Anti-tumor efficacy of polymer-platinum(II) complex micelles fabricated from folate conjugated PEG-graft-α,β-poly [(N-amino acidyl)-aspartamide] and cis-dichlorodiammine platinum(II) in tumor-bearing mice

In the present study eugenol loaded solid lipid nanoparticles (SLN) was prepared and characterized for particle size, polydispersity index, zeta potential, encapsulation efficiency, in vitro release and in vivo antifungal activity. Effect of addition of liquid lipid (caprylic triglyceride) to solid lipid (stearic acid) on crystallinity of lipid matrix of SLN was determined by using Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) techniques. Transmission electron microscopy (TEM) was carried out to determine the morphology of SLN. In vivo antifungal activity of eugenol loaded lipid nanoparticles was evaluated by using a model of oral candidiasis in immunosuppressed rats. Particle size results showed that d(90) of SLN(1) (single lipid matrix) and SLN(2) (binary lipid matrix) was 332±14.2 nm and 87.8±3.8 nm, respectively. Polydispersity index was found to be in the range of 0.27-0.4 which indicate moderate size distribution. Encapsulation efficiency of SLN(2) (98.52%) was found to be more than that of SLN(1) (91.80%) at same lipid concentration (2%, w/v). Increasing of the solid lipid concentration from 2% (w/v) to 4% (w/v) resulted in increase in encapsulation efficiency and the particle size. SLN(2) shows faster release of eugenol than that of SLN(1) due to smaller size and presence of liquid lipid which provide less barriers to the diffusion of drug from matrix. TEM study reveals the spherical shape of SLN. FT-IR, DSC and XRD results indicate less crystallinity of SLN(2) than that of SLN(1). In vivo studies show no significant difference in log cfu value of all the groups at 0 day. At 8th day, log cfu value of group treated with saline (control), standard antifungal agent, eugenol solution, SLN(1) and SLN(2) was found to be 3.89±.032, 2.69, 3.39±.088, 3.19±.028 and 3.08±0.124, respectively. The in vivo study results indicate improvement in the antifungal activity of eugenol when administrated in the form of SLN.     

Preparation and characteristics of nanostructured lipid carriers for control-releasing progesterone by melt-emulsification

Nanostructured lipid carriers (NLC) made from mixtures of solid and spatially incompatible liquid lipids were prepared by melt-emulsification. Their drug loading capacity and releasing properties of progesterone were compared with those of solid lipid nanoparticles (SLN), and the NLC prepared by solvent diffusion method. Monostearin (MS) and stearic acid (SA) were used as solid lipid, whilst the oleic acid (OA) was used as liquid lipid. Properties of carriers such as the particle size and its distribution, drug loading, drug encapsulation efficiency and drug release behavior were investigated. As a result, the drug encapsulation efficiencies were improved by adding the liquid lipid into the solid lipid of nanoparticles. The drug release behavior could be adjusted by the addition of liquid lipid, and the NLC with higher OA content showed the faster rate of drug releasing. NLC had higher efficiency of encapsulation and slower rate of drug release than those of NLC prepared by solvent diffusion method. On the other hand, the NLC with higher drug loading was obtained, though the drug encapsulation efficiency was decreased slightly due to the increase of the amount of drug. The NLC modified with polyethylene glycol (PEG) was also prepared by using polyethylene glycol monostearate (PEG-SA). It was observed that the incorporation of PEG-SA reduced the drug encapsulation efficiency, but increased the rate of drug release. A sample with almost complete drug release in 24 h was obtained by modifying with 1.30 mol% PEG-SA. It indicated that the modified NLC was a potential drug delivery system for oral administration.     

Preparation and characteristics of nanostructured lipid carriers for control-releasing progesterone by melt-emulsification

Nanostructured lipid carriers (NLC) made from mixtures of solid and spatially incompatible liquid lipids were prepared by melt-emulsification. Their drug loading capacity and releasing properties of progesterone were compared with those of solid lipid nanoparticles (SLN), and the NLC prepared by solvent diffusion method. Monostearin (MS) and stearic acid (SA) were used as solid lipid, whilst the oleic acid (OA) was used as liquid lipid. Properties of carriers such as the particle size and its distribution, drug loading, drug encapsulation efficiency and drug release behavior were investigated. As a result, the drug encapsulation efficiencies were improved by adding the liquid lipid into the solid lipid of nanoparticles. The drug release behavior could be adjusted by the addition of liquid lipid, and the NLC with higher OA content showed the faster rate of drug releasing. NLC had higher efficiency of encapsulation and slower rate of drug release than those of NLC prepared by solvent diffusion method. On the other hand, the NLC with higher drug loading was obtained, though the drug encapsulation efficiency was decreased slightly due to the increase of the amount of drug. The NLC modified with polyethylene glycol (PEG) was also prepared by using polyethylene glycol monostearate (PEG-SA). It was observed that the incorporation of PEG-SA reduced the drug encapsulation efficiency, but increased the rate of drug release. A sample with almost complete drug release in 24 h was obtained by modifying with 1.30 mol% PEG-SA. It indicated that the modified NLC was a potential drug delivery system for oral administration.     

Loading of praziquantel in the crystal lattice of solid lipid nanoparticles

Praziquantel (PZQ) is the drug of choice for oral treatment of schistosomiasis and other fluke infections that affect humans. Its low oral bioavailability demands the development of innovative strategies to overcome the first pass metabolism. In this article, solid lipid nanoparticles loaded with PZQ (PZQ-SLN) were prepared by a modified oil-in-water microemulsion method selecting stearic acid as lipid phase after solubility screening studies. The mean particle size (Z-Ave) and zeta potential (ZP) were 500 nm and −34.0 mV, respectively. Morphology and shape of PZQ-SLN were analysed by scanning electron microscopy revealing the presence of spherical particles with smooth surface. Differential scanning calorimetry suggested that SLN comprised a less ordered arrangement of crystals and the drug was molecularly dispersed in the lipid matrix. No supercooled melts were detected. The entrapment efficiency (EE) and loading capacity of PZQ, determined by high performance liquid chromatography, were 99.06 ± 0.3 and 17.48 ± 0.05, respectively. Effective incorporation of PZQ into the particles was confirmed by small angle X-ray scattering revealing the presence of a lipid lamellar structure. Stability parameters of PZQ-SLN stored at room temperature (25 °C) and at 4 °C were checked by analysing Z-Ave, ZP and the EE for a period of 60 days. Results showed a relatively long-term physical stability after storage at 4 °C, without drug expulsion.     

Studies on crystallinity state of puerarin loaded solid lipid nanoparticles prepared by double emulsion method

In this work, solid lipid nanoparticles (SLN) have been prepared from water-in-oil-in-water double emulsion, using monocaprate as solid lipid, sorbitan monooleate (Span 80) and polyoxyethylene sorbitan monolaurate (Tween 20) as emulsifier, and puerarin as target drug. The morphology of SLN with drug loaded or not was investigated by the transmission electron microscope (TEM). The crystal order and structure of particles were studied by differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WAXD), respectively. The results indicate that the diameters of SLN with puerarin inside are larger than those without drugs. The analysis of WAXD and DSC shows that the state of crystallinity SLN prepared by double emulsion method was worse than that of SLN prepared by microemulsion. And also the drug-loaded SLN presents a less ordered crystallinity than the drug-free SLN. But both the drug-free and drug-loaded SLN exist in an amorphous state. The reasons of the phenomenon have been discussed.     

The enhancement on thermal stability and charring–forming capability of nitration group

Lipid nanoparticles, both solid lipid nanoparticles and nanostructured lipid carriers (NLC), containing tacrolimus (FK) were obtained by solvent diffusion method associated with ultrasonication using stearic acid (SA) or beeswax as solid lipid. The oleic acid was used as liquid lipid in the NLC. Lipid nanoparticles were characterized by determining the drug loading, particle size, polydispersity index (PDI) and zeta potential (ZP). Analysis by differential scanning calorimetry and X-ray diffraction were performed. Lipid nanoparticles presented nano-sized from 139 to 275 nm. The PDI results show the particles present from 0.3 to 0.5, and ZP was higher than |25| mV. Drug loading ranged of 2.3–3.2%. SA nanoparticles presented better ZP, average size and distribution. However, beeswax nanoparticles showed higher drug loading. Results suggest there are no incompatibilities between FK and the raw materials. Polymorphic modifications were not observed. The results presented show that lipid nanoparticles using both lipids were successfully obtained and may represent promising delivery system of FK in topical formulations.     

Preparation, characterization and pharmacokinetics of enrofloxacin-loaded solid lipid nanoparticles: influences of fatty acids

Enrofloxacin-loaded solid lipid nanoparticles (SLN) were prepared using fatty acids (tetradecanoic acid, palmitic acid, stearic acid) as lipid matrix by hot homogenization and ultrasonication method. The effect of fatty acids on the characteristics and pharmacokinetics of the SLN were investigated. The results showed that the encapsulation efficiency and loading capacity of nanoparticles varied with fatty acids in the order of stearic acid>palmitic acid>tetradecanoic acid. Furthermore, stearic acid-SLN had larger particle size, bigger polydispersity index (PDI) and higher zeta potential compared with the other two fatty acid formulated SLN. The SLN showed sustained releases in vitro and the released enrofloxacin had the same antibacterial activity as that of the native enrofloxacin. Although in vitro release exhibited similar patterns, within 24 h the releasing rates of the three formulations were significantly different (tetradecanoic acid-SLN>palmitic acid-SLN>stearic acid-SLN). Pharmacokinetic study after a single dose of intramuscular administration to mice demonstrated that tetradecanoic acid-SLN, palmitic acid-SLN, and stearic acid-SLN increased the bioavailability by 6.79, 3.56 and 2.39 folds, and extended the mean residence time (MRT) of the drug from 10.60 h to 180.36, 46.26 and 19.09 h, respectively. These results suggest that the enrofloxacin-fatty acid SLN are promising formulations for sustained release while fatty acids had significant influences on the characteristics and performances of the SLN.     

Preparation, characterization and biocompatibility studies on risperidone-loaded solid lipid nanoparticles (SLN): high pressure homogenization versus ultrasound

The suitability of solid lipid nanoparticles (SLN) for the encapsulation of risperidone (RISP), an antipsychotic lipophilic drug, was assessed for oral administration. The hot high pressure homogenization (HPH) and the ultrasound (US) technique were used as production methods for SLN. All the studies on the SLN formulations were done in parallel, in order to compare the results and conclude about the advantages and limitations of both techniques. The particle sizes were in the nanometer range for all prepared SLN formulations and the zeta potential absolute values were high, predicting good long-term stability. Optical analyses demonstrated the achievement of stable colloidal dispersions. Physicochemical characterization of dispersions and bulk lipids, performed by differential scanning calorimetry (DSC) and X-ray assays, support prediction of occurrence of drug incorporation in the SLN and good long term stability of the systems. The toxicity of SLN with Caco-2 cells and the existence of contaminations derived from the production equipments were assessed by the (4,5-dimethylthiazol-2-yl)2,5-diphenyl-tetrazolium bromide (MTT) assay. The results showed 90% of cell viability after SLN exposure, with no significant differences within all prepared formulations (p > 0.05). From this study, we conclude that SLN can be considered as efficient carriers for RISP encapsulation. Moreover, HPH and US revealed to be both effective methods for SLN production.     

Formulation design, preparation and physicochemical characterizations of solid lipid nanoparticles containing a hydrophobic drug: effects of process variables

This study aimed to prepare solid lipid nanoparticles (SLNs) of a hydrophobic drug, tretinoin, by emulsification-ultrasonication method. Solubility of tretinoin in the solid lipids was examined. Effects of process variables were investigated on particle size, polydispersity index (PI), zeta potential (ZP), drug encapsulation efficiency (EE), and drug loading (L) of the SLNs. Shape and surface morphology of the SLNs were investigated by cryogenic field emission scanning electron microscopy (cryo-FESEM). Complete encapsulation of drug in the nanoparticles was checked by cross-polarized light microscopy and differential scanning calorimetry (DSC). Crystallinity of the formulation was analyzed by DSC and powder X-ray diffraction (PXRD). In addition, drug release and stability studies were also performed. The results indicated that 10mg tretinoin was soluble in 0.45±0.07 g Precirol? ATO5 and 0.36±0.06 g Compritol? 888ATO, respectively. Process variables exhibited significant influence in producing SLNs. SLNs with <120 nm size, <0.2 PI, >I30I mV ZP, >75% EE, and ～0.8% L can be produced following the appropriate formulation conditions. Cryo-FESEM study showed spherical particles with smooth surface. Cross-polarized light microscopy study revealed that drug crystals in the external aqueous phase were absent when the SLNs were prepared at ≤0.05% drug concentration. DSC and PXRD studies indicated complete drug encapsulation within the nanoparticle matrix as amorphous form. The drug release study demonstrated sustained/prolonged drug release from the SLNs. Furthermore, tretinoin-loaded SLNs were stable for 3 months at 4°C. Hence, the developed SLNs can be used as drug carrier for sustained/prolonged drug release and/or to improve oral absorption/bioavailability.     

Encapsulation of cyclodextrin complexed simvastatin in chitosan nanocarriers: A novel technique for oral delivery

The purpose of the present work was to design and investigate the potential of novel hydroxylpropyl-beta-cyclodextrin (HP-β-CD) and chitosan nanocarriers (NCs) for effective delivery of model, poorly water soluble drug simvastatin. The prepared system was characterized for particle size, particle size distribution (PDI), zeta potential, differential scanning calorimetery, x-ray diffraction, encapsulation efficiency and drug release studies. The results revealed that among the selected ratios of tripolyphosphate/chitosan, ratio 1:4 and 1:5 proved to be optimum in terms of particle size, particle distribution and drug release profile. The average size of nanoparticles increased from 516 to 617 and 464 to 562 nm for ratio 1:4 and 1:5 with increase in drug/HP-β-CD amount. To assess interactions and whether the simvastatin was incorporated in the NCs in its crystalline or amorphous form DSC and XRD were performed. These results suggest that the encapsulation process produces a marked decrease in crystallinity of simvastatin and/or confers to a nearly amorphous state of drug in NCs. Results reveled that with increase in the amount of HP-β-CD/drug the final loading of the NCs increased due to increased solubilization of simvastatin in the presence of HP-β-CD. The in vitro release profile of prepared NCs showed initial fast release (burst effect) followed by a delayed release pattern. In conclusion, these nanocarriers constitute a novel and efficient system for encapsulation and oral delivery of poorly soluble drugs.     

可生物降解固体脂质纳米粒的制备、表征及药物的体外释放

以可生物降解材料硬脂酸为载体, 以葛根总黄酮为模型药物, 采用乳化蒸发-低温固化法制备固体脂质纳米粒. 采用透射电镜研究载药纳米粒形态, 激光粒度分析仪测定其粒径, X射线衍射仪进行物相鉴别, 并对纳米粒的包封率及体外释药特性等进行了研究. 分析结果表明, 所制备硬脂酸固态脂质纳米粒为类球实体, 粒径分布比较均匀, 平均粒径为(263.82±3.6) nm, 包封率为(67.53±0.12)%. X射线衍射分析证明药物以分子或细小粒子分散于脂质骨架中. 体外释药研究结果表明, 纳米粒体外释药先快后慢, 12 h累积释药50%, 包封于降解材料骨架内的药物通过骨架溶蚀缓慢释放. 药物的体外释放符合Higuchi方程.     

Characterization and biological evaluation of paclitaxel-loaded poly(L-lactic acid) microparticles prepared by supercritical CO2

In this study, paclitaxel loaded poly( L-lactic acid) (PTX-PLLA) microparticles were prepared using solution enhanced dispersion by supercritical CO2(SEDS) technique. This supercritical antisolvent technique offers the advantage of negligible organic solvent residua in the drug loaded microparticles. Scanning electron microscopy (SEM) showed that microparticles exhibited rather spherical shape and small particle size with narrow particle size distribution. X-ray diffraction (XRD) and differential scanning calorimeter (DSC) indicated that PTX was amorphously dispersed in the PLLA matrix. The drug loading and encapsulation efficiency of PTX-PLLA microparticles were 14.33% and 62.68%, respectively. In vitro cytotoxicity evaluation of PTX-PLLA microparticles against nonsmall-cell lung cancer A549 and ovarian cancer SKOV3 cell lines indicated that PTX-PLLA had superior antiproliferation activity against the A549 and SKOV3 cell lines, compared with free PTX formulations. The cellular internalization of fluorescent microparticles was evidenced by fluorescence microscope and further confirmed by transmission electron microscopy (TEM). This was attributed to the efficient intracellular accumulation of PTX via cell phagocytosis and sustained release of PTX from PLLA matrix. The anticancer activity of PTX-PLLA was associated with PTX-induced cell apoptosis such as nuclear aberrations, condensation of chromatin and swelling damage in mitochondria. The cell apoptosis index detected by flow cytometry was higher in PTX-PLLA group than in free PTX. The PTX-PLLA formulation, which was obtained through micronization of PTX and encapsulation of micronized PTX into PLLA simultaneously in the SEDS process, significantly potentiated the anticancer activity of PTX.     

Preparation of gamma cyclodextrin stabilized solid lipid nanoparticles (SLNS) using stearic acid–γ-cyclodextrin inclusion complex

The inclusion complexation behaviour of higher chain fatty acid, stearic acid (SA) with gamma cyclodextrin has been investigated. The inclusion complex was characterized by FT-IR, ¹H NMR, 2D NMR, XRD and DSC techniques. The results showed that the SA molecule was entrapped inside the gamma cyclodextrin cavity. Further, inclusion complex was treated with lopinavir at 85 °C and emulsified with hot water at 85 °C. The resulted nanoemulsion was cooled down to form solid lipid nanoparticles (SLNs) stabilized with gamma cyclodextrin. Prepared SLNs were having average particle size of 212.5 ± 4.8 nm, zeta potential of ?19.7 ± 0.66 mV and drug loading of 57.54 ± 0.62 %. The surface characteristics of SLNs were also observed with transmission electron microscopy and atomic force microscopy. Results indicate that inclusion complex of SA and gamma cyclodextrin can be used for SLNs preparation.     

Synthesis of a New Polyoxometalate Loaded Stearic Acid Nanoparticles

The stearic acid nanoparticles loaded polyoxometalate K6[γ-(CpTi)2SiW10O38][(CpTi)2SiW10] have been prepared and structurally characterized by elemental analysis, IR spectra.The particle size was estimated by transition electron microscope and zatesizer instrument. The result showed that the polyoxometalate retained the parent structure after encapsulation by stearic acid nanoparticles.     

Preparation and characterization of stearic acid nanostructured lipid carriers by solvent diffusion method in an aqueous system

Nanostuctured lipid carriers (NLC) based on mixture of solid lipids with spatially incompatible liquid lipids are a new type of lipid nanoparticles, which offer the advantage of improved drug loading capacity and release properties. In present study, stearic acid (SA) nanostuctured lipid carriers with various oleic acid (OA) content were successfully prepared by solvent diffusion method in an aqueous system. The size and surface morphology of nanoparticles were significantly influenced by OA content. As OA content increased up to 30 wt%, the obtained particles showed pronounced smaller size and more regular morphology in spherical shape with smooth surface. Compared with solid lipid nanoparticles (SLN), NLC exhibited improved drug loading capacity, and the drug loading capacity increased with increasing OA content. These results were explained by differential scanning calorimetry (DSC) investigations. The addition of OA to nanoparticles formulation resulted in massive crystal order disturbance and less ordered matrix of NLC, and hence, increased the drug loading capacity. The drug in vitro release behavior from NLC displayed biphasic drug release pattern with burst release at the initial stage and prolonged release afterwards, and the successful control of release rate at the initial stage can be achieved by controlling OA content.     

Novasomes as Nano-Vesicular Carriers to Enhance Topical Delivery of Fluconazole: A New Approach to Treat Fungal Infections

The occurrence of fungal infections has increased over the past two decades. It is observed that superficial fungal infections are treated by conventional dosage forms, which are incapable of treating deep infections due to the barrier activity possessed by the stratum corneum of the skin. This is why the need for a topical preparation with advanced penetration techniques has arisen. This research aimed to encapsulate fluconazole (FLZ) in a novasome in order to improve the topical delivery. The novasomes were prepared using the ethanol injection technique and characterized for percent entrapment efficiency (EE), particle size (PS), zeta potential (ZP), drug release, Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and antifungal activity. The FN7 formulation with 94.45% EE, 110 nm PS and −24 ZP proved to be the best formulation. The FN7 formulation showed a 96% release of FLZ in 8 h. FTIR showed the compatibility of FLZ with excipients and DSC studies confirmed the thermal stability of FLZ in the developed formulation. The FN7 formulation showed superior inhibition of the growth of Candida albicans compared to the FLZ suspension using a resazurin reduction assay, suggesting high efficacy in inhibiting fungal growth.     

Characterization of silver sulfadiazine-loaded solid lipid nanoparticles by thermal analysis

The aim of this study is the solid-state characterization of solid lipid nanoparticles (SLN) based on Compritol^® 888 (C888) and Lutrol^® F68 (F68), loaded with silver sulfadiazine (AgSD), used to develop sponge-like dressings to treat chronic skin ulcers such as decubitis and leg ulcers. Silver compounds like AgSD, in fact, are used to prevent and/or to treat wound colonization that could impair healing, also in the case of antibiotic-resistant bacteria. Thermal analysis, with support from powder X-ray diffractometry and Fourier transform infrared spectroscopy, is used to characterize lipid and drug bulk, unloaded and drug-loaded SLN. In particular, differential scanning calorimetry is used to investigate the degree of crystallinity and the solid-state modification of lipid, two parameters correlated to drug incorporation and drug release rates. The solid-state characterization demonstrates AgSD entrapment in C888 as a core enclosed into F68 shell. AgSD SLN are also stored at different temperatures 25 and 37 °C, respectively, to study the effect of storage conditions, that induce an increase of the lipid crystallinity index correlated to drug release from the lipid matrix.     

Preparation,Characterization, and In Vitro Release of Chloramphenicol Loaded Solid Lipid Nanoparticles

In the present contribution, solid lipid nanoparticles have been prepared from oil-in-water microemulsion, using various monoglycerides (monocaprate, monolaurate and monomyristin) as solid matrix, polyethylene glycol sorbitan monooleate (Tween 80) as emulsifier, and chloramphenicol as target drug. The morphology and microstructure of drug loaded SLNs were investigated by use of the transmission electron microscope (TEM) and x-ray diffraction (XRD) techniques. The pictures of TEM showed that SLNs are spherical particles, and the average diameters measured by dynamic light scattering (DLS) were under 100 nm. The crystallographic properties of them were characterized by XRD. It was found that chloramphenicol do not exist in crystalline state in SLN. Both drug-free and drug-loaded SLN existed in amorphous state. In addition, zeta potentials of SLNs were investigated. Zeta potentials of all the samples were around ?6 to ?23 mv. Further more, the core-shell model with drug enriched shell was proposed for the present system. Release kinetics of chloramphenicol from SLN showed a relative fast release in the initial several hours, and the release profile was accordance with the drug incorporation model we presented. Effects of types and concentration of lipids, and surface modifiers on drug release behavior were studied.     

Chitosan nanoparticles of 5-fluorouracil for ophthalmic delivery: characterization, in-vitro and in-vivo study

The aim of this investigation was to develop 5-fluorouracil (5-FU) loaded chitosan nanoparticles (CH-DNPs) for ophthalmic delivery. CH-DNPs were fabricated by ionotropic gelation mechanism using chitosan (CH) and a polyanion (TPP). The nanoparticles were smooth and spherical, confirmed by scanning electron microscopy (SEM) and atomic force microscope (AFM). CH/TPP mass ratio and TPP significantly changed the particles size morphology and encapsulation efficiency. The nanoparticles size ranged from approximately 114 to 192 nm and had a positive zeta potential (30±4 mV). The encapsulation efficiency, loading capacity and recovery of DNPs were 8.12-34.32%, 3.14-15.24% and 24.22 to 67% respectively. Physical characterization was done by Fourier transform infrared (FT-IR) and X-ray diffraction (XRD). No interaction was observed in between drug and polymer and crystallinity of drug was not changed in drug loaded nanoparticles. In-vitro release study of DNPs showed diffusion controlled release. Bioavailability study of batch CS9 was studied in rabbit eye and compare to 5-FU solution. 5-FU level was significantly higher in aqueous humor of rabbit eye. Ocular tolerance was studied in the eye of New Zealand rabbits and tested formulation was non-irritant with no sign of inflammation.     

Insulin-Loaded SLN Prepared with the Emulsion Dilution Technique: In Vivo Tracking of Nanoparticles after Oral Administration to Rats

Insulin-loaded solid lipid nanoparticles (SLN) were prepared according to a solvent dilution method from O/W emulsions using isovaleric acid as organic phase. Insulin was derivatized with fluorescein isothyocianate (FITC) obtaining a fluorescent marker to be used in in vivo experiments. FITC-insulin and native insulin–loaded SLN were quite similar with regard to their mean sizes and encapsulation efficiency. SLN intestinal uptake was then investigated administering FITC-insulin loaded SLN on healthy male Wistar rats. Significant drug accumulation within intestinal lymphatic system was recovered, but the immune system seems to play an important role in SLN degradation: further studies are necessary to improve the results on blood glucose level.