Nanostructured lipid carriers (NLCs): A promising candidate for lung cancer targeting

Lung cancer stands as the foremost health issue and the principal reason for mortality worldwide. It is projected that India will see over 1.73 million new cases and more than 880,000 deaths related to cancer, with lung cancer being a significant contributor. The efficiency of existing chemotherapy procedures is not optimal because of less soluble nature and short half-life of anticancer substances. More precipitated toxicity and non-existence of targeting propensity can lead to severe side effects, non-compliance, and inconvenience for patients. Nonetheless, the domain of nanomedicine has undergone a revolution in the past few years with the advent of novel drug delivery mechanisms that tackle the drawbacks of conventional approaches. Diverse nanoparticle-based drug delivery methods, including liposomes, nanoparticles, nanostructured lipid carrier and solid lipid nanoparticle that encapsulated chemotherapy drugs, are currently employed for efficient lung cancer therapy. NLCs, recognized as the second-generation lipid nanocarriers, are a focused drug delivery mechanism that has garnered significant interest owing to their multitude of advantages such as increased stability, minimal toxicity, prolonged shelf life, superior encapsulation capability, and biocompatible nature. This review focuses on the NLCs carrier system, discussing its preparation methods, types, characterization, applications, and future prospects in lung cancer treatment.

Combining the potential of 3D printed buccal films and nanostructured lipid carriers for personalised cannabidiol delivery

Cannabidiol (CBD) has been recognized for its numerous therapeutic benefits, such as neuroprotection, anti-inflammatory effects, and cardioprotection. However, CBD has some limitations, including unpredictable pharmacokinetics and low oral bioavailability. To overcome the challenges associated with CBD delivery, we employed Design of Experiments (DoE), lipid carriers, and 3D printing techniques to optimize and develop buccal film loaded with CBD-NLCs. Three-factor Box-Behnken Design was carried out to optimise the NLCs and analyse the effect of independent factors on dependent factors. The emulsification-ultrasonication technique was used to prepare the NLCs. A pressure-assisted micro-syringe printing technique was used to produce the films. The produced films were studied for physicochemical, and mechanical properties, release profiles, and predicted in vivo performance. The observed particle size of the NLCs ranged from 12.17 to 84.91 nm whereas the PDI varied from 0.099 to 0.298. Lipid and sonication time positively affected the particle size whereas the surfactant concentration was inversely related. CBD was incorporated into the optimal formulation and the observed particle size, PDI, and zeta potential for the CBD-NLCs were 94.2 ± 0.47 nm, 0.11 ± 0.01 and - 11.8 ± 0.52 mV. Hydroxyethyl cellulose (HEC)-based gel containing the CBD-NLCs was prepared and used as a feed for 3D printing. The CBD-NLCs film demonstrated a slow and sustained in vitro release profile (84. 11 ± 7.02% in 6 h). The predicted AUC0-10 h, Cmax, and Tmax were 201.5 µg·h/L, 0.74 µg/L, and 1.28 h for a film with 0.4 mg of CBD, respectively. The finding demonstrates that a buccal film of CBD-NLCs can be fabricated using 3D printing.

Quercetin-Loaded Nanostructured Lipid Carrier In Situ Gel for Brain Targeting Through Intranasal Route: Formulation, In Vivo Pharmacokinetic and Pharmacodynamic Studies

Quercetin (QT) shows potential for protecting against neurodegenerative diseases like Alzheimer's. However, its limited bioavailability and instability in physiological pH hinder its clinical use. The purpose of this work is to construct QT-filled nanostructured lipid carriers (QT-NLC) intranasal in situ gel to enhance pharmacokinetic and pharmacodynamic performance. NLCs were developed using a melt emulsification-high-pressure homogenization and were optimized using design expert software with the Box-Behnken design. NLCs were then incorporated into an in situ gel based on Lutrol F127 and further characterized. The pharmacodynamics of the formulation was evaluated in neurodegeneration induced by trimethyl tin (TMT) Wistar rats. The optimized QT in situ gel had spherical shape, entrapment efficiency of 96.1 ± 4.40%, and in vitro drug release of 83.74 ± 1.40%. The mean particle size was 123.3 ± 5.46 nm. After intranasal administration, in vivo single-dose pharmacokinetic studies demonstrated a significant therapeutic concentration of drug in CNS, having Cmax 183.41 ± 11.76 ng/mL and Tmax of 2 h. The more brain targeting efficiency of NLCs was proved by the developed QT in situ gel, which had a higher drug targeting efficiency (DTE) of 117.47% and drug targeting potential (DTP) of 88.9%. As compared to the neurodegeneration control group, the QT in situ gel-treated group had significantly decreased escape latency and pathlength. Biochemical analysis and histological investigations demonstrated that QT in situ gel exhibited superior anti-Alzheimer's potential compared to standard drug, donepezil. The promising results of the developed and optimized intranasal QT in situ gel suggest its potential and can be used in Alzheimer's disease management.

Fabrication of TPGS decorated Etravirine loaded lipidic nanocarriers as a neoteric oral bioavailability enhancer for lymphatic targeting

Etravirine (ERVN) is a potential NNRTI (non-nucleoside reverse transcriptase inhibitor) in treating HIV infection. It possesses extremely low oral bioavailability. The present research aims to optimize the formulation and characterization of TPGS-enriched ERVN-loaded lipid-based nanocarriers (NLCs) for HIV-infected patients. The formulation, ERVN-TPGS-NLCs, was optimized by central composite rotational design using a modified-solvent emulsification process. Various characterization parameters of NLCs were evaluated, including globule size of 121.56 ± 2.174 nm, PDI of 0.172 ± 0.042, the zeta potential of - 7.32 ± 0.021 mV, %EE of 94.42 ± 8.65% of ERVN and %DL was 8.94 ± 0.759% of ERVN and spherical shape was revealed by TEM. PXRD was also performed to identify the crystallinity of the sample. In-vitro drug release showed % a cumulative drug release of 83.72 ± 8.35% at pH 1.2 and 90.61 ± 9.11% at pH 6.8, respectively, whereas the % cumulative drug release from drug suspension (ERVN-S) was found to be 21.13 ± 2.01% at pH 1.2 and 24.84 ± 2.51 at pH 6.8 at the end of 48 h. Further, the intestinal permeation study and confocal microscope showed approximately three-fold and  two-fold increased permeation in ERVN-TPGS-NLCs and ERVN-NLCs across the gut sac compared to ERVN-S. Hemolysis compatibility and lipolysis studies were performed to predict the in-vivo fate of the formulation. The pharmacokinetic study revealed a 3.13-fold increment in the relative bioavailability, which agrees with the ex-vivo studies, and lymphatic uptake was validated by using cycloheximide along with designed formulation, which showed the impact of lymphatic uptake in AUC. This study ensures that ERVN-TPGS-NLCs take lymphatic uptake to minimize the first-pass metabolism followed by improved oral bioavailability of ERVN. Thus, the enhanced bioavailability of ERVN can reduce the high dose of ERVN to minimize the adverse effects related to dose-related burden.

Eco-Friendly Sustainable Nanocarriers to Treat Oxidative Stresses and Skin Aging-Related Ailments, Valorization of a By-Product

The peel from Citrus-sinensis L. is a medicinally significant food waste, and its extract (O-Ext) could be significant against oxidative stresses and skin aging, However, the penetration barriers, instability in formulation, undefined toxicities, and enzymatic activities make the O-Ext difficult to formulate and commercialize. The goal of this study was to evaluate O-Ext against oxidative stress, prepare O-Ext-loaded nano-lipid carriers (O-NLCs), and load them into topical O/W-emulsion (O-NLC-E) to improve O-Ext permeation and its in vivo antiaging effects. TPC, TFC, DPPH activity, and mineral/metal contents of O-Ext were determined via atomic-absorption spectroscopy. For bioactive compounds profiling, GC-MS analysis was carried out. O-NLCs were prepared and tested for physicochemical attributes, while HaCaT and fibroblast cells were used to study permeation and cytotoxicity. The kinetic characteristics of ex vivo permeation through rat skin were established, following the Higuchi model. Following written consent, safety investigations were conducted on human volunteers for three months, where optimized O-NLC-E and B-NLC-E were regularly applied on cheeks. Non-invasive procedures were used to assess the volunteer's skin erythema, TEWL, sebum level, melanin, hydration, pH, elasticity, and pore sizes after specified intervals. The results demonstrated that applying O-NLC-E formulation to the skin of volunteers directed significant antiaging benefits. The study offers nanotechnology-based sustainability approach against skin ageing.

Assessment of Anti-Arthritic Activity of Lipid Matrix Encased Berberine in Rheumatic Animal Model

AIM

The purpose of this study was to evaluate the drug delivery and therapeutic potential of berberine (Br) loaded nanoformulation in rheumatoid arthritis (RA)-induced animal model.

METHOD

The Br-loaded NLCs (nanostructured lipid carriers) were prepared employing melt-emulsification process, and optimized through box-behnken design. The prepared NLCs were assessed for in-vitro and in-vivo evaluations.

RESULT

The optimized NLCs exhibited a mean diameter of 180.2 ± 0.31nm with 88.32 ± 2.43% entrapment efficiency. An enhanced anti-arthritic activity with reduced arthritic scores to 0.66 ± 0.51, reduction in ankle diameter to 5.80 ± 0.27mm, decline in paw withdrawal timing, and improvements in walking behavior were observed in the Br-NLCs treated group. The radiographic images revealed a reduction in bone and cartilage deformation.

CONCLUSION

The Br-NLCs showed promising results in the management of RA disease, can be developed as an efficient delivery system at commercial levels, and may be explored for clinical application after suitable experiments in the future.

Formulation and Development of Hyaluronic Acid based gel with Ketoconazole -Loaded Nanostructured Lipid Carriers in Fungal Infection

BACKGROUND

Ketoconazole is an imidazole ring containing antifungal agent used in the treatment of systemic fungal infections. It acts by blocking the synthesis of ergosterol, an essential component of the fungal cell membrane.

OBJECTIVE

The purpose of this work is to construct skin targeting ketoconazole nanostructured lipid carriers (NLCs) loaded hyaluronic acid (HA) modified gel to minimize side effects and provide a controlled release.

METHODS

The NLCs were prepared using emulsion sonication method and their optimized batches were characterized for X-ray diffraction, scanning electron microscopy and fourier transform infrared spectroscopy study. These batches were then incorporated into HA containing gel for convenient application. The final formulation was compared with the marketed formulation for studying its antifungal activity and drug diffusion.

RESULTS

Ketoconazole NLCs loaded hyaluronic acid formulation was successfully developed with desirable formulation parameters by using 23 Factorial design. In-vitro release study of developed formulation showed prolonged drug release (up to 5 hrs) while ex-vivo drug diffusion study on human cadaver skin showed better drug diffusion as compared with marketed formulation. Moreover, the release study and diffusion study results reflected the improvement of antifungal activity of the developed formulation against Candida albicans.

CONCLUSION

The work suggests that ketoconazole NLCs loaded HA modified gel provides prolonged release. The formulation also has good drug diffusion and antifungal activity and thus can act as a promising carrier for topical delivery of ketoconazole.

Development of Computational In Silico Model for Nano Lipid Carrier Formulation of Curcumin

The oral delivery system is very important and plays a significant role in increasing the solubility of drugs, which eventually will increase their absorption by the digestive system and enhance the drug bioactivity. This study was conducted to synthesize a novel curcumin nano lipid carrier (NLC) and use it as a drug carrier with the help of computational molecular docking to investigate its solubility in different solid and liquid lipids to choose the optimum lipids candidate for the NLCs formulation and avoid the ordinary methods that consume more time, materials, cost, and efforts during laboratory experiments. The antiviral activity of the formed curcumin-NLC against SARS-CoV-2 (COVID-19) was assessed through a molecular docking study of curcumin's affinity towards the host cell receptors. The novel curcumin drug carrier was synthesized as NLC using a hot and high-pressure homogenization method. Twenty different compositions of the drug carrier (curcumin nano lipid) were synthesized and characterized using different physicochemical techniques such as UV-Vis, FTIR, DSC, XRD, particle size, the zeta potential, and AFM. The in vitro and ex vivo studies were also conducted to test the solubility and the permeability of the 20 curcumin-NLC formulations. The NLC as a drug carrier shows an enormous enhancement in the solubility and permeability of the drug.

Design of Quercetin-Loaded Natural Oil-Based Nanostructured Lipid Carriers for the Treatment of Bacterial Skin Infections

The biological activity of natural plant-oil-based nanostructured lipid carriers (NPO-NLCs) can be enhanced by the encapsulation of bioactive compounds, and they in turn can improve topical delivery of the drugs. Quercetin (QR), a vital plant flavonoid, expresses antibacterial properties, and we recently showed that empty NPO-NLCs also have antimicrobial activity. The main objective of this study was to evaluate the synergetic effect of loading natural plant-oil-based nanostructured lipid carriers with quercetin (QR-NPO-NLCs) as a topical delivery system for the treatment of bacterial skin infections. Five nanostructured lipid carrier systems containing different oils (sunflower, olive, corn, coconut, and castor) were engineered. The particles’ stability, structural properties, bioavailability, and antimicrobial activity were studied. NLCs with an average size of <200 nm and Z-potential of −40 mV were developed. Stable QR-NPO-NLCs were obtained with high encapsulation efficiency (>99%). The encapsulation of QR decreased cytotoxicity and increased the antioxidant effect of nanocarriers. An increase in antibacterial activity of the systems containing QR was demonstrated against Staphylococcus aureus. QR-NPO-NLCs could transport QR to an intranuclear location within HaCaT cells, indicating that QR-NPO-NLCs are promising candidates for controlled topical drug delivery.

Formulation of intranasal surface engineered nanostructured lipid carriers of rotigotine: Full factorial design optimization, in vitro characterization, and pharmacokinetic evaluation

The objective of the present research was to develop, optimize, and evaluate rotigotine (RT)-loaded chitosan (CH) coated nanostructured lipid carriers (RT-CH-NLCs) for nose-to-brain delivery. The NLCs were prepared by homogenization and sonication technique as well as optimized by using three factors at three-level Box-Behnken design. The prepared NLCs were evaluated for particle size, zeta potential, entrapment efficiency, drug release, and ex vivo permeation. The pharmacokinetic study was conducted on albino Wistar rats to evaluate the bioavailability and neuropharmacokinetic parameters after intranasal administration of the optimized formulation (RT-CH-NLCs-OPT). The optimized formulation showed the particle size (170.48 ± 8.37 nm), PDI (0.19 ± 0.03), zeta potential (+ 26.73 mV), and entrapment efficiency (82.37 ± 2.48 %). In vitro drug release study displayed a sustained drug release pattern from RT-CH-NLCs-OPT (86.73±8.58 % in 24 h) in comparison to RT-Dis (98.61±7.24 % in 16 h). The permeability coefficient (PC) was found to be 11.39 ± 1.08×10^-4 cm.h^-1 and 2.34 folds higher than RT-Dis (4.85±1.53×10^-4 cm.h^-1). The relative bioavailability of RT from RT-CH-NLCs-OPT was 3.2-fold greater as compared to RT-Dis. The absolute bioavailability of RT after intranasal administration of RT-CH-NLCs-OPT was 2.1-fold higher than RT-CH-NLCs-OPT administered intravenously. The brain targeting and targeting potential was displayed by DTE (422.03 %) and DTP (76.03 %) after intranasal administration of RT-CH-NLCs-OPT as compared to RT-Dis (DTE 173.91 % and DTP 59.97 %). Furthermore, confocal laser scanning microscopy results confirmed better brain targeting for RT-CH-NLCs-OPT as compared to RT-Dis. From these findings, it could be concluded that RT-CH-NLCs could serve as a promising strategy for targeting RT through the intranasal route.

Co-Delivery of Erlotinib and Resveratrol via Nanostructured Lipid Carriers: A Synergistically Promising Approach for Cell Proliferation Prevention and ROS-Mediated Apoptosis Activation

Cancer treatments are always associated with various challenges, and scientists are constantly trying to find new therapies and methods. Erlotinib (ELT) is a well-known medicine against non-small cell lung cancer (NSCLC). However, treatments by ELT disrupt therapy due to drug resistance and pose severe challenges to patients. To achieve high-performance treatment, we gained nanostructured lipid carriers (NLCs) to evaluate synergistic anticancer effects of co-delivery of ELT and resveratrol (RES), a natural herbal derived phenol against NSCLC. NLCs are prepared via the hot homogenization method and characterized. In vitro cytotoxicity of formulations were evaluated on adenocarcinoma human alveolar basal epithelial (A549) cells. Prepared NLCs showed a narrow particle size (97.52 ±17.14 nm), negative zeta potential (-7.67 ± 4.55 mV), and high encapsulation efficiency (EE%) was measured for the prepared co-delivery system (EE% 89.5 ± 5.16 % for ELT and 90.1 ± 6.61 % for RES). In vitro outcomes from cell viability study (12.63 % after 48 h of treatment), apoptosis assay (85.50%.), cell cycle (40.00% arrest in G2-M), and western blotting investigations (decreasing of protein expression levels of survivin, Bcl-2, P-Caspase 3 P-caspase 9, and P-ERK 1/2, and additionally, increasing protein levels of BAX, P53, C-Caspase 3 and 9), DAPI staining, and colony formation assays showed the augment cytotoxic performances for co-delivery of ELT and RES loaded NLCs. Our study introduced the co-delivery of ELT and RES by NLCs as a novel strategy to elevate the efficacy of chemotherapeutics for NSCLC.

Transferrin decorated-nanostructured lipid carriers (NLCs) are a promising delivery system for rapamycin in Alzheimer's disease: An in vivo study

Alzheimer's disease (AD), the most common neurodegenerative disorder, is characterized by progressive cognitive impairment and memory loss. The mammalian target of rapamycin (mTOR) signaling pathway could regulate learning and memory. The effect of rapamycin (Rapa) on mTOR activity could slow or prevent the progression of AD by affecting various essential cellular processes. Previously, we prepared transferrin (Tf) decorated-nanostructured lipid carriers (NLCs) for rapamycin (150 ± 9 nm) to protect the drug from chemical and enzymatic degradation and for brain targeted delivery of rapamycin. Herein, the effect of Tf-NLCs compared to untargeted anionic-NLCs and free rapamycin, were studied in amyloid beta (Aβ) induced rat model of AD. Behavioral test revealed that the Rapa Tf-NLCs were able to significantly improve the impaired spatial memory induced by Aβ. Histopathological studies of hippocampus also showed neural survival in Rapa Tf-NLCs treated group. The immunosuppressive, and delayed wound healing adverse effects in the rapamycin solution treated group were abolished by incorporating the drug into NLCs. The Aβ induced oxidative stress was also reduced by Rapa Tf-NLCs. Molecular studies on the level of Aβ, autophagy (LC3) and apoptotic (caspase-3) markers, and mTOR activity revealed that the Rapa Tf-NLCs decreased the Aβ level and suppressed the toxic effects of Aβ plaques by modulating the mTOR activity and autophagy, and decreasing the apoptosis level. As a conclusion, the designed Tf-NLCs could be an appropriate and a safe brain delivery system for rapamycin and make this drug more efficient in AD for improving memory and neuroprotection.

Enhanced BBB and BBTB penetration and improved anti-glioma behavior of Bortezomib through dual-targeting nanostructured lipid carriers

The effective treatment of glioma through conventional chemotherapy is proved to be a great challenge in clinics. The main reason is due to the existence of two physiological and pathological barriers respectively including the blood-brain barrier (BBB) and blood-brain tumor barrier (BBTB) that prevent most of the chemotherapeutics from efficient delivery to the brain tumors. To address this challenge, an ideal drug delivery system would efficiently traverse the BBB and BBTB and deliver the therapeutics into the glioma cells with high selectivity. Herein, a targeted delivery system was developed based on nanostructured lipid carriers (NLCs) modified with two proteolytically stable D-peptides, D8 and RI-VAP (Dual NLCs). D8 possesses high affinity towards nicotine acetylcholine receptors (nAChRs), overexpressed on brain capillary endothelial cells (BCECs), and can penetrate through BBB with high efficiency. RI-VAP is a specific ligand of cell surface GRP78 (csGRP78), a specific angiogenesis and cancer cell-surface marker, capable of circumventing the BBTB with superior glioma-homing property. Dual NLCs could internalize into BCECs, tumor neovascular endothelial cells, and glioma cells with high specificity and could penetrate through in vitro BBB and BBTB models with excellent efficiency compared to non-targeted or mono-targeted NLCs. In vivo whole-animal imaging and ex vivo imaging further confirmed the superior targeting capability of Dual NLCs towards intracranial glioma. When loaded with Bortezomib (BTZ), Dual NLCs attained the highest therapeutic efficiency by means of in vitro cytotoxicity and apoptosis and prolonged survival rate and anti-glioma behavior in intracranial glioma bearing mice. Collectively, the designed targeting platform in this study could overcome multiple barriers and effectively deliver BTZ to glioma cells, which represent its potential for advanced brain cancer treatment with promising therapeutic outcomes.

Formulation and Characterization of Febuxostat Loaded Nanostructured Lipid Carriers (NLCs) - Gel for Topical Treatment of Gout

BACKGROUND

The aim of the present study was to formulate and characterize Nano- Structured Lipid Carriers (NLCs) of Febuxostat (FB) incorporated in the gel for the treatment of Gout. FB is a Xanthine Oxidase (XO) inhibitor drug used for chronic Gout and hyperuricemia. FB is a BCS class II drug, therefore, water solubility is very poor, and due to its poor solubility and wettability, it leads to poor dissolution. The hot high-pressure homogenization technique was used in this study to improve the physicochemical property of FB.

METHODS

The carbopol 934 was used to prepare NLCs gel of FB. The NLCs of FB was prepared in different drug: polymer ratios w/w (2:1), (1:1), (1:2), (1:3) and (1:4) with solid lipid (Stearic Acid) and liquid lipid (Oleic acid). The preformulation study of FB included FTIR study melting point, standard calibration curves, and drug-polymer interaction study.

RESULTS

The NLCs (1:3) showed high entrapment and drug content. The NLCs gel formulation was 87% released within 6 hours in a controlled manner.

CONCLUSION

NLCs gel modifies the drug release, increases the bioavailability, and reduces side effects of FB. The prepared gel is the efficient formulation for the better treatment of chronic gout and hyperuricemia. The research findings have shown the undesirable side effects associated with the oral route that can be reduced by the use of NLCs formulation through the transdermal route in an effective manner.

Engineered Solid Lipid Nanoparticles and Nanostructured Lipid Carriers as New Generations of Blood-Brain Barrier Transmitters

The blood-brain barrier (BBB) is considered as the most challenging barrier in brain drug delivery. Indeed, there is a definite link between the BBB integrity defects and central nervous systems (CNS) disorders, such as neurodegenerative diseases and brain cancers, increasing concerns in the contemporary era because of the inability of most therapeutic approaches. Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) have already been identified as having several advantages in facilitating the transportation of hydrophilic and hydrophobic agents across the BBB. This review first explains BBB functions and its challenges in brain drug delivery, followed by a brief description of nanoparticle-based drug delivery for brain diseases. A detailed presentation of recent progressions in optimizing SLNs and NLCs for controlled release drug delivery, gene therapy, targeted drug delivery, and diagnosis of neurodegenerative diseases and brain cancers is approached. Finally, the problems, challenges, and future perspectives in optimizing these carriers for potential clinical application were described briefly.

Biocompatibility and Antimicrobial Activity of Nanostructured Lipid Carriers for Topical Applications Are Affected by Type of Oils Used in Their Composition

Nanostructured lipid carriers (NLCs) have gained significant attention as tools for the dermal delivery of therapeutics due to their stability, biocompatibility, and ability to improve drug bioavailability. The use of natural plant oils (NPO) in NLC formulations has numerous benefits for the skin due to their therapeutic potential. This work shows the effect of NLC composition on bioavailability in epidermal cells and antimicrobial activity against Staphylococcus aureus. Sixteen systems containing fixed (sunflower, olive, corn, peanut, coconut, castor, and sweet almond) and essential (eucalyptus) oils, with different solid lipid (SL): liquid lipid (LL) ratios, were engineered. The structural properties, bioavailability, and antimicrobial action of the particles was studied. The choice of NPO influenced the physicochemical stability by changing the diameter of NLC formulations (between 160 nm and 185 nm) and Z-potential (between −46 mV and −61 mV). All of the systems were characterized by concentration-dependent cytocompatibility with human epidermal keratinocytes (HaCaT) and human dermal fibroblasts (HDFn). The SL:LL ratio in some NLC systems impacted cell cytotoxicity differently. Antimicrobial properties were observed in all 16 systems; however, the type of oil and SL:LL ratio affected the activity of the formulations. Two NLC-NPO systems were found to be non-cytotoxic to human cells lines at concentrations that completely inhibited bacterial growth. These results present a strong argument that the use of natural oils in NLC formulations presents a promising tool for the treatment of skin infections.

Nanostructured lipid carriers (NLCs) as drug delivery platform: Advances in formulation and delivery strategies

NLCs have provoked the incessant impulsion for the development of safe and valuable drug delivery systems owing to their exceptional physicochemical and then biocompatible characteristics. Throughout the earlier period, a lot of studies recounting NLCs based formulations have been noticeably increased. They are binary system which contains both solid and liquid lipids aiming to produce less ordered lipidic core. Their constituents particularly influence the physicochemical properties and effectiveness of the final product. NLCs can be fabricated by different techniques which are classified according to consumed energy. More utilization NLCs is essential due to overcome barriers surrounded by the technological procedure of lipid-based nanocarriers' formulation and increased information of the core mechanisms of their transport via various routes of administration. They can be used in different applications and by different routes such as oral, cutaneous, ocular and pulmonary. This review article seeks to present an overview on the existing situation of the art of NLCs for future clinics through exposition of their applications which shall foster their lucid use. The reported records evidently demonstrate the promise of NLCs for innovate therapeutic applications in the future.

Quercetin and piperine enriched nanostructured lipid carriers (NLCs) to improve apoptosis in oral squamous cellular carcinoma (FaDu cells) with improved biodistribution profile

Oral squamous cellular carcinoma (OSCC) is considered a life-threatening disease with detection in late stages, which forces us to opt for dangerous treatment with a combination of chemotherapy and radiotherapy. Herbal components such as piperine and quercetin are derived from edible sources, proving their anticancer potential against oral cancer cells in vitro. Encapsulation into lipid matrix-mediated nanostructured lipid carriers (NLCs) can make both drugs bio-accessible. NLCs were synthesised using the high shear homogenisation method and characterised for their physicochemical properties, followed by in vitro cellular evaluation in FaDu oral cancer cells. NLCs showed negatively charged particles smaller than 180 nm with a polydispersity index (PDI) of <0.3. Both drugs were found to encapsulate sufficiently, with >85% entrapment efficiency and an improved drug release profile compared to their pristine counterparts. Differential scanning calorimetry (DSC) thermograms showed conversion into an amorphous matrix in lyophilized NLCs, which was supported by X-ray diffraction (XRD) analysis. The cytotoxicity assay showed the IC₅₀ concentration for dual drug-loaded NLCs, which was more effective than the pure drug solution. NLCs were found to be internalised in cells in a short time with an almost 95% co-localization rate. Dual drug-loaded NLCs showed maximum depolarisation of the mitochondrial membrane along with more apoptotic changes. Improved apoptosis was confirmed in NLCs using flow cytometry. The in vivo biodistribution of Coumarin-6 labelled NLCs in rats confirmed their efficient distribution in various parts of the oral cavity through oral administration. Optimised dual drug-loaded NLCs provide a better option for delivering both drugs through a single lipid matrix against oral cancer.

Formulation and Optimization of Butenafine-Loaded Topical Nano Lipid Carrier-Based Gel: Characterization, Irritation Study, and Anti-Fungal Activity

The present study aims to prepare and optimize butenafine hydrochloride NLCs formulation using solid and liquid lipid. The optimized selected BF-NLCopt was further converted into Carbopol-based gel for topical application for the treatment of fungal infection. Box Behnken design was employed to optimize the nanostructure lipids carriers (NLCs) using the lipid content (A), Tween 80 (B), and homogenization cycle (C) as formulation factors at three levels. Their effects were observed on the particle size (Y₁) and entrapment efficiency (Y₂). The selected formulation was converted into gel and further assessed for gel characterization, drug release, anti-fungal study, irritation study, and stability study. The solid lipid (Compritol 888 ATO), liquid lipid (Labrasol), and surfactant (tween 80) were selected based on maximum solubility. The optimization result showed a particle size of 111 nm with high entrapment efficiency of 86.35% for BF-NLCopt. The optimized BF-NLCopt converted to gel (1% w/v, Carbopol 934) and showed ideal gel evaluation results (drug content 99.45 ± 2.11, pH 6.5 ± 0.2, viscosity 519 ± 1.43 CPs). The drug release study result depicted a prolonged drug release (65.09 ± 4.37%) with high drug permeation 641.37 ± 46.59 µg (32.07 ± 2.32%) than BF conventional gel. The low value of irritation score (0.17) exhibited negligible irritation on the skin after application. The anti-fungal result showed greater efficacy than the BF gel at both time points. The overall conclusion of the results revealed NLCs-based gel of BF as an ideal delivery system to treat the fungal infection.

Lipid based nanocarriers for effective drug delivery and treatment of diabetes associated liver fibrosis

Non-alcoholic fatty liver disease (NAFLD) is a cluster of several liver diseases like hepatic steatosis, non-alcoholic steatohepatitis (NASH), non-alcoholic fatty liver (NAFL), liver fibrosis, and cirrhosis which may eventually progress to liver carcinoma. One of the primary key factors associated with the development and pathogenesis of NAFLD is diabetes mellitus. The present review emphasizes on diabetes-associated development of liver fibrosis and its treatment using different lipid nanoparticles such as stable nucleic acid lipid nanoparticles, liposomes, solid lipid nanoparticles, nanostructured lipid carriers, self-nanoemulsifying drug delivery systems, and conjugates including phospholipid, fatty acid and steroid-based. We have comprehensively described the various pathological and molecular events linking effects of elevated free fatty acid levels, insulin resistance, and diabetes with the pathogenesis of liver fibrosis. Various passive and active targeting strategies explored for targeting hepatic stellate cells, a key target in liver fibrosis, have also been discussed in detail in this review.

Development of Inhalable Nanostructured Lipid Carriers for Ciprofloxacin for Noncystic Fibrosis Bronchiectasis Treatment

Purpose

Ciprofloxacin (CIP) has poor lung targeting after oral inhalation. This study developed optimized inhalable nanostructured lipid carriers (NLCs) for CIP to enhance deposition and accumulation in deeper parts of the lungs for treatment of noncystic fibrosis bronchiectasis (NCFB).

Methods

NLC formulations based on stearic acid and oleic acid were successfully prepared by hot homogenization and in vitro-characterized. CIP-NLCs were formulated into nanocomposite micro particles (NCMPs) for administration in dry powder inhalation (DPI) formulations by spray-drying (SD) using different ratios of chitosan (CH) as a carrier. DPI formulations were evaluated for drug content and in vitro deposition, and their mass median aerodynamic diameter (MMAD), fine particle fraction (FPF), fine particle dose (FPD), and emitted dose (ED) were determined.

Results

The CIP-NLCs were in the nanometric size range (102.3 ± 4.6 nm), had a low polydispersity index (0.267 ± 0.12), and efficient CIP encapsulation (98.75% ± 0.048%), in addition to a spherical and smooth shape with superior antibacterial activity. The in vitro drug release profile of CIP from CIP-NLCs showed 80% release in 10 h. SD of CIP-NLCs with different ratios of CH generated NCMPs with good yield (>65%). The NCMPs had a corrugated surface, but with increasing lipid:CH ratios, more spherical, smooth, and homogenous NCMPs were obtained. In addition, there was a significant change in the FPF with increasing lipid:CH ratios (P ˂ 0.05). NCMP-1 (lipid:CH = 1:0.5) had the highest FPD (45.0 µg) and FPF (49.2%), while NCMP-3 (lipid:CH = 1:1.5) had the lowest FPF (37.4%). All NCMP powders had an MMAD in the optimum size range of 3.9–5.1 μm.

Conclusion

Novel inhalable CIP NCMP powders are a potential new approach to improved target ability and delivery of CIP for NCFB treatment.

Fate of β-Carotene within Loaded Delivery Systems in Food: State of Knowledge

Nanotechnology has opened new opportunities for delivering bioactive agents. Their physiochemical characteristics, i.e., small size, high surface area, unique composition, biocompatibility and biodegradability, make these nanomaterials an attractive tool for β-carotene delivery. Delivering β-carotene through nanoparticles does not only improve its bioavailability/bioaccumulation in target tissues, but also lessens its sensitivity against environmental factors during processing. Regardless of these benefits, nanocarriers have some limitations, such as variations in sensory quality, modification of the food matrix, increasing costs, as well as limited consumer acceptance and regulatory challenges. This research area has rapidly evolved, with a plethora of innovative nanoengineered materials now being in use, including micelles, nano/microemulsions, liposomes, niosomes, solidlipid nanoparticles, nanostructured lipids and nanostructured carriers. These nanodelivery systems make conventional delivery systems appear archaic and promise better solubilization, protection during processing, improved shelf-life, higher bioavailability as well as controlled and targeted release. This review provides information on the state of knowledge on β-carotene nanodelivery systems adopted for developing functional foods, depicting their classifications, compositions, preparation methods, challenges, release and absorption of β-carotene in the gastrointestinal tract (GIT) and possible risks and future prospects.

Ezetimibe-Loaded Nanostructured Lipid Carrier Based Formulation Ameliorates Hyperlipidaemia in an Experimental Model of High Fat Diet

Ezetimibe (EZE) possesses low aqueous solubility and poor bioavailability and in addition, its extensive hepatic metabolism supports the notion of developing a novel carrier system for EZE. Ezetimibe was encapsulated into nanostructured lipid carriers (EZE-NLCs) via a high pressure homogenization technique (HPH). A three factor, two level (2³) full factorial design was employed to study the effect of amount of poloxamer 188 (X1), pressure of HPH (X2) and number of HPH cycle (X3) on dependent variables. Particle size, polydispersity index (PDI), % entrapment efficiency (%EE), zeta potential, drug content and in-vitro drug release were evaluated. The optimized formulation displays pragmatic inferences associated with particle size of 134.5 nm; polydispersity index (PDI) of 0.244 ± 0.03; zeta potential of −28.1 ± 0.3 mV; % EE of 91.32 ± 1.8% and % CDR at 24-h of 97.11%. No interaction was observed after X-ray diffraction (XRD) and differential scanning calorimetry (DSC) studies. EZE-NLCs (6 mg/kg/day p.o.) were evaluated in the high fat diet fed rats induced hyperlipidemia in comparison with EZE (10 mg/kg/day p.o.). Triglyceride, HDL-c, LDL-c and cholesterol were significantly normalized and histopathological evaluation showed normal structure and architecture of the hepatocytes. The results demonstrated the superiority of EZE-NLCs in regard to bioavailability enhancement, dose reduction and dose-dependent side effects.

Polymeric Nanoscale Drug Carriers Mediate the Delivery of Methotrexate for Developing Therapeutic Interventions Against Cancer and Rheumatoid Arthritis

Methotrexate (MTX) is widely used as an anticancer and anti-inflammtory drug for treating various types of cancer and autoimmune diseases. The optimal dose of MTX is known to inhibit the dihydrofolatereductase that hinders the replication of purines. The nanobiomedicine has been extensively explored in the past decade to develop myriad functional nanostructures to facilitate the delivery of therapeutic agents for various medical applications. This review is focused on understanding the design and development of MTX-loaded nanoparticles alongside the inclusion of recent findings for the treatment of cancers. In this paper, we have made a coordinated effort to show the potential of novel drug delivery systems by achieving effective and target-specific delivery of methotrexate.

Development of a cell-line model to mimic the pro-survival effect of nurse-like cells in chronic lymphocytic leukemia

The interaction between Chronic lymphocytic leukemia (CLL) cells and monocyte-derived nurse-like cells (NLCs) is fundamentally important to CLL biology. However, studies of how CLL cells and NLCs interact have been hampered by the need for freshly obtained CLL blood samples, coupled with wide variation in the number of monocytes present in the blood of individual patients. Here, we report the development and validation of a cell-line model of NLCs which overcomes these difficulties. Co-culture of primary CLL cells with THP-1 cells induced to differentiate into macrophages by phorbol 12-myristate 13-acetate (PMA) significantly reduced both spontaneous and fludarabine-induced cell death of leukemic cells. Furthermore, compared with their M1-polarized counterparts, M2-polarized macrophages derived from PMA-differentiated THP-1 cells conferred to CLL cells greater protection from spontaneous and fludarabine-induced apoptosis. Since NLCs resemble M2 tumor-associated macrophages, this cell-line model could be useful for investigating the mechanisms through which NLCs protect CLL cells from spontaneous and drug-induced apoptosis.

Progress and perspectives of brain-targeting lipid-based nanosystems via the nasal route in Alzheimer's disease

Since health care systems dedicate substantial resources to Alzheimer's disease (AD), it poses an increasing challenge to scientists and health care providers worldwide, especially that many decades of research in the medical field revealed no optimal effective treatment for this disease. The intranasal administration route seems to be a preferable route of anti-AD drug delivery over the oral one as it demonstrates an ability to overcome the related obstacles reflected in low bioavailability, limited brain exposure and undesired pharmacokinetics or side effects. This delivery route can bypass the systemic circulation through the intraneuronal and extraneuronal pathways, providing truly needleless and direct brain drug delivery of the therapeutics due to its large surface area, porous endothelial membrane, the avoidance of the first-pass metabolism, and ready accessibility. Among the different nano-carrier systems developed, lipid-based nanosystems have become increasingly popular and have proven to be effective in managing the common symptoms of AD when administered via the nose-to-brain delivery route, which provides an answer to circumventing the BBB. The design of such lipid-based nanocarriers could be challenging since many factors can contribute to the quality of the final product. Hence, according to the authors, it is recommended to follow the quality by design methodology from the early stage of development to ensure high product quality while saving efforts and costs. This review article aims to draw attention to the up-to-date findings in the field of lipid-based nanosystems and the potential role of developing such forms in the management of AD by means of the nose-to-brain delivery route, in addition to highlighting the significant role of applying QbD methodology in this development.

Nose to brain delivery of antiretroviral drugs in the treatment of neuroAIDS

NeuroAIDS (Neuro Acquired Immunodeficiency Syndrome) or HIV (Human Immunodeficiency Virus) associated neuronal abnormality is continuing to be a significant health issue among AIDS patients even under the treatment of combined antiretroviral therapy (cART). Injury and damage to neurons of the brain are the prime causes of neuroAIDS, which happens due to the ingress of HIV by direct permeation across the blood-brain barrier (BBB) or else via peripherally infected macrophage into the central nervous system (CNS). The BBB performs as a stringent barricade for the delivery of therapeutics drugs. The intranasal route of drug administration exhibits as a non-invasive technique to bypass the BBB for the delivery of antiretroviral drugs and other active pharmaceutical ingredients inside the brain and CNS. This method is fruitful for the drugs that are unable to invade the BBB to show its action in the CNS and thus erase the demand of systemic delivery and thereby shrink systemic side effects. Drug delivery from the nose to the brain/CNS takes very less time through both olfactory and trigeminal nerves. Intranasal delivery does not require the involvement of any receptor as it occurs by an extracellular route. Nose to brain delivery also involves nasal associated lymphatic tissues (NALT) and deep cervical lymph nodes. However, very little research has been done to explore the utility of nose to brain delivery of antiretroviral drugs in the treatment of neuroAIDS. This review focuses on the potential of nasal route for the effective delivery of antiretroviral nanoformulations directly from nose to the brain.

Repaglinide-loaded nanostructured lipid carriers with different particle sizes for improving oral absorption: preparation, characterization, pharmacokinetics, and in situ intestinal perfusion

Repaglinide-loaded nanostructured lipid carriers (REP-NLCs) with different particle sizes were successfully designed and prepared to investigate the permeation and absorption ability by in situ single-pass intestinal perfusion (SPIP) study and pharmacokinetics. Both of the formulations prepared by solvent diffusion method exhibited a spherical shape under transmission electron microscopy (TEM) and similar zeta potential value of –11 mV. The particles size, encapsulation efficiency (EE), drug loading (DL) of REP-NLCs-Small and REP-NLCs-Large size preparations were about 79 nm and 325 nm, 96.83% and 98.60%, 4.41% and 3.05%, respectively. Besides, both REP-NLCs showed good colloidal stability and had no burst release phenomenon compared with REP-Sol. SPIP demonstrated the improved membrane permeability for NLCs compared with REP-Sol, especially NLCs-Small size preparation. The bioavailability increased sequentially in REP-Sol, REP-NLCs-Large, and REP-NLCs-Small, and the difference between each other was statistical significant. Our investigations demonstrate that NLCs with small particles size of 50–100 nm, such as 79 nm, are able to enhance absorption performance of a poorly soluble repaglinide compared with large particles size, such as 325 nm, by significantly improving the absorption in jejunum, and colon of rats and thus well improving oral bioavailability.

Colloidal nanostructured lipid carriers of pentoxifylline produced by microwave irradiation ameliorates imiquimod-induced psoriasis in mice

Psoriasis is a chronic inflammatory disease occurring due to a large cascade of molecular and biological processes. Pentoxifylline (PTX) has a profound anti-inflammatory activity and is clinically indicated in the management of psoriasis. PTX is highly hydrophilic and thus is permeation-limited to exert its action on the psoriatic lesions. Colloidal nanostructured lipid carriers (NLCs) is a boon for dermal drug delivery, but incorporation of hydrophilic medicaments is not only difficult to be achieved but is accompanied by suboptimal loading, erratic drug release and time-consuming. The present study was designed to develop NLCs incorporating PTX using the recently explored thin lipid film based microwave assisted rapid technique. Prior to the formulation, the crystal structure of PTX was analyzed by molecular modeling. NLCs formed within 4 min having a size of <200 nm, PDI of <0.250 and a surface charge <-28 mV. PTX was loaded and encapsulated to an extent of 10% and 90% in the NLCs. The drug flux was 4.848 μg/cm²/h at the end of 24 h with a detection of 14% in the receptor fluid indicating a higher retention of PTX within the skin (>84%). In addition, the PTX loaded NLCs were tested against imiquimod-induced psoriasis in mouse model. Histological examinations clearly showed a higher levels of remodeling of the skin layers compared to disease control. These results justify NLCs to be a promising topical delivery system for PTX during psoriasis and can be rapidly produced without the requirement of complex equipment and conditions.

Preclinical Explorative Assessment of Dimethyl Fumarate-Based Biocompatible Nanolipoidal Carriers for the Management of Multiple Sclerosis

Multiple sclerosis (MS) is a neurodegenerative disease in which myelin sheath damage occurs due to internal and external factors. MS especially affects the young population. Dimethyl fumarate (DMF) is a promising agent for MS treatment, although it is associated with concerns such as poor brain permeation, multiple dosing, and gastrointestinal flushing. The present study attempts to evaluate the preclinical performance of specially designed DMF-based lipoidal nanoparticles in a cuprizone-induced demyelination model in rodents. The studies proved the efficacy of lipid-based nanoparticles containing DMF in a once-a-day dosage regimen over that of thrice-a-day plain DMF administration on crucial parameters like motor coordination, grip strength, mortality, body weight, and locomotor activity. However, neither blank lipid nor blank neuroprotective (vitamins A, D, and E) loaded nanoparticles were able to elicit any desirable behavioral response. Histopathological studies showed that the designed once-a-day DMF nanomedicines were well tolerated and rejuvenated the myelin sheath vis-à-vis the plain DMF thrice-a-day regimen. These findings provide proof of concept for a biocompatible nanomedicine for MS with tremendous promise for effective brain delivery and patient compliance on the grounds of a reduction in the dosage frequency.

Lipid Nanoparticles: A Novel Approach for Brain Targeting

BACKGROUND

Brain is a delicate organ, separated from general circulation and is characterized by the presence of relatively impermeable Blood Brain Barrier (BBB). The BBB maintains homeostasis in the brain thus restricting the entrance of foreign bodies and several molecules from reaching the brain. As a result several promising molecules do not reach the target site and fail to produce in vivo response. Nevertheless, lipid nanoparticles are taken up readily by the brain because of their lipophilic nature. The bioacceptable and biodegradable nature of lipid nanoparticles makes them less toxic and suited for brain targeting.

OBJECTIVE

In the present review the BBB, mechanism of transport across the BBB, strategies to bypass the blood-brain barrier have been presented. The aptness of lipid nanoparticles for brain targeting has been highlighted. The proposed mechanism of uptake of the lipid nanoparticles, methods of prolonging the plasma retention and various methods of preparation for formulation of effective delivery systems for brain targeting have been included and dealt in this review.

CONCLUSION

Lipid based formulations can be designated as the current and future generation of drug delivery systems as these possess tremendous potential to bypass BBB and reach the target site due to their small size and ability to dodge the reticular endothelial system. However, these nanostructures need to be investigated intensively to successfully reach the clinical trials stage.

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.

Enhanced Brain Delivery of Dimethyl Fumarate Employing Tocopherol-Acetate-Based Nanolipidic Carriers: Evidence from Pharmacokinetic, Biodistribution, and Cellular Uptake Studies

Dimethyl fumarate (DMF) is an approved drug for the management of relapsing multiple sclerosis. Despite efficacy, DMF is also reported to be a challenging drug owing to concerns like gastrointestinal tract flushing, multiple dosing, lower brain permeability, less patient compliance, and economic hurdles. The present study aims to develop DMF-tocopherol acetate nanolipidic carrier (NLCs) to enhance brain permeability and improve the gastric tolerance. The developed DMF-tocopherol acetate NLCs offered an average size of 69.70 nm, PDI of 0.317, and a zeta potential of -9.71 mV. Higher drug entrapment (90.12%) and drug loading (20.13%) assured controlled drug release behavior both in gastric and intestinal pH. Cellular uptake studies on Caco-2 and SH-SY5Y monolayers confirmed better intestinal absorption and neuronal uptake of the developed system, which was further corroborated by the pharmacokinetic and biodistribution studies. The oral bioavailability was enhanced by 4.09 times and brain availability was substantially improved vis-à-vis plain drug. The findings are promising and offer preclinical evidence for better brain availability of DMF, which can be exploited in the better management of diseases like multiple sclerosis.

Nanostructured Lipid Carrier for Topical Application of N-Acetyl Glucosamine

Purpose: Hyperpigmentation occurs when melanin is overproduced in certain spots on the skin and is one of the most challenging skin conditions to treat. Although it is usually harmless, for cosmetic reasons, it is dreadfully bothersome to those who undergo it. It was reported that N-acetyl-glucosamine (NAGA) prevents melanin synthesis and alters the expression of numerous genes related to pigmentation. In spite of these advantages, NAGA cannot be employed in topical formulations due to its extremely polar characteristics. Nanoparticles, especially lipid-based ones, have been introduced as an efficient carrier for dermal drug delivery. Methods: The aim of the present study was to load adequate hydrophilic NAGA to the lipophilic nanostructured lipid carriers (NLCs) for potential dermal application.

METHODS

NAGA-loaded NLCs were formulated, using hot homogenization technique, and the characteristics of the optimized formulation were analyzed by laser light scattering, X-ray diffraction, and scanning electron microscopy methods. Loading capacity percentage and in vitro release study were carried out by applying a validated HPLC method. The optimum formulation was utilized for the in vivo skin lightening evaluations in healthy volunteers. Results: NAGA-loaded NLCs demonstrated promising results (the size of 190 nm, narrow size distribution, loading capacity of 9%, and appropriate NAGA release profile) suitable for dermal delivery. XRD results exhibited a dramatic reduction in the crystalline structure of encapsulated NAGA. Dermoscopy images indicated a considerable decline in melanin distribution pattern in the majority of the cases treated with NAGA-loaded NLCs. Conclusion: Thus, this study has opened new horizons for the potential use of lipid based nanoparticles in the managing of hyperpigmentation.

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.

Nanostructured lipid carriers for the topical delivery of tretinoin

Cosmetic skin care products currently in the market demonstrate an increasing trend toward antiaging products. Selection of the right formulation approach is the key to successful consumer acceptance. Nanostructured lipid carriers (NLCs) for dermal application can render added benefits to the formulation. Tretinoin a derivative of vitamin A, is a retinoid with anti-aging and anti-acne potential. The present study was aimed at formulating NLCs of tretinoin for reducing the skin irritation potential, increasing the drug loading capacity and prolonging the duration of action. The NLCs were optimized using the response surface methodology based on the particle size. Preliminary study, suggested the use of stearic acid, oleic acid, Tween 80 and Span 60 as solid lipid, liquid lipid and surfactants respectively formed a stable dispersion. NLCs of tretinoin were prepared by hot melt microemulsion and hot melt probe sonication methods. The properties of the optimized NLCs such as morphology, size, Zeta potential, stability and in vitro drug release were investigated. Tretinoin loaded NLCs in carbopol gel showed a sustained release pattern with isopropyl alcohol as the receptor fluid compared to the marketed gel using Franz diffusion cells. Eight prepared gel formulations tested were found to follow the Higuchi model of drug release. Stability studies indicated that the formulations stored at refrigeration and room temperature showed no noticeable differences in the drug content and release profiles in vitro, after a period of 4 weeks. In vivo skin irritation test on male Wister rats indicated no irritation or erythema after application of the NLCs loaded gel repeated for a period of 7 days compared to the application of marketed tretinoin gel which showed irritation and slight erythema within 3 days. The results showed that the irritation potential of tretinoin was reduced, the drug loading was increased and the drug release was prolonged by the incorporation into the NLCs.

Carvedilol nano lipid carriers: formulation, characterization and in-vivo evaluation

The purpose of this study was to develop Carvedilol nanostructured lipid carriers (CAR-NLCs) using stearic acid and oleic acid as lipid, and to estimate the potential as oral delivery system for poorly water soluble drug. The particle-size analysis revealed that all the developed formulations were within the nanometer range. The EE and loading were found to be between 69.45-88.56% and 9.58-12.56%, respectively. The CAR-NLCopt showed spherical morphology with smooth surface under transmission electron microscope (TEM). The crystallization of the drug in NLC was investigated by powder X-ray diffraction and differential scanning calorimetry (DSC) and revealed that the drug was in an amorphous state in the NLC matrix. The ex vivo gut permeation study showed many folds increment in the permeation of CAR-NLCs compared to Carvedilol suspension (CAR-S). The oral bioavailability study of CAR was carried out using Wistar rats and relative bioavailability of CAR-NLCopt was found to be 3.95 fold increased in comparison with CAR-S. In vivo antihypertensive study in Wistar rats showed significant reduction in mean systolic BP by CAR-NLCopt vis-à-vis CAR-S (p < 0.05) owing to the drug absorption through lymphatic pathways. In conclusion, the NLC formulation remarkably improved the oral bioavailability of CAR and demonstrated a promising perspective for oral delivery of poorly water-soluble drugs. The promising findings in this investigation suggest the practicability of these systems for the enhancement of bioavailability of CAR.

Solid Lipid Nanoparticles and Nanostructured Lipid Carriers: Structure, Preparation and Application

Lipid nanoparticles (LNPs) have attracted special interest during last few decades. Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) are two major types of Lipid-based nanoparticles. SLNs were developed to overcome the limitations of other colloidal carriers, such as emulsions, liposomes and polymeric nanoparticles because they have advantages like good release profile and targeted drug delivery with excellent physical stability. In the next generation of the lipid nanoparticle, NLCs are modified SLNs which improve the stability and capacity loading. Three structural models of NLCs have been proposed. These LNPs have potential applications in drug delivery field, research, cosmetics, clinical medicine, etc. This article focuses on features, structure and innovation of LNPs and presents a wide discussion about preparation methods, advantages, disadvantages and applications of LNPs by focusing on SLNs and NLCs.

Dextran-protamine coated nanostructured lipid carriers as mucus-penetrating nanoparticles for lipophilic drugs

The main objectives of the present study were (i) to evaluate the effect of the mucus layer on saquinavir-loaded nanostructured lipid carriers (SQV-NLCs) uptake and (ii) to evaluate the mucopenetrating properties of dextran-protamine (Dex-Prot) coating on NLCs as per SQV permeability enhancement. Three different NLC formulations differing on particle size and surfactant content were obtained and coated with Dex-Prot complexes. SQV permeability was then evaluated across Caco-2 cell monolayers (enterocyte-like model) and Caco-2/HT29-MTX cell monolayers (mucus model). In the Caco-2 monolayers, Dex-Prot-NLCs increased up to 9-fold SQV permeability in comparison to uncoated nanoparticles. In the Caco-2/HT29-MTX monolayers, Dex-Prot-NLCs presenting a surface charge close to neutrality significantly increased SQV permeability. Hence, Dex-Prot complex coating is a promising strategy to ensure successful nanoparticle mucus-penetration, and thus, an efficient nanoparticle oral delivery. To our knowledge, this is the first time that Dex-Prot coating has been described as a nanoparticle muco-penetration enhancer across the intestinal mucus barrier.