrapment efficiency (EE) of 83.631?±?0.495% and low crystallinity index (CI) (17.12%), indicating a better drug incorporation. Moreover, they kept stable during storage at 4?°C for 3?months. Permeability coefficient of NLCs was 1.227 folds higher than that of SLNs. Histological examination revealed localisation of NLCs in the anterior ocular chamber. NLCs revealed the most sustained and highest intraocular pressure (IOP) lowering activity (?13.14?±?1.28?mmHg) in rabbits. In conclusion, NLCs is a promising approach for IOP reduction compared to eye drops and SLNs.     

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.     

Nanostructured lipid carriers as a delivery system of biochanin A

Abstract

The aim of this study was to explore the nanostructured lipid carriers as a delivery system of biochanin A so as to supply a method to improve its bioavailability. Biochanin A–loaded nanostructured lipid carriers (BCA-NLCs) were prepared by the method of emulsion-evaporation and low temperature solidification. Pharmacokinetics was carried out in rats upon oral administration at a dose of 10?mg/kg. BCA-NLC showed spherical formulation and had mean diameter174.68?±?0.96?nm, zeta potential ?20.9?±?0.8?mv and entrapment efficiency 97.36?±?0.14%. DSC and XRD studies indicated that BCA was not in crystal state in NLC. In in vitro release study, the BCA from BCA-NLC exhibited a biphasic release pattern with burst release initially and sustained release afterwards. BCA-NLC showed higher AUC value and circulated in blood for a longer time than BCA suspension. The studies demonstrated that NLC could be a potential delivery system for BCA to improve bioavailability.     

Nanostructured lipid carriers as novel drug delivery system for lung cancer gene therapy

Context: Nanostructured lipid carriers (NLC) are potentially good colloidal drug carriers for gene delivery. They are advised to be the second lifetime of lipid nanocarriers.

Objective: The aim of this study is to develop novel modified NLC as nanomedicine for delivery of plasmid-containing enhanced green fluorescence protein (pEGFP). This system could target the lung cancer cells through receptor-mediated pathways to increase the nuclear uptake of genetic materials.

Methods: In the present study, pEGFP-loaded NLC (NLC/pEGFP) were prepared. Transferrin (Tf) containing ligands were used for the surface coating of the vectors. In vitro transfection efficiency of the modified vectors was evaluated in human alveolar adenocarcinoma cell line (A549 cells) and in vivo transfection efficiency of the modified vectors was evaluated on mice bearing A549 cells model.

Results: Tf-modified NLC/pEGFP (Tf-NLC/pEGFP) has a particle size of 157?nm, and ～82% of gene loading quantity. Tf-NLC/pEGFP displayed remarkably higher transfection efficiency than non-modified NLC/pEGFP both in vitro and in vivo.

Conclusion: The results demonstrate that the novel NLC gene delivery system offers an effective strategy for lung cancer gene therapy.     

Lipid nanoparticles: Different preparation techniques,characterization, hurdles,and strategies for the production of solid lipid nanoparticles and nanostructured lipid carriers for oral drug delivery

The bioavailability of an orally administered drug primarily depends on its solubility in the GIT and its permeability across cell membranes. Also, a drug in solution form is preferred for conducting pharmacological, toxicological and pharmacokinetic studies during the drug development stage. Thus, poor water solubility not only limits a drug’s biological application but also challenges its pharmaceutical development. The use of lipid nanoparticles (LNs) in pharmaceutical technology has been reported for several years due to its important in green chemistry for several reasons specifically for its biochemical as “green” materials and biochemical processes as green processes that can be very environmentally friendly. Also, the physiological/physiologically related lipids (GRAS) made LNs usually enhance the drug absorption in the GIT. Hence, the pathways for absorption, metabolism, and transportation are present in the body, which may contribute to a large extent to the bio-fate of the lipidic carrier. Moreover, the LNs improves the mucosal adhesion and increases their GIT residence time. The LNs with a solid matrix are two types: solid lipid nanoparticle (SLN) and nanostructured lipid carrier (NLC). Also, their hydrophobic core provides a suitable environment for entrapment of hydrophobic drugs to improve its bioavailability. This review highlights and discusses the simple and easily scaled-up novel SLN and NLC along with their different production techniques, hurdles, and strategies for the production of LNs, characterization, lyophilization and drug release. Also, this review summarizes the research findings reported by the different researchers regarding the different method of preparation, excipients and their significant findings.     

几种不同实验设计在低分子肝素活性测定中的比较

目的:对低分子肝素(LMWH)生物活性测定中几种不同的实验设计进行比较。方法:对LMWH生物活性测定采用酶促反应的分光光度法,进行了量反应平行线实验设计中4.4法与4.3法、3.4法、3.3法的比较。结果:量反应平行线实验设计中4.4法与4.3法、3.4法、3.3法结果相似,其差异无统计学意义(P>0.05)。结论:采用酶促反应的分光光度法对LMWH的效价测定,应采用量反应平行线法实验设计;在符合标准规定前提下,4.4法与4.3法、3.4法、3.3法不同剂量组实验设计都可应用。     

穿山龙薯蓣皂苷纳米结构脂质载体的大鼠在体肠吸收特性研究

目的:研究穿山龙薯蓣皂苷纳米结构脂质载体的大鼠在体肠吸收特性。方法:采用高效液相色谱法测定穿山龙薯蓣皂苷纳米结构脂质载体中穿山龙薯蓣皂苷含量;大鼠在体单向灌流法研究吸收部位,药物浓度对穿山龙薯蓣皂苷肠吸收的影响;比较穿山龙提取物和纳米制剂在体肠吸收特性。结果:穿山龙薯蓣皂苷纳米结构脂质载体在大鼠全肠段均有吸收,其在不同肠段的吸收速率常数(absorption rate constant,Ka)和表观吸收系数(apparent absorption coefficient,Papp)从大到小依次为:回肠>空肠>十二指肠>结肠;不同质量浓度(30,60和120μg·m L-1)的穿山龙薯蓣皂苷纳米结构脂质载体,其Ka和Papp没有显著性差异,提示在实验浓度范围内,穿山龙薯蓣皂苷纳米结构脂质载体在大鼠全肠段的吸收没有浓度依赖性,吸收机制可能属于被动扩散;穿山龙薯蓣皂苷纳米结构脂质载体组和薯蓣皂苷提取物组比较,Ka和Papp有显著性差异(P <0. 05),且纳米制剂在空肠的吸收系数是薯蓣皂苷提取物的1. 28倍。结论:穿山龙薯蓣皂苷纳米结构脂质载体在空肠和回肠肠段吸收...     

Nanostructured lipid (NLCs) carriers as a bioavailability enhancement tool for oral administration

ABSTRACT

Context: Nanostructured lipid carrier (NLCs) is the second generation solid lipid nanoparticles (NPs) made up of physiological, biocompatible, biodegradable, non-sensitizing and non-irritating lipids.

Objective: The main objective of this review is to explore the role of NLCs system for delivering drugs by oral route and thus increasing the oral bioavailability.

Methods: The present review article highlights the definition and types of NLCs and their importance as colloidal carriers including the production techniques and their formulation. This review article also deals with the fate of lipids used in the NLCs formulation and the NLCs toxicity.

Conclusion: On the basis of the literature survey done, it was concluded that the NLCs enhances the oral bioavailability of the drug and may decrease the side effects and toxicity of the lipids used in other polymeric NPs as NLCs uses physiological and biodegradable lipids.     

纳米结构脂质载体肺部给药研究进展

传统吸入疗法不能使药物靶向到肺的特定部位,而纳米载体药物的肺部给药系统可克服传统吸入药物的不足。其中纳米结构脂质载体是固体和液体脂质的混合物经表面活性剂乳化后形成的纳米粒,具有更好的胶体稳定性和持续的药物释放行为。其组成成分具有无毒、生理惰性和生物相容性的特点,还具有良好的雾化特性,特别适用于肺部应用,并且生产过程简单（高压均质）,适合大规模生产。本文介绍了常见肺部给药纳米载体,概述了纳米结构脂质载体应用于肺部的优势,为其在肺部给药领域中的深度开发提供参考。     

Coenzyme Q10 and retinaldehyde co-loaded nanostructured lipid carriers for efficacy evaluation in wrinkles

This study depicts coenzyme Q10 (CoQ10) and retinaldehyde (RAL) co-loaded nanostructured lipid carriers (NLCs); having activity on different targets of photoageing, which can overcome deficits of conventional topical dosage forms. The developed NLCs were characterised for particle size, polydispersity index and percent entrapment efficiency (%EE), followed by their incorporation into Carbopol^® 934?P-NF gel. In vitro cellular uptake and cytotoxicity assay was performed to evaluate NLCs and in vivo study on ultraviolet- (UV) induced wrinkle model to determine efficacy of NLCs. The developed stable, homogenous and spherical NLCs with size range of 200–230?nm and more than 80 %EE, showed prolonged, biphasic in vitro release pattern for CoQ10 and RAL. Ex vivo study portrayed negligible permeation through skin but appreciable penetration and distribution in skin layers. This has shown good uptake of both drugs with least cytotoxicity in cell culture studies. In vivo irritation study on Sprague Dawley (SD) rats and pharmacodynamic study on female Swiss albino mice proved it less irritant and efficacious. The developed NLCs thus hold promise in the efficient management of wrinkle and their reduction as indicated by the data obtained.     

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.     

Long circulation nanostructured lipid carriers for gambogenic acid: formulation design,characterization, and pharmacokinetic

1.?GNA-PEG-NLC and GNA-NLC were prepared by emulsification and low-temperature solidification methods. The optimized GNA-PEG-NLC and GNA-NLC were not only found to have small mean size (146.33?±?2.11 and 144.07?±?1.44) nm, high Zeta potential (?25.10?±?1.35 and ?28.03?±?0.29) mV, but also great entrapment efficiency (79.07?±?1.11 and 84.65?±?0.98%). TEM proved that particles were nearly spherical with smooth surface shape. Furthermore, in vitro release revealed a burst release initially, followed by a sustained profiles up to 48?h, and the cumulative drug release of GNA-PEG-NLC and GNA-NLC was 65.90?±?2.34% and 69.25?±?1.77%, respectively.

2.?In pharmacokinetic, GNA-PEG-NLC exhibited prolonged MRT and higher AUC values compared with GNA-NLC and GNA solution. Moreover, the tissue distribution demonstrated a high uptake of GNA-PEG-NLC in stomach.

3.?These results indicated that PEG-NLC is a promising delivery system for GNA, which could prolong drug circulation time in body and thus improved its bioavailability.     

聚乙二醇修饰的羟基喜树碱纳米脂质载体的制备及其小鼠组织分布

本研究采用熔融乳化-高压均质法制备了聚乙二醇(PEG)修饰的羟基喜树碱(HCPT)纳米脂质载体(HCPT-PEG-NLC)及非修饰的羟基喜树碱纳米脂质载体(HCPT-NLC)，并考察了其形态、粒径及包封率。测定了HCPT注射液、HCPT-PEG-NLC及HCPT-NLC 3种制剂经小鼠尾静脉注射后在血浆、心、肝、脾、肺、肾及卵巢等主要组织的浓度，评价了HCPT-PEG-NLC及HCPT-NLC在各组织的靶向性效果。透射电镜下观察，HCPT-PEG-NLC及HCPT-NLC呈球形；测得平均粒径分别为(88.6±22.5)和(127.2±43.4)nm；包封率分别为(90.51±3.29)%和(84.37±2.81)%。经小鼠尾静脉注射后，HCPT-PEG-NLC及HCPT-NLC在多数取样时间点的血药浓度较HCPT注射液有所提高，HCPT在各组织中的消除半衰期明显延长。HCPT-NLC蓄集于网状内皮系统(RES)，在肝、脾的相对摄取率(R_e)和峰浓度比(C_e)明显高于HCPT-PEG-NLC。HCPT-PEG-NLC延长了药物在血浆中的滞留时间，提高了生物利用度，MRT及AUC_{0-24 h}分别为注射液的19.80和17.02倍，并且与HCPT-NLC比较显著降低了RES的吞噬作用，在肺部表现出明显的靶向作用(R_e及C_e分别为14.51，41.35)。综上，HCPT-PEG-NLC可延长HCPT的体内循环时间，呈现明显的肺靶向性，有望作为HCPT肺癌治疗的理想载体。     

Nanostructured lipid carriers (NLC) for the delivery of natural molecules with antimicrobial activity: production,characterisation and in vitro studies

This study describes the preparation, characterisation and in vitro activity of nanostructured lipid carriers (NLCs) encapsulating natural molecules with antimicrobial activity, such as plumbagin, hydroquinon, eugenol, alpha-asarone and alpha-tocopherol. NLCs were prepared by melt and ultrasonication method, characterised by Cryo-TEM for morphology and SdFFF for dimensional distribution and active encapsulation yields. In vitro tests were conducted on bacteria, fungi and human cell cultures. In vitro tests demonstrated that plumbagin is strongly toxic towards F. oxysporum especially when active molecules are loaded on NLC. Plumbagin was completely non toxic on cyanobacterial model strain up to a threshold over which cell viability was completely lost. NLC loaded with active molecules showed a lower toxicity as compared to their free form on human cultured cells. Although further studies need to be performed, these systems can be potentially proposed to control phytopathogenic organisms.