Showing papers on "Solid lipid nanoparticle published in 2002"
TL;DR: As a novel type of lipid nanoparticles with solid matrix, the nanostructured lipid carriers (NLC) are presented and improvements discussed, for example, increase in loading capacity, physical and chemical long-term stability, triggered release and potentially supersaturated topical formulations.
1,783 citations
TL;DR: A special preparation process-applicable to NLC but also SLN-allows the production of highly concentrated particle dispersions (>30-95%).
981 citations
TL;DR: This general biophysical basis helps to understand pharmaceutically relevant aspects such as liposome stability during storage and towards serum, the biodistribution and specific targeting of cargo, and how to trigger drug release and membrane fusion.
Abstract: Liposomes are used as biocompatible carriers of drugs, peptides, proteins, plasmic DNA, antisense oligonucleotides or ribozymes, for pharmaceutical, cosmetic, and biochemical purposes. The enormous versatility in particle size and in the physical parameters of the lipids affords an attractive potential for constructing tailor-made vehicles for a wide range of applications. Some of the recent literature will be reviewed here and presented from a biophysical point of view, thus providing a background for the more specialized articles in this special issue on liposome technology. Different properties (size, colloidal behavior, phase transitions, and polymorphism) of diverse lipid formulations (liposomes, lipoplexes, cubic phases, emulsions, and solid lipid nanoparticles) for distinct applications (parenteral, transdermal, pulmonary, and oral administration) will be rationalized in terms of common structural, thermodynamic and kinetic parameters of the lipids. This general biophysical basis helps to understand pharmaceutically relevant aspects such as liposome stability during storage and towards serum, the biodistribution and specific targeting of cargo, and how to trigger drug release and membrane fusion. Methods for the preparation and characterization of liposomal formulations in vitro will be outlined, too.
461 citations
TL;DR: It was shown that the rate of release is strongly dependent upon the formulation and could be decreased by 30-60% in SLN formulations, and oxybenzone was released and penetrated into human skin more quickly and to a greater extent from the emulsion.
384 citations
TL;DR: The principle suitability of SLN as a prolonged release formulation for lipophilic drugs is demonstrated and the optimized separation parameters in the present research for SLN were established.
257 citations
TL;DR: SLN formulation of ATRA with similar characteristics to those of parenteral emulsions could be obtained even after freeze-drying, and no significant change was observed in the SLN-loaded concentration of AT RA and the zeta potential of SLNs after freeze -drying.
256 citations
TL;DR: It is indicated that SLN could be effective colloidal carriers for lymphoscintigraphy or therapy upon pulmonary delivery and an important and significant uptake of the radiolabelled SLN into the lymphatics after inhalation, and a high rate of distribution in periaortic, axillar and inguinal lymph nodes.
Abstract: Lymphatic drainage plays an important role in the uptake of particulates in the respiratory system, being also associated to the spreading of lung cancer through metastasis development. In recent years solid lipid nanoparticles (SLN) have been proposed as carriers of anti-tumoural drugs, for their low toxicity and surface characteristics make them suitable for either imaging (gamma-scintigraphy) or therapy upon encapsulation of cytotoxic drugs. Assessment of inhaled radiolabelled SLN biodistribution is described in the present work. Methods : Nanoparticles (200 nm) were radiolabelled with 99m Tc using the lipophilic chelator d, l -hexamehylpropyleneamine oxime (HMPAO). Biodistribution studies were carried out following aerosolisation and administration of a 99m Tc-HMPAO-SLN suspension to a group of adult male Wistar rats. A 60 min dynamic image acquisition was performed in a gamma-camera, followed by static image collection at 30 min intervals up to 4 h postinhalation. Radiation counting was performed in ...
204 citations
TL;DR: Interestingly, PC incorporation into nanoparticles appeared to induce a localizing effect in the epidermal layer which was pronounced at 6 h and declined later, and may increase the benefit/risk ratio of topical therapy.
Abstract: Long term topical glucocorticoid treatment can induce skin atrophy by the inhibition of fibroblasts. We, therefore, looked for the newly developed drug carriers that may contribute to a reduction of this risk by an epidermal targeting. Prednicarbate (PC, 0.25%) was incorporated into solid lipid nanoparticles of various compositions. Conventional PC cream of 0.25% and ointment served for reference. Local tolerability as well as drug penetration and metabolism were studied in excised human skin and reconstructed epidermis. With the latter drug recovery from the acceptor medium was about 2% of the applied amount following PC cream and ointment but 6.65% following nanoparticle dispersion. Most interestingly, PC incorporation into nanoparticles appeared to induce a localizing effect in the epidermal layer which was pronounced at 6 h and declined later. Dilution of the PC-loaded nanoparticle preparation with cream (1:9) did not reduce the targeting effect while adding drug-free nanoparticles to PC cream did not induce PC targeting. Therefore, the targeting effect is closely related to the PC-nanoparticles and not a result of either the specific lipid or PC adsorbance to the surface of the formerly drug free nanoparticles. Lipid nanoparticle-induced epidermal targeting may increase the benefit/risk ratio of topical therapy.
177 citations
TL;DR: DO-FUdR-SLN can improve the ability of the drug to penetrate through the blood-brain barrier and is a promising drug targeting system for the treatment of central nervous system disorders.
168 citations
TL;DR: It could be shown that the occlusion factor depends strongly on the degree of crystallinity of the lipid matrix, i.e. this effect is proportional and the desired degree of occlusivity can be achieved by choosing suitable lipids for the matrices of topical SLN formulations.
167 citations
TL;DR: It is shown that CyA-loaded SLNs can be proposed for most administration routes, in particular for the duodenal route, and in vitro release of CyA from SLNs is low.
TL;DR: SLN produced with a higher crystalline lipid in combination with the crystallisation-disturbing NaCh required a 'ripening time' to reach sufficient crystallinity, and showed a decrease in degradation velocity with increasing crystallinity during storage.
TL;DR: Results provide a first basis of using LDC-polysorbate 80 nanoparticles for brain delivery of diminazene to treat second stage human African trypanosomiasis (HAT).
Abstract: The objective of the present study was to incorporate the hydrophilic drug diminazenediaceturate at a high loading into lipid nanoparticles by creating nanoparticles from lipid-drug conjugates (LDC). IR and DSC data showed that the antitrypanosomal drug diminazene is able to react with fatty acids to form water-insoluble salts like diminazenedistearate and -dioleate. The salts could be transformed into nanoparticles using high-pressure homogenization technique, established for solid lipid nanoparticles (SLN). By using polysorbate 80 as surfactant, physically stable LDC nanoparticle dispersions of both salts could be obtained. The mean PCS diameters and polydispersity indices were 364 nm and 0.233 for diminazenedistearate and 442 nm and 0.268 for diminazenedioleate, respectively. Due to the composition of the LDC bulk materials, nanoparticles with a high drug load of 33% (w/w) were obtained even for this highly water-soluble drug diminazenediaceturate. The new carrier system of LDC nanoparticles overcomes one limitation of SLN, i.e. the limited loading capacity for hydrophilic drugs. Transforming water-soluble hydrophilic drugs into LDC and formation of nanoparticles allows prolonged drug release and targeting to specific sites by i.v. injection. These results provide a first basis of using LDC-polysorbate 80 nanoparticles for brain delivery of diminazene to treat second stage human African trypanosomiasis (HAT).
TL;DR: Investigation of the influence of lipid matrix, concentration, and size of SLN on murine peritoneal macrophages revealed that the nature of the lipid matrix and the concentration ofSLN dramatically impact cytotoxicity of SLn on mononuclear cells.
TL;DR: Based on the chosen fat components, a novel and easy manufacturing and scaling-up method was developed to maintain chemical and physical integrity of the encapsulated active ingredients in the carrier.
Abstract: Solid lipid nanoparticles (SLN/Lipopearls) are widely discussed as a new colloidal drug carrier system. In contrast to polymeric systems, such as Polylactic copolyol microcapsules, these systems show with a good biocompatibility, if applied parenterally. The solid lipid matrices can be comprised of fats or waxes, and allow protection of incorporated active ingredients against chemical and physical degradation. The SLN can either be produced by 'hot homogenization' of melted lipids at elevated temperatures or by a 'cold homogenization' process. This paper deals with production technologies for SLN formulations, based on non-ethoxylated fat components for topical application and high pressure homogenization. Based on the chosen fat components, a novel and easy manufacturing and scaling-up method was developed to maintain chemical and physical integrity of the encapsulated active ingredients in the carrier.
TL;DR: Viscoelastic measurements including oscillation stress sweep tests and oscillation frequency sweep tests demonstrated that the existence of a solid particle matrix with a particle size in the nanometer range is a prerequisite to form a semisolid dispersion having the appropriate consistency for topical application.
TL;DR: The results indicate that SLNs might be good potential sustained-release delivery vehicles for camptothecin or other lipophilic drugs.
Abstract: Camptothecin (CA), an antitumor drug, was incorporated into solid lipid nanoparticles (SLNs) prepared by high-pressure homogenization. A Taguchi orthogonal experimental design was used to study the influence of four different variables, with each variable having three value levels on nanoparticle size. Analysis of variance (ANOVA) has been used to evaluate the preparation of CA-SLNs and perform product optimization. The optimized CA-SLNs suspension was lyophilized using mannitol and glucose as cryoprotectants. The physicochemical characteristics of CA-SLNs were evaluated using transmission electron microscopy (TEM), electrophoresis, and differential scanning calorimetry (DSC). The release of camptothecin from CA-SLNs in various media was evaluated using a high-performance liquid chromatography (HPLC) method. The results showed that the concentration of emulsifier and the homogenization pressure had a significant influence on the particle size. The optimized CA-SLNs had an average diameter of about...
TL;DR: The magnetite entrapment efficiency was determined by use of a magnetophoretic sedimentation method and gives spherical nanoparticles of a mean size of 62 nm measured by Photon Correlation Spectroscopy and Transmission Electronic Microscopy.
Journal Article•
TL;DR: Stearic acid might be a new drug carrier material in the future after being found to stay in the blood circulation and release paclitaxel slowly and linearly.
Abstract: Aim To prepare long-circulating solid lipid nanoparticles containing paclitaxel with stearic acid, and investigate the in vitro and in vivo characterization of nanoparticles. Methods The method of "emulsion evaporation-solidification at low temperature" was used to prepare the stearic acid solid lipid nanoparticles containing paclitaxel. Its morphology was examined by transmission electron microscope. The HPLC method for determination of paclitaxel in nanoparticles or serum samples was established. The release of paclitaxel in vitro and the pharmacokinetics after i.v. bolus injection to mice were studied. Results The mean diameter of Brij78-SLN and F68-SLN is (103.5 +/- 29.2) nm and (220 +/- 98) nm, respectively. The nanoparticles release paclitaxel slowly and linearly, within 24 h, Brij78-SLN and F68-SLN release 8% and 20% of total drug, respectively. Long-circulation nanoparticles was found to stay in the blood circulation, with T 1/2 beta 10.1 h of F68-SLN, and T 1/2 beta 4.88 h of Brij78-SLN more than one commercialized paclitaxel injection, T 1/2 beta 1.3 h. Conclusion Stearic acid might be a new drug carrier material in the future.
01 Jan 2002
Journal Article•
TL;DR: The long circulating nanoparticles can pronouncedly increase the circulation time of paclitaxel in blood stream.
Abstract: Objective: To prepare long circulating solid lipid nanoparticles containing paclitaxel with stearic acid Methods: The stearic acid solid lipid nanoparticles containing paclitaxel were prepared by the method of "emulsion evaporation solidification at low temperature" Its morphology was examined by transmission electron microscope The HPLC method for determination of paclitaxel in nanoparticles or blood samples was established The release of paclitaxel in vitro and the pharmacokinetics after iv bolus injection to mice were studied Results: Long circulating nanoparticles containing paclitaxel had a mean diameter of 220 nm Long circulation nanoparticles could stay in the blood circulation for a longer time, with an increased T 1/2β 101 h , against T 1/2β 23 h of conventional nanoparticles and T 1/2β 13 h of paclitaxel injection Conclusion: The long circulating nanoparticles can pronouncedly increase the circulation time of paclitaxel in blood stream
Journal Article•
TL;DR: The application of poloxamer in pharmaceutics used as additives or substrates in tablets, solid lipid nanoparticles, suppositories, controlled release gels, ophthalmic delivery system was summarized.
Abstract: The application of poloxamer in pharmaceutics used as additives or substrates in tablets, solid lipid nanoparticles, suppositories,controlled release gels, ophthalmic delivery system was summarized.
Journal Article•
TL;DR: The main production techniques of the SLN are the high pressure homogenization and microemulsion technique and the drug incorporation and release profiles can be modified as a function of production parameters.
Abstract: Objective To review the new research development of the solid lipid nanoparticles as a drug delivery system.Methods According to the recent relevant literature,the production technique for the SLN,drug incorporation,drug release,characterization analysis and its application in the pharmaceutical field were summarized.Results The main production techniques of the SLN are the high pressure homogenization and microemulsion technique; the drug incorporation and release profiles can be modified as a function of production parameters;the SLN can be used by different administration routes.Conclusions The solid lipid nanoparticles have broad prospects in the pharmaceutical field.