Loading, release profile and accelerated stability assessment of monoterpenes-loaded solid lipid nanoparticles (SLN)

Solid lipid nanoparticles and their application in the treatment of bacterial infectious diseases

Nano pharmacology is considered an effective, safe, and applicable approach for drug delivery applications. Solid lipid nanoparticle (SLNs) colloids contain biocompatible lipids which are capable of encapsulating and maintaining hydrophilic or hydrophobic drugs in the solid matrix followed by releasing the drug in a sustained manner in the target site. SLNs have more promising potential than other drug delivery systems for various purposes. Nowadays, the SLNs are used as a carrier for antibiotics, chemotherapeutic drugs, nucleic acids, herbal compounds, etc. The SLNs have been widely applied in biomedicine because of their non-toxicity, biocompatibility, and simple production procedures. In this review, the complications related to the optimization, preparation process, routes of transplantation, uptake and delivery system, and release of the loaded drug along with the advantages of SLNs as therapeutic agents were discussed.

Development and characterization of potential larvicidal nanoemulsions against Aedes aegypti

Plant-based insecticides offer advantages such as negligible residual effects, reduced risks to both humans and the environment, and immunity to resistance issues that plague conventional chemicals. However, the practical use of monoterpenes in insect control has been hampered by challenges including their poor solubility and stability in aqueous environments. In recent years, the application of nanotechnology-based formulations, specifically nanoemulsions, has emerged as a prospective strategy to surmount these obstacles. In this study, we developed and characterized nanoemulsions based on cymene and myrcene and assessed their toxicity both in vitro using human keratinocytes (HaCAT) cells and in an in vivo model involving Galleria mellonella larvae. Additionally, we investigated the insecticidal efficacy of monoterpenes against the mosquito Aedes aegypti, the primary dengue vector, via larval bioassay. Employing a low-energy approach, we successfully generated nanoemulsions. The cymene-based nanoemulsion exhibited a hydrodynamic diameter of approximately 98 nm and a zeta potential of -25 mV. The myrcene-based nanoemulsion displayed a hydrodynamic diameter of 118 nm and a zeta potential of -20 mV. Notably, both nanoemulsions demonstrated stability over 60 days, accompanied by controlled release properties and low toxicity towards HaCAT cells and Galleria mellonella larvae. Moreover, the nanoemulsions exhibited significant lethality against third-instar Aedes aegypti larvae at a concentration of 50 mg/L. In conclusion, the utilization of nanoemulsions encapsulating cymene and myrcene presents a promising avenue for overcoming the limitations associated with poor solubility and stability of monoterpenes. This study sheds light on the potential of the nanoemulsions as effective and environmentally friendly insecticides in the ongoing battle against mosquito-borne diseases.

Docetaxel-Loaded Methoxy poly(ethylene glycol)-poly (L-lactic Acid) Nanoparticles for Breast Cancer: Synthesis, Characterization, Method Validation, and Cytotoxicity

This study aimed to synthesize and characterize DTX-mPEG-PLA-NPs along with the development and validation of a simple, accurate, and reproducible method for the determination and quantification of DTX in mPEG-PLA-NPs. The prepared NPs were characterized using AFM, DLS, zetasizer, and drug release kinetic profiling. The RP-HPLC assay was developed for DTX detection. The cytotoxicity and anti-clonogenic effects were estimated using MTT and clonogenic assays, respectively, using both MCF-7 and MDA-MB-231 cell lines in a 2D and 3D culture system. The developed method showed a linear response, high precision, accuracy, RSD values of ≤2%, and a tailing factor ≤2, per ICH guidelines. The DTX-mPEG-PLA-NPs exhibited an average particle size of 264.3 nm with an encapsulation efficiency of 62.22%. The in vitro drug kinetic profile, as per the Krosmeyers-Peppas model, demonstrated Fickian diffusion, with initial biphasic release and a multistep sustained release over 190 h. The MTT assay revealed improved in vitro cytotoxicity against MCF-7 and MDA-MB-231 in the 2D cultures and MCF-7 3D mammosphere cultures. Significant inhibitions of the clonogenic potential of MDA-MB-231 were observed for all concentrations of DTX-mPEG-PLA-NPs. Our results highlight the feasibility of detecting DTX via the robust RP-HPLC method and using DTX-mPEG-PLA-NPs as a perceptible and biocompatible delivery vehicle with greater cytotoxic and anti-clonogenic potential, supporting improved outcomes in BC.

Stabilization of High Internal Phase Oil-in-Water Emulsions Using "Whole" Gracilaria lemaneiformis Slurry

In this study, a Gracilaria lemaneiformis slurry (GLS) was prepared using low-energy mechanical shearing. The resulting GLS, which was rich in polysaccharides, was utilized as an effective stabilizer for oil-in-water emulsions. The microstructures and stability of the resulting emulsions were controlled by adjusting the emulsion formulations, including Gracilaria lemaneiformis (GL) mass concentration and oil volume fraction (φ). The optimized GL mass concentration and φ conditions yielded high internal phase emulsions (HIPEs) with gel-like textures. Moreover, the presence of exogenous Ca2+ resulted in bridging structures in the emulsions, enhancing their viscoelasticity and forming a robust physical barrier against droplet coalescence. Our findings highlight the effectiveness of the GLS as an emulsifier for stabilizing HIPEs. Notably, this method relies solely on physical processes, aligning with the desirability of avoiding chemical additives, particularly in the food industry.

Enhancing Oral Bioavailability and Brain Biodistribution of Perillyl Alcohol Using Nanostructured Lipid Carriers

Perillyl alcohol (POH), a bioactive monoterpenoid derived from limonene, shows promise as an antitumor agent for brain tumor treatment. However, its limited oral bioavailability and inadequate brain distribution hinder its efficacy. To address these challenges, this study developed nanostructured lipid carriers (NLCs) loaded with POH to improve its brain biodistribution. The NLCs prepared using hot homogenization exhibited an average diameter of 287 nm and a spherical morphology with a polydispersity index of 0.143. High encapsulation efficiency of 99.68% was achieved. X-ray diffraction analyses confirmed the semicrystalline state of POH-loaded NLCs. In vitro release studies demonstrated a biphasic release profile. Stability studies in simulated gastric and intestinal fluids confirmed their ability to withstand pH variations and digestive enzymes. In vivo pharmacokinetic studies in rats revealed significantly enhanced oral bioavailability of POH when encapsulated in the NLCs. Biodistribution studies showed increased POH concentration in brain tissue with NLCs compared with free POH, which was distributed more in non-target tissues such as the liver, lungs, kidneys, and spleen. These findings underscore the potential of NLCs as effective delivery systems for enhancing oral bioavailability and brain biodistribution of POH, providing a potential therapeutic strategy for brain tumor treatment.

Box-Behnken Design of Experiments of Polycaprolactone Nanoparticles Loaded with Irinotecan Hydrochloride

BACKGROUND

The Box-Behnken design of experiments (BBD) is a statistical modelling technique that allows the determination of the significant factors in developing nanoparticles (NPs) using a limited number of runs. It also allows the prediction of the best levels of variables to obtain the desired characteristics (size, charge, and encapsulation efficiency) of the NPs. The aim of this study was to examine the effect of the independent variables (amount of polymer and drug, and surfactant concentration) and their interaction on the characteristics of the irinotecan hydrochloride (IRH)-loaded polycaprolactone (PCL) NPs and to determine the most optimum conditions for producing the desired NPs.

METHODS

The development of the NPs was carried out by a double emulsion solvent evaporation technique with yield enhancement. The NPs data were fitted in Minitab software to obtain the best fit model.

RESULTS

By using BBD, the most optimum conditions for producing the smallest size, highest magnitude of charge, and highest EE% of PCL NPs were predicted to be achieved by using 61.02 mg PCL, 9 mg IRH, and 4.82% PVA, which would yield 203.01 nm, -15.81 mV, and 82.35% EE.

CONCLUSION

The analysis by BBD highlighted that the model was a good fit to the data, confirming the suitability of the design of the experiments.

Design, Synthesis, Characterization, and Evaluation of the Anti-HT-29 Colorectal Cell Line Activity of Novel 8-Oxyquinolinate-Platinum(II)-Loaded Nanostructured Lipid Carriers Targeted with Riboflavin

Colorectal cancer is occasionally called colon or rectal cancer, depending on where cancer begins to form, and is the second leading cause of cancer death among both men and women. The platinum-based [PtCl(8-O-quinolinate)(dmso)] (8-QO-Pt) compound has demonstrated encouraging anticancer activity. Three different systems of 8-QO-Pt-encapsulated nanostructured lipid carriers (NLCs) with riboflavin (RFV) were investigated. NLCs of myristyl myristate were synthesized by ultrasonication in the presence of RFV. RFV-decorated nanoparticles displayed a spherical shape and a narrow size dispersion in the range of 144-175 nm mean particle diameter. The 8-QO-Pt-loaded formulations of NLC/RFV with more than 70% encapsulation efficiency showed sustained in vitro release for 24 h. Cytotoxicity, cell uptake, and apoptosis were evaluated in the HT-29 human colorectal adenocarcinoma cell line. The results revealed that 8-QO-Pt-loaded formulations of NLC/RFV showed higher cytotoxicity than the free 8-QO-Pt compound at 5.0 µM. All three systems exhibited different levels of cellular internalization. Moreover, the hemotoxicity assay showed the safety profile of the formulations (less than 3.7%). Taken together, RFV-targeted NLC systems for drug delivery have been investigated for the first time in our study and the results are promising for the future of chemotherapy in colon cancer treatment.

Intramuscular compatibility of an injectable anti-inflammatory nanodispersion from a standardized Bixa orellana oil (Chronic®): a toxicological study in Wistar rats

Bixa orellana L. is a plant popularly known as "ucurum", "annatto", and "achiote". It is native to South America, and its seeds are an abundant source of geranylgeraniol and tocotrienols. Nanoencapsulation is a valuable technique that can decrease the drug needed to achieve an effect, decreasing potential toxicity, side effects and potentiate the anti-inflammatory effect. This study aimed to evaluate the acute toxicity of an intramuscular application of a nanodispersion containing a standardized extract from the seeds of Bixa orellana (NBO) in Wistar rats. The chemical evaluation showed δ-tocotrienol at 0.725 ± 0.062 mg/mL (72.6 ± 0.9%). The stability study showed the nanoparticles had an average size from 53.15 ± 0.64 to 59.9 ± 3.63 nm, with a polydispersity index ranging from 0.574 ± 0.032 to 0.574 ± 0.32, Zeta potential from 18.26 ± 0.59 to 19.66 ± 1.45 mV. After testing the intramuscular application of NBO with doses from 1 to 5 mg/kg in animals, it was observed that the acute treatment did not elicit any toxic effects within this range. The dose of 10 mg/kg, although not affecting hematological and biochemical parameters (CPK, LDH, myoglobin, AST, ALT, TC, TG, glucose levels, creatinine, and urea), could induce some muscle tissue changes, including leukocyte infiltration, morphological chances, and potentially necrosis. In conclusion, the results showed that the treatments devoided toxicity between 1 and 5 mg/kg.

Development of Lipid Nanoparticles Containing Omega-3-Rich Extract of Microalga Nannochlorpsis gaditana

Microalgae are described as a new source of a wide range of bioactive compounds with health-promoting properties, such as omega-3 lipids. This biomass product is gaining attention mainly due to its potential to accumulate different compounds depending on the species and environment, and it has been commonly recognized as a valuable nutraceutical alternative to fish and krill oils. In this work, we obtained the extract of the microalga Nannochloropsis gaditana, selected on the basis of its content of eicosapentaenoic acid (EPA) and glycolipids, which were determined using GC-MS and high-performance liquid chromatography (HPLC), respectively. To develop an oral formulation for the delivery of the extract, we used a 2³ factorial design approach to obtain an optimal lipid nanoparticle formulation. The surfactant and solid lipid content were set as the independent variables, while the particle size, polydispersity index, and zeta potential were taken as the dependent variables of the design. To ensure the potential use of the optimum LN formulation to protect and modify the release of the loaded microalga extract, rheological and differential scanning calorimetry analyses were carried out. The developed formulations were found to be stable over 30 days, with an encapsulation efficiency over 60%.

Cold-Pressed Pomegranate Seed Oil: Study of Punicic Acid Properties by Coupling of GC/FID and FTIR

Over the last decades, we have witnessed an increasing interest in food-related products containing vegetable oils. These oils can be obtained either by extraction or by mechanical pressing of different parts of plants (e.g., seeds, fruit, and drupels). Producers of nutraceuticals have ceaselessly searched for unique and effective natural ingredients. The enormous success of argan oil has been followed by discoveries of other interesting vegetable oils (e.g., pomegranate oil) containing several bioactives. This work describes the pomegranate fruit extract and seed oil as a rich source of conjugated linolenic acid as a metabolite of punicic acid (PA), deriving from the omega-5 family (ω-5). Through the chemical characterization of PA, its nutritional and therapeutic properties are highlighted together with the physiological properties that encourage its use in human nutrition. We analyzed the composition of all fatty acids with beneficial properties occurring in pomegranate seed oil using gas chromatography (GC) with flame-ionization detection (FID) analysis combined with Fourier transform infrared spectroscopy (FTIR). Pomegranate seed oil mainly consists of 9,11,13-octadic-trienoic acid (18:3), corresponding to 73 wt % of the total fatty acids. Nine components were identified by GC in PSO, varying between 0.58 and 73.19 wt %. Using midinfrared (MIR) spectroscopy, we compared the composition of pomegranate seed oil with that of meadowfoam seed oil (MSO), which is also becoming increasingly popular in the food industry due to its high content of long chain fatty acids (C20-22), providing increased oil stability. From the results of FTIR and MIR spectroscopy, we found that punicic acid is unique in PSO (73.19 wt %) but not in MSO.

Non-melanoma skin cancers: physio-pathology and role of lipid delivery systems in new chemotherapeutic treatments

Non-melanoma carcinoma has high incidence rates and has two most common subtypes: basal cell carcinoma and squamous cell carcinoma. This type of carcinoma is usually not fatal; however, it can destroy sensory organs such as the nose, ears, and lips. The treatment of these injuries using non-invasive methods is thus strongly recommended. Some treatments for non-melanoma carcinoma are already well defined, such as surgery, cryosurgery, curettage and electrode section, and radiotherapy; however, these conventional treatments cause inflammation and scarring. In the non-surgical treatment of non-melanoma carcinoma, the topical administration of chemotherapeutic drugs contributes for an effective treatment with reduced side effects. However, the penetration of anticancer drugs in the deeper layers of the skin is required. Lipid delivery systems (liposomes, solid lipid nanoparticles, nanostructured lipid carriers) have been developed to overcome epidermal barrier of the skin and to allow the drugs to reach tumor cells. These lipid nanoparticles contribute to control the release profile of the loaded chemotherapeutic drugs, maintaining their stability and increasing death of tumor cells. In this review, the characteristics of non-melanoma carcinoma will be discussed, describing the main existing treatments, together with the contribution of lipid delivery systems as an innovative approach to increase the effectiveness of topical therapies for non-melanoma carcinomas.

The effects of combination therapy by solid lipid nanoparticle and dental stem cells on different degenerative diseases

Stem cells have multiple therapeutic applications, as well as solid lipid nanoparticles. Solid lipid nanoparticle has appeared as a field of nano lipid technology with various potential applications in drug delivery, clinical medicine and research. Besides, the stem cells have a high proliferation rate and could differentiate into a variety of tissues. Stem cells derived from human dental pulp tissue differ from other sources of mesenchymal stem cells due to their embryonic neural crest source and neurotrophic potential. These consist of both dental pulp stem cells from dental pulp tissues of human permanent teeth and stem cells from human exfoliated deciduous teeth. With the emergence of stem cell banks, stem cells are considering for tissue engineering with respect to therapies attitude and regenerative medicine. The present study aimed to evaluate the advantages and disadvantages of the solid lipid nanoparticle and stem cells combination therapy in different therapeutic applications. The solid lipid nanoparticles have anticancer activity against tumors, induce neural differentiation in pluripotent stem cells, and regulate the mesenchymal stem cells. They also have immunomodulatory effects on human mesenchymal stem cells, the gene transfection efficiency, osteogenic differentiation and bone regeneration. But, the crucial health hazards related to stem cell transplantation such as immune rejection reactions and the interaction with other tissues and the effect of solid lipid nanoparticles must not be neglected. Overall, more experiments need to approve the synergism and antagonism effects of the stem cells and solid lipid nanoparticle combination therapy on different degenerative diseases.

ZIF-8 nanoparticles coated with macrophage-derived microvesicles for sustained, targeted delivery of dexamethasone to arthritic joints

Dexamethasone sodium phosphate (Dex) is widely used in the clinic for the treatment of rheumatoid arthritis. However, it circulates in blood for a short time and it is linked to high risk of severe side effects caused by repeated dosing. Here, we encapsulated Dex onto zeolitic imidazolate framework-8 (ZIF-8) to prepare metal-organic framework nanoparticles with high drug loading efficiency. To prevent clearance by the mononuclear phagocyte system and extend time in circulation, the nanoparticles were also camouflaged with macrophage-derived microvesicles (MV) to obtain the biomimetic drug delivery system MV/Dex/ZIF-8. In vitro and in vivo experiments showed that the nanosystem had high drug loading and encapsulation efficiency, high stability, and long circulation time, and it permitted sustained drug release longer in inflamed joint tissues. Our study provides new insights into designing camouflaged drug carriers to prevent their phagocytosis and prolong their time in circulation.

Co-Delivery of Doxycycline and Hydroxychloroquine Using CdTe-Labeled Solid Lipid Nanoparticles for Treatment of Acute and Chronic Brucellosis

Brucellosis is a systemic disease in both acute and chronic forms which can affect any organ or tissue in the body. One of the biggest issues in treating this disease is its relapse. In this study, a complete treatment of brucellosis was evaluated using enhanced performance of doxycycline and hydroxychloroquine drugs by using solid lipid nanoparticles (SLN) conjugated cadmium-telluride quantum dots. The double emulsion method was used to prepare SLN and cadmium-telluride quantum dots. The physicochemical properties of NPs were determined. The effect of nanoparticle-loaded antibiotics against Brucella melitensis was determined by well diffusion, minimum inhibitory concentration (MIC), cell culture, and animal studies. The means of particle size, PDI, zeta potential, drugs loading, and encapsulation efficiency were 214 ± 25 nm, 0.385 ± 0.022, −18.7 ± 2.3 mV, 17.7 ± 1.5%, and 94.15 ± 2.6%, respectively. The results of FTIR and DSC showed that no chemical reaction occurred between the components of the NPs. The effect of free drug and NPs on bacteria was the same by well diffusion and MIC method. Drug-loaded NPs significantly reduced the number of CFUs in the cell line and acute and chronic brucellosis compared to the free drug. In conclusion, the synthesized nanoparticles were safe and green. With the slow release of the drug (100 h), the accumulation of the drug at the bacterial site increases and causes a greater effect on the B. melitensis and improves the disease of brucellosis. The use of synthesized nanodrugs in this study had promising therapeutic results.

A comparative study on physicochemical and micellar solubilization performance between monoglucosyl rebaudioside A and rebaudioside A

BACKGROUND

Rebaudioside A (RA) and its monoglucosyl derivative, as like rebaudioside D (RD) are the most popular stevia glycosides but possess poor solubility in water, which limited their application as edible surfactants, the applications as in micellar solubilization and drug delivery. Meanwhile, effect of the monoglucosyl attached to RA moiety remains unclear.

RESULTS

Monoglucosyl rebaudioside A (RAG1) was synthesized via hydrolyzing the transglycosylation product of RA with 95% of RA converted. RAG1 content in raw reaction mixture was as high as 69.5% of total glycosides, and harvested with a content of 88.2% by simple filtration. The RAG1 exhibited an aqueous solubility of 87 folds of RA or 391 folds of RD at 25 °C. The surface activity of RAG1 solution was higher than RA and invincible to RD. The RAG1 micelles promoted aqueous solubility of idebenone (IDE) up to 500 folds higher at 25 °C. The cumulative release rate of IDE encapsulated in RAG1 micelles was 777.5% or 456.7% higher of that of free IDE in simulated gastric/intestinal fluids in 14 h, respectively. The RAG1-IDE remained the same in 98 days at 25 °C.

CONCLUSION

The α-linked glucosyl to RA induced higher hydrophilicity and surface activity than that resulted by β-linked glucosyl, making RAG1 not only dramatically raise the aqueous solubility of RA, but also endow IDE folds higher in bioaccessibility, yet making the capsule stable at storage. The results would provide a new edible delivery nanocarrier for encapsulation of hydrophobic bioactive components. © 2021 Society of Chemical Industry.

Optimization of the Conditions of Solid Lipid Nanoparticles (SLN) Synthesis

Solid lipid nanoparticles (SLNs) have been synthesized as potential drug delivery systems. They are classified as solid lipid nanocarriers that can successfully carry both hydrophilic and hydrophobic drugs. SLNs are based on a biocompatible lipid matrix that is enzymatically degraded into natural components found in the human body. Solid lipid nanoparticles are suitable for the incorporation of hydrophobic active ingredients such as curcumin. The study included the optimization of lipid nanoparticle composition, incorporation of the active compound (curcumin), a stability evaluation of the obtained nanocarriers and characterization of their lipid matrix. Through process optimization, a dispersion of solid lipid nanoparticles (solid lipid:surfactant—2:1.25 weight ratio) predisposed to the incorporation of curcumin was developed. The encapsulation efficiency of the active ingredient was determined to be 99.80%. In stability studies, it was found that the most suitable conditions for conducting high-pressure homogenization are 300 bar pressure, three cycles and a closed-loop system. This yields the required values of the physicochemical parameters (a particle size within a 200−450 nm range; a polydispersity index of <30%; and a zeta potential of about |±30 mV|). In this work, closed-loop high-pressure homogenization was used for the first time and compared to the currently preferred open-loop method.

Physicochemical and biopharmaceutical aspects influencing skin permeation and role of SLN and NLC for skin drug delivery

The skin is a complex and multifunctional organ, in which the static versus dynamic balance is responsible for its constant adaptation to variations in the external environment that is continuously exposed. One of the most important functions of the skin is its ability to act as a protective barrier, against the entry of foreign substances and against the excessive loss of endogenous material. Human skin imposes physical, chemical and biological limitations on all types of permeating agents that can cross the epithelial barrier. For a molecule to be passively permeated through the skin, it must have properties, such as dimensions, molecular weight, pKa and hydrophilic-lipophilic gradient, appropriate to the anatomy and physiology of the skin. These requirements have limited the number of commercially available products for dermal and transdermal administration of drugs. To understand the mechanisms involved in the drug permeation process through the skin, the approach should be multidisciplinary in order to overcome biological and pharmacotechnical barriers. The study of the mechanisms involved in the permeation process, and the ways to control it, can make this route of drug administration cease to be a constant promise and become a reality. In this work, we address the physicochemical and biopharmaceutical aspects encountered in the pathway of drugs through the skin, and the potential added value of using solid lipid nanoparticles (SLN) and nanostructured lipid vectors (NLC) to drug permeation/penetration through this route. The technology and architecture for obtaining lipid nanoparticles are described in detail, namely the composition, production methods and the ability to release pharmacologically active substances, as well as the application of these systems in the vectorization of various pharmacologically active substances for dermal and transdermal applications. The characteristics of these systems in terms of dermal application are addressed, such as biocompatibility, occlusion, hydration, emollience and the penetration of pharmacologically active substances. The advantages of using these systems over conventional formulations are described and explored from a pharmaceutical point of view.

Cyclodextrins-in-Liposomes: A Promising Delivery System for Lippia sidoides and Syzygium aromaticum Essential Oils

Biological activity of essential oils (EOs) has been extensively reported; however, their low aqueous solubility, high photosensitivity, and volatility compromise a broad industrial use of these compounds. To overcome these limitations, we proposed a nanoencapsulation approach to protect EOs, that aims to increase their stability and modulate their release profile. In this study, drug-in-cyclodextrin-in-liposomes encapsulating two essential oils (Lippia sidoides and Syzygium aromaticum) and their respective major compounds (thymol and eugenol) were produced by ethanol injection and freeze-dried to form proliposomes and further physicochemically characterized. Liposomes showed high physical stability over one month of storage at 4 °C, with slight changes in the mean size, polydispersity index (PDI), and zeta potential. Reconstituted proliposomes showed a mean size between 350 and 3300 nm, PDI from 0.29 to 0.41, and zeta potential between -22 and -26 mV. Differential scanning calorimetry and X-ray diffraction of proliposomes revealed a less-ordered crystalline structure, leading to high retention of the major bioactive compounds (between 73% and 93% for eugenol, and 74% and 84% for thymol). This work highlights the advantages of using drug-in-cyclodextrin-in-liposomes as delivery systems to retain volatile compounds, increasing their physicochemical stability and their promising potential to be utilized as carriers in products in the pharmaceutical, food, and cosmetic industries.

Encapsulation of volatile compounds in liquid media: Fragrances, flavors, and essential oils in commercial formulations

The first marketed example of the application of microcapsules dates back to 1957. Since then, microencapsulation techniques and knowledge have progressed in a plethora of technological fields, and efforts have been directed toward the design of progressively more efficient carriers. The protection of payloads from the exposure to unfavorable environments indeed grants enhanced efficacy, safety, and stability of encapsulated species while allowing for a fine tuning of their release profile and longer lasting beneficial effects. Perfumes or, more generally, active-loaded microcapsules are nowadays present in a very large number of consumer products. Commercial products currently make use of rigid, stable polymer-based microcapsules with excellent release properties. However, this type of microcapsules does not meet certain sustainability requirements such as biocompatibility and biodegradability: the leaking via wastewater contributes to the alarming phenomenon of microplastic pollution with about 4% of total microplastic in the environment. Therefore, there is a need to address new issues which have been emerging in relation to the poor environmental profile of such materials. The progresses in some of the main application fields of microencapsulation, such as household care, toiletries, cosmetics, food, and pesticides are reviewed herein. The main technologies employed in microcapsules production and the mechanisms underlying the release of actives are also discussed. Both the advantages and disadvantages of every technique have been considered to allow a careful choice of the most suitable technique for a specific target application and prepare the ground for novel ideas and approaches for encapsulation strategies that we expect to be proposed within the next years.

Lipid Nanocarriers for Hyperproliferative Skin Diseases

Simple Summary

Different drugs, including antiproliferative and corticosteroids in general, are recommended for the treatment of hyperproliferative skin diseases (HSD). The effectiveness of many of these drugs is limited due to their low solubility in water and low penetration in the skin. The loading of these drugs in lipid nanocarriers, such as lipid nanoparticles and liposomes, has been considered as a successful solution to improve the drug bioavailability through the skin, to control their release kinetics and thus reduce the risk of potential side effects. In this work, we discuss the use of lipid nanocarriers loading drugs against HSD.

Abstract

Hyperproliferative skin diseases (HSD) are a group of diseases that include cancers, pre-cancerous lesions and diseases of unknown etiology that present different skin manifestations in terms of the degree and distribution of the injuries. Anti-proliferative agents used to treat these diseases are so diverse, including 5-aminolevulinic acid, 5-fluorouracil, imiquimod, methotrexate, paclitaxel, podophyllotoxin, realgar, and corticosteroids in general. These drugs usually have low aqueous solubility, which consequently decreases skin permeation. Thus, their incorporation in lipid nanocarriers has been proposed with the main objective to increase the effectiveness of topical treatment and reduce side effects. This manuscript aims to describe the advantages of using lipid nanoparticles and liposomes that can be used to load diversity of chemically different drugs for the treatment of HSD.

Major difference in particle size, minor difference in release profile: a case study of solid lipid nanoparticles

Solid lipid nanoparticles (SLN) have been widely used in a variety of drug delivery routes, which have the outstanding advantage of controlled drug release. The release of SLN is dominated by many factors, among which the particle size of SLN is a critical one. The aim of this project was to explore the relationship between drug release profile and particle size of SLN. SLN were synthesized via the hot high-pressure homogenization (HPH) method, budesonide (BUD) was used as the model drug, and BUD-SLN1-BUD-SLN4 with increasing particle size was obtained, i.e. 120, 240, 360, and 480 nm. The prepared SLN has good encapsulation efficiency, drug loading capacity, and stability. In vitro release behavior studies showed that the cumulative release of BUD-SLN in Tris-Maleate (Tris-M) media was negligible, while that in Tris-M plus pancreatin media or Tris-M-ethanol media obeyed Ritger-Peppas model or first-order kinetic model, respectively. Noticeably, the release behavior of SLN was to some extent related to the average particle size of SLN, but the correlation was insignificant when the intersection degree of particle size distribution was great. This study provides a new idea for the understanding of in vitro release of SLN and has a certain referencing value for the research and development of novel nanomedicines.

Polymeric Lipid Hybrid Nanoparticles (PLNs) as Emerging Drug Delivery Platform-A Comprehensive Review of Their Properties, Preparation Methods, and Therapeutic Applications

Polymeric lipid hybrid nanoparticles (PLNs) are core–shell nanoparticles made up of a polymeric kernel and lipid/lipid–PEG shells that have the physical stability and biocompatibility of both polymeric nanoparticles and liposomes. PLNs have emerged as a highly potent and promising nanocarrier for a variety of biomedical uses, including drug delivery and biomedical imaging, owing to recent developments in nanomedicine. In contrast with other forms of drug delivery systems, PLNs have been regarded as seamless and stable because they are simple to prepare and exhibit excellent stability. Natural, semi-synthetic, and synthetic polymers have been used to make these nanocarriers. Due to their small scale, PLNs can be used in a number of applications, including anticancer therapy, gene delivery, vaccine delivery, and bioimaging. These nanoparticles are also self-assembled in a reproducible and predictable manner using a single or two-step nanoprecipitation process, making them significantly scalable. All of these positive attributes therefore make PLNs an attractive nanocarrier to study. This review delves into the fundamentals and applications of PLNs as well as their formulation parameters, several drug delivery strategies, and recent advancements in clinical trials, giving a comprehensive insight into the pharmacokinetic and biopharmaceutical aspects of these hybrid nanoparticles.

Systematically designed chitosan-coated solid lipid nanoparticles of ferulic acid for effective management of Alzheimer's disease: A preclinical evidence

Ferulic acid (FA) is a ubiquitous natural plant bioactive with distinctive promise in neurodegenerative disorders. However, its therapeutic efficacy gets compromised owing to its poor aqueous solubility, inadequate permeability across lipophilic barriers, and extensive first-pass metabolism. The current studies, therefore, were undertaken to systematically develop chitosan-coated solid lipid nanoparticles (SLNs) using QbD paradigms for improved efficacy of FA in the management of Alzheimer's disease (AD). SLNs of FA were formulated employing Compritol as lipid and polysorbate 80 as surfactant and optimised using a 3² Central Composite Design (CCD). The optimized formulation, surface-coated with chitosan using ionic gelation, exhibited particle size of 185 nm, entrapment efficiency of 51.2 % and zeta potential of 12.4 mV. FTIR and DSC studies verified the compatibility of FA with formulation excipients, PXRD construed significant loss of drug crystallinity, while FESEM depicted existence of uniform spherical nanoparticles with little aggregation. Notable improvement in ex vivo mucoadhesion and permeation studies using goat nasal mucosa, coupled with extension in in vitro drug release, was obtained with SLNs. Substantial improvement with SLNs in cognitive ability through the reduction in escape latency time during behavioural studies, together with significant improvement in various biochemical parameters and body weight gain was observed in AD-induced rats. Histopathological images of different rat organs showed no perceptible change(s) in tissue morphology. Overall, these preclinical findings successfully demonstrate improved anti-AD efficacy, superior nasal mucoadhesion and permeation, extended drug release, improved patient compliance potential, safety and robustness of the developed lipidic nanoconstructs of FA through intranasal route.

Cancer Nanopharmaceuticals: Physicochemical Characterization and In Vitro/In Vivo Applications

Physicochemical, pharmacokinetic, and biopharmaceutical characterization tools play a key role in the assessment of nanopharmaceuticals' potential imaging analysis and for site-specific delivery of anti-cancers to neoplastic cells/tissues. If diagnostic tools and therapeutic approaches are combined in one single nanoparticle, a new platform called nanotheragnostics is generated. Several analytical technologies allow us to characterize nanopharmaceuticals and nanoparticles and their properties so that they can be properly used in cancer therapy. This paper describes the role of multifunctional nanoparticles in cancer diagnosis and treatment, describing how nanotheragnostics can be useful in modern chemotherapy, and finally, the challenges associated with the commercialization of nanoparticles for cancer therapy.

Plant oils: From chemical composition to encapsulated form use

The last decade has witnessed a burgeoning global movement towards essential and vegetable oils in the food, agriculture, pharmaceutical, cosmetic, and textile industries thanks to their natural and safe status, broad acceptance by consumers, and versatile functional properties. However, efforts to develop new therapy or functional agents based on plant oils have met with challenges of limited stability and/or reduced efficacy. As a result, there has been increased research interest in the encapsulation of plant oils, whereby the nanocarriers serve as barrier between plant oils and the environment and control oil release leading to improved efficacy, reduced toxicity and enhanced patient compliance and convenience. In this review, special concern has been addressed to the encapsulation of essential and vegetable oils in three types of nanocarriers: polymeric nanoparticles, liposomes and solid lipid nanoparticles. First, the chemical composition of essential and vegetable oils was handled. Moreover, we gather together the research findings reported by the literature regarding the different techniques used to generate these nanocarriers with their significant findings. Finally, differences and similarities between these nanocarriers are discussed, along with current and future applications that are warranted by their structures and properties.

Applications of Natural, Semi-Synthetic, and Synthetic Polymers in Cosmetic Formulations

Cosmetics composed of synthetic and/or semi-synthetic polymers, associated or not with natural polymers, exhibit a dashing design, with thermal and chemo-sensitive properties. Cosmetic polymers are also used for the preparation of nanoparticles for the delivery of, e.g., fragrances, with the purpose to modify their release profile and also reducing the risk of evaporation. Besides, other cosmetically active nutrients, dermal permeation enhancers, have also been loaded into nanoparticles to improve their bioactivities on the skin. The use of natural polymers in cosmetic formulations is of particular relevance because of their biocompatible, safe, and eco-friendly character. These formulations are highly attractive and marketable to consumers, and are suitable for a plethora of applications, including make-up, skin, and hair care, and as modifiers and stabilizers. In this review, natural synthetic, semi-synthetic, and synthetic polymers are discussed considering their properties for cosmetic applications. Their uses in conventional and novel formulations are also presented.

Croton argyrophyllus Kunth Essential Oil-Loaded Solid Lipid Nanoparticles: Evaluation of Release Profile, Antioxidant Activity and Cytotoxicity in a Neuroblastoma Cell Line

The essential oil from Croton argyrophyllus Kunth is known for its antiproliferative, anti-inflammatory, antinociceptive, and anticancer activities, and is recognized as a source of phytochemicals for potential use in pharmaceutic and food sectors. Solid lipid nanoparticles (SLN) have been produced to load Croton argyrophyllus (CA) Kunth essential oil (CAEO) and its antioxidant properties evaluated in vitro as a new approach for the treatment of neurodegenerative diseases. Cetyl palmitate SLN loading CAEO (CAEO-SLN) with a mean particle size of 201.4 ± 2.3 nm (polydispersity index 0.211) have been produced by hot high-pressure homogenisation. The release of the oil followed the Korsmeyers-Peppas model. The risk of lipid peroxidation has been determined by applying the production of thiobarbituric acid-reactive substances (TBARS) standard assay. The antioxidant activity was determined by the capacity of the antioxidants existing in CAEO to scavenge the stable radical DPPH•. The cytotoxicity of CA Kunth essential oil-loaded SLN (CAEO-SLN) was evaluated in a human cell line SH-SY5Y (derived from human neuroblastoma) by determining the reduction of the yellow dye 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT). Both free essential oil (fEO) and loaded essential oil (CAEO-SLN) were demonstrated to inhibit the Fenton reaction. CAEO-SLN showed DPPH• radical scavenging capacity. The loading of the oil into cetyl palmitate SLN reduced the risk of cytotoxicity.

Stearic Acid, Beeswax and Carnauba Wax as Green Raw Materials for the Loading of Carvacrol into Nanostructured Lipid Carriers

The use of lipid nanoparticles as drug delivery systems has been growing over recent decades. Their biodegradable and biocompatible profile, capacity to prevent chemical degradation of loaded drugs/actives and controlled release for several administration routes are some of their advantages. Lipid nanoparticles are of particular interest for the loading of lipophilic compounds, as happens with essential oils. Several interesting properties, e.g., anti-microbial, antitumoral and antioxidant activities, are attributed to carvacrol, a monoterpenoid phenol present in the composition of essential oils of several species, including Origanum vulgare, Thymus vulgaris, Nigellasativa and Origanum majorana. As these essential oils have been proposed as the liquid lipid in the composition of nanostructured lipid carriers (NLCs), we aimed at evaluating the influence of carvacrol on the crystallinity profile of solid lipids commonly in use in the production of NLCs. Different ratios of solid lipid (stearic acid, beeswax or carnauba wax) and carvacrol were prepared, which were then subjected to thermal treatment to mimic the production of NLCs. The obtained binary mixtures were then characterized by thermogravimetry (TG), differential scanning calorimetry (DSC), small angle X-ray scattering (SAXS) and polarized light microscopy (PLM). The increased concentration of monoterpenoid in the mixtures resulted in an increase in the mass loss recorded by TG, together with a shift of the melting point recorded by DSC to lower temperatures, and the decrease in the enthalpy in comparison to the bulk solid lipids. The miscibility of carvacrol with the melted solid lipids was also confirmed by DSC in the tested concentration range. The increase in carvacrol content in the mixtures resulted in a decrease in the crystallinity of the solid bulks, as shown by SAXS and PLM. The decrease in the crystallinity of lipid matrices is postulated as an advantage to increase the loading capacity of these carriers. Carvacrol may thus be further exploited as liquid lipid in the composition of green NLCs for a range of pharmaceutical applications.

Polymeric Nanoparticles: Production, Characterization, Toxicology and Ecotoxicology

Polymeric nanoparticles (NPs) are particles within the size range from 1 to 1000 nm and can be loaded with active compounds entrapped within or surface-adsorbed onto the polymeric core. The term "nanoparticle" stands for both nanocapsules and nanospheres, which are distinguished by the morphological structure. Polymeric NPs have shown great potential for targeted delivery of drugs for the treatment of several diseases. In this review, we discuss the most commonly used methods for the production and characterization of polymeric NPs, the association efficiency of the active compound to the polymeric core, and the in vitro release mechanisms. As the safety of nanoparticles is a high priority, we also discuss the toxicology and ecotoxicology of nanoparticles to humans and to the environment.

Spray-Dried Structured Lipid Carriers for the Loading of Rosmarinus officinalis: New Nutraceutical and Food Preservative

Rosemary, an aromatic herb with significant antioxidative activity, is frequently used as food preservative and a source of nutraceuticals. Its antioxidant effect is mainly related to the presence of phenolic compounds, molecules considerably unstable and prone to irreversible physicochemical changes when exposed to external agents. We here proposed the loading of rosemary into structured lipid systems to improve its physicochemical properties. Four formulations were prepared using the same amount of rosemary lyophilized extract. The lipid phase was composed of stearic acid and oleic acid, and the aqueous phase, a varying combination of drying carriers (whey protein concentrate or gum Arabic) and surfactant (Poloxamer 188). The formulations were sonicated, spray-dried, and the obtained powders were characterized regarding the density (0.18 g/mL to 0.26 g/mL), particle size distribution (7 µm and 52 µm), and water solubility (29% to 48%). The antioxidant activity was determined by applying ABTS•+ radical-scavenging assay and the results expressed per gram of lyophilized extract (150.6 μmol Trolox/g to 376.4 μmol Trolox/g), with a significantly lower/higher result seen for formulations containing gum Arabic and a higher concentration of Poloxamer. The prepared systems may have potential applications as preservative in foodstuff and as nutraceutical.

Natural Ergot Alkaloids in Ocular Pharmacotherapy: Known Molecules for Novel Nanoparticle-Based Delivery Systems

Several pharmacological properties are attributed to ergot alkaloids as a result of their antibacterial, antiproliferative, and antioxidant effects. Although known for their biomedical applications (e.g., for the treatment of glaucoma), most ergot alkaloids exhibit high toxicological risk and may even be lethal to humans and animals. Their pharmacological profile results from the structural similarity between lysergic acid-derived compounds and noradrenalin, dopamine, and serotonin neurotransmitters. To reduce their toxicological risk, while increasing their bioavailability, improved delivery systems were proposed. This review discusses the safety aspects of using ergot alkaloids in ocular pharmacology and proposes the development of lipid and polymeric nanoparticles for the topical administration of these drugs to enhance their therapeutic efficacy for the treatment of glaucoma.

Formulating octyl methoxycinnamate in hybrid lipid-silica nanoparticles: An innovative approach for UV skin protection

Sunscreens have been employed on daily skin care for centuries. Their role in protecting the skin from sun damage, avoiding accelerated photoaging and even limiting the risk of development of skin cancer is unquestionable. Although several chemical and physical filters are approved as sunscreens for human use, their safety profile is dependent on their concentration in the formulation which governs their acceptance by the regulatory agencies. A strategic delivery of such molecules should provide a UV protection and limit the skin penetration. Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) may offer an alternative approach to achieve a synergistic effect on the UV protection when loaded with sunscreens as particles themselves also have a UV light scattering effect. Besides, the lipid character of SLN and NLC improves the encapsulation of lipophilic compounds, with enhanced loading capacity. Silica nanoparticles have also been employed in sunscreen formulations. Due to the formed sol-gel complexes, which covalently entrap sunscreen molecules, a controlled release is also achieved. In the present work, we have developed a new sunscreen formulation composed of hybrid SLN-Silica particles loaded with octyl methoxycinnamate (Parsol®MCX), and their further incorporation into a hydrogel for skin administration. Hybrid SLN-silica particles of 210.0 ± 3.341 nm of mean size, polydispersity below 0.3, zeta potential of ca. |7| mV, loading capacity of 19.9% and encapsulation efficiency of 98.3% have been produced. Despite the slight negative surface charge, the developed hybrid nanoparticles remained physicochemically stable over the study period. Turbiscan transmission profiles confirmed the colloidal stability of the formulations under stress conditions. The texture profile analysis of Parsol-SLN and Parsol-SLN-Si revealed semi-solid properties (e.g. adhesiveness, hardness, cohesiveness, springiness, gumminess, chewiness, resilience) suitable for topical application, together with the bioadhesiveness in the skin of pig ears. The non-irritation profile of the hybrid nanoparticles before and after dispersion into Carbopol hydrogels was confirmed by HET-CAM test.