Nanostructured lipid carriers for parenteral delivery of silybin: Biodistribution and pharmacokinetic studies

Modification of mesenchymal stromal cells with silibinin-loaded PLGA nanoparticles improves their therapeutic efficacy for cutaneous wound repair

The use of mesenchymal stromal cells (MSCs) for treating chronic inflammatory disorders, wounds, and ischemia-reperfusion injuries has shown improved healing efficacy. However, the poor survival rate of transplanted cells due to oxidative stress in injured or inflamed tissue remains a significant concern for MSC-based therapies. In this study, we developed a new approach to protect MSCs from oxidative stress, thereby improving their survival in a wound microenvironment and enhancing their therapeutic effect. We produced PLGA nanoparticles loaded with the cytoprotective phytochemical silibinin (SBN), and used them to modify MSCs. Upon internalization, these nanoformulations released SBN, activating the Nrf2/ARE signaling pathway, resulting in threefold reduction in intracellular ROS content and improved cell survival under oxidative stress conditions. Modification of MSCs with SBN-loaded PLGA nanoparticles increased their survival upon transplantation to full-thickness cutaneous wounds and improved wound healing. This study suggests that MSC modification with cytoprotective nanoparticles could be a promising approach for improving wound healing.

Nano Lipid Carriers as a Promising Drug Delivery Carrier for Neurodegenerative Disorders - An Overview of Recent Advances

The last few decades have seen a rise in the number of deaths caused by neurological disorders. The blood-brain barrier (BBB), which is very complex and has multiple mechanisms, makes drug delivery to the brain challenging for many scientists. Lipid nanoparticles (LNPs) such as nanoemulsions, solid-lipid nanoparticles, liposomes, and nano lipid carriers (NLCs) exhibit enhanced bioavailability and flexibility among these nanocarriers. NLCs are found to be very effective. In the last few decades, they have been a center of attraction for controlled drug delivery. According to the current global status of specific neurological disorders, out of all LNPs, NLC significantly reduces the cross-permeability of drugs through the BBB due to their peculiar properties. They offer a host of advantages over other carriers because of their biocompatibility, safety, non-toxicity, non-irritating behavior, stability, high encapsulation efficiency, high drug loading, high drug targeting, control of drug release, and ease in manufacturing. The biocompatible lipid matrix is ideally suited as a drug carrier system due to the nano-size range. For certain neurological conditions such as Parkinsonism, Alzheimer's, Epilepsy, Multiple sclerosis, and Brain cancer, we examined recent advances in NLCs to improve brain targeting of bioactive with special attention to formulation aspects and pharmacokinetic characteristics. This article also provides a brief overview of a critical approach for brain targeting, i.e., direct nose-to-brain drug delivery and some recent patents published on NLC".

Integrating Artificial Intelligence with Quality by Design in the Formulation of Lecithin/Chitosan Nanoparticles of a Poorly Water-Soluble Drug

The aim of the current study is to explore the potential of artificial intelligence (AI) when integrated with Quality by Design (QbD) approach in the formulation of a poorly water-soluble drug, for its potential use in carcinoma. Silymarin is used as a model drug for its potential effectiveness in liver cancer. A detailed QbD approach was applied. The effect of the critical process parameters was studied on each of the particle size, size distribution, and entrapment efficiency. Response surface designs were applied in the screening and optimization of lecithin/chitosan nanoparticles, to obtain an optimized formula. The release rate was tested, where artificial neural network models were used to predict the % release of the drug from the optimized formula at different time intervals. The optimized formula was tested for its cytotoxicity. A design space was established, with an optimized formula having a molar ratio of 18.33:1 lecithin:chitosan and 38.35 mg silymarin. This resulted in nanoparticles with a size of 161 nm, a polydispersity index of 0.2, and an entrapment efficiency of 97%. The optimized formula showed a zeta potential of +38 mV, with well-developed spherical particles. AI successfully showed high prediction ability of the drug's release rate. The optimized formula showed an enhancement in the cytotoxic effect of silymarin with a decreased IC50 compared to standard silymarin. Lecithin/chitosan nanoparticles were successfully formulated, with deep process and product understanding. Several tools were used as AI which could shift pharmaceutical formulations from experience-dependent studies to data-driven methodologies in the future.

Lipid-Based Delivery Systems for Flavonoids and Flavonolignans: Liposomes, Nanoemulsions, and Solid Lipid Nanoparticles

Herbal chemicals with a long history in medicine have attracted a lot of attention. Flavonolignans and flavonoids are considered as two classes of the above-mentioned compounds with different functional groups which exhibit several therapeutic capabilities such as antimicrobial, anti-inflammatory, antioxidant, antidiabetic, and anticancer activities. Based on the studies, high hydrophobic properties of the aforementioned compounds limit their bioavailability inside the human body and restrict their wide application. Nanoscale formulations such as solid lipid nanoparticles, liposomes, and other types of lipid-based delivery systems have been introduced to overcome the above-mentioned challenges. This approach allows the aforementioned hydrophobic therapeutic compounds to be encapsulated between hydrophobic structures, resulting in improving their bioavailability. The above-mentioned enhanced delivery system improves delivery to the targeted sites and reduces the daily required dosage. Lowering the required daily dose improves the performance of the drug by diminishing its side effects on non-targeted tissues. The present study aims to highlight the recent improvements in implementing lipid-based nanocarriers to deliver flavonolignans and flavonoids.

Tailoring of Selenium-Plated Novasomes for Fine-Tuning Pharmacokinetic and Tumor Uptake of Quercetin: In Vitro Optimization and In Vivo Radiobiodistribution Assessment in Ehrlich Tumor-Bearing Mice

Quercetin (QRC) is a bioflavonoid with anti-inflammatory, antioxidant, and anticancer activities, yet QRC poor bioavailability has hampered its clinical implementation. The aim of the current work was to harness novasomes (NOVs), free fatty acid enriched vesicles, as a novel nano-cargo for felicitous QRC delivery with subsequent functionalization with selenium (SeNOVs), to extend the systemic bio-fate of NOVs and potentiate QRC anticancer efficacy through the synergy with selenium. QRC-NOVs were primed embedding oleic acid, Brij 35, and cholesterol adopting thin-film hydration technique according to Box–Behnken design. Employing Design-Expert^® software, the impact of formulation variables on NOVs physicochemical characteristics besides the optimum formulation election were explored. Based on the optimal NOVs formulation, QRC-SeNOVs were assembled via electrostatic complexation/in situ reduction method. The MTT cytotoxicity assay of the uncoated, and coated nanovectors versus crude QRC was investigated in human rhabdomyosarcoma (RD) cells. The in vivo pharmacokinetic and biodistribution studies after intravenous administrations of technetium-99m (^99mTc)-labeled QRC-NOVs, QRC-SeNOVs, and QRC-solution were scrutinized in Ehrlich tumor-bearing mice. QRC-NOVs and QRC-SeNOVs disclosed entrapment efficiency of 67.21 and 70.85%, vesicle size of 107.29 and 129.16 nm, ζ potential of −34.71 and −43.25 mV, and accumulatively released 43.26 and 31.30% QRC within 24 h, respectively. Additionally, QRC-SeNOVs manifested a far lower IC₅₀ of 5.56 μg/mL on RD cells than that of QRC-NOVs (17.63 μg/mL) and crude QRC (38.71 μg/mL). Moreover, the biodistribution study elicited higher preferential uptake of ^99mTc-QRC-SeNOVs within the tumorous tissues by 1.73- and 5.67-fold as compared to ^99mTc-QRC-NOVs and ^99mTc-QRC-solution, respectively. Furthermore, the relative uptake efficiency of ^99mTc-QRC-SeNOVs was 5.78, the concentration efficiency was 4.74 and the drug-targeting efficiency was 3.21. Hence, the engineered QRC-SeNOVs could confer an auspicious hybrid nanoparadigm for QRC delivery with fine-tuned pharmacokinetics, and synergized antitumor traits.

Susceptibility of Lung Carcinoma Cells to Nanostructured Lipid Carrier of ARV-825, a BRD4 Degrading Proteolysis Targeting Chimera

The present work was aimed at developing an optimized and modified nanostructured lipid carrier of BRD4 protein degrading Proteolysis Targeting Chimera (PROTAC) against non-small cell lung carcinoma. PROTACs are an emerging class of anticancer molecules with nanomolar activity but associated with significant solubility challenges. Lipid-based colloidal systems like nanostructured lipid carriers are widely explored for such highly lipophilic molecules. ARV-825, a cereblon-based PROTAC was investigated for its anticancer efficacy in vitro in 2D and 3D lung cancer models. ARV-825 loaded PEGylated nanostructured lipid carriers (AP-NLC) was prepared using melt emulsification technique. ARV-825 was stabilized using Precirol® ATO5 and Captex® 300 EP/NF as the solid and liquid lipid, respectively. However, hydrophobic ion-pairing with medium chain fatty acid was required to improve drug loading and stability. A hydrodynamic diameter and polydispersity index of 56.33 ± 0.42 nm and 0.16 respectively with zeta potential of -21 ± 1.24 mV was observed. In vitro migration and colony formation assay confirmed the anticancer activity of ARV-825 alone and AP-NLC. Nearly 38% and 50% apoptotic cell population were observed after ARV-825 and AP-NLC treatment. Immunoblotting assay showed complete suppression of BRD4 and c-Myc protein expression for AP-NLC. Most importantly, significant reduction in the growth of multicellular 3D spheroid of A549 cells confirmed the effectiveness of BRD4 PROTAC and its lipid nanoparticle in non-small cell lung cancer (NSCLC). AP-NLC. Higher amount of red fluorescence throughout the spheroid surface further confirmed superior efficacy of AP-NLC in tumor penetration and cell killing.

Synthesis and Potential Applications of Lipid Nanoparticles in Medicine

Currently, carriers of active ingredients in the form of particles of a size measured in nanometers are the focus of interest of research centers worldwide. So far, submicrometer emulsions, liposomes, as well as microspheres, and nanospheres made of biodegradable polymers have been used in medicine. Recent studies show particular interest in nanoparticles based on lipids, and at the present time, are even referred to as the "era of lipid carriers". With the passage of time, lipid nanoparticles of the so-called first and second generation, SLN (Solid Lipid Nanoparticles) and nanostructured lipid carriers and NLC (Nanostructured Lipid Carriers), respectively, turned out to be an alternative for all imperfections of earlier carriers. These carriers are characterized by a number of beneficial functional properties, including, among others, structure based on lipids well tolerated by the human body, high stability, and ability to carry hydro- and lipophilic compounds. Additionally, these carriers can enhance the distribution of the drug in the target organ and alter the pharmacokinetic properties of the drug carriers to enhance the medical effect and minimize adverse side effects. This work is focused on the current review of the state-of-the-art related to the synthesis and applications of popular nanoparticles in medicine, with a focus on their use, e.g., in COVID-19 vaccines.

Systematic review of pharmacokinetics and potential pharmacokinetic interactions of flavonolignans from silymarin

Silymarin is an extract from the seeds (fruits) of Silybum marianum that contains flavonolignans and flavonoids. Although it is frequently used as a hepatoprotective agent, its application remains somewhat debatable, in particular, due to the low oral bioavailability of flavonolignans. Moreover, there are claims of its potential interactions with concomitantly used drugs. This review aims at a systematic summary and critical assessment of known information on the pharmacokinetics of particular silymarin flavonolignans. There are two known major reasons for poor systemic oral bioavailability of flavonolignans: (1) rapid conjugation in intestinal cells or the liver and (2) efflux of parent flavonolignans or formed conjugates back to the lumen of the gastrointestinal tract by intestinal cells and rapid excretion by the liver into the bile. The metabolism of phase I appears to play a minor role, in contrast to extensive conjugation and indeed the unconjugated flavonolignans reach low plasma levels after common doses. Only about 1%-5% of the administered dose is eliminated by the kidneys. Many in vitro studies tested the inhibitory potential of silymarin and its components toward different enzymes and transporters involved in the absorption, metabolism, and excretion of xenobiotics. In most cases, effective concentrations are too high to be relevant under real biological conditions. Most human studies showed no silymarin-drug interactions explainable by these suggested interferences. More interactions were found in animal studies, likely due to the much higher doses administered.

Development of Lecithin/Chitosan Nanoparticles for Promoting Topical Delivery of Propranolol Hydrochloride: Design, Optimization and In-Vivo Evaluation

Propranolol (PPL) administered orally is considered as the first line drug for the treatment of infantile hemangioma, however several systemic adverse effects limit its use. For this reason, our work tackles the development and evaluation of PPL loaded chitosan nanoparticles (NPs), as an effective alternative for the treatment of infantile hemangioma. PPL -NPs were prepared using the double emulsion technique and the influence of the formulation variables on drug entrapment efficiency (EE), particle size (PS), percent released after 24 h (%R_24h) and zeta potential (ZP) were optimized using full factorial design. Two systems, namely F3 and F28 showing highest E.E., ZP and %R_24h with lowest PS, were fully characterized for DSC and TEM and incorporated into hydrogel with adequate viscosity. After ensuring safety for the selected nanoparticle, the hydrogel containing the optimized system was applied topically to rats. The in-vivo skin deposition in rats showed an accumulation of propranolol from the lecithin/chitosan nanocarrier by 1.56-1.91-fold when compared to the drug solution. The obtained result was further supported by the confocal laser scanning microscopy which showed fluorescence across the skin. PPL-HCL-loaded lecithin/chitosan nanoparticles could be considered as a potential candidate for treating infantile hemangiomas (IH) by maintaining therapeutic concentration topically while minimizing systemic side effects.

Path of Silibinin from diet to medicine: A dietary polyphenolic flavonoid having potential anti-cancer therapeutic significance

In the last few decades, targeting cancer by the use of dietary phytochemicals has gained enormous attention. The plausible reason and believe or mind set behind this fact is attributed to either lesser or no side effects of natural compounds as compared to the modern chemotherapeutics, or due to their conventional use as dietary components by mankind for thousands of years. Silibinin is a naturally derived polyphenol (a flavonolignans), possess following biochemical features; molecular formula C₂₅H₂₂O₁₀, Molar mass: 482.44 g/mol, Boiling point 793 °C, with strikingly high antioxidant and anti-tumorigenic properties. The anti-cancer properties of Silibinin are determined by a variety of cellular pathways which include induction of apoptosis, cell cycle arrest, inhibition of angiogenesis and metastasis. In addition, Silibinin controls modulation of the expression of aberrant miRNAs, inflammatory response, and synergism with existing anti-cancer drugs. Therefore, modulation of a vast array of cellular responses and homeostatic aspects makes Silibinin an attractive chemotherapeutic agent. However, like other polyphenols, the major hurdle to declare Silibinin a translational chemotherapeutic agent, is its lesser bioavailability. After summarizing the chemistry and metabolic aspects of Silibinin, this extensive review focuses on functional aspects governed by Silibinin in chemoprevention with an ultimate goal of summarizing the evidence supporting the chemopreventive potential of Silibinin and clinical trials that are currently ongoing, at a single platform.

Pre-treatment With PLGA/Silibinin Nanoparticles Mitigates Dacarbazine-Induced Hepatotoxicity

Drug-induced hepatotoxicity is one of the major barriers limiting application of current pharmaceuticals as well as clinical translation of novel and perspective drugs. In this context, numerous hepatoprotective molecules have been proposed to prevent or mitigate drug-induced hepatotoxicity. To date, silibinin (SBN) is a one the most studied hepatoprotective plant-derived agents for prevention/alleviation of drug-induced liver injury. Hepatoprotective mechanisms of SBN include scavenging of free radicals, upregulation of detoxifying enzymes via Nrf2 activation and inhibition of inflammatory activation of resident macrophages. However, low solubility of this phytochemical in water prevents its intravenous administration and constrains its bioavailability and efficacy. Here, we developed SBN-loaded poly(lactic-co-glycolic) acid (PLGA)-based nanoparticles for intravenous administration aiming at mitigation of drug-induced hepatotoxicity. Obtained nanoparticles demonstrated a slow drug release profile in vitro and caused upregulation of antioxidant and phase II enzymes in AML12 hepatocytes including superoxide dismutase 2, glutathione-S-transferase P1, and glutathione-reductase. Intravenous administration of PLGA nanoparticles to mice led to their fast liver accumulation. In vivo analysis of hepatoprotective effects of PLGA/SBN nanoparticles was carried out on melanoma tumor-bearing syngeneic mouse model treated with the antineoplastic drug dacarbazine (DTIC), which often causes severe hepatotoxicity including development of veno-occlusive disease. It was found that PLGA/SBN caused effective induction of detoxifying liver enzymes. Moreover, pre-treatment with PLGA/SBN nanoparticles reduced elevated transaminase and bilirubin levels in blood, caspase 3 activation, and morphological histology changes in liver tissue upon DTIC treatment. Treatment with PLGA/SBN nanoparticles did not interfere with therapeutic efficacy of DTIC.

β-Sitosterol Loaded Nanostructured Lipid Carrier: Physical and Oxidative Stability, In Vitro Simulated Digestion and Hypocholesterolemic Activity

The objective of the present study was to explore the potential of nanostructured lipid carriers (NLCs) for improving the oral delivery of β-sitosterol, a poorly water-soluble bioactive component with hypocholesterolemic activity. Two β-sitosterol formulations with different solid lipid compositions were prepared by melt emulsification, followed by the sonication technique, and the effect of storage conditions and simulated digestion on the physical, chemical and oxidative stability, bioaccessibility and release were extensively studied. Both NLC preparations remained relatively stable during the four weeks of storage at different conditions (4, 25 and 40 °C), with more superior stability at lower temperatures. The in vitro digestion experiment indicated a high physical stability after exposure to the simulated mouth and stomach stages and an improved overall β-sitosterol bioaccessibility at the end of the digestion. The NLCs presented an increased solubility and gradual release which could be justified by the remarkable affinity of β-sitosterol to the complex lipid mixture. An in vivo study demonstrated an improved reduction in the total cholesterol and low-density lipoprotein cholesterol plasma levels in mice compared with the drug suspension. These investigations evidenced the potential of the developed NLC formulations for the enhancement of solubility and in vivo performance of β-sitosterol.

Nanostructured Lipid Carriers for Delivery of Chemotherapeutics: A Review

The efficacy of current standard chemotherapy is suboptimal due to the poor solubility and short half-lives of chemotherapeutic agents, as well as their high toxicity and lack of specificity which may result in severe side effects, noncompliance and patient inconvenience. The application of nanotechnology has revolutionized the pharmaceutical industry and attracted increasing attention as a significant means for optimizing the delivery of chemotherapeutic agents and enhancing their efficiency and safety profiles. Nanostructured lipid carriers (NLCs) are lipid-based formulations that have been broadly studied as drug delivery systems. They have a solid matrix at room temperature and are considered superior to many other traditional lipid-based nanocarriers such as nanoemulsions, liposomes and solid lipid nanoparticles (SLNs) due to their enhanced physical stability, improved drug loading capacity, and biocompatibility. This review focuses on the latest advances in the use of NLCs as drug delivery systems and their preparation and characterization techniques with special emphasis on their applications as delivery systems for chemotherapeutic agents and different strategies for their use in tumor targeting.

Recent strategies and advances in the fabrication of nano lipid carriers and their application towards brain targeting

In last two decades, the lipid nanocarriers have been extensively investigated for their drug targeting efficiency towards the critical areas of the human body like CNS, cardiac region, tumor cells, etc. Owing to the flexibility and biocompatibility, the lipid-based nanocarriers, including nanoemulsion, liposomes, SLN, NLC etc. have gained much attention among various other nanocarrier systems for brain targeting of bioactives. Across different lipid nanocarriers, NLC remains to be the safest, stable, biocompatible and cost-effective drug carrier system with high encapsulation efficiency. Drug delivery to the brain always remains a challenging issue for scientists due to the complex structure and various barrier mechanisms surrounding the brain. The application of a suitable nanocarrier system and the use of any alternative route of drug administration like nose-to-brain drug delivery could overcome the hurdle and improves the therapeutic efficiency of CNS acting drugs thereof. NLC, a second-generation lipid nanocarrier, upsurges the drug permeation across the BBB due to its unique structural properties. The biocompatible lipid matrix and nano-size make it an ideal drug carrier for brain targeting. It offers many advantages over other drug carrier systems, including ease of manufacturing and scale-up to industrial level, higher drug targeting, high drug loading, control drug release, compatibility with a wide range of drug substances, non-toxic and non-irritant behavior. This review highlights recent progresses towards the development of NLC for brain targeting of bioactives with particular reference to its surface modifications, formulations aspects, pharmacokinetic behavior and efficacy towards the treatment of various neurological disorders like AD, PD, schizophrenia, epilepsy, brain cancer, CNS infection (viral and fungal), multiple sclerosis, cerebral ischemia, and cerebral malaria. This work describes in detail the role and application of NLC, along with its different fabrication techniques and associated limitations. Specific emphasis is given to compile a summary and graphical data on the area explored by scientists and researchers worldwide towards the treatment of neurological disorders with or without NLC. The article also highlights a brief insight into two prime approaches for brain targeting, including drug delivery across BBB and direct nose-to-brain drug delivery along with the current global status of specific neurological disorders.

Development and evaluation of a film-forming system hybridized with econazole-loaded nanostructured lipid carriers for enhanced antifungal activity against dermatophytes

Treatment of skin infection by dermatophytes is still limited, and the application of conventional topical formulations (ointments, creams, etc.) cause patient discomfort due to repeated administration and low efficacy. This study describes the film-forming system (FFS) hybridized with econazole (ECO)-loaded nanostructured lipid carriers (NLC) for enhanced antifungal activity against dermatophytes. We assumed that the application of NLC could effectively increase the skin permeability of ECO, thereby suppressing the growth of dermatophytes in stratum corneum as well as in epidermis. Meanwhile, ECO-NLC hybrid FFS (ECO-NLC@FFS) could increase the adhesion of ECO-NLC to the skin and prolong the antifungal activity of ECO. First, we optimized ECO-NLC, which shows nanosized particle (199 nm), high encapsulation efficiency (92.5%), and biocompatibility. ECO-NLC@FFS formed a transparent, homogeneous, and hard-to-remove film after topical application. In vitro skin permeation and deposition studies demonstrated that ECO-NLC@FFS showed 1.5-fold higher skin permeation and 3-fold higher ECO deposition in the epidermis layer than a commercial product, which resulted from the nanosized particle and its occlusion effect. And, ex vivo and in vivo antifungal activity studies confirmed that ECO-NLC@FFS improved the skin adhesion of ECO-NLC, thereby allowing ECO to be continuously exposed to the infection sited and reducing the number of applications with a single dose. These results showed that this hybrid system could be a potential for effectively improving the efficacy of antifungal agents and the patient compliance in the treatment of dermatophytes. STATEMENT OF SIGNIFICANCE: Treatment of skin infection by dermatophytes is difficult due to the inconvenience and low efficacy of conventional topical formulations. Here, we demonstrated the potential of a film-forming system (FFS) hybridized with nanostructured lipid carriers (NLC). First, we confirmed that the enhanced skin permeability of drug was improved by NLC. In addition, the hybridization of NLC with FFS improved the skin adhesion of NLC, allowing the drug to exhibit a sustained release profile and prolong antifungal activity. Given the maximized antifungal activity, this hybrid system can be used as a potential pharmaceutical technique to improve patient convenience and achieve complete treatment of skin infection.

Efavirenz oral delivery via lipid nanocapsules: formulation, optimisation, and ex-vivo gut permeation study

Present investigation aimed to prepare, optimise, and characterise lipid nanocapsules (LNCs) for improving the solubility and bioavailability of efavirenz (EFV). EFV-loaded LNCs were prepared by the phase-inversion temperature method and the influence of various formulation variables was assessed using Box-Behnken design. The prepared formulations were characterised for particle size, polydispersity index (PdI), zeta potential, encapsulation efficiency (EE), and release efficiency (RE). The biocompatibility of optimised formulation on Caco-2 cells was determined using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay. Then, it was subjected to ex-vivo permeation using rat intestine. EFV-loaded LNCs were found to be spherical shape in the range of 20-100 nm with EE of 82-97%. The best results obtained from LNCs prepared by 17.5% labrafac and 10% solutol HS15 when the volume ratio of the diluting aqueous phase to the initial emulsion was 3.5. The mean particle size, zeta potential, PdI, EE, drug loading%, and RE during 144 h of optimised formulation were confirmed to 60.71 nm, -35.93 mV, 0.09, 92.60, 7.39 and 55.96%, respectively. Optimised LNCs increased the ex vivo intestinal permeation of EFV when compared with drug suspension. Thus, LNCs could be promising for improved oral delivery of EFV.

Liver Targeting Albumin-Coated Silybin-Phospholipid Particles Prepared by Nab™ Technology for Improving Treatment Effect of Acute Liver Damage in Intravenous Administration

In this study, a novel human serum albumin nanoparticle loading silybin-phospholipid complex (SLNPs) was developed for liver targeting after intravenous administration. The preparation of the drug delivery system consisted of two steps; initially, a silybin-phospholipid complex (SLC) was produced to improve the lipophilicity of SLB to then achieve enhanced encapsulation of SLB in albumin nanoparticles. FT-IR and XRD analysis confirmed the successful formation of SLC. The complex ratio of SLC in the first step was 99.6%. The encapsulation efficiency and drug loading of SLNPs in the second step were 96.2% and 5.6%, respectively. SLNPs were spherical and well-dispersed, with a zeta potential of approximately - 10 mV, and a mean particle size around 200 nm. An in vivo tissue distribution experiment and a pharmacodynamic experiment showed that, compared with SLB solution, SLNPs had an improved SLB accumulation in the liver. The hepatoprotective effect of SLNPs on CCl₄-induced acute liver damage was evaluated. CCl₄-damaged mice showed an increased enzymatic activity of ALT and AST; however, enzyme levels returned to near-normal levels in high-dose SLNP-treated mice. As SLNPs combine the enhanced oil solubility of SLC and the passive targeting of albumin nanoparticles, they possess great potential for the treatment of acute liver damage.

Formulation Strategies for Enhancing the Bioavailability of Silymarin: The State of the Art

Silymarin, a mixture of flavonolignan and flavonoid polyphenolic compounds extractable from milk thistle (Silybum marianum) seeds, has anti-oxidant, anti-inflammatory, anti-cancer and anti-viral activities potentially useful in the treatment of several liver disorders, such as chronic liver diseases, cirrhosis and hepatocellular carcinoma. Equally promising are the effects of silymarin in protecting the brain from the inflammatory and oxidative stress effects by which metabolic syndrome contributes to neurodegenerative diseases. However, although clinical trials have proved that silymarin is safe at high doses (>1500 mg/day) in humans, it suffers limiting factors such as low solubility in water (<50 μg/mL), low bioavailability and poor intestinal absorption. To improve its bioavailability and provide a prolonged silymarin release at the site of absorption, the use of nanotechnological strategies appears to be a promising method to potentiate the therapeutic action and promote sustained release of the active herbal extract. The purpose of this study is to review the different nanostructured systems available in literature as delivery strategies to improve the absorption and bioavailability of silymarin.

Formulation and Evaluation of Neuroactive Drug Loaded Chitosan Nanoparticle for Nose to Brain Delivery: In-vitro Characterization and In-vivo Behavior Study

BACKGROUND

The present work was designed to explore the efficacy of neuroactive drug (risperidone) loaded chitosan lipid nanoparticle (RIS-CH-LNPs) to enhance the bioactivity in schizophrenia via the nasal route.

METHODS

The three-factor and three-level formulation by design approach was used for optimization and their effects were observed on (Y1) size in nm, (Y2) % drug loading, and (Y3) % drug release. The optimized formulation RIS-CH-LNPopt was further evaluated for its surface morphology, ex-vivo permeation study, in-vivo behavior study, and stability study. The developed RIS-CH-LNPs showed nanometric size range with high drug loading and prolonged drug release.

RESULTS

The optimized formulation (RIS-CH-LNPopt) has shown the particle size (132.7 nm), drug loading (7.6 %), drug release (80.7 %) and further ex-vivo permeation study showed 2.32 fold enhancement over RIS-SUS(suspension). In-vivo behavior studies showed that RIS-CH-LNPopt is able to show significant greater bioefficacy as compared to RIS-SUS [intranasal (i.n), intravenous (i.v)]. The pharmacokinetic and brain/plasma ratio of developed chitosan nanoparticle was higher at all time-points as compared to RIS-SUS either given by intranasal or intravenous route that proves the direct nose to brain transport pathway of the drug via nasal administration. The developed chitosan nanoparticle increases nose to brain drug delivery as compared to the dispersion of equivalent dose.

CONCLUSION

The findings of this study substantiate the existence of a direct nose-to-brain delivery route for RIS-CH-LNPs.

Orcinol Glucoside Loaded Polymer - Lipid Hybrid Nanostructured Lipid Carriers: Potential Cytotoxic Agents against Gastric, Colon and Hepatoma Carcinoma Cell Lines

PURPOSE

Orcinol glucoside (OG) - loaded nanostructured lipid carrier (NLC), coated with polyethylene glycol-25/55-stearate (PEG-25/55-SA), were explored for delivering OG to improve in vitro cytotoxicity against gastrointestinal tract (GIT), colon and hepatoma carcinoma cell lines. It is being expected that the PEGylated formulations would possess the sustainability in withstanding the adverse physiological extremities like the most significant metabolic activities and phase I / II enzymatic activities in the intestines.

METHODS

NLCs were prepared using tristearin, oleic acid and PEG-25/55-stearate by hot homogenization-ultrasonic dispersion; characterized by DLS, TEM, SEM, AFM, entrapment efficiency and drug loading capacity studies.

RESULTS

NLC diameter ranged from 160 to 230 nm with negative zeta potential of -8 to -20 mV. TEM/SEM and AFM studies suggest spherical and smooth surface morphologies. Differential scanning calorimetry studies reveal the loss of crystallinity when OG was incorporated into the NLC. NLCs showed initial burst release, followed by sustained release of OG. PEG-NLC exhibited superior anticancer activity against GIT and also in hepatoma cancer cell lines.

CONCLUSIONS

This is the first report demonstrating a practical approach for possible oral delivery of OG in GIT and targeting hepatoma cancer, warranting further in vivo studies for superior management of GIT cancer.

Enhancement of Silymarin Anti-fibrotic Effects by Complexation With Hydroxypropyl (HPBCD) and Randomly Methylated (RAMEB) β-Cyclodextrins in a Mouse Model of Liver Fibrosis

Silymarin (Sy) shows limited water solubility and poor oral bioavailability. Water-soluble hydroxypropyl (HPBCD) and randomly methylated (RAMEB) β-cyclodextrins were designed to enhance anti-fibrotic efficiency of silymarin in CCl₄-induced liver fibrosis in mice. Experimental fibrosis was induced by intraperitoneal injection with 2 ml/kg CCl₄ (20% v/v) twice a week, for 7 weeks. Mice were orally treated with 50 mg/kg of Sy-HPBCD, Sy-RAMEB and free silymarin. For assessment of the spontaneous reversion of fibrosis, CCl₄ treated animals were investigated after 2 weeks of recovery time. The CCl₄ administration increased hepatic oxidative stress, augmented the expression of transforming growth factor-β1 (TGF-β1) and Smad 2/3, and decreased Smad 7 expression. Furthermore, increased α-smooth muscle actin (α-SMA) expression indicated activation of hepatic stellate cells (HSCs), while up-regulation of collagen I (Col I) and matrix metalloproteinases (MMPs) expression led to an altered extracellular matrix enriched in collagen, confirmed as well by trichrome staining and electron microscopy analysis. Treatment with Sy-HPBCD and Sy-RAMEB significantly reduced liver injury, attenuating oxidative stress, restoring antioxidant balance in the hepatic tissue, and significantly decreasing collagen deposits in the liver. The levels of pro-fibrogenic markers' expression were also significantly down-regulated, whereas in the group for spontaneous regression of fibrosis, they remained significantly higher, even at 2 weeks after CCl₄ administration was discontinued. The recovery was significantly lower for free silymarin group compared to silymarin/β cyclodextrins co-treatments. Sy-HPBCD was found to be the most potent anti-fibrotic complex. We demonstrated that Sy-HPBCD and Sy-RAMEB complexes decreased extracellular matrix accumulation by inhibiting HSC activation and diminished the oxidative damage. This might occur via the inhibition of TGF-β1/Smad signal transduction and MMP/tissue inhibitor of MMPs (TIMP) rebalance, by blocking the synthesis of Col I and decreasing collagen deposition. These results suggest that complexation of silymarin with HPBCD or RAMEB represent viable options for the its oral delivery, of the flavonoid as a potential therapeutic entity candidate, with applications in the treatment of liver fibrosis.

Solid lipid nanoparticles and nanostructured lipid carriers as novel drug delivery systems: applications, advantages and disadvantages

During the recent years, more attentions have been focused on lipid base drug delivery system to overcome some limitations of conventional formulations. Among these delivery systems solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) are promising delivery systems due to the ease of manufacturing processes, scale up capability, biocompatibility, and also biodegradability of formulation constituents and many other advantages which could be related to specific route of administration or nature of the materials are to be loaded to these delivery systems. The aim of this article is to review the advantages and limitations of these delivery systems based on the route of administration and to emphasis the effectiveness of such formulations.

The efficiency and mechanism of N-octyl-O, N-carboxymethyl chitosan-based micelles to enhance the oral absorption of silybin

This study demonstrates the preparation of a silybin-loaded N-octyl-O, N-carboxymethyl chitosan micelle (OCC-SLB) to enhance the oral absorption efficiency of silybin (SLB) and investigate the related mechanisms of enhancement. Firstly, the physicochemical properties of OCC and OCC-SLB micelles, including critical micelle concentration (CMC), particle size, zeta potential, drug-loading, etc., were determined. Results of pharmacokinetic studies on rats then confirmed a desirable enhancement in the oral bioavailability of SLB by OCC-SLB micelles compared with a stock SLB suspension solution. Subsequently, uptake studies on the Caco-2 cell line demonstrated that OCC-SLB micelles effectively accumulated SLB or rhodamine-123 into cells through clathrin and caveolae-mediated endocytosis and the inhibition of P-glycoprotein (P-gp) efflux. In addition, results of the Caco-2 transport study further clarified that OCC-SLB micelles enhanced the permeability of SLB via tight junction opening and clathrin-mediated transcytosis across the endothelium. These findings indicated the OCC micelle platform as a potential delivery vehicle for oral administration of P-gp substrates such as SLB.

Adefovir dipivoxil loaded proliposomal powders with improved hepatoprotective activity: formulation, optimization, pharmacokinetic, and biodistribution studies

The present study aimed to prepare proliposomal formulae for improving the oral bioavailability of adefovir dipivoxil (AD), a nucleoside reverse transcriptase inhibitor effective against hepatitis B virus (HBV). The prepared proliposomal formulae were characterized for entrapment efficiency (E.E.%), vesicle size and in vitro drug release after reconstitution to conventional liposomes. The optimized formula (F9) with a maximum desirability value of 0.858 was selected having E.E.% of 71 ± 3.3% with an average vesicle size of 164.6 ± 5 nm. Moreover, the crystallization of AD within the optimized formula investigated via powder X-ray diffraction (XRD) and differential scanning calorimetry (DSC) confirmed the presence of the drug in an amorphous state within the lipid vesicles with enhanced stability over a storage period of 12 months. Thioacetamide-induced liver damage in rats evidenced by elevated liver enzymes was significantly improved after treatment with the optimum formula. Pharmacokinetic and biodistribution studies of formula F9 showed a higher accumulation of AD in the liver with enhanced bioavailability compared to AD suspension which highlights its potential advantage for an effective treatment of chronic HBV. Hence, proliposomal drug delivery is considered as a better choice for the oral delivery of AD.

Alginate/Gelatin scaffolds incorporated with Silibinin-loaded Chitosan nanoparticles for bone formation in vitro

Silibinin is a plant derived flavonolignan known for its multiple biological properties, but its role in the promotion of bone formation has not yet been well studied. Moreover, the delivery of Silibinin is hindered by its complex hydrophobic nature, which limits its bioavailability. Hence, in this study, we fabricated a drug delivery system using chitosan nanoparticles loaded with Silibinin at different concentrations (20μM, 50μM, and 100μM). They were then incorporated into scaffolds containing Alginate and Gelatin (Alg/Gel) for the sustained and prolonged release of Silibinin. The Silibinin-loaded chitosan nanoparticles (SCN) were prepared using the ionic gelation technique, and the scaffolds (Alg/Gel-SCN) were synthesized by the conventional method of freeze drying. The scaffolds were subjected to physicochemical and material characterization studies. The addition of SCN did not affect the porosity of the scaffolds, yet increased the protein adsorption, degradation rates, and bio-mineralization. These scaffolds were biocompatible with mouse mesenchymal stem cells. The scaffolds loaded with 50μM Silibinin promoted osteoblast differentiation, which was determined at cellular and molecular levels. Recent studies indicated the role of microRNAs (miRNAs) in osteogenesis and we found that the Silibinin released from scaffolds regulated miRNAs that control the bone morphogenetic protein pathway. Hence, our results suggest the potential for sustained and prolonged release of Silibinin to promote bone formation and, thus, these Alg/Gel-SCN scaffolds may be candidates for bone tissue engineering applications.

Folic acid-functionalized drug delivery platform of resveratrol based on Pluronic 127/D-α-tocopheryl polyethylene glycol 1000 succinate mixed micelles

A folic acid (FA)-functionalized drug vehicle platform based on Pluronic 127 (P127)/D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) mixed micelles was orchestrated for an effective delivery of the model drug resveratrol in order to address the problem of poor water solubility and rapid metabolism of resveratrol and improve its targeted accumulation at tumor site. The FA-decorated mixed micelles were prepared using thin-film hydration method and optimized by central composite design approach. The micelles were also characterized in terms of size and morphology, drug entrapment efficiency and in vitro release profile. In addition, the cytotoxicity and cell uptake of the micelles were evaluated in folate receptor-overexpressing MCF-7 cell line. In vivo pharmacokinetic and biodistribution studies were also performed. The average size of the micelles was ~20 nm with a spherical shape and high encapsulation efficiency (99.67%). The results of fluorescence microscopy confirmed the targeting capability of FA-conjugated micelles in MCF-7 cells. FA-modified micelles exhibited superior pharmacokinetics in comparison with that of solution. Further, the low accumulation of resveratrol-loaded FA micelles formulation in the heart and kidney avoided toxicity of these vital organs. It could be concluded that folate-modified P127/TPGS mixed micelles might serve as a potential delivery platform for resveratrol.

Nanovesicle delivery to the liver via retinol binding protein and platelet-derived growth factor receptors: how targeting ligands affect biodistribution

Aim: Nanovesicles (NVs) conjugating ligands can deliver to the specific nidus. We designed a nanosystem targeting the injectable niosomes to liver for examining biodistribution. Methodology: Vitamin A and antiplatelet-derived growth factor receptor antibody were employed as the ligands to be taken by hepatic stellate cells. The biodistribution in rats was visualized by bioimaging. Results: A significant liver accumulation was detected for antibody-embedded NVs at 2 h after dosing. The vitamin A embedded NVs exhibited a delayed targeting to the liver (5 h). The spleen, intestine and kidneys were the nontargeted organs where the vitamin A loaded niosomes largely accumulated. The antibody-loaded NVs could deliver to the spleen, kidneys and lungs. The antibody-loaded nanocarriers increased silibinin uptake to lungs by fourfold than the plain NVs. Conclusion: The results have practical application for better designing of active targeting nanocarriers.

Industrialization of lipid nanoparticles: From laboratory-scale to large-scale production line

This work aimed at developing a large-scale modular production line, which referred to coenzyme Q₁₀ loaded-NLC as well as its continuous and scalable emulsification and homogenization process. The production line exhibited good control over the emulsification and homogenization process and enabled the particle size of NLC below 210nm at a throughput of 25kg/h (for lipid solution at a flow rate of 0.4kg/min). Among the several process parameters investigated, the size of the NLC was mainly influenced by the pre-emulsification temperature, homogenization pressure and homogenization. Suitable emulsification temperature (70°C), homogenization pressure (600, 800bar), and homogenization cycle (3, 4cycles) resulted in relatively smaller particles. These results proved that coenzyme Q₁₀, a model active, had been successfully loaded into the NLC. Meanwhile, the large-scale production line can be effectively applied for continuous and modular production of NLC. The line had modern networking features-essential in the Internet age-and a modular design that was easily modified and upgraded. In addition, the long-term stability over 6month was monitored at 30°C and at 40°C to assess a potential effect of the laboratory scale and large scale on stability. All batches at room temperature and below were stable, and only a negligible increase in size was observed.

Brain Targeting of Temozolomide via the Intranasal Route Using Lipid-Based Nanoparticles: Brain Pharmacokinetic and Scintigraphic Analyses

The aim of the present work was to investigate the efficacy of temozolomide nanostructured lipid carriers (TMZ-NLCs) to enhance brain targeting via nasal route administration. The formulation was optimized by applying a four-factor, three-level Box-Behnken design. The developed formulations and the functional relationships between their independent and dependent variables were observed. The independent variables used in the formulation were gelucire (X₁), liquid lipid/total lipid (X₂), Tween 80 (X₃), and sonication time (X₄), and their effects were observed with regard to size (Y₁), % drug release (Y₂), and drug loading (Y₃). The optimized TMZ-NLC was further evaluated for its surface morphology as well as ex vivo permeation and in vivo studies. All TMZ-NLC formulations showed sizes in the nanometer range, with high drug loading and prolonged drug release. The optimized formulation (TMZ-NLCopt) showed an entrapment efficiency of 81.64 ± 3.71%, zeta potential of 15.21 ± 3.11 mV, and polydispersity index of less than 0.2. The enhancement ratio was found to be 2.32-fold that of the control formulation (TMZ-disp). In vivo studies in mice showed that the brain/blood ratio of TMZ-NLCopt was found to be significantly higher compared to that of TMZ-disp (intranasal, intravenous). Scintigraphy images of mouse brain showed the presence of a high concentration of TMZ. The AUC ratio of TMZ-NLCopt to TMZ-disp in the brain was the highest among the organs. The findings of this study substantiate the existence of a direct nose-to-brain delivery route for NLCs.

Surface Modified Multifunctional and Stimuli Responsive Nanoparticles for Drug Targeting: Current Status and Uses

Nanocarriers, due to their unique features, are of increased interest among researchers working with pharmaceutical formulations. Polymeric nanoparticles and nanocapsules, involving non-toxic biodegradable polymers, liposomes, solid lipid nanoparticles, and inorganic-organic nanomaterials, are among the most used carriers for drugs for a broad spectrum of targeted diseases. In fact, oral, injectable, transdermal-dermal and ocular formulations mainly consist of the aforementioned nanomaterials demonstrating promising characteristics such as long circulation, specific targeting, high drug loading capacity, enhanced intracellular penetration, and so on. Over the last decade, huge advances in the development of novel, safer and less toxic nanocarriers with amended properties have been made. In addition, multifunctional nanocarriers combining chemical substances, vitamins and peptides via coupling chemistry, inorganic particles coated by biocompatible materials seem to play a key role considering that functionalization can enhance characteristics such as biocompatibility, targetability, environmental friendliness, and intracellular penetration while also have limited side effects. This review aims to summarize the "state of the art" of drug delivery carriers in nanosize, paying attention to their surface functionalization with ligands and other small or polymeric compounds so as to upgrade active and passive targeting, different release patterns as well as cell targeting and stimuli responsibility. Lastly, future aspects and potential uses of nanoparticulated drug systems are outlined.

Pharmacokinetics and tissue distribution of larotaxel in rats: comparison of larotaxel solution with larotaxel-loaded folate receptor-targeting amphiphilic copolymer-modified liposomes

1. The aim of this study was to compare the pharmacokinetics (PKs) and tissue distribution of larotaxel (LTX) solution with a newly developed formulation called LTX-loaded folate-poly (PEG-cyanoacrylate-co-cholesteryl cyanoacrylate) (FA-PEG-PCHL)-modified liposomes in rats. 2. An ultra-performance liquid chromatography-tandem mass spectrometry method has been developed and validated for the determination of LTX in rat plasma and tissues to investigate the influence of FA-PEG-PCHL-modified lipid carrier on LTX PKs and tissue distribution. 3. The PK study result showed significantly higher area under the concentration-time curve (97.2%, **p < 0.01), slower clearance (49.2%, **p < 0.01) and lower volume of distribution (42.5%, **p < 0.01) in rats following intravenous administration of modified liposomes. The biodistribution results exhibited significantly lower uptake of LTX-loaded modified liposomes in heart (20.4%, **p < 0.01), lung (8.33%, **p < 0.01), muscle (13.4%, *p < 0.05) and spleen (15.0%, **p < 0.01) among all sampled tissues, indicating that the modified lipid carriers may avoid the trapping by the reticuloendothelial system and the modified liposomes may reduce toxicity in cardiovascular system compared to LTX solution. Moreover, markedly higher concentrations of LTX in the kidney (100%, **p < 0.01) were found in LTX-loaded modified liposome treated rats and could be explained by the high folate receptor level in kidney. 4. These results indicated that the FA-PEG-PCHL-modified liposome could be an effective parenteral carrier for the delivery of LTX in cancer treatment.