Chitosan-coated Solid Lipid Nanoparticles Research Articles

Design and optimization of chitosan-coated solid lipid nanoparticles containing insulin for improved intestinal permeability using piperine

The objective of this research was to optimize the composition and performance of chitosan-coated solid lipid nanoparticles carrying insulin (Ch-In-SLNs) and to assess the potential of piperine in enhancing the intestinal permeability of insulin from these SLNs in vitro. The SLNs were formulated from glyceryl behenate (GB), soya lecithin, and poloxamer® 407, and then coated with a combination of chitosan and piperine to facilitate insulin penetration across the gastrointestinal (GI) mucosa. A Box-Behnken Design (BBD) was utilized to optimize the Ch-In-SLNs formulations, with PDI, particle size, zeta potential, and association efficiency (AE) serving as the response variables. The resulting Ch-In-SLNs exhibited excellent monodispersity (PDI = 0.4), optimal particle size (654.43 nm), positive zeta potential (+36.87 mV), and low AE values. The Ch-In-SLNs demonstrated sustained release of insulin for 12 h in simulated gastric fluid (SGF) and intestinal fluid (SIF), with increased release in the latter. After incubation in SGF and SIF for 12 h, the insulin SLNs retained 54 and 41 % of their initial insulin load, respectively, indicating effective protection from gastric enzymes. Permeation studies using goat intestine and Caco-2 cell lines indicated improved insulin permeation in the presence of piperine. Additionally, cell uptake studies confirmed the role of piperine in enhancing insulin permeation.

IN VITRO EVALUATION OF THE ANTIBACTERIAL EFFECT OF CHITOSAN COATED TEICOPLANIN-LOADED LIPID NANOPARTICLES AGAINST STAPHYLOCOCCUS AUREUS

Objective: The aim of this research is to formulate teicoplanin-loaded solid lipid nanoparticles (SLN) coated with chitosan to sustain teicoplanin release for effective antibacterial therapy. Material and Method: “Double emulsion-solvent evaporation technique was used for the production of SLNs. The nanoparticles were characterised in terms of morphology, size, encapsulation efficacy, in-vitro drug release and antibacterial activity studies after optimization of process and formulation parameters. Result and Discussion: Transmission electron microscopy images confirmed the formation of spherical SLNs. With chitosan coating, the size increased (from 80 nm to 106 nm) and the negative value of zeta potential (- 11.29) changed to positive (+34.41). The in-vitro release data showed prolonged release of teicoplanin from optimized SLN and chitosan-coated SLN (c-SLN) formulations over 1 week. The antibacterial activity study (S. aureus and Methicillin-resistant S. aureus) showed the activity of the teicoplanin loaded SLN formulations. In conclusion, this study demonstrated the potential of c-SLN for effective delivery of teicoplanin.

Dopamine-loaded chitosan-coated solid lipid nanoparticles as a promise nanocarriers to the CNS

Dopamine is unable to access the central nervous system through the bloodstream. Only its precursor can do so, and with an effectiveness below 100% of the dose administered, as it is metabolized before crossing the blood-brain barrier. In this study, we describe a new solid lipid nanocarrier system designed and developed for dopamine. The nanoparticles were prepared by the melt-emulsification method and then coated with chitosan. The nanocarriers developed had a droplet size of about 250 nm, a polydispersity index of 0.2, a positive surface charge (+30 mV), and a percentage encapsulation efficiency of 36.3 ± 5.4. Transmission and scanning electron microscopy verified uniformity of particle size with spherical morphology. Various types of tests were performed to confirm that the nanoparticles designed are suitable for carrying dopamine through the blood-brain barrier. In vitro tests demonstrated the ability of these nanocarriers to pass through endothelial cell monolayers without affecting their integrity. This study shows that the formulation of dopamine in chitosan-coated solid lipid nanoparticles is a potentially viable formulation strategy to achieve the bioavailability of the drug for the treatment of Parkinson's disease in the central nervous system.

Folic Acid-Conjugated Chitosan-Coated Solid Lipid Nanoparticles: Precision Targeting of Artemisia vulgaris Essential Oils for Anticancer Therapy.

In this study, we developed Solid Lipid Nanoparticles (SLN-NPs) loaded with Artemisia vulgaris essential oil and coated with folic acid-chitosan (AVEO-SCF-NPs) to enhance drug delivery in biotechnology and pharmaceutical sectors. AVEO-SCF-NPs were synthesized using homogenization and ultra-sonication methods and comprehensively characterized. These nanoparticles exhibited a particle size of 253.67 nm, Polydispersity Index (PDI) of 0.26, zeta potential (ζ-p) of +39.96 mV, encapsulation efficiency (%EE) of 99.0 %, and folic acid binding efficiency (% FB) of 46.25 %. They effectively inhibited MCF-7, HT-29, and PC-3 cancer cells with IC50 values of 48.87 μg/mL, 88.48 μg/mL, and 121.34 μg/mL, respectively, and demonstrated antibacterial properties against Gram-positive strains. AVEO-SCF-NPs also exhibited scavenging effects on ABTS (IC50 : 203.83 μg/mL) and DPPH (IC50: 680.86 μg/mL) free radicals and inhibited angiogenesis, as confirmed through CAM and qPCR assays. Furthermore, these nanoparticles induced apoptosis, evidenced by up-regulation of caspase 3 and 9, down-regulation of TNF-α genes, and an increase in SubG1 phase cells. The high loading capacity of SCF-NPs for AVEO, coupled with their multifaceted biological properties, highlights AVEO-SCF-NPs as promising candidates for cancer therapy in the biotechnology and pharmaceutical industries.

Design and Evaluation of SLNs Encapsulated Curcumin-based Topical Formulation for the Management of Cervical Cancer.

Curcumin has the propensity to inhibit cancer growth, slow cancer development, increase chemotherapy effectiveness, and shield healthy cells from radiation treatment harm. As a result of curcumin's ability to block several signaling pathways, cervical cancer cells can once again proliferate normally. To optimize topically applied curcumin-loaded solid lipid nanoparticles (SLNPs) for the treatment of cervical cancer, this study set out to establish the relationship between design variables and experimental data. It also performed in vitro characterizations to determine the formulation's efficacy and safety. Curcumin-loaded SLNPs were constructed and optimized using a systematic design of experiment (DoE) technique. SLNPs that were loaded with curcumin were produced utilizing a cold emulsification ultrasonication process. Using the Box Behnken Design, it was determined how independent variables (factors) like the quantity of lipid (A), the quantity of phospholipid (B), and the concentration of surfactant (C) affected the responses of the dependent variables (responses), such as particle size (Y1), polydispersity index (PDI) (Y2), and entrapment efficiency (EE) (Y3) (BBD). The ideal formulation (SLN9) was chosen using the desirability technique based on 3-D surface response graphs. Using polynomial equations and three-dimensional surface plots, the influence of independent factors on the dependent variables was evaluated. The observed responses were almost equal to the levels that the optimal formulation expected. The improved SLNP gel's shape and other physicochemical characteristics were also assessed, and they were determined to be ideal. The sustained release profile of the produced formulations was validated by in vitro release tests. Studies on hemolysis, immunogenic response, and in vitro cell cytotoxicity demonstrate the efficacy and safety of the formulations. To improve the treatment effect, chitosan-coated SLNPs may carry encapsulated curcumin to the desired location and facilitate its localization and deposition in the desired vaginal tissue.

Chitosan-Coated SLN: A Potential System for Ocular Delivery of Metronidazole.

Ophthalmic drops for ocular delivery exhibit inadequate residence time, which often requires multiple daily dosing that may result in patient non-adherence. In this study, the development of a once-daily-dosed chitosan-coated metronidazole (MTZ)-loaded solid lipid nanoparticles (SLNs) for ocular delivery was undertaken. Melt emulsification and ultrasonication were used to manufacture MTZ-loaded SLN, which were subsequently coated with chitosan (CS) by mechanical stirring using a 0.1% w/v solution. Gelucire® 48/16 and Transcutol® HP were used as the solid lipid and synthetic solvent, respectively, with Tween® 20 included as a stabilizing agent. The critical quality attributes (CQA) of the optimized CS-coated SLN that was monitored included particle size, polydispersity index, Zeta potential, % entrapment efficiency, % MTZ loading, pH, and osmolarity. The optimized coated nanocarriers were evaluated using laser Doppler anemometry (LDA) and were determined to be stable, with particle sizes in the nanometre range. In vitro mucoadhesion, MTZ release and short-term stability, in addition to the determination of the shape of the optimized CS-coated SLN, were undertaken. The mucoadhesive properties of the optimized CS-coated MTZ-loaded SLN demonstrated increased ocular availability, which may allow dose reduction or longer intervals between doses by improving precorneal retention and ocular availability. Overall, our findings suggest that CS-coated MTZ-loaded SLNs have the potential for clinical application, to enhance ocular delivery through the release of MTZ.

Chitosan-Coated Solid Lipid Nanoparticles as an Efficient Avenue for Boosted Biological Activities of Aloe perryi: Antioxidant, Antibacterial, and Anticancer Potential.

Aloe perryi (ALP) is an herb that has several biological activities such as antioxidant, antibacterial, and antitumor effects and is frequently used to treat a wide range of illnesses. The activity of many compounds is augmented by loading them in nanocarriers. In this study, ALP-loaded nanosystems were developed to improve their biological activity. Among different nanocarriers, solid lipid nanoparticles (ALP-SLNs), chitosan nanoparticles (ALP-CSNPs), and CS-coated SLNs (C-ALP-SLNs) were explored. The particle size, polydispersity index (PDI), zeta potential, encapsulation efficiency, and release profile were evaluated. Scanning electron microscopy was used to see the nanoparticles' morphology. Moreover, the possible biological properties of ALP were assessed and evaluated. ALP extract contained 187 mg GAE/g extract and 33 mg QE/g extract in terms of total phenolic and flavonoid content, respectively. The ALP-SLNs-F1 and ALP-SLNs-F2 showed particle sizes of 168.7 ± 3.1 and 138.4 ± 9.5 nm and the zeta potential values of -12.4 ± 0.6, and -15.8 ± 2.4 mV, respectively. However, C-ALP-SLNs-F1 and C-ALP-SLNs-F2 had particle sizes of 185.3 ± 5.5 and 173.6 ± 11.3 nm with zeta potential values of 11.3 ± 1.4 and 13.6 ± 1.1 mV, respectively. The particle size and zeta potential of ALP-CSNPs were 214.8 ± 6.6 nm and 27.8 ± 3.4 mV, respectively. All nanoparticles exhibited PDI < 0.3, indicating homogenous dispersions. The obtained formulations had EE% and DL% in the ranges of 65-82% and 2.8-5.2%, respectively. After 48 h, the in vitro ALP release rates from ALP-SLNs-F1, ALP-SLNs-F2, C-ALP-SLNs-F1, C-ALP-SLNs-F2, and ALP-CSNPs were 86%, 91%, 78%, 84%, and 74%, respectively. They were relatively stable with a minor particle size increase after one month of storage. C-ALP-SLNs-F2 exhibited the greatest antioxidant activity against DPPH radicals at 73.27%. C-ALP-SLNs-F2 demonstrated higher antibacterial activity based on MIC values of 25, 50, and 50 µg/mL for P. aeruginosa, S. aureus, and E. coli, respectively. In addition, C-ALP-SLNs-F2 showed potential anticancer activity against A549, LoVo, and MCF-7 cell lines with IC50 values of 11.42 ± 1.16, 16.97 ± 1.93, and 8.25 ± 0.44, respectively. The results indicate that C-ALP-SLNs-F2 may be promising nanocarriers for enhancing ALP-based medicines.

Curcumin-Loaded Chitosan Nanoparticle Preparation and Its Protective Effect on Celecoxib-induced Toxicity in Rat isolated Cardiomyocytes and Mitochondria.

Curcumin has a wide range of pharmacological activities, including antioxidant, anti-inflammatory and tissue protective. In here we hypothesized that curcumin-loaded chitosan-coated solid lipid nanoparticles (CuCsSLN) are able to increase its overall bioavailability and hence its antioxidant and mitochondria;/lysosomal protective properties of curcumin. CuCsSLN were prepared using solvent diffusion technique for formation of solid lipid nanoparticles (SLNs) and electrostatic coating of positive-charged chitosan to negative surface of SLNs. CuCsSLN showed the encapsulation efficiency of 91.4±2.7%, the mean particle size of 208±9 nm, the polydispersity index of 0.34±0.07, and the zeta potential of+53.5±3.7 mV. The scanning electron microscope (SEM) images of nanoparticles verified their nanometric size and also spherical shape. Curcumin was released from CuCsSLN in a sustain release pattern up to 24 hours. Then isolated cardiomyocytes and mitochondria were simultaneously treated with (1) control (0.05% ethanol), (2) celecoxib (20 µg/ml) treatment, (3) celecoxib (20 µg/ml)+++CuCsSLN (1 µg/ml) treatment, (4) CuCsSLN (1 µg/ml) treatment, (5) celecoxib (20 µg/ml)+++curcumin (10 µM) treatment and (6) curcumin (10 µM) treatment for 4 h at 37°C. The results showed that celecoxib (20 µg/ml) induced a significant increase in cytotoxicity, reactive oxygen species (ROS) formation, mitochondria membrane potential (ΔΨm) collapse, lipid peroxidation, oxidative stress and mitochondrial swelling while CuCsSLN and curcumin reverted the above toxic effect of celecoxib. Our data indicated that the effect of CuCsSLN in a number of experiments, is significantly better than that of curcumin which shows the role of chitosan nanoparticles in increasing effect of curcumin.

Physicochemical Characterization of Chitosan-Decorated Finasteride Solid Lipid Nanoparticles for Skin Drug Delivery.

Finasteride is considered the drug of choice for androgenic alopecia and benign prostate hyperplasia. The aim of the study was to formulate nanodrug carriers of finasteride with enhanced retentive properties in the skin. The finasteride was formulated as solid lipid nanoparticles that were decorated with different concentrations of chitosan for improved retentive properties. Solid lipid nanoparticles (SLNs) were synthesized by “high-speed homogenization technique” using stearic acid as a solid lipid while PEG-6000 and Tween-80 were used as surfactants. The SLNs were evaluated for particle size, polydispersity index (PDI), zeta potential, drug entrapment efficiency, and drug release behavior. The mean particle size of SLNs was in the range of 10.10 nm to 144.2 nm. The PDI ranged from 0.244 to 0.412 while zeta potential was in the range of 8.9 mV to 62.6 mV. The drug entrapment efficiency in chitosan undecorated formulations was 48.3% while an increase in drug entrapment was observed in chitosan-decorated formulations (51.1% to 62%). The in vitro drug release studies of SLNs showed an extended drug release for 24 hours after 4 hours of initial burst release. The extended drug release was observed in chitosan-coated SLNs in comparison with uncoated nanoparticles. The permeation and retention study revealed higher retention of drug in the skin and low permeation with chitosan-decorated SLNs that ranged from 39.4 μg/cm2 to 13.2 μg/cm2. TEM images depicted spherical shape of SLNs. The stability study confirmed stable formulations in temperature range of 5°C and 40°C for three months. It is concluded from this study that the SLNs of finasteride were successfully formulated and chitosan decoration enhanced the drug retention in the skin layers. Therefore, these formulations could be used in androgenic alopecia and benign prostate hyperplasia to avoid the side effects, drug degradation, and prolonged use of drug with conventional oral therapy.

Preparation and Characterization of pH-Sensitive Capsosomes for Oral Delivery of Therapeutic Proteins.

Oral administration of therapeutic proteins is very challenging because of gastrointestinal instability and decomposition. In this study, we developed a system for oral delivery of superoxide dismutase (SOD) as one of the therapeutic proteins. SOD-loaded capsosomes (SOD-C) were formed by the assembly of chitosan-coated solid lipid nanoparticles and SOD-loaded liposomes (SOD-L). Unlike raw SOD activity decreases to 19.41% in SGF and 13.70% in SIF, the SOD-C in SGF (89.30%) condition retained its initial catalytic activity and decreased but exhibited a three-fold higher raw SOD activity even after incubation in SIF (41.63%). TEM analysis indicated that after intestinal digestion, the residual amount of intact liposomes affected the higher catalytic activity of SOD-C compared to raw SOD and SOD-L. Based on these results, significantly higher cellular uptake of SOD-C was observed compared to raw SOD. Also, SOD-C remarkably suppressed the cellular malondialdehyde (MDA) concentration by maintaining the antioxidative capacity of SOD to remove MDA produced in the oxidative stress-induced cells, thereby contributing to a significant five-fold difference with SOD-R (p < 0.05). This delivery system can facilitate the oral application of other therapeutic proteins, improving gastrointestinal stability.

Development and optimization of solid lipid nanoparticles coated with chitosan and poly(2-ethyl-2-oxazoline) for ocular drug delivery of ciprofloxacin

Many formulation strategies have been employed to improve ocular bioavailability of topical eye drops. The aim of this study was to develop and evaluate a series of solid lipid nanoparticles coated with poly(2-ethyl-2-oxazoline) and chitosan for ocular delivery of ciprofloxacin. Ciprofloxacin-loaded poly(2-ethyl-2-oxazoline) (PSLN) formulation was prepared by a combination of melt-emulsion sonication and low-temperature solidification methods. A Box-Behnken design, was employed to statistically optimize the effects of the amount of drug (X1), lipid:polymer ratio (X2) and surfactant concentration (X3) on particle size (Y1) and entrapment efficiency (Y2). Analysis of variance was used to validate the optimization design; and regression equations and response surface plots were generated. The optimized formulation was selected through numerical point prediction approach. These nanoparticles were characterized using dynamic light scattering, transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and powder X-ray diffractometry (PXRD). In vitro drug release and corneal permeation studies were carried out, while the mucoadhesive properties were evaluated ex vivo using porcine corneal tissue. The particle size and zeta potential of the optimized formulations ranged from 141 to 213 nm and +24.6 to −35.6 mV, respectively. PSLN possessed higher encapsulation efficiency than chitosan-coated solid lipid nanoparticles (CSLN). The in vitro drug release from all the formulations showed an initial burst release followed by prolonged release over 24 h. The release mechanism followed Korsemeyer-Peppas model and Fickian diffusion (n < 0.5). DSC revealed lower enthalpy and crystallinity of the formulations as also detected by PXRD, while TEM showed spherical particles in the lower nanometer range with a layer of polymer coating. The results of this study demonstrated that CSLN exhibited higher mucoadhesion and retention on corneal tissues compared with PSLN and also showed higher flux and apparent permeability, but with lower entrapment efficiency.

A comparison study of lipid and polymeric nanoparticles in the nasal delivery of meloxicam: Formulation, characterization, and in vitro evaluation

With the increasingly widespread of central nervous system (CNS) disorders and the lack of sufficiently effective medication, meloxicam (MEL) has been reported as a possible medication for Alzheimer’s disease (AD) management. Unfortunately, following the conventional application routes, the low brain bioavailability of MEL forms a significant limitation. The intranasal (IN) administration route is considered revolutionary for CNS medications delivery. The objective of the present study was to develop two types of nanocarriers, poly (lactic-co-glycolic acid) nanoparticles (PLGA NPs) and solid lipid nanoparticles (SLNs), for the IN delivery of MEL adapting the Quality by Design approach (QbD). Turning then to further enhance the optimized nanoformulation behavior by chitosan-coating. SLNs showed higher encapsulation efficacy (EE) and drug loading (DL) than PLGA NPs 87.26% (EE) and 2.67% (DL); 72.23% (EE) and 2.55% (DL), respectively. MEL encapsulated into the nanoformulations improved in vitro release, mucoadhesion, and permeation behavior compared to the native drug with greater superiority of chitosan-coated SLNs (C-SLNs). In vitro-in vivo correlation (IVIVC) results estimated a significant in vivo brain distribution of the nanoformulations compared to native MEL with estimated greater potential in the C-SLNs. Hence, MEL encapsulation into C-SLNs towards IN route can be promising in enhancing its brain bioavailability.

Systematically designed chitosan-coated solid lipid nanoparticles of ferulic acid for effective management of Alzheimer’s disease: A preclinical evidence

Ferulic acid (FA) is a ubiquitous natural plant bioactive with distinctive promise in neurodegenerative disorders. However, its therapeutic efficacy gets compromised owing to its poor aqueous solubility, inadequate permeability across lipophilic barriers, and extensive first-pass metabolism. The current studies, therefore, were undertaken to systematically develop chitosan-coated solid lipid nanoparticles (SLNs) using QbD paradigms for improved efficacy of FA in the management of Alzheimer’s disease (AD). SLNs of FA were formulated employing Compritol as lipid and polysorbate 80 as surfactant and optimised using a 32 Central Composite Design (CCD). The optimized formulation, surface-coated with chitosan using ionic gelation, exhibited particle size of 185 nm, entrapment efficiency of 51.2 % and zeta potential of 12.4 mV. FTIR and DSC studies verified the compatibility of FA with formulation excipients, PXRD construed significant loss of drug crystallinity, while FESEM depicted existence of uniform spherical nanoparticles with little aggregation. Notable improvement in ex vivo mucoadhesion and permeation studies using goat nasal mucosa, coupled with extension in in vitro drug release, was obtained with SLNs. Substantial improvement with SLNs in cognitive ability through the reduction in escape latency time during behavioural studies, together with significant improvement in various biochemical parameters and body weight gain was observed in AD-induced rats. Histopathological images of different rat organs showed no perceptible change(s) in tissue morphology. Overall, these preclinical findings successfully demonstrate improved anti-AD efficacy, superior nasal mucoadhesion and permeation, extended drug release, improved patient compliance potential, safety and robustness of the developed lipidic nanoconstructs of FA through intranasal route.

A Composite Nanosystem as a Potential Tool for the Local Treatment of Glioblastoma: Chitosan-Coated Solid Lipid Nanoparticles Embedded in Electrospun Nanofibers.

Glioblastoma multiforme (GBM) is one of the most prevalent and aggressive brain tumors for which there is currently no cure. A novel composite nanosystem (CN), consisting of chitosan-coated Solid Lipid Nanoparticles (c-SLN) embedded in O-carboxymethyl chitosan (O-CMCS)-containing nanofibers (NFs), was proposed as a potential tool for the local delivery of lipophilic anti-proliferative drugs. Coacervation was selected as a solvent-free method for the preparation of stearic acid (SA) and behenic acid (BA)-based SLN (SA-SLN and BA-SLN respectively). BA-SLN, containing 0.75% w/w BA sodium salt and 3% w/w poly(vinyl alcohol) (PVA), were selected for the prosecution of the work since they are characterized by the lowest size functional to their subsequent coating and incorporation in nanofibers. BA-SLN were coated with chitosan (CS) by means of a two-step coating method based on the physical absorption of positively charged CS chains on the SLN negative surface. Nile Red (NR), chosen as the hydrophobic model dye, was dissolved in a micellar solution of BA sodium salt and then added with a coacervating solution until pH ≅ 2.5 was reached. Immunocytochemistry analyses highlighted that CS-coated BA-SLN (c-BA-SLN) exhibited a higher accumulation in human glioblastoma cells (U-373) after 6 h than CS-free BA-SLN. Finally, the c-BA-SLN dispersion was blended with a solution consisting of freely soluble polymers (O-CMCS, poly(ethylene oxide) and poloxamer) and then electrospun to obtain NFs with a mean diameter equal to 850 nm. After the NFs dissolution in an aqueous media, c-BA-SLN maintained their physicochemical properties and zeta potential.

Folic Acid Decorated Chitosan-Coated Solid Lipid Nanoparticles for the Oral Treatment of Rheumatoid Arthritis

Background: Systemic treatment of rheumatoid arthritis has been accompanied with several side effects. This study attempts to reduce leflunomide systemic side effects besides increasing its joint healing outcomes via formulation of layer-by-layer coated, leflunomide-loaded solid lipid nanoparticles (SLNs). Methods: SLNs were coated with chitosan (CS) followed by folic acid (FA). FA-CS-SLNs were about 284.9nm and carried negative surface charge. Results & conclusion: FA-CS-SLNs showed sustained release profile for 168h. Results of oral administration of FA-CS-SLNs in rats with adjuvant-induced arthritis revealed improved joint healing and reduced hepatotoxicity compared with leflunomide suspension. This may be attributed to the ability of FA-CS-SLNs to actively target FA receptors that are overexpressed in inflamed rheumatic joints in addition to innate joint healing properties of CS.

Oral Insulin Delivery by Chitosan Coated Solid Lipid Nanoparticles: Ex vivo and in vivo Studies

<p style="text-align: justify;"><strong>Objectives: </strong>The objective of this investigation was to formulate chitosan coated, insulin-loaded solid lipid nanoparticles (SLN) for oral administration and investigate their potential as an effective alternative to the subcutaneous injection. <strong>Methods: </strong>The SLN were prepared from glyceryl monostearate and coated with the mucoadhesive polymer, chitosan and were investigated for physical properties, <em>ex vivo</em> permeation through Caco-2-cell monolayer and goat intestinal mucosa. The<em> in vivo</em> efficacy of the optimized formulation in controlling blood glucose levels was studied in streptozotocin induced diabetic rats.<strong> Results: </strong>Coating in the presence of Poloxamer 407 resulted in significantly smaller nanoparticles than those with Tween 80. Scanning electron microscopy and transmission electron microscopy revealed spherical particles of uniform size distribution. The insulin association efficiency and loading efficiency of SLN prepared with Poloxamer were much greater than those with Tween 80. <em>Ex vivo p</em>ermeability studies in Caco-2 cell monolayer revealed a 4 fold increase in insulin permeation from chitosan coated SLN (<em>P</em>&lt; 0.005) as compared to uncoated SLN at the end of 6 h. The percentage permeation through excised sheep intestinal mucosa from coated SLN was twice that from uncoated SLN and nearly 20 times from insulin solution. The oral administration of chitosan-coated insulin SLN to streptozotocin-induced diabetic rats resulted in a significant hypoglycemic effect (<em>P</em>&lt;0.05) when compared to the groups that received uncoated insulin-loaded SLN or the oral insulin solution and was comparable to that of subcutaneous insulin at the end of an 8 h study. <strong>Conclusion:</strong> Chitosan coated SLN can be considered promising as an effective oral insulin formulation. <p style="text-align: justify;"><strong>Key words:</strong> Chitosan, Diabetes, Glyceryl monostearate, Insulin, Nanoparticles, Permeation.

Chitosan coated solid lipid nanoparticles as promising carriers for docetaxel

Due to its excellent biocompatibility, biodegradability, and its ability to modify the physicochemical properties of nanoparticles, chitosan has been widely used as a coating substance for different nanoparticles. The development and optimization of chitosan coated solid lipid nanoparticles (CS-SLNs) encapsulating docetaxel was the aim of this study. Solid lipid nanoparticles (SLNs) with and without chitosan coat were prepared by high-pressure hot homogenization technique. Characterization of these nanoparticles was carried out by measuring particle size, zeta potential, entrapment efficiency, transmission electron microscope and in-vitro release of docetaxel from these nanoparticles. Furthermore, evaluation of the cytotoxic and antitumor activities of both docetaxel CS-SLNs and uncoated SLNs was carried out.Coating solid lipid nanoparticles with chitosan increased particle size from 143 ± 2.5–225 nm ± 3.6 and inverted the surface charge from −35 ± 3.3 to +25 mV ± 2.1. Furthermore, chitosan coated nanoparticles exhibited a slower docetaxel release compared to the uncoated nanoparticles. Additionally, docetaxel CS-SLN showed higher in vitro cytotoxicity and tumor inhibition compared with uncoated nanoparticles. In conclusion, docetaxel solid lipid nanoparticles could be successfully coated with chitosan which improved the in vitro and in vivo performance of these nanoparticles compared to uncoated nanoparticles.

Pharmacokinetic Evaluation of 99mTc-radiolabeled Solid Lipid Nanoparticles and Chitosan Coated Solid Lipid Nanoparticles.

Solid Lipid Nanoparticles (SLNs) possess unique in vivo features such as high resistivity, bioavailability, and habitation at the target site. Coating nanoparticles with polymers such as chitosan greatly affects their pharmacokinetic behavior, stability, tissue uptake, and controlled drug delivery. The aim of this study was to prepare and evaluate the biodistribution of 99mTc-labeled SLNs and chitosan modified SLNs in mice. 99mTc-oxine was prepared and utilized to radiolabel pre-papered SLNs or chitosan coated SLNs. After purification of radiolabeled SLNs (99mTc-SLNs) and radiolabeled chitosan-coated SLNs (99mTc-Chi-SLNs) using Amicon filter, they were injected into BALB/c mice to evaluate their biodistribution patterns. In addition, nanoparticles were characterized using Transmission Electron Microscopy (TEM), Fourier-transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), X-ray Powder Diffraction (XRD) and Dynamic Light Scattering (DLS). 99mTc-oxine with high radiochemical purity (RCP~100%) and stability (RCP > 97% at 24 h) was used to provide 99mTc-SLNs and 99mTc-Chi-SLNs with high initial RCP (100%). TEM image and DLS data suggest 99mTc- SLNs susceptibility to aggregation. To that end, the main portion of 99mTc-SLNs radioactivity accumulates in the liver and intestines, while 99mTc-Chi-SLNs sequesters in the liver, intestines and kidneys. The blood radioactivity of 99mTc-Chi-SLNs was higher than that of 99mTc-SLNs by 7.5, 3.17 and 3.5 folds at 1, 4 and 8 h post-injection. 99mTc- Chi-SLNs uptake in the kidneys in comparison with 99mTc-SLNs was higher by 37.48, 5.84 and 11 folds at 1, 4 and 8h. The chitosan layer on the surface of 99mTc-Chi-SLNs reduces lipophilicity in comparison with 99mTc- SLNs. Therefore, 99mTc-Chi-SLNs are less susceptible to aggregation, which leads to their lower liver uptake and higher kidney uptake and blood concentration.

Development of Solid Lipid Nanoparticles by Cold Dilution of Microemulsions: Curcumin Loading, Preliminary In Vitro Studies, and Biodistribution.

Background: Solid lipid nanoparticles (SLNs) are attractive drug delivery systems for lipophilic molecules like curcumin (CURC) with low chemical stability. Methods: A simple, innovative, and cold-operating method, named “cold dilution of microemulsion” is developed by the authors to produce SLNs. An oil-in-water microemulsion (µE), whose disperse phase consisted of a solution of trilaurin in a partially water-miscible solvent, was prepared after mutually saturating solvent and water. Trilaurin SLNs precipitated following solvent removal upon water dilution of the µE. After SLN characterization (mean size, Zeta potential, CURC entrapment efficiency, and over time stability), they were tested for in vitro cytotoxicity studies on pancreatic adenocarcinoma cell lines and for in vivo preliminary biodistribution studies in Wistar healthy rats. Results: CURC loaded SLNs (SLN-CURC) had mean diameters around 200 nm, were negatively charged, stable over time, and able to entrap CURC up to almost 90%, consequently improving its stability. SLN-CURC inhibited in vitro pancreatic carcinoma cell growth in concentration-dependent manner. Their in vivo intravenous administration suggested a possible long circulation. Conclusions: These results, according to a concomitant study on chitosan-coated SLNs, confirm the possibility to apply the developed SLN-based delivery systems as a means to entrap CURC, to improve both its water dispersibility and chemical stability, facilitating its application in therapy.

Solid Lipid Nanoparticles and Chitosan-coated Solid Lipid Nanoparticles as Promising Tool for Silybin Delivery: Formulation, Characterization, and In vitro Evaluation

Silybin (Sb) is the major flavolignan of the extract of Silybum marianum. It is used for the treatment of various acute and chronic liver toxicities, inflammation, fibrosis and oxidative stress. Many studies indicate that Sb is also active against different carcinomas and it has been very recently proposed to be beneficial in type 2 diabetes patients. However, Sb is a low water soluble and low permeable compound. In this study, Solid Lipid Nanoparticles (SLNs) were proposed to enhance the solubility and the intestinal absorption of Sb. SLNs were made of stearic acid and Brij 78 and subsequently coated with chitosan. Formulations were physically and chemically characterized. Stability studies were also assessed. Sb in vitro release was evaluated in different pH media. In vitro permeability test with artificial membranes and Caco-2 cells were performed. Cellular uptake and mucoadhesion studies were conducted. Both nanoparticles were found to be stable. In vitro release indicated that SLNs may prevent burst release and gastric degradation of Sb. Higher extent of Sb permeation was observed for both nanoparticles in PAMPA and Caco-2 cell monolayer models. The results of the cellular uptake study suggested the involvement of active endocytic processes. Chitosan significantly improves mucoadhesion properties of nanoparticles. Together with the excellent stability, strong mucoadhesive property, and slow release, chitosan coated SLNs demonstrated promising potential to enhance absorption of hydrophobic Sb after oral administration.