Design and characterization of Amoitone B-loaded nanostructured lipid carriers for controlled drug release

Comparative Study of Liposomal and Ethosomal Formulations of Curcuma heyneana Rhizome Extract in a Transdermal Delivery System

AIMS

This study aimed to develop an anti-aging nanoformulation with Curcuma heyneana extract as bioactive substance.

BACKGROUND

Curcuma heyneana Valeton & Zipj extract has been proven in previous research to have antioxidant, anti-ageing, anti-inflammatory, and wound healing properties, which makes it a potential bioactive material for anti-ageing and sunscreen cosmetic products. Phytoantioxidants need to penetrate into deeper skin layers to ensure effectivity. Thus, a transdermal delivery system is needed to deliver the extract to a deeper skin layer.

OBJECTIVES

The objective of the study was to compare the permeability and anti-ageing activity of liposomal and ethosomal formulations of C. heynena rhizome ethanolic extract.

METHODS

In this study, C. heyneana extract was loaded into a phospholipid vesicular system in the form of liposome and ethosome formulations using the ethanolic injection method. The anti-ageing activity was assessed by analyzing the epidermal thickness, number of sunburn cells, distance between collagen fibers, and number of fibroblasts. While the histologic specimen scoring was carried out for the in vivo penetration study.

RESULTS

The ethosomal formulation had been found to have better penetration ability since it was able to reach the lower dermis area compared to the liposomes, which only reached the upper dermis. The ethosomal formulation of C. heyneana extract exhibited a better anti-ageing activity based on the parameters of epidermal thickness, sunburn cell count, fibroblast count, and the distance between collagen fibres in rat skin histology.

CONCLUSION

Ethosomes have been found to be a more proficient carrier system for transdermal delivery of C. heyneana extract compared to liposomes. Meanwhile, their penetration correlated with the effectivity of the formulation, suggesting that the vesicular system enhanced the penetration ability of the extract.

Eco-friendly Nanostructured Liquid Crystals Loaded with Clove Oil as a Sustainable Approach for Managing Infected Burn Wounds

Infections are a leading complication in patients with burns. Effective antimicrobial treatment with regenerative tissue healing is required. Utilizing components derived from plant origin such as natural oils as a sustainable and eco-friendly approach for managing disease is highly required nowadays. The aim of the current study is to assess the antibacterial and wound-healing activity of clove oil and its novel eco-friendly nanostructured liquid crystals (Eco-friendly-NLCs) formulation in treating infected burn wounds. A 23 full factorial design was used to optimize the Eco-friendly-NLCs. Clove oil and its novel nano-formulation were characterized and subjected to in vitro and in vivo assessments for their efficacy. Twenty rats were used experimentally. The optimum Eco-friendly-NLCs had 189.2 ± 1.9 nm, -22.8 ± 0.7 mV and 0.308 as values for particle size, zeta potential and polydispersity index. Transmission electron microscope images showed discrete spherical shape NLCs with no aggregations. The microbiological and pharmacological results revealed a superior efficacy regarding clove loaded Eco-friendly-NLCs in inhibiting bacterial growth (inhibition zone of 38 mm), significantly reducing inflammatory biomarker levels (p < 0.001), promoting angiogenesis and prompt wound healing. The Eco-friendly-NLCs loaded with clove oil could be considered as a promising formulation providing anti-inflammatory, anti-bacterial and wound healing effects.

Natural compounds-based nanomedicines for cancer treatment: Future directions and challenges

Several efforts have been extensively accomplished for the amelioration of the cancer treatments using different types of new drugs and less invasives therapies in comparison with the traditional therapeutic modalities, which are widely associated with numerous drawbacks, such as drug resistance, non-selectivity and high costs, restraining their clinical response. The application of natural compounds for the prevention and treatment of different cancer cells has attracted significant attention from the pharmaceuticals and scientific communities over the past decades. Although the use of nanotechnology in cancer therapy is still in the preliminary stages, the application of nanotherapeutics has demonstrated to decrease the various limitations related to the use of natural compounds, such as physical/chemical instability, poor aqueous solubility, and low bioavailability. Despite the nanotechnology has emerged as a promise to improve the bioavailability of the natural compounds, there are still limited clinical trials performed for their application with various challenges required for the pre-clinical and clinical trials, such as production at an industrial level, assurance of nanotherapeutics long-term stability, physiological barriers and safety and regulatory issues. This review highlights the most recent advances in the nanocarriers for natural compounds secreted from plants, bacteria, fungi, and marine organisms, as well as their role on cell signaling pathways for anticancer treatments. Additionally, the clinical status and the main challenges regarding the natural compounds loaded in nanocarriers for clinical applications were also discussed.

An in vitro study for reducing the cytotoxicity and dose dumping risk of remdesivir via entrapment in nanostructured lipid carriers

The aim of this study was to synthesize and evaluate nanostructured lipid carriers (NLCs) loaded with Remdesivir (RDV) to control its side effects in COVID-19 patients. Due to the low solubility and short half-life of RDV in the blood, an injectable formulation was prepared using sulphobutylether-beta-cyclodextrin. However, it can accumulate in the kidney and cause renal impairment. NLCs improve the parenteral delivery of hydrophobic drugs such as RDV by increasing drug solubility and bioavailability. For the synthesis of RDV-NLCs, the aqueous phase containing Tween 80 was injected into the lipid phase under rapid stirring and was sonicated. The experimental conditions were optimized using Box-Behnken design and Design Expert software. The optimum formulation contained a total lipid of 2.13%, a total surfactant of 1%, and a hot bath time of 71 min. The optimum formulation showed particle size, polydispersity index, zeta potential, and entrapment efficiency values of 151.0 ± 1.7 nm (from 149.1 to 152.1), 0.4 ± 0.1 (from 0.3 to 0.5), -43.8 ± 1.2 mV (from -42.4 to -44.7), and 81.34 ± 1.57% (from 79.52 to 82.33%), respectively. RDV-NLCs showed acceptable stability for 30 days at 25 ℃ and were compatible with commonly used intravenous infusion fluids for 48 h. FE-SEM images of RDV-NLC showed spherical particles with a mean diameter of 207 nm. The NLC-RDV formulation showed a sustained release of RDV with a low risk of dose-dumping, minimizing potential side effects. In addition, RDV in the form of RDV-NLC causes less cytotoxicity to healthy normal kidney cells, which is expected to reduce renal impairment in COVID-19 patients.

Box-Behnken Design-Based Optimization and Evaluation of Lipid-Based Nano Drug Delivery System for Brain Targeting of Bromocriptine

Bromocriptine (BCR) presents poor bioavailability when administered orally because of its low solubility and prolonged first-pass metabolism. This poses a significant challenge in its utilization as an effective treatment for managing Parkinson's disease (PD). The utilization of lipid nanoparticles can be a promising approach to overcome the limitations of BCR bioavailability. The aim of the research work was to develop and evaluate bromocriptine-loaded solid lipid nanoparticles (BCR-SLN) and bromocriptine-loaded nanostructured lipid carriers (BCR-NLC) employing the Box-Behnken design (BBD). BCR-SLNs and BCR-NLCs were developed using the high-pressure homogenization method. The prepared nanoparticles were characterized for particle size (PS), polydispersity index (PDI), and entrapment efficiency (EE). In vitro drug release, cytotoxicity studies, in vivo plasma pharmacokinetic, and brain distribution studies evaluated the optimized lipid nanoparticles. The optimized BCR-SLN had a PS of 219.21 ± 1.3 nm, PDI of 0.22 ± 0.02, and EE of 72.2 ± 0.5. The PS, PDI, and EE of optimized BCR-NLC formulation were found to be 182.87 ± 2.2, 0.16 ± 0.004, and 83.57 ± 1.8, respectively. The in vitro release profile of BCR-SLN and BCR-NLC showed a biphasic pattern, immediate release, and then trailed due to the sustained release. Furthermore, a pharmacokinetic study indicated that both the optimized BCR-SLN and BCR-NLC formulations improve the plasma and brain bioavailability of the drug compared to the BCR solution. Based on the research findings, it can be concluded that the BCR-loaded lipid nanoparticles could be a promising carrier by enhancing the BBB penetration of the drug and helping in the improvement of the bioavailability and therapeutic efficacy of BCR in the management of PD.

In vitro plasma hydrolysis of phenolic esters and their absorption kinetics in rats: Controlled release of phenolic compounds and enhanced health benefits

Phenolic esters are considered as promising functional food ingredients. However, their digestion, absorption and metabolism are still unclear. Tyrosol acyl esters (TYr-Es), hydroxytyrosol acyl esters (HTy-Es) and alkyl gallates (A-GAs) were hydrolyzed by carboxylesterase in plasma and exhibited slow release of polyphenols (phenolic acids). In vitro hydrolysis degrees initially increased and then decreased with the increasing carbon chain length (C2-C16). TYr-Es exhibited higher hydrolysis degrees compared to HTy-Es, and hydrolysis degrees of TYr-Es and HTy-Es were markedly higher than those of A-GAs. Due to the fast hydrolysis rates of TYr-Es and HTy-Es, they were undetectable in all rat plasma samples collected at several times within 24 h after administration. Whereas, A-GAs could be detected in rat plasmas and three absorption peaks were found in the pharmacokinetic profiles. Importantly, the T1/2, MRT, AUC0-∞, AUC0-t in octyl gallate group were longer (or stronger) than those in propyl gallate and dodecyl gallate groups.

Solid Lipid Nanoparticles vs. Nanostructured Lipid Carriers: A Comparative Review

Solid-lipid nanoparticles and nanostructured lipid carriers are delivery systems for the delivery of drugs and other bioactives used in diagnosis, therapy, and treatment procedures. These nanocarriers may enhance the solubility and permeability of drugs, increase their bioavailability, and extend the residence time in the body, combining low toxicity with a targeted delivery. Nanostructured lipid carriers are the second generation of lipid nanoparticles differing from solid lipid nanoparticles in their composition matrix. The use of a liquid lipid together with a solid lipid in nanostructured lipid carrier allows it to load a higher amount of drug, enhance drug release properties, and increase its stability. Therefore, a direct comparison between solid lipid nanoparticles and nanostructured lipid carriers is needed. This review aims to describe solid lipid nanoparticles and nanostructured lipid carriers as drug delivery systems, comparing both, while systematically elucidating their production methodologies, physicochemical characterization, and in vitro and in vivo performance. In addition, the toxicity concerns of these systems are focused on.

Phytocannabinoids: Chromatographic Screening of Cannabinoids and Loading into Lipid Nanoparticles

Solid Lipid Nanoparticles (SLN) and Nanostructured Lipid Carriers (NLC) are receiving increasing interest as an approach to encapsulate natural extracts to increase the physicochemical stability of bioactives. Cannabis extract-derived cannabidiol (CBD) has potent therapeutic properties, including anti-inflammatory, antioxidant, and neuroprotective properties. In this work, physicochemical characterization was carried out after producing Compritol-based nanoparticles (cSLN or cNLC) loaded with CBD. Then, the determination of the encapsulation efficiency (EE), loading capacity (LC), particle size (Z-Ave), polydispersity index (PDI), and zeta potential were performed. Additionally, the viscoelastic profiles and differential scanning calorimetry (DSC) patterns were recorded. As a result, CBD-loaded SLN showed a mean particle size of 217.2 ± 6.5 nm, PDI of 0.273 ± 0.023, and EE of about 74%, while CBD-loaded NLC showed Z-Ave of 158.3 ± 6.6 nm, PDI of 0.325 ± 0.016, and EE of about 70%. The rheological analysis showed that the loss modulus for both lipid nanoparticle formulations was higher than the storage modulus over the applied frequency range of 10 Hz, demonstrating that they are more elastic than viscous. The crystallinity profiles of both CBD-cSLN (90.41%) and CBD-cNLC (40.18%) were determined. It may justify the obtained encapsulation parameters while corroborating the liquid-like character demonstrated in the rheological analysis. Scanning electron microscopy (SEM) study confirmed the morphology and shape of the developed nanoparticles. The work has proven that the solid nature and morphology of cSLN/cNLC strengthen these particles' potential to modify the CBD delivery profile for several biomedical applications.

Nanostructured lipid carriers: a promising drug carrier for targeting brain tumours

Background

In recent years, the field of nanotechnology and nanomedicine has transformed the pharmaceutical industry with the development of novel drug delivery systems that overcome the shortcomings of traditional drug delivery systems. Nanostructured lipid carriers (NLCs), also known as the second-generation lipid nanocarriers, are one such efficient and targeted drug delivery system that has gained immense attention all across due to their myriad advantages and applications. Scientific advancements have revolutionized our health system, but still, brain diseases like brain tumour have remained formidable owing to poor prognosis and the challenging drug delivery to the brain tissue. In this review, we highlighted the application and potential of NLCs in brain-specific delivery of chemotherapeutic agents.

Main body

NLCs are lipid-based formulations with a solid matrix at room temperature and offer advantages like enhanced stability, low toxicity, increased shelf life, improved drug loading capacity, and biocompatibility over other conventional lipid-based nanocarriers such as nanoemulsions and solid lipid nanoparticles. This review meticulously articulates the structure, classification, components, and various methods of preparation exemplified with various research studies along with their advantages and disadvantages. The concept of drug loading and release has been discussed followed by a brief about stability and strategies to improve stability of NLCs. The review also summarizes various in vitro and in vivo research studies on NLCs encapsulated with cytotoxic drugs and their potential application in brain-specific drug delivery.

Conclusion

NLCs are employed as an important carrier for the delivery of food, cosmetics, and medicines and recently have been used in brain targeting, cancer, and gene therapy. However, in this review, the applications and importance of NLCs in targeting brain tumour have been discussed in detail stating examples of various research studies conducted in recent years. In addition, to shed light on the promising role of NLCs, the current clinical status of NLCs has also been summarized.

Graphical Abstract

Lipid Nanoparticles as Carriers for Bioactive Delivery

Nanotechnology has made a great impact on the pharmaceutical, biotechnology, food, and cosmetics industries. More than 40% of the approved drugs are lipophilic and have poor solubility. This is the major rate-limiting step that influences the release profile and bioavailability of drugs. Several approaches have been reported to administer lipophilic drugs with improved solubility and bioavailability. Nanotechnology plays a crucial role in the targeted delivery of poorly soluble drugs. Nanotechnology-based drug delivery systems can be classified as solid lipid nanoparticulate drug delivery systems, emulsion-based nanodrug delivery systems, vesicular drug delivery systems, etc. Nanotechnology presents a new frontier in research and development to conquer the limitations coupled with the conventional drug delivery systems through the formation of specific functionalized particles. This review presents a bird's eye view on various aspects of lipid nanoparticles as carriers of bioactive molecules that is, synthesis, characterization, advantage, disadvantage, toxicity, and application in the medical field. Update on recent development in terms of patents and clinical trials of solid lipid nanoparticles (SLNs) and nanostructure lipid carriers (NLCs) have also been discussed in this article.

Nanostructured Lipid Carriers: A Groundbreaking Approach for Transdermal Drug Delivery

Nanostructured lipid carriers (NLCs) are novel pharmaceutical formulations which are composed of physiological and biocompatible lipids, surfactants and co-surfactants. Over time, as a second generation lipid nanocarrier NLC has emerged as an alternative to first generation nanoparticles. This review article highlights the structure, composition, various formulation methodologies, and characterization of NLCs which are prerequisites in formulating a stable drug delivery system. NLCs hold an eminent potential in pharmaceuticals and cosmetics market because of extensive beneficial effects like skin hydration, occlusion, enhanced bioavailability, and skin targeting. This article aims to evoke an interest in the current state of art NLC by discussing their promising assistance in topical drug delivery system. The key attributes of NLC that make them a promising drug delivery system are ease of preparation, biocompatibility, the feasibility of scale up, non-toxicity, improved drug loading, and stability.

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

Background:

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

Methods:

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

Results:

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

Conclusion:

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

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.

Improved Stability of Polyglycerol Polyricinoleate-Substituted Nanostructured Lipid Carrier Cholecalciferol Emulsions with Different Carrier Oils

Cholecalciferol, also known as vitamin D₃ , is a recognized therapeutic agent for treatment of bone diseases and cancer. However, instability and poor bioavailability have been major challenges for delivering Vitamin D₃ . The objective of this study was to formulate improved nanostructured lipid carrier (NLC) vitamin D₃ emulsions. We tested the effect of different carrier oils and the use of a solid lipid nanoparticle emulsifier, polyglycerol polyricinoleate (PGPR) on the stability of the vitamin D₃ emulsions. In contrast to the control that used glyceryl monostearate (GMS) the PGPR substitution resulted in relatively small particle sizes (0.30 to 0.43 μm), with high absolute value of zeta potentials (39.5 to 67.8 mV) and high encapsulation efficiency (85.2% to 90.4%). The stability of the NLC emulsions against environmental stresses was evaluated under varying conditions of ionic strength, pH, freeze-thaw cycles, and storage at different temperatures. Although NLC emulsions were stable at high ionic strengths, they were found to be unstable at low pH (<3), which led to aggregation and coalescence of emulsion droplets. In case of freeze-thaw stress, although relatively stable compared to control NLC, the PGPR substituted groups exhibited a slight increase in particle size and a decrease in zeta potential when the cycle was repeated five times. Additionally, we found that PGPR-substituted emulsions showed higher liquid dispersion stability than controls at 25 and 65 °C. Thus, we have formulated a modified NLC vitamin D₃ emulsion that can be widely used in the food industry. PRACTICAL APPLICATION: Vitamin D₃ , an essential micronutrient, is often added as supplements in food products and beverages for added health benefits. However, the stability of vitamin D₃ emulsions that are used in the preparation of such products has been a major concern. We have developed a modified emulsion that has improved stability against environmental stresses. We believe, in future, this formulation can be efficiently used in the food industry.

Characterization and toxicity of citral incorporated with nanostructured lipid carrier

The nanoparticle as a cancer drug delivery vehicle is rapidly under investigation due to its promising applicability as a novel drug delivery system for anticancer agents. This study describes the development, characterization and toxicity studies of a nanostructured lipid carrier (NLC) system for citral. Citral was loaded into the NLC using high pressure homogenization methods. The characterizations of NLC-citral were then determined through various methods. Based on Transmission Electron Microscope (TEM) analysis, NLC-Citral showed a spherical shape with an average diameter size of 54.12 ± 0.30 nm and a polydipersity index of 0.224 ± 0.005. The zeta potential of NLC-Citral was −12.73 ± 0.34 mV with an entrapment efficiency of 98.9 ± 0.124%, and drug loading of 9.84 ± 0.041%. Safety profile of the formulation was examined via in vitro and in vivo routes to study its effects toward normal cells. NLC-Citral exhibited no toxic effects towards the proliferation of mice splenocytes. Moreover, no mortality and toxic signs were observed in the treated groups after 28 days of treatment. There were also no significant alterations in serum biochemical analysis for all treatments. Increase in immunomodulatory effects of treated NLC-Citral and Citral groups was verified from the increase in CD4/CD3 and CD8/CD3 T cell population in both NLC-citral and citral treated splenocytes. This study suggests that NLC is a promising drug delivery system for citral as it has the potential in sustaining drug release without inducing any toxicity.

Ethosomes for skin delivery of ropivacaine: preparation, characterization and ex vivo penetration properties

Ropivacaine, a novel long-acting local anesthetic, has been proved to own superior advantage. However, Naropin® Injection, the applied form in clinic, can cause patient non-convenience. The purpose of this study was to formulate ropivacaine (RPV) in ethosomes and evaluate the potential of ethosome formulation in delivering RPV transdermally. The RPV-loaded ethosomes were prepared with thin-film dispersion technique and the formulation was characterized in terms of size, zeta potential, differential scanning calorimetry (DSC) analysis and X-ray diffraction (XRD) study. The results showed that the optimized RPV-ethosomes displayed a typical lipid bilayer structure with a narrow size distribution of 73.86 ± 2.40 nm and drug loading of 8.27 ± 0.37%, EE of 68.92 ± 0.29%. The results of DSC and XRD study indicated that RPV was in amorphous state when encapsulated into ethosomes. Furthermore, the results of ex vivo permeation study proved that RPV-ethosomes could promote the permeability in a high-efficient, rapid way (349.0 ± 11.5 μg cm(-2) at 12 h and 178.8 ± 7.1 μg cm(-2) at 0.5 h). The outcomes of histopathology study forecasted that the interaction between ethosomes and skin could loosen the tight conjugation of corneocyte layers and weaken the permeation barrier. In conclusion, RPV-ethosomes could be a promising delivery system to encapsulate RPV and deliver RPV for transdermal administration.

Research on the in vitro anticancer activity and in vivo tissue distribution of Amoitone B nanocrystals

Amoitone B, a natural agonist to Nur77, is a promising anticancer drug. However, its application is seriously restricted due to the water-insolubility and short biological half-life. Amoitone B nanocrystals (AmB-NC) were formulated by microfluidization method to overcome the above obstacles. This study aims to evaluate the cytotoxicity and tissue distribution of AmB-NC. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay revealed the improved in vitro antitumor activity of AmB-NC against stomach, colon, liver and lung cancer cells compared with Amoitone B solution. Meanwhile, observation of morphological changes, cell cycle and apoptosis examination using flow cytometry exhibited that AmB-NC could induce G1 cycle arrest and markedly enhance the apoptosis of human gastric cancer BGC-823 cell line. Tissue distribution study demonstrated that AmB-NC had a higher distribution in liver and lung, which was helpful for relevant cancer treatment. In conclusion, AmB-NC could be a potential delivery system for treatment of human cancer.