An improved method for the preparations of nanostructured lipid carriers containing heat-sensitive bioactives

Design and development of essential oil based nanoemulsion for topical application of triclosan for effective skin antisepsis

The skin acts as physical barrier to protect the body from external physical and chemical environment. When skin is infected, the outer epidermal barrier is compromised and colonized with microbial growth. Wound infection presents an immense burden in healthcare costs and decreased quality of life for patients. Topical application of nanoemulsions (NE) at pathological sites offers the potential advantage of direct drug delivery to the skin including potential for follicular targeting. This may have application in the improvement of skin antisepsis. In this study, NEs of triclosan (TSN) were prepared using hot high shear homogenization followed by ultrasonication. The oil phases comprised eucalyptus oil (EO) and olive oil (OO) and pseudo-ternary phase diagrams used to select optimum concentrations of surfactant. EO-based NEs had smaller droplet size and higher entrapment efficiency compared to OO-based NEs. Skin permeation was higher for EO-containing formulations, likely due to higher solubility of TSN in EO, smaller droplet size, low viscosity, and permeation enhancement effects of EO. Significantly, TSN was retained within the skin, demonstrating the potential of NEs for targeting hair follicular delivery within the skin, which may help improve the success of topical antisepsis.

Punicalagin and Ketogenic Amino Acids Loaded Organic Lipid Carriers Enhance the Bioavailability, Mitochondrial β-Oxidation, and Ketogenesis in Maturing Adipocytes

The identification of lipolytic bioactive compounds via the functional stimulation of carbohydrate response element-binding protein-1 (CREBp-1) and AMP-activated protein kinase (AMPK) is most warranted. Nano lipid carriers (NLCs) are currently being considered within drug delivery development as they facilitate controlled drug release and have intracellular bioavailability after encapsulating the active principles with lipid matrix. The present study has been designed to synthesize punicalagin, and ketogenic amino acids (KAA) loaded with organic lipid carriers to optimize the liposome-assisted intracellular delivery’s bioavailability. Punicalagin (PUNI) and KAA (tryptophan, methionine, threonine, lysine, and leucine) were encapsulated with chia seed phospholipids by homogenization, emulsification, and cold ultra-sonication method to obtain nano lipid carriers (NLC). The physicochemical characterization of NLCs has been carried out using Zetasizer, FT-IR, and TEM analysis. Punicalagin and ketogenic amino acid-loaded NLCs (NLC-PUNI-KAA) were identified with an average diameter of 240 to 800 nm. The biosafety of NLC-PUNI-KAA has been evaluated in human mesenchymal stem cells. PI staining confirmed that a 0.4, 0.8 or 1.6μg/dL dose of NLC-PUNI-KAA potentially maintains nuclear integration. NLC-PUNI-KAA treated with maturing adipocytes decreased lipid accumulation and significantly increased the gene expression levels of fatty acid beta-oxidation (PPARγC1α, UCP-1 and PRDM-16) pathways when compared to free PUNI (5 μg/dL) treatment. The lipolytic potential has been confirmed by the functional activation of AMPK and CREBp-1 protein levels. In conclusion, NLC-PUNI-KAA treatment effectively increased mitochondrial efficiency more than free punicalagin or orlistat treated maturing adipocyte. Enhanced lipolysis and decreased hypertrophic adipocyte resulted in decreased adipokine secretion, which has been associated with the suppression of obesity-associated comorbidities and vascular cell inflammation. The bioefficacy and lipolytic potential of water-soluble punicalagin have been improved after functional modification into NLCs.

An Overview on Topical Administration of Carotenoids and Coenzyme Q10 Loaded in Lipid Nanoparticles

Carotenoids and coenzyme Q10 are naturally occurring antioxidant compounds that are also found in human skin. These bioactive compounds have been the focus of considerable research due to their antioxidant, anti-inflammatory, and photoprotective properties. In this review, the current state of the art in the encapsulation of carotenoids and coenzyme Q10 in lipid nanoparticles to improve their bioavailability, chemical stability, and skin absorption is discussed. Additionally, the main findings are highlighted on the cytotoxic and photoprotective effects of these systems in the skin.

In vivo β-carotene skin permeation modulated by Nanostructured Lipid Carriers

Nanostructured Lipid Carriers (NLC) were investigated with the purpose of promoting skin permeation of the highly lipophilic β-carotene (BC) across the stratum corneum (SC) barrier so that it may perform its antioxidant properties in photo-aging and epithelial skin cancer prevention. Two differently sized NLC samples were developed using stearic acid and squalene as lipid matrix and evaluated in comparison with Microstructured Lipid Carriers (MLC). The carriers were characterized for morphology, size, Z-potential, BC loading and release as well as physical state by means of DSC and XRPD analyses. In vivo penetration of the carriers was assessed on humans by determining BC concentrations within the SC stratum disjunctum and stratum compactum layers removed by means of the tape stripping test in comparison with pure BC. Unlike MLC and pure BC that were mostly retained within the outermost layers of the SC, the NLC sample having the smallest size (about 200 nm) has proved to penetrate more deeply into the SC barrier. Accordingly, the goal of providing β-carotene actions against oxidative damages within the looser skin viable tissues could be envisaged.

The colorful world of carotenoids: a profound insight on therapeutics and recent trends in nano delivery systems

The therapeutic effects of carotenoids as dietary supplements to control or even treat some specific diseases including diabetic retinopathy, cardiovascular diseases, bacterial infections, as well as breast, prostate, and skin cancer are discussed in this review and also thoughts on future research for their widespread use are emphasized. From the stability standpoint, carotenoids have low bioavailability and bioaccessibility owing to their poor water solubility, deterioration in the presence of environmental stresses such as oxygen, light, and high heat as well as rapid degradation during digestion. Nanoencapsulation technologies as wall or encapsulation materials have been increasingly used for improving food product functionality. Nanoencapsulation is a versatile process employed for the protection, entrapment, and the delivery of food bioactive products including carotenoids from diverse environmental conditions for extended shelf lives and for providing controlled release. Therefore, we present here, recent (mostly during the last five years) nanoencapsulation methods of carotenoids with various nanocarriers. To us, this review can be considered as the first highlighting not only the potential therapeutic effects of carotenoids on various diseases but also their most effective nanodelivery systems.HighlightsBioactive compounds are of deep interest to improve food properties.Carotenoids (such as β-carotene and xanthophylls) play indispensable roles in maintaining human health and well-being.A substantial research effort has been carried out on developing beneficial nanodelivery systems for various carotenoids.Nanoencapsulation of carotenoids can enhance their functional properties.Stable nanoencapsulated carotenoids could be utilized in food products.

Nanostructured Lipid Carrier-Mediated Transdermal Delivery of Aceclofenac Hydrogel Present an Effective Therapeutic Approach for Inflammatory Diseases

Aceclofenac (ACE), a cyclooxygenase-2 inhibitor, is the derivative of the diclofenac group that has been in use for the symptomatic treatment of systemic inflammatory autoimmune disease, rheumatoid arthritis (RA). Partial solubility, high lipophilic nature, and stability challenge its use in developing topical formulations. Hence, we developed and characterized nanostructured lipid carrier (NLC)-based ACE (ACE-NLC) hydrogel for an efficient transdermal delivery. NLC microemulsion was prepared using different lipids by various methods and was characterized with respect to particle size, zeta potential, surface morphology, and drug encapsulation efficiency. The optimized NLC formulation was incorporated into Carbopol^® 940 gel, and this arrangement was characterized and compared with the existing marketed gel (Mkt-gel) formulation to assess in vitro drug release, rheology, texture profile, in vivo skin retention and permeation, and stability. Furthermore, prepared and characterized ACE-loaded NLC formulation was evaluated for skin integrity and fitted in a dermatokinetic model. The results of this study confirmed the spherical shape; smooth morphology and nanometric size attested by Zetasizer and scanning and transmission electron microcopy; and stability of the ACE-NLC formulation. The ACE-NLC-gel formulation showed good rheological and texture characteristics, and better skin distribution in the epidermis and dermis. Moreover, ACE-NLC permeated deeper in the skin layers and kept the skin integrity intact. Overall, NLC-based gel formulation of ACE might be a promising nanoscale lipid carrier for topical application when compared with the conventional Mkt-gel formulation.

Preparation of 9Z-β-Carotene and 9Z-β-Carotene High-Loaded Nanostructured Lipid Carriers: Characterization and Storage Stability

Cis (Z)-β-carotenes with 25.3% 9Z-β-carotene were prepared for nanostructured lipid carriers (NLCs). The optimal conditions for NLC preparation using an orthogonal experimental method were as follows: the total lipid concentration was 9% (w/v), the surfactant concentration was 1.4% (w/v), the solid to liquid lipid ratio was 3:1 (w/w), and the homogenization pressure was set at 500 bar for three cycles. Under these conditions, the encapsulation efficiency (%) of the NLC was 95.64%, and the total β-carotene in NLCs was 2.9 mg/mL, which was significantly higher than those reported by others. The proportion of total Z-β-carotenes was as high as 53.3%, the particle size was 191 ± 6.46 nm, and the polydispersity index was 0.2 ± 0.03. Storage stability results indicated that the β-carotene-loaded NLC stabilizes both 9Z-β-carotene and total β-carotene from leakage and degradation during 21 days of storage at pH 3.5-7.5 at low temperatures (4 °C), especially for the more bioactive 9Z-β-carotene. The technique with an improved ratio of 9Z-β-carotene, loading capacity, water solubility, and bioaccessibility of the β-carotene NLC provides an effective strategy for β-carotene applications in functional foods or beverages and in nutraceutical preparations.

Production and characterization of nanostructured lipid carriers and solid lipid nanoparticles containing lycopene for food fortification

In this study, lycopene, was loaded on nanostructured lipid carrier and solid lipid nanoparticles using combination of high shear homogenization and ultrasonication method. Effect of applied lipids types, nanocarrier's type and lycopene loading on physicochemical properties of developed nanocarriers were studied. Particle sizes of developed nanocarriers were between 74.93 and 183.40 nm. Encapsulation efficiency of nanostructured lipid carrier was significantly higher than solid lipid nanoparticles. Morphological study of developed nanocarriers using scanning electron microscopy showed spherical nanoparticles with smooth surface. Lycopene was entrapped in nanocarriers without any chemical interaction with coating material according to Fourier transform infrared spectroscopy spectrum and differential scanning calorimetry thermogram. Glycerol monostearate containing nanoparticles showed phase separation after 30 days in 6 and 25 °C, whereas this event was not observed in nanosuspensions that produced by glycerol distearate. Lycopene release in gastrointestinal condition was studied by the dialysis bag method. To evaluate nanocarrier's potential for food fortification, developed lycopene-loaded nanocarriers were added to orange drink. Results of sensory analysis indicated that nanoencapsulation could obviate the poor solubility and tomato after taste of lycopene. Fortified sample with lycopene nanocarriers didn't show significant difference with blank orange drink sample except in orange odor.

Nanostructured lipid carriers employing polyphenols as promising anticancer agents: Quality by design (QbD) approach

Cancer is one of the leading causes of death worldwide. There are several hurdles in cancer therapy because of side-effects which limits its usage. Nanoparticulate drug delivery systems have been tested against cancer in a range of scientific studies. In the recent years, advanced research on Nanostructured Lipid Carriers (NLCs) has garnered considerable attention owing to the advantages over their first-generation counterparts, Solid Lipid Nanoparticles (SLN). NLCs facilitate efficient loading of poorly water soluble drugs with simple methods of drug loading. Recently, there is an increased interest in polyphenols because of the evidence of their promising role in prevention of cancer. Polyphenols are produced as secondary metabolites by plants. Their role in prevention of development of tumors through variety of mechanisms and reduction of tumor cell mass has been reported. This article aims to review the science behind development of NLCs and role of polyphenols as promising anticancer agents. Principles of Quality by Design (QbD) have also been explained which are used in formulation-development of many nanoparticles, including NLCs, as reported in literature.

A Review of the Structure, Preparation, and Application of NLCs, PNPs, and PLNs

Nanostructured lipid carriers (NLCs) are modified solid lipid nanoparticles (SLNs) that retain the characteristics of the SLN, improve drug stability and loading capacity, and prevent drug leakage. Polymer nanoparticles (PNPs) are an important component of drug delivery. These nanoparticles can effectively direct drug delivery to specific targets and improve drug stability and controlled drug release. Lipid–polymer nanoparticles (PLNs), a new type of carrier that combines liposomes and polymers, have been employed in recent years. These nanoparticles possess the complementary advantages of PNPs and liposomes. A PLN is composed of a core–shell structure; the polymer core provides a stable structure, and the phospholipid shell offers good biocompatibility. As such, the two components increase the drug encapsulation efficiency rate, facilitate surface modification, and prevent leakage of water-soluble drugs. Hence, we have reviewed the current state of development for the NLCs’, PNPs’, and PLNs’ structures, preparation, and applications over the past five years, to provide the basis for further study on a controlled release drug delivery system.

Vitamin D3-Loaded Nanostructured Lipid Carriers as a Potential Approach for Fortifying Food Beverages; in Vitro and in Vivo Evaluation

Purpose: Nanostructured lipid carriers (NLCs) composed of solid lipid and oil are a new generation of lipid nanoparticles which have exhibited some merits over traditional used lipid nanoparticles in fortifying food and beverages and nutraceuticals delivery systems such as liposomes and solid lipid nanoparticles.

Methods: In this study, Precirol and Compritol as solid lipids, Miglyol and Octyloctanoat as liquid lipids, Tween80, Tween20 and Poloxamer407 as surfactants were used to prepare vitamin D₃-loaded NLC dispersion using hot homogenization method. The particle size and size distribution for all formulations were evaluated by immediately after production and during a storage period of 60 days.

Results: The Precirol-based NLC showed superiority over Compritol-based NLC in the point of physical stability. Results clearly suggested that an optimum concentration of 3% of Poloxamer407 or 2% of Tween20 was sufficient to cover the surface of nanoparticles effectively and prevent agglomeration during the homogenization process. Octyloctanoat was introduced for the first time as a good substituent for Miglyol in the preparation of NLC formulations. The vitamin D₃ Intestinal absorption enhanced by the incorporating in NLCs.

Conclusion: It was concluded that NLC showed a promising approach for fortifying beverages by lipophilic nutraceuticals such as vitamin D.

Modulating effect of lipid bilayer-carotenoid interactions on the property of liposome encapsulation

Liposomes have become an attractive alternative to encapsulate carotenoids to improve their solubility, stability and bioavailability. The interaction mechanism of carotenoid with lipid bilayer is one of the major concerns in improving the delivery efficiency of liposomes. In this study, the microstructure and carotenoid encapsulation efficiency of liposomes composed of native phospholipid (egg yolk phosphatidylcholine, EYPC) and nonionic surfactant Tween 80 were investigated by atomic force microscopy, dynamic light scattering, and Raman spectroscopy, respectively. Subsequently, the effects of carotenoid incorporation on the physical properties of liposomal membrane were performed by Raman spectroscopy, fluorescence polarization, and electron paramagnetic resonance. Results showed that the incorporation of carotenoids affected the liposomes morphology, size and size distribution to various extents. Analysis on the Raman characteristic peaks of carotenoids revealed that lutein exhibited the strongest incorporating ability into liposomes, followed by β-carotene, lycopene, and canthaxanthin. Furthermore, it was demonstrated that carotenoids modulated the dynamics, structure and hydrophobicity of liposomal membrane, highly depending on their molecular structures and incorporated concentration. These modulations were closely correlated with the stabilization of liposomes, including mediating particle aggregation and fusion. These findings should guide the rationale designing for liposomal encapsulation technology to efficiently deliver carotenoids in pharmaceutics, nutraceuticals and functional foods.

Effect of compositions in nanostructured lipid carriers (NLC) on skin hydration and occlusion

Purpose

To study the effects of varying lipid concentrations, lipid and oil ratio, and the addition of propylene glycol and lecithin on the long-term physical stability of nanostructured lipid nanocarriers (NLC), skin hydration, and transepidermal water loss.

Methods

The various NLC formulations (A1–A5) were prepared and their particle size, zeta potential, viscosity, and stability were analyzed. The formulations were applied on the forearms of the 20 female volunteers (one forearm of each volunteer was left untreated as a control). The subjects stayed for 30 minutes in a conditioned room with their forearms uncovered to let the skin adapt to the temperature (22°C ± 2°C) and humidity (50% ± 2%) of the room. Skin hydration and skin occlusion were recorded at day one (before treatment) and day seven (after treatment). Three measurements for skin hydration and skin occlusion were performed in each testing area.

Results

NLC formulations with the highest lipid concentration, highest solid lipid concentration, and additional propylene glycol (formulations A1, A2, and A5) showed higher physical stability than other formulations. The addition of propylene glycol into an NLC system helped to reduce the particle size of the NLC and enhanced its long-term physical stability. All the NLC formulations were found to significantly increase skin hydration compared to the untreated controls within 7 days. All NLC formulations exhibited occlusive properties as they reduced the transepidermal water loss within 7 days. This effect was more pronounced with the addition of propylene glycol or lecithin into an NLC formulation, whereby at least 60% reduction in transepidermal water loss was observed.

Conclusion

NLCs with high lipid content, solid lipid content, phospholipid, and lecithin are a highly effective cosmetic delivery system for cosmetic topical applications that are designed to boost skin hydration.

Nanostructured lipid carriers system: recent advances in drug delivery

Nanostructured lipid carrier (NLC) is second generation smarter drug carrier system having solid matrix at room temperature. This carrier system is made up of physiological, biodegradable and biocompatible lipid materials and surfactants and is accepted by regulatory authorities for application in different drug delivery systems. The availability of many products in the market in short span of time reveals the success story of this delivery system. Since the introduction of the first product, around 30 NLC preparations are commercially available. NLC exhibit superior advantages over other colloidal carriers viz., nanoemulsions, polymeric nanoparticles, liposomes, SLN etc. and thus, have been explored to more extent in pharmaceutical technology. The whole set of unique advantages such as enhanced drug loading capacity, prevention of drug expulsion, leads to more flexibility for modulation of drug release and makes NLC versatile delivery system for various routes of administration. The present review gives insights on the definitions and characterization of NLC as colloidal carriers including the production techniques and suitable formulations. This review paper also highlights the importance of NLC in pharmaceutical applications for the various routes of drug delivery viz., topical, oral, pulmonary, ocular and parenteral administration and its future perspective as a pharmaceutical carrier.

Plausible antioxidant biomechanics and anticonvulsant pharmacological activity of brain-targeted β-carotene nanoparticles

β-Carotene has been established as a known free radical scavenger with chain-breaking antioxidant properties. It has been documented for the treatment of epileptic convulsions at a 200 mg/kg body weight dose. The reported pathogenesis for epileptic convulsions is oxidative stress. Hence, experimental epileptic convulsions via oxidative stress was induced in albino mice epileptic models (maximal electroshock seizure and pentylenetetrazole [PTZ]). A dose concentration equivalent to 2 mg/kg was efficaciously administered in the form of brain-targeted polysorbate-80-coated poly(d,l-lactide-co-glycolide) nanoparticles. The nanoparticles were prepared by solvent evaporation technique and further characterized for their physical parameters, in-vitro release kinetics, and in-vivo brain release via various standard methods. Normal β-carotene nanoparticles (BCNP) and polysorbate-80-coated β-carotene nanoparticles (P-80-BCNP) of 169.8 ± 4.8 nm and 176.3 ± 3.2 nm in size, respectively, were formulated and characterized. Their zeta potential and polydispersity index were subsequently evaluated after 5 months of storage to confirm stability. In vivo activity results showed that a 2 mg unformulated β-carotene dose was ineffective as an anticonvulsant. However, salutary response was reported from BCNP at the same dose, as the hind limb duration decreased significantly in maximal electroshock seizure to 9.30 ± 0.86 seconds, which further decreased with polysorbate-80 coating to 2.10 ± 1.16 seconds as compared to normal control (15.8 ± 1.49 seconds) and placebo control (16.50 ± 1.43 seconds). In the PTZ model, the duration of general tonic-clonic seizures reduced significantly to 2.90 ± 0.98 seconds by the use of BCNP and was further reduced on P-80-BCNP to 1.20 ± 0.20 seconds as compared to PTZ control and PTZ-placebo control (8.09 ± 0.26 seconds). General tonic-clonic seizures latency was increased significantly to 191.0 ± 9.80 seconds in BCNP and was further increased in P-80-BCNP to 231.0 ± 16.30 seconds, as compared to PTZ (120.10 ± 4.50 seconds) and placebo control (120.30 ± 7.4 seconds). The results of this study demonstrate a plausible novel anticonvulsant activity of β-carotene at a low dose of 2 mg/kg, with brain-targeted nanodelivery, thus increasing its bioavailability and stability.