Nanostructured lipid carrier versus solid lipid nanoparticles of simvastatin: Comparative analysis of characteristics, pharmacokinetics and tissue uptake

Enhancement of Simvastatin ex vivo Permeation from Mucoadhesive Buccal Films Loaded with Dual Drug Release Carriers

BACKGROUND

Simvastatin (SMV), a hypocholesterolemic agent, suffers from very low bioavailability due to its poor aqueous solubility and extensive first-pass metabolism.

METHODS

Two SMV carrier systems, namely, polymeric drug inclusion complex (IC) and mixed micelles (MM) nanoparticles, were developed and loaded into mucoadhesive buccal films to enhance SMV bioavailability. The two carrier systems were characterized and their permeation across human oral epithelial cells (OEC) was studied. The effect of IC to MM ratio (X1) and the mucoadhesive polymer concentration (X2) on the cumulative percent of drug released, elongation percent and the mucoadhesive strength, from the prepared mucoadhesive films, were optimized. Ex vivo permeation across bovine mucosal tissue was investigated. The permeation parameters for the in vitro and ex vivo release data were calculated.

RESULTS

Complexation of SMV with hydroxypropyl beta-cyclodextrin (HP β-CD) was superior to all other polymers as revealed by the equilibrium saturation solubility, stability constant, complexation efficiency and thermodynamic potential. SMV-HP β-CD IC was utilized to develop a saturated polymeric drug solution. Both carrier systems showed enhanced permeation across OEC when compared to pure drug. X1 and X2 were significantly affecting the characteristics of the prepared films. The optimized mucoadhesive buccal film formulation loaded with SMV IC and drug MM nanoparticles demonstrated superior ex vivo permeation when compared to the corresponding pure drug buccal film, and the calculated permeation parameters confirmed this finding.

CONCLUSION

Mucoadhesive buccal films containing SMV IC and drug MM can be used to improve drug bioavailability; however, additional pharmacokinetic and pharmacodynamic studies are required.

QbD aided development of ibrutinib-loaded nanostructured lipid carriers aimed for lymphatic targeting: evaluation using chylomicron flow blocking approach

Ibrutinib (IBR) is the choice of drug for the treatment of chronic lymphocytic leukaemia (CLL) and mantle cell lymphoma (MCL). IBR has low oral bioavailability of 2.9% owing to its high first pass metabolism. Present study was aimed to develop the nanostructured lipid carriers (NLC) using glyceryl monostearate (GMS) as solid lipid and Capryol™ PGMC as liquid lipid. Plackett-Burman design (PBD) was applied to screen the significant factors; furthermore, these significant factors were subjected to optimisation using Central Composite design (CCD). The size, poly dispersity index (PDI) and entrapment efficiency (E.E.) of the developed NLC were 106.4 ± 8.66 nm, 0.272 ± 0.005 and 70.54 ± 5.52% respectively. Morphological evaluation using transmission electron microscope (TEM) and field emission scanning electron microscope (FESEM) revealed spherical particles. Furthermore, differential scanning calorimetry (DSC) indicates the formation of molecular dispersion of drug in the melted lipid matrix while Powder X-Ray Diffraction (PXRD) studies reveal the absence of crystalline drug peaks in the formulation diffractogram. In-vivo pharmacokinetics of NLC displayed an increase in C_max (2.89-fold), AUC_0-t (5.32-fold) and mean residence time (MRT) (1.82-fold) compared with free drug. Furthermore, lymphatic uptake was evaluated by chylomicron flow blocking approach using cycloheximide (CXI). The pharmacokinetic parameters C_max, AUC_0-t and MRT of NLC without CXI were 2.75, 3.57 and 1.30 folds higher compared with NLC with CXI. The difference in PK parameters without CXI indicates significant lymphatic uptake of the formulation. Hence, NLC can be a promising approach to enhance the oral bioavailability of drugs with high first-pass metabolism. Graphical abstract.

Biocompatible Delivery System for Metformin: Characterization, Radiolabeling and In Vitro Studies

BACKGROUND

In recent years, the uses of nanotechnology in medicine have an increasing potential as an effective nanocarrier system. These systems are improved with the purpose of maximizing therapeutic activity and minimizing undesirable side-effects. Moreover, radiolabeled nanoparticles can be used as agents for diagnosis and therapeutic purposes in clinical applications. They have three main components: the core, the targeting biomolecule, and the radionuclide.

OBJECTIVE

It is aimed to synthesize Metformin (MET) loaded Solid Lipid Nanoparticles (MET-SLN) and radiolabeled with technetium-99m tricarbonyl core.

METHODS

The structure of synthesized nanoparticles was characterized by Fourier Transform Infrared Spectroscopy (FTIR). The particle size and morphology of nanoparticles were examined by Dynamic Light Scattering (DLS), and Scanning Electron Microscope (SEM). Quality control studies of radiolabeled MET-SLN [99mTc(CO)3-MET-SLN] were performed by High-Performance Liquid Radiochromatography (HPLRC) and Thin Layer Radiochromatography (TLRC).

RESULTS

The radiolabeling yield of [99mTc(CO)3-MET-SLN] was found to be 88%. In vitro studies have been performed on cancer lines(MCF7, MDA-MD-231 breast, and HEPG2 liver cancer cells) to determine the biological behavior of 99mTc(CO)3-MET-SLNs.

CONCLUSION

The results showed that higher uptake values were observed on estrogen-positive MCF7 breast cancer cell line according to estrogen negative MDA-MB-231 breast cancer and HEPG2 liver cancer cell lines.

Pumpkin Oil-Based Nanostructured Lipid Carrier System for Antiulcer Effect in NSAID-Induced Gastric Ulcer Model in Rats

Background

Peptic ulcer disease, a painful lesion of the gastric mucosa, is considered one of the most common gastrointestinal disorders. This study aims to investigate the formulation of pumpkin seed oil (PSO)-based nanostructured lipid carriers (NLCs) to utilize PSO as the liquid lipid component of NLCs and to achieve oil dispersion in the nano-range in the stomach.

Methods

Box–Behnken design was utilized to deduce the optimum formula with minimum particle size. The optimized PSO-NLCs formula was investigated for gastric ulcer protective effects in Wistar rats by evaluating ulcer index and determination of gastric mucosa oxidative stress parameters.

Results

PSO was successfully incorporated as the liquid lipid (LL) component of NLCs. The prepared optimum PSO-NLCs formula showed a size of 64.3 nm. Pretreatment of animals using the optimized PSO-NLCs formula showed significantly (p< 0.001) lower ulcer index compared to indomethacin alone group and significantly (p<0.05) less mucosal lesions compared to the raw oil.

Conclusion

These results indicated great potential for future application of optimized PSO-NLCs formula for antiulcer effect in non-steroidal anti-inflammatory drug (NSAID)-induced gastric ulcer.

Chitosan coated nanostructured lipid carriers for enhanced in vivo efficacy of albendazole against Trichinella spiralis

The study investigated chitosan coated nanostructured lipid carriers (NLCs) for oral delivery of albendazole in treatment of trichinellosis. NLCs comprised precirol and oleic acid with Tween and Span 80. Dicetylphosphate was used as charging agent to allow chitosan coating. Trichinella spiralis infected mice were used and albendazole suspension, coated or uncoated NLCs were orally administered at different stages of infection. NLCs were spherical with size of 188 and 200 nm for coated and uncoated NLC, respectively. Treatment during intestinal phase reduced worm count with NLCs showing better rank. This was reflected further by reduced larvae count and improved histopathological features. Starting treatment in the migrating phase reduced larval count by 62.9, 99.6 and 89.5 % after administration of suspension, coated and uncoated NLCs, respectively. The same rank was recorded for the encysted phase. NLCs enhanced the efficacy of albendazole against Trichinella spiralis compared with suspension with chitosan coated NLCs being superior.

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

BACKGROUND

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.

METHODS

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).

RESULTS

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.

CONCLUSION

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.

A window into the brain: Tools to assess pre-clinical efficacy of biomaterials-based therapies on central nervous system disorders

Therapeutic conveyance into the brain is a cardinal requirement for treatment of diverse central nervous system (CNS) disorders and associated pathophysiology. Effectual shielding of the brain by the blood-brain barrier (BBB) sieves out major proportion of therapeutics with the exception of small lipophilic molecules. Various nano-delivery systems (NDS) provide an effective solution around this obstacle owing to their small size and targeting properties. To date, these systems have been used for several pre-clinical disease models including glioma, neurodegenerative diseases and psychotic disorders. An efficacy screen for these systems involves a test battery designed to probe into the multiple facets of therapeutic delivery. Despite their wide application in redressing various disease targets, the efficacy evaluation strategies for all can be broadly grouped into four modalities, namely: histological, bio-imaging, molecular and behavioural. This review presents a comprehensive insight into all of these modalities along with their strengths and weaknesses as well as perspectives on an ideal design for a panel of tests to screen brain nano-delivery systems.

In Vitro Release Test of Nano-drug Delivery Systems Based on Analytical and Technological Perspectives

Background:

Nanotech products are gaining more attention depending on their advantages for improving drug solubility, maintenance of drug targeting, and attenuation of drug toxicity. In vitro release test is the critical physical parameter to determine the pharmaceutical quality of the product, to monitor formulation design and batch-to-batch variation.

Methods:

Spectrophotometric and chromatographic methods are mostly used in quantification studies from in vitro release test of nano-drug delivery systems. These techniques have advantages and disadvantages with respect to each other considering dynamic range, selectivity, automation, compatibility with in vitro release media and cost per sample.

Results:

It is very important to determine the correct kinetic profile of active pharmaceutical substances. At this point, the analytical method used for in vitro release tests has become a very critical parameter to correctly assess the profiles. In this review, we provided an overview of analytical methods applied to the in vitro release assay of various nanopharmaceuticals.

Conclusion:

This review presents practical direction on analytical method selection for in vitro release test on nanopharmaceuticals. Moreover, precautions on analytical method selection, optimization and validation were discussed.

Solid lipid matrix mediated nanoarchitectonics for improved oral bioavailability of drugs

Introduction: Solid matrix mediated lipid nanoparticle formulations (LNFs) retain some of the best features of ideal drug carriers necessary for improving the oral absorption and bioavailability (BA) of both hydrophilic and hydrophobic drugs. LNFs with solid matrices may be typically categorized into three major types of formulations, viz., solid lipid nanoparticles (SLNs), nanostructured lipid carriers (NLCs) and lipid-drug conjugate nanoparticles (LDC-NPs). Solid matrix based LNFs are, potentially, the most appropriate delivery systems for poorly water soluble drugs in need of improved drug solubility, permeability, absorption, or increased oral BA. In addition, LNFs as matrices are able to encapsulate both hydrophobic and hydrophilic drugs in a single matrix based on their excellent ability to form cores and shells. Interestingly, LNFs also act as delivery devices to impart chemical stability to various orally administered drugs. Areas covered: Aim of the review is to forecast the presentation of pharmacokinetic characteristics of solid lipid matrix based nanocarriers which are typically biocompatible, biodegradable and non-toxic carrier systems for efficient oral delivery of various drugs. Efficient delivery is broadly mediated by the fact that lipophilic drugs are readily soluble in lipidic substrates that are capable of permeating across the gut epithelium following oral administration, subsequently delivering the moiety of interest more efficiently across the gut mucosal membrane. This enhances the overall BA of many drugs facing oral delivery challenges by improving their pharmacokinetic profile. This article specifically focuses on the biopharmaceutical and pharmacokinetic aspects of such solid lipid matrix based nanoformulations and possible mechanisms for better drug absorption and improved BA following oral administration. It also briefly reviews methods to access the efficacy of LNFs for improving oral BA of drugs, regulatory aspects and some interesting lipid-derived commercial formulations, with a concluding remark. Expert opinion: LNFs enhance the overall BA of many drugs facing oral delivery challenges by improving their pharmacokinetic profile.

In Vitro Drug Dissolution/Permeation Testing of Nanocarriers for Skin Application: a Comprehensive Review

This review highlights in vitro drug dissolution/permeation methods available for topical and transdermal nanocarriers that have been designed to modulate the propensity of drug release, drug penetration into skin, and permeation into systemic circulation. Presently, a few of USFDA-approved in vitro dissolution/permeation methods are available for skin product testing with no specific application to nanocarriers. Researchers are largely utilizing the in-house dissolution/permeation testing methods of nanocarriers. These drug release and permeation methods are pending to be standardized. Their biorelevance with reference to in vivo plasma concentration-time profiles requires further exploration to enable translation of in vitro data for in vivo or clinical performance prediction.

Antifungal and Mucoadhesive Properties of an Orally Administered Chitosan-Coated Amphotericin B Nanostructured Lipid Carrier (NLC)

Surface-modified nanostructured lipid carriers (NLC) represent a promising mode of drug delivery used to enhance retention of drugs at absorption site. Formulated chitosan-coated amphotericin-B-loaded NLC (ChiAmp NLC) had a size of 394.4 ± 6.4 nm, encapsulation and loading efficiencies of 86.0 ± 3% and 11.0 ± 0.1% respectively. Amphotericin-B release from NLCs was biphasic with no changes in physical properties upon exposure to simulated gastrointestinal conditions. Antifungal properties of Amphotericin-B and ChiAmpB NLC were comparable but ChiAmpB NLC was twice less toxic to red blood cells and ten times safer on HT-29 cell lines. In vitro mucoadhesion data were observed ex vivo, where ChiAmpB NLC resulted in higher retention within the small intestine compared to the uncoated formulation. The data strongly offers the possibility of orally administering a non-toxic, yet effective Amphotericin-B nanoformulation for the treatment of systemic fungal infections.

Simvastatin-loaded solid lipid nanoparticles for enhanced anti-hyperlipidemic activity in hyperlipidemia animal model

The objective of current study was to develop solid lipid nanoparticles-loaded with simvastatin (SIM-SLNs) and investigate their in vivo anti-hyperlipidemic activity in poloxamer-induced hyperlipidemia model. Nano-template engineering technique was used to prepare SIM-SLNs with palmityl alcohol as lipid core and a mixture of Tween 40/Span 40/Myrj 52 to stabilize the core. The prepared SIM-SLNs were evaluated for physicochemical parameters including particle diameter, surface charge, morphology, incorporation efficiency, thermal behaviour and crystallinity. In vitro release profile of SIM-SLNs in simulated gastric and intestinal fluids was evaluated by using dialysis bag technique and anti-hyperlipidemic activity was assessed in hyperlipidemia rat model. SIM-SLNs revealed uniform particle size with spherical morphology, zeta potential of -24.9 mV and high incorporation efficiency (∼85%). Thermal behaviour and crystallinity studies demonstrated successful incorporation of SIM in the lipid core and its conversion to amorphous form. SIM-SLNs demonstrated a sustained SIM release from the lipid core of nanoparticles. SIM-SLNs significantly reduced the elevated serum lipids as indicated by ∼3.9 and ∼1.5-times decreased total cholesterol compared to those of untreated control and SIM dispersion treated hyperlipidemic rats. In conclusion, SIM-SLNs showed a great promise for improving the therapeutic outcomes of SIM via its effective oral delivery.

Intranasal Surface-Modified Mosapride Citrate-Loaded Nanostructured Lipid Carriers (MOS-SMNLCs) for Treatment of Reflux Diseases: In vitro Optimization, Pharmacodynamics, and Pharmacokinetic Studies

Gastroesophageal reflux disease (GERD) is an esophageal injury occurred when the stomach contents reflux abnormally into the esophagus. GERD complications include esophageal adenocarcinoma. Mosapride (MOS) is a safe prokinetic agent potentially used to treat GERD. Yet, its low solubility and bioavailability due to extensive first-pass metabolism limits its applications. This study aimed to formulate MOS nanostructured lipid carriers (MOS-NLCs) via the intranasal route to improve its bioavailability. Melt-emulsification low temperature-solidification technique using 2³ full factorial design was adopted to formulate MOS-NLCs. Eight formulae were prepared and assessed in terms of entrapment efficiency (%EE), particle size, and in vitro release. Glycerol addition significantly reduced the particle sizes and improved %EE and %drug released. Surface modification using chitosan was applied. The optimized MOS surface-modified nanostructured lipid carriers (MOS-SMNLCs-F7)(stearic acid, 4% glycerol, 0.5% LuterolF127, 0.5% chitosan) showed low particle size 413.8 nm ± 11.46 nm and high %EE 90.19% ± 0.06% and a threefold increase in permeation of MOS with respect to the drug suspension. MOS-SMNLCs (F7) was also evaluated for its bioavailability compared with drug suspension and commercial product. Statistical analysis revealed a significant increase in gastric emptying rate to be 21.54 ± 1.88 contractions/min compared with10.02 ± 0.62 contractions/min and 8.9 ± 0.72 contractions/min for drug suspension and oral marketed product respectively. Pharmacokinetic studies showed 2.44-fold rise in bioavailability as compared to MOS suspension and 4.54-fold as compared to the oral marketed product. In vitro/in vivo studies proven to level A correlation between in vitro permeation through sheep nasal mucosa and in vivo absorption. Therefore, MOS-SMNLCs could be considered a step forward towards enhancing the clinical efficacy of Mosapride.

Developments in drug delivery of bioactive alkaloids derived from traditional Chinese medicine

The bioactive alkaloids (e.g. vincristine, hydroxycamptothecin, ligustrazine, and so on) from traditional Chinese medicine (TCM) have exerted potent efficacies (e.g. anti-tumor, anti-inflammation, immunosuppression, etc.). However, a series of undesirable physicochemical properties (like low solubility and weak stability) and baneful pharmacokinetic (PK) profiles (e.g. low bioavailability, short half time, rapid clearance, etc.) have severely restricted their applications in clinic. In addition, some side effects (like cumulative toxicities caused by high-frequency administration and their own toxicities) have recently been reported and also confined their clinical uses. Therefore, developments in drug delivery of such alkaloids are of significance in improving their drug-like properties and, thus, treatment efficiencies in clinic. Strategies, including (i) specific delivery via liposomes; (ii) sustained delivery via nanoparticles, gels, and emulsions; and (iii) transdermal delivery via ethosomes, solid lipid nanoparticles, and penetrating enhancers, have been reported to improve the pharmacokinetic and physicochemical characters of problematic TCM alkaloids, decline their adverse effects, and thus, boost their curative efficacies. In this review, the recent reports in this field were comprehensively summarized with the aim of providing an informative reference for relevant readers.

Application of nanotechnology to improve the therapeutic benefits of statins

Hyperlipidemia is defined as an elevated level of lipids and lipoproteins in the blood and is considered to be a significant risk factor for accelerating the process of atherosclerosis and, consequently, cardiovascular disease. The level of cholesterol, especially low-density lipoprotein cholesterol (LDL-C), is commonly elevated in hyperlipidemia and represents the primary therapeutic target. Statins are a group of drugs that function by inhibiting 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and are extremely efficacious in reducing elevated LDL-C in the serum and preventing atherosclerotic cardiovascular disease. However, statins have some limitations, such as poor aqueous solubility, low oral absorption, and, consequently, limited bioavailability when administered by the oral route. The field of nanotechnology is now well developed and some of these newer nanotechnology strategies offer systems with enhanced aqueous solubility of the statin, increased absorption, bioavailability, and controlled release of the statin at the site of administration. Here, we discuss nano-sized drug delivery systems to enhance the therapeutic potential of statins.

Skin permeation, biocompatibility and antitumor effect of chloroaluminum phthalocyanine associated to oleic acid in lipid nanoparticles

The objective of this study was to develop and characterize lipid nanoparticles (LNs) containing chloroaluminum phthalocyanine (ClAlPc) to reduce the aggregation of the drug and improve its skin penetration and its antitumor effect. LNs were prepared and characterized by using stearic acid (SA) as solid lipid and oleic acid (OA) as liquid lipid in different proportions. in vitro and in vivo skin penetration was evaluated using modified Franz diffusion cells and fluorescence microscopy, respectively. in vitro biocompatibility and Photodynamic Therapy (PDT) were performed using L929-fibroblasts cell line and A549 cancer cell line and melanoma BF16-F10, respectively. OA promoted the increase in the encapsulation efficiency and drug loading, reaching values of 95.8% and 4%, respectively. The formulation with 40% OA (NLC 40) showed a significantly higher (p < 0.01) amount of drug retained in the skin compared to other formulations. All formulations developed were considered biocompatible. PDT evidenced the antitumor efficacy of NLC 40 with reduced cell viability for approximately 10% of cancer cells, demonstrating that the presence of OA in the NLC seems to potentialize this antitumor effect. PDT in BF16-F10 melanoma using NLC 40 resulted in a reduction in mean cell viability of approximately 99%. According to the results obtained, the systems developed may be promising for the incorporation of ClAlPc in the treatment of skin cancer by photodynamic therapy.

pH-Sensitive Nanocarrier-Mediated Codelivery of Simvastatin and Noggin siRNA for Synergistic Enhancement of Osteogenesis

The inexpensive hypolipidemic drug simvastatin (SIM), which promotes bone regeneration by enhancing bone morphogenetic protein 2 (BMP-2) expression, has been regarded as an ideal alternative to BMP-2 therapy. However, SIM has low bioavailability and may induce the upregulation of the BMP-2-antagonistic noggin protein, which greatly limits the osteogenic effect. Here, a pH-sensitive copolymer, monomethoxy-poly(ethylene glycol)- b-branched polyethyleneimine- b-poly( N-( N', N'-diisopropylaminoethyl)- co-benzylamino)aspartamide (mPEG-bPEI-PAsp(DIP-BzA)) (PBP), was synthesized and self-assembled into a cationic micelle. SIM and siRNA targeting the noggin gene (N-siRNA) were loaded into the PAsp(DIP-BzA) core and the cationic bPEI interlayer of the micelle via hydrophobic and electrostatic interactions, respectively. The SIM-loaded micelle effectively delivered SIM into preosteoblast MC3T3-E1 cells and rapidly released it inside the acidic lysosome, resulting in the elevated expression of BMP-2. Meanwhile, the codelivered N-siRNA effectively suppressed the expression of noggin. Consequently, SIM and N-siRNA synergistically increased the BMP-2/noggin ratio and resulted in an obviously higher osteogenetic effect than did simvastatin or N-siRNA alone, both in vitro and in vivo.

A review on the role of lipid-based nanoparticles in medical diagnosis and imaging

Molecular and diagnostic imaging has been recently a subject of intense research in the treatment of numerous diseases. In medical imaging, there are different modalities with unique strengths including MRI, ultrasound imaging, computed tomography, positron emission tomography and single photon emission computed tomography. These systems need specific contrast agents to achieve a suitable image with the best quality. Nanoparticles represent an innovative tool in imaging field research and diagnostics of various diseases, especially cancerous ones. Among the nanocarriers, lipid-based nanoparticles, such as nanostructured lipid carriers, solid lipid nanoparticles and liposomes, are the most used carriers in imaging because of having many advantageous properties. This review addresses advancements in different lipid-based nanoparticles as tools in medical diagnostic and imaging.

Development of novel rosuvastatin nanostructured lipid carriers for oral delivery in an animal model

Objective

The aim of this study was to prepare rosuvastatin nanostructured lipid carriers (RST-NLCs) in order to increase the bioavailability of RST.

Materials and methods

RST-NLCs were prepared by hot melt high-pressure homogenization method. The physicochemical parameters of RST-NLCs were characterized in terms of particle size, zeta potential, morphology, entrapment efficiency, and in vitro release behavior.

Results

The mean particle size was found to be 98.4±0.3 nm. The entrapment efficiency was 84.3%±1.3%. The RST was slowly released from NLCs over a period of 48 h in the PBS. A similar phenomenon was also observed in a pharmacokinetic study in rats, in which the area under the curve of NLCs was 1.65-fold higher than that of tablet powder.

Conclusion

The results of pharmacodynamics showed that the effective lipid-lowering activity of NLCs could be explained by the fact that NLCs resulted in sustained release of RST, which could have increased absorption and provided a higher bioavailability.

Unstructured Formulation Data Analysis for the Optimization of Lipid Nanoparticle Drug Delivery Vehicles

Designing nanoparticle formulations with features tailored to their therapeutic targets in demanding timelines assumes increased importance. In this context, nanostructured lipid carriers (NLCs) offer an excellent example of a drug delivery nanosystem that has been broadly explored in the treatment of glioblastoma multiforme (GBM). Distinct fundamental NLC quality attributes can be harnessed to fit this purpose, namely particle size, size distribution, and zeta potential. These critical aspects intrinsically depend on the formulation components, influencing drug loading capacity, drug release, and stability of the NLCs. Wide variations in their composition, including the type of lipids and other surface modifier excipients, lead to differences on these parameters. NLC target product profile involves small mean particle sizes, narrow size distributions, and absolute values of zeta potential higher than 30 mV. In this work, a wealth of data previously obtained in experiments on NLC preparation, encompassing, e.g., results of preliminary studies and those of intermediate formulations, is analyzed in order to extract information useful in further optimization studies. Principal component analysis (PCA) and partial least squares (PLS) are performed to evaluate the influence of NLC composition on the respective characteristics. These methods provide a rapid and discriminatory analysis for establishing a preformulation framework, by selecting the most suitable types of lipids, surfactants, surface modifiers, and drugs, within the set of investigated variables. The results have direct implications in the optimization of formulation and processes.

Ameliorating the in vivo antimalarial efficacy of artemether using nanostructured lipid carriers

Cerebral malaria (CM) is a fatal neurological complication of Plasmodium falciparum infection that affects children (below five years old) in sub-Saharan Africa and adults in South-East Asia each year having the fatality rate of 10-25%. The survivors of CM also have high risk of long term neurological or cognitive deficits. The objective of the present investigation was to develop optimised nanostructured lipid carriers (NLCs) of artemether (ARM) for enhanced anti-malarial efficacy of ARM. NLCs of ARM were prepared by a combination of high speed homogenisation (HSH) and probe sonication techniques. Preliminary solubility studies for ARM showed highest solubility in trimyristin (solid lipid), capmul MCM NF (liquid lipid) and polysorbate 80 (surfactant). Trimyristin and capmul showed superior miscibility at a ratio of 70:30.The optimised NLC formulation has the particle size (PS) of: 48.59 ± 3.67 nm, zeta potential (ZP) of: -32 ± 1.63 mV and entrapment efficiency (EE) of: 91 ± 3.62%. In vitro cell line (human embryonic kidney fibroblast cell line (HEK 293 T)) cytotoxicity studies showed that prepared formulation was non-toxic. The results of in vivo studies in CM induced mice prevented the recrudescence of parasite after administration of NLCs of ARM. Additionally, NLCs of ARM showed better parasite clearance, higher survival (60%) in comparison to ARM solution (40%). Also it was observed that lesser entrapment of Evans blue stain (prepared in PBS as solution) in the NLCs of ARM treated brains of C57BL/6 mice than ARM solution treated mice. Hence NLCs of ARM may be a better alternative for improving therapeutic efficacy than ARM solution.

Hyaluronic acid modified nanostructured lipid carriers for transdermal bupivacaine delivery: In vitro and in vivo anesthesia evaluation

For effective transdermal local anesthetic therapy, to reduce the barrier of stratum corneum and improve the antinociceptive effect, hyaluronic acid (HA) modified, bupivacaine (BPV) loaded nanostructured lipid carriers (NLCs) were designed. HA and linoleic acid (LOA) conjugated propylene glycol (PEG) was synthesized (HA-PEG-LOA). HA-PEG-LOA was added during the preparation process of NLCs, thus LOA was inserted into the NLCs, The physicochemical properties of NLCs, particle size, zeta potential, drug loading capacity, in vitro skin permeation, drug release profiles and in vivo therapeutic effect were evaluated. HA-BPV/NLCs have small particle size of 150?nm, with a zeta potential of ?40?mV. Nearly 90% high drug encapsulation efficiency and good stability were also observed. In vitro release rate of BPV from HA-BPV/NLCs was complying with a sustained behavior until 72?h of study. HA-BPV/NLCs and BPV/NLCs exhibited 2.5 and 1.6 fold of percutaneous penetration improvement than free BPV. BPV loaded NLCs produced a more prolonged antinociceptive effect when compared with free BPV. In vitro and in vivo results pointed out HA modified NLCs have the capability to act as effective drug carriers, thus prolonging and enhancing the anesthetic effect of BPV. The NLCs developed in this study might provide a useful platform for developing a sophisticated dermal delivery system for analgesic.

Atorvastatin-loaded nanostructured lipid carriers (NLCs): strategy to overcome oral delivery drawbacks

Atorvastatin (AT) is a widely used lipid-regulating drug to reduce cholesterol and triglycerides. Its poor aqueous solubility and hepatic metabolism require development of drug delivery systems able to improve its solubility and bypass hepatic effect. For this purpose, atorvastatin nanostructured lipid carriers (AT-NLCs) were prepared and characterized. AT-NLCs were prepared by emulsification using high-speed homogenization followed by ultrasonication. The prepared NLCs showed particle size between 162.5 ± 12 and 865.55 ± 28 nm while zeta potential values varied between −34 ± 0.29 and −23 ± 0.36 mV. They also showed high encapsulation efficiency (>87%) and amorphous state of the drug in lipid matrix. Pharmacokinetic parameters of optimized formulation (NLC-1; composed of 2% Gelucire^® 43/01, 8% Capryol^® PGMC, 2% Pluronic^®F68 and 0.5% lecithin) revealed 3.6- and 2.1-fold increase in bioavailability as compared to atorvastatin suspension and commercial product (Lipitor^®), respectively. Administration of NLC-1 led to significant reduction (p < .05) in the rats’ serum levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL) and significant increase in high-density lipoprotein (HDL). This improvement was confirmed histologically by minimizing the associated hepatic steatosis. These investigations demonstrated the superiority of NLCs for improvement of oral bioavailability and in vivo performance of AT.

Advances in the design of solid lipid nanoparticles and nanostructured lipid carriers for targeting brain diseases

Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) comprise a category of versatile drug delivery systems that have been used in the biomedical field for >25years. SLNs and NLCs have been used for the treatment of various diseases including cardiovascular and cerebrovascular, and are considered a standard treatment for the latter, due to their inherent ability to cross the blood brain barrier (BBB). In this review, a presentation of the most important brain diseases (brain cancer, ischemic stroke, Alzheimer's disease, Parkinson's disease and multiple sclerosis) is approached, followed by the basic fabrication techniques of SLNs and NLCs. A detailed description of the reported studies of the last seven years, of active and passive targeting SLNs and NLCs for the treatment of glioblastoma multiforme and of other brain cancers, as well as for the treatment of neurodegenerative diseases is also carried out. Finally, a brief description of the advantages, the disadvantages, and the future perspectives in the use of these nanocarriers is reported, aiming at giving an insight of the limitations that have to be overcome in order to result in a delivery system with high therapeutic efficacy and without the limitations of the existing nano-systems.

A New Level A Type IVIVC for the Rational Design of Clinical Trials Toward Regulatory Approval of Generic Polymeric Long-Acting Injectables

Chronic neuropsychiatric disorders and diabetes mellitus affect millions of patients and require long-term supervision and expensive medical care. Although repeated drug administration can help manage these diseases, relapses and re-hospitalization owing to patient non-adherence and reduced therapeutic efficacy remain challenging. In response, long-acting injectables, which provide sustained drug release over longer periods at concentrations close to therapeutic ranges, have been proposed. Recent advancements include polymeric long-acting injectables (pLAIs), in which the active pharmaceutical ingredient (API) is encapsulated within U.S. Food and Drug Administration (FDA)-approved biocompatible polymers, such as poly(lactic-co-glycolic acid), or PLGA. Despite significant progress and development in the global pLAI market, FDA guidance for the approval of complex drug products, such as generic pLAIs, is not clearly defined. Although in vitro to in vivo correlation (IVIVC) can facilitate the identification of critical quality attributes (CQAs), drug formulations, and in vitro test platforms for evaluating drug performance in vivo, the application of IVIVC in order to shortlist time- and resource-intensive clinical trials for generic pLAIs has not been reported. Here, we propose a new Level A Type IVIVC that directly correlates the in vitro outcomes, such as drug dissolution, of candidate generic formulations with the clinical characteristics, such as drug absorption, of a reference listed drug (RLD), to help identify the specific generic pLAI formulations with clinical absorptions that are likely to be similar to that of the RLD, thereby reducing the number of clinical trials required for evaluation of clinical bioequivalence (BE). Therefore, the scope of the proposed method is intended only for the rational design of clinical trials, i.e., to shortlist the specific pLAI generic formulations for clinical BE evaluation, and not necessarily to analyze drug performances (i.e., drug safety and effectiveness) in the shortlisted clinical trials or post-approval. Once validated, this method will be of great value to developers of generic pLAIs and regulatory bodies to accelerate their approval of these generic pLAIs.

Pharmacokinetic studies and anticancer activity of curcumin-loaded nanostructured lipid carriers

In order to investigate the potential of nanostructured lipid carriers for efficient and targeted delivery of curcumin, the pharmacokinetic parameters of curcumin-loaded nanostructured lipid carriers (Cur-NLC) were evaluated in rats after a single intraperitoneal dose of Cur-NLC. In addition, the anticancer activity of Cur-NLC against human lung adenocarcinoma A549 cells was verified by a cellular uptake study, and a cytotoxicity and apoptosis assay. Bioavailability of Cur-NLC was better than that of native curcumin (p > 0.01), as seen from the area under the plasma concentration-time curve (AUC), maximum plasma concentration (Cmax), mean residence time (MRT) and total plasma clearance (CLz/F). Cur-NLC has a more obvious lung-targeting property in comparison with native curcumin. Cur-NLC showed higher anticancer activity in vitro against A549 cells than native curcumin (IC50 value of 5.66 vs. 9.81 mg L-1, respectively). Meanwhile, Cur-NLC treated A549 cells showed a higher apoptosis rate compared to that of native curcumin. These results indicate that NLC is a promising system for the delivery of curcumin in the treatment of lung adenocarcinoma.

Stabilization and Amorphization of Lovastatin Using Different Types of Silica

Lovastatin (LOV), an antihyperlipidimic agent, is characterized by low solubility/poor dissolution and, thus, low bioavailability (<5%). A beneficial effect on its bioavailability could result from improving its dissolution. One of the most common methods used to enhance dissolution is the preparation of solid dispersions. Solid dispersions of LOV and silica with different surface areas were prepared. The effects of the type of silica, ratio of drug/silica, incubation period with silica, and the effect of surface area were all studied. Characterization of the prepared formulae for possible interaction between drug and polymer was carried out using differential scanning calorimetery, Fourier transform infrared spectroscopy, powder X-ray diffraction, surface area determination, and scanning electron microscopy. The dissolution profiles of all prepared formulae were constructed and evaluated. It was found that the formula made of LOV and Sylysia 350 FCP in a ratio of 1:5 after an incubation period of 48 h resulted in the best release, and it was stable after 3 months storage at 75% RH and 40°C.

Ocular disposition of ciprofloxacin from topical, PEGylated nanostructured lipid carriers: Effect of molecular weight and density of poly (ethylene) glycol

Ciprofloxacin (CIP) is an antibacterial agent prescribed for the treatment of ocular infections. The objective of the present project is to investigate the effect of surface PEG functionalization of the Nano structured lipid carriers (NLCs) on formulation stability, ocular penetration and distribution. CIP NLCs were tested with different molecular weight (poly ethylene glycol) PEGs ranging from (2K to 20K) grafted onto the phospholipid and with different chain lengths (14-18 carbons) of phospholipids derivatized with PEG-2K. Drug load in the formulations was maintained at 0.3%w/v. Formulations prepared were evaluated with respect to in vitro release, transcorneal permeation, autoclavability, morphological characteristics and in vivo ocular tissue distribution. Scanning Transmission electron microscopy (STEM) studies revealed that the PEG-CIP-NLCs were spherical in shape. Transcorneal penetration of CIP was optimum with PEG molecular weight in between 2K-10K. Carbon chain length of the phospholipid, however, did not affect transcorneal penetration of CIP. In vivo ocular tissue CIP concentrations attained from the various formulations was consistent with the in vitro data obtained. The results suggest that surface functionalization of PEGs, within a specified range of molecular weight and surface packing density, significantly enhance trans-ocular penetration and impart sterilization-stabilization characteristics into the formulations.

Evaluation of Organogel Nanoparticles as Drug Delivery System for Lipophilic Compounds

The purpose of the study was to evaluate organogel nanoparticles as a drug delivery system by investigating their stability, according to the formulation strategy, and their release profile. The gelled nanoparticles were prepared by hot emulsification (above the gelation temperature) of an organogel in water, and cooling at room temperature. In the first step, we used DLS and DSC to select the most suitable formulations by optimizing the proportion of ingredients (HSA, PVA, castor oil) to obtain particles of the smallest size and greatest stability. Then, two lipophilic drug models, indomethacin and ketoconazole were entrapped in the nanoparticles made of castor oil gelled by 12-hydroxystearic acid. Thermal studies (DSC) confirmed that there was no significant alteration of gelling due to the entrapped drugs, even at 3% w/w. Very stable dispersions were obtained (>3 months), with gelled oil nanoparticles presenting a mean diameter between 250 and 300 nm. High encapsulation efficiency (>98%) was measured for indomethacin and ketoconazole. The release profile determined by in vitro dialysis showed an immediate release of the drug from the organogel nanoparticles, due to rapid diffusion. The study demonstrates the interest of these gelled oil nanoparticles for the encapsulation and the delivery of lipophilic active compounds.

Surface density of polyarginine influence the size, zeta potential, cellular uptake and tissue distribution of the nanostructured lipid carrier

Poly-arginines are strong tools to elevate the cellular uptake of nanopreparations. To learn the influence of poly-arginine (RRRRRRRR, R8) density on a series of properties of nanostructured lipid carrier (NLC), we build six R8 modified NLCs with different R8 densities (nR-NLC, where n represents the R8 ratio) by fusion–emulsion method with the aid of stearyl-R8. The pharmaceutical characteristics like size, zeta potential and in vitro drug release, cellular uptake, cytotoxicity to A549 cells and tissue distribution in S180 tumor-bearing mice of the six nR-NLCs are all investigated. It turns out that with as little as 2% weight ratio of stearyl-R8 modified on NLC, its pharmaceutical properties, especially zeta potential changes astonishingly; however, the stearyl-R8 ratio should be higher than 4% to upgrade the cellular uptake and cytotoxicity evidently; in the ex vivo tissue distribution assessment, the nR-NLC with less than 8% R8 showed similar tissue accumulation, while NLC with 10% R8 shows obvious acute toxicity to mice. Our study pays attention to the effect of the R8 ratio on the changes of cargo properties, and the results indicate that this topic is essential and worth to be further developed.