Recent advances in non-ionic surfactant vesicles (niosomes): self-assembly, fabrication, characterization, drug delivery applications and limitations

Nanocarriers for Drug Delivery: An Overview with Emphasis on Vitamin D and K Transportation

Mounting evidence shows that supplementation with vitamin D and K or their analogs induces beneficial effects in various diseases, e.g., osteoarticular, cardiovascular, or carcinogenesis. The use of drugs delivery systems via organic and inorganic nanocarriers increases the bioavailability of vitamins and analogs, enhancing their cellular delivery and effects. The nanotechnology-based dietary supplements and drugs produced by the food and pharmaceutical industries overcome the issues associated with vitamin administration, such as stability, absorption or low bioavailability. Consequently, there is a continuous interest in optimizing the carriers' systems in order to make them more efficient and specific for the targeted tissue. In this pioneer review, we try to circumscribe the most relevant aspects related to nanocarriers for drug delivery, compare different types of nanoparticles for vitamin D and K transportation, and critically address their benefits and disadvantages.

Pharmaceutical, Biomedical and Ophthalmic Applications of Biodegradable Polymers (BDPs): Literature and Patent Review

In the last few decades, the interest in biodegradable materials for biomedical applications has increased significantly. Both natural and synthetic biodegradable polymers (BDPs) have been broadly explored for various biomedical applications. These include sutures and wound dressings, screws for bone fracture, scaffolds in tissue engineering, implants, and other carriers for targeted and sustained release drug delivery. Owing to their unique characteristics, including their surface charge variable copolymer block and composition and film-forming properties, BDPs have been widely used as favourable materials for ophthalmic drug delivery. Mucoadhesive BDPs have been used in ophthalmic formulations to prolong drug retention time and improve bioavailability, allowing ophthalmic controlled release systems to design. Furthermore, BDPs-based implants, microneedles, and injectable nano- and micro-particles enabled ocular posterior segment targeting and, most importantly, circumvented the need for removing the delivery systems after application. This review outlines the major advances of BDPs and highlights the latest progress of employing natural and synthetic BDPs for various biomedical applications, emphasising the treatment and management of ophthalmic conditions.

Development, Therapeutic Evaluation and Theranostic Applications of Cubosomes on Cancers: An Updated Review

Cancer is a group of disorders characterized by aberrant gene function and alterations in gene expression patterns. In 2020, it was anticipated that 19 million new cancer cases would be diagnosed globally, with around 10 million cancer deaths. Late diagnosis and interventions are the leading causes of cancer-related mortality. In addition, the absence of comprehensive cancer therapy adds to the burden. Many lyotropic non-lamellar liquid-crystalline-nanoparticle-mediated formulations have been developed in the last few decades, with promising results in drug delivery, therapeutics, and diagnostics. Cubosomes are nano-structured liquid-crystalline particles made of specific amphiphilic lipids in particular proportions. Their ability to encapsulate lipophilic, hydrophilic, and amphiphilic molecules within their structure makes them one of a kind. They are biocompatible, versatile drug carriers that can deliver medications through various routes of administration. Many preclinical studies on the use of cubosomes in cancer treatment and theranostic applications have been conducted. However, before cubosomes may be employed in clinical practice, significant technical advances must be accomplished. This review summarizes the development of cubosomes and their multifunctional role in cancer treatment based on the most recent reports.

Formulation and Evaluation of Luteolin-Loaded Nanovesicles: In Vitro Physicochemical Characterization and Viability Assessment

Luteolin (LT) is a natural polyphenol water-insoluble compound. LT-loaded nanovesicles (NVs) were prepared by using the solvent evaporation method. LT-NVs were prepared using cholesterol, phosphatidylcholine, span 60, and labrasol in a different composition. The prepared LT-NVs were evaluated for encapsulation efficiency, in vitro drug release, and permeation study. The optimized LT-NVs were further evaluated for antioxidant activity and cytotoxicity using the lung cancer cell line. LT-NVs showed nanometric size (less than 300 nm), an optimum polydispersibility index (less than 0.5), and a negative zeta potential value. The formulations also showed significant variability in the encapsulation efficiency (69.44 ± 0.52 to 83.75 ± 0.35%) depending upon the formulation composition. The in vitro and permeation study results revealed enhanced drug release as well as permeation profile. The formulation LT-NVs (F2) showed the maximum drug release of 88.28 ± 1.13%, while pure LT showed only 20.1 ± 1.21% in 12 h. The release data revealed significant variation (p < 0.001) in the release pattern. The permeation results also depicted significant (p < 0.001) enhancement in the permeation across the membrane. The enhanced permeation from LT-NVs was achieved due to the enhanced solubility of LT in the presence of the surfactant. The antioxidant activity results proved that LT-NVs showed greater activity compared to pure LT. The cytotoxicity study showed lesser IC50 value from LT-NVs than the pure LT. Thus, it can be concluded that LT-NVs are a natural alternative to the synthetic drug in the treatment of lung cancer.

Fabrication and optimization of amoxicillin-loaded niosomes: An appropriate strategy to increase antimicrobial and anti-biofilm effects against multidrug-resistant strains of Staphylococcus aureus

In this study, different formulations of amoxicillin-loaded niosomes were fabricated using the thin-film hydration method and their physicochemical properties were determined using scanning electron microscopy (SEM), dynamic light scattering (DLS), and Fourier-transform infrared spectroscopy (FTIR). The optimum prepared niosomes had a spherical morphology with an average size of 170.6 ± 6.8 nm and encapsulation efficiency of 65.78 ± 1.45%. The drug release study showed that the release rate of amoxicillin from niosome containing amoxicillin was slow and 47 ± 1% of the drug was released within 8 hours, while 97 ± 0.5% of the free drug was released. In addition, amoxicillin-loaded niosome increased the antimicrobial activity by 2-4 folds against multidrug-resistant (MDR) Staphylococcus aureus strains using broth microdilution assay. Moreover, at ½ minimum inhibitory concentrations, amoxicillin-loaded niosome significantly enhanced the anti-biofilm activity compared to free amoxicillin. Amoxicillin-loaded niosome had negligible cytotoxicity against HEK-293 normal cell line compared to free amoxicillin. The free niosomes exhibited no toxicity against HEK-293 cells and presented a biocompatible nanoscale delivery system. Based on the results, it can be concluded that amoxicillin-loaded niosome can be used as a promising candidate for enhancing antimicrobial and anti-biofilm effects against MDR strains of S. aureus.

Development of niosomes for encapsulating captopril-quercetin prodrug to combat hypertension

Novel and effective anti-hypertensive agents are required to manage hypertension; therefore, we synthesised a novel antihypertensive drug from captopril and quercetin (cap-que) and explored its antihypertensive potential in a niosomal formulation via molecular hybridisation. The cap-que hybrid was synthesised, and its structure was characterised via NMR, FTIR, and HRMS. Niosomes were then loaded with cap-que using the thin-film hydration method. The particle size, polydispersity index, surface charge and drug entrapment efficiency (EE%) of the formulation were 418.8 ± 4.21 nm, 0.393 ± 0.063, 16.25 ± 0.21 mV, and 87.74 ± 2.82%, respectively. The drug release profile showed a sustained release of the active compound (43 ± 0.09%) from the niosomal formulation, compared to the parent drug (80.7 ± 4.68%), over 24 h. The cell viability study confirmed the biosafety of the formulation. The in vivo study in a rat model showed enhanced antihypertensive activity of the hybrid molecule and niosomal formulation which reduced systolic and diastolic pressure when compared to the individual, bare drugs. The findings of this study concluded that the antihypertensive potential of captopril can be enhanced by its hybridisation with quercetin, followed by niosomal nano drug delivery.

The technology of transdermal delivery nanosystems: from design and development to preclinical studies

Transdermal administration has gained much attention due to the remarkable advantages such as patient compliance, drug escape from first-pass elimination, favorable pharmacokinetic profile and prolonged release properties. However, the major limitation of these systems is the limited skin penetration of the stratum corneum, the skin's most important barrier, which protects the body from the insertion of substances from the environment. Transdermal drug delivery systems are aiming to the disruption of the stratum corneum in order for the active pharmaceutical ingredients to enter successfully the circulation. Therefore, nanoparticles are holding a great promise because they can act as effective penetration enhancers due to their small size and other physicochemical properties that will be analyzed thoroughly in this report. Apart from the investigation of the physicochemical parameters, a comparison between the different types of nanoparticles will be performed. The complexity of skin anatomy and the unclear mechanisms of penetration should be taken into consideration to reach some realistic conclusions regarding the way that the described parameters affect the skin permeability. To the best of the authors knowledge, this is among the few reports on the literature describing the technology of transdermal delivery systems and how this technology affects the biological activity.

Characterization and distribution of niosomes containing ursolic acid coated with chitosan layer

Background and purpose

Ursolic acid (UA) exhibits anti-hepatocarcinoma and hepatoprotective activities, thus promising as an effective oral cancer therapy. However, its poor solubility and permeability lead to low oral bioavailability. In this study, we evaluated the effect of different ratios of Span^® 60-cholesterol-UA and also chitosan addition on physical characteristics and stability of niosomes to improve oral biodistribution.

Experimental approach

UA niosomes (Nio-UA) were composed of Span^® 60-cholesterol-UA at different molar ratios and prepared by using thin layer hydration method, and then chitosan solution was added into the Nio-UA to prepare Nio-CS-UA.

Findings/Results

The results showed that increasing the UA amount increased the particle size of Nio-UA. However, the higher the UA amount added to niosomes, the lower the encapsulation efficiency. The highest physical stability was achieved by preparing niosomes at a molar ratio of 3:2:10 for Span^® 60, cholesterol, and UA, respectively, with a zeta-potential value of -41.99 mV. The addition of chitosan increased the particle size from 255 nm to 439 nm, as well as the zeta-potential value which increased from -46 mV to -21 mV. Moreover, Nio-UA-CS had relatively higher drug release in PBS pH 6.8 and 7.4 than Nio-UA. In the in vivo study, the addition of chitosan produced higher intensities of coumarin-6-labeled Nio-UA-CS in the liver than Nio-UA.

Conclusion and implications

It can be concluded that the ratio of Span^® 60-cholesterol-UA highly affected niosomes physical properties. Moreover, the addition of chitosan improved the stability and drug release as well as oral biodistribution of Nio-UA.

Low-Frequency Sonophoresis as an Active Approach to Potentiate the Transdermal Delivery of Agomelatine-Loaded Novasomes: Design, Optimization, and Pharmacokinetic Profiling in Rabbits

The first melatonergic antidepressant drug, agomelatine (AGM), is commonly used for controlling major depressive disorders. AGM suffers low (< 5%) oral bioavailability owing to the hepatic metabolism. The current work investigated the potential of low-frequency sonophoresis on enhancing transdermal delivery of AGM-loaded novasomes and, hence, bioavailability of AGM. Drug-loaded novasomes were developed using free fatty acid (stearic acid or oleic acid), surfactant (span 60 or span 80), and cholesterol via thin-film hydration technique. The systems (N1-N16) were assessed for zeta potential (ZP), particle size (PS), encapsulation efficiency (EE%), and drug percent released after 0.5 h (Q_0.5 h) and 8 h (Q_8h), drug-crystallinity, morphology, and ex vivo drug permeation. Skin pre-treatment with low-frequency ultrasound (LFU) waves, via N13-novasomal gel systems, was optimized to enhance ex vivo drug permeation. Influences of LFU mode (continuous or pulsed), duty cycle (50% or 100%), and application period (10 or 15 min) were optimized. The pharmacokinetics of the optimized system (N13-LFU-C4) was assessed in rabbits. N13 was the best achieved novasomal system with respect to PS (471.6 nm), ZP (- 63.6 mv), EE% (60.5%), Q_0.5 h (27.8%), Q_8h (83.9%), flux (15.5 μg/cm²/h), and enhancement ratio (6.9). N13-LFU-C4 was the optimized novasomal gel system (desirability; 0.997) which involves skin pre-treatment with LFU in a continuous mode, at 100% duty cycle, for 15 min. Compared to AGM dispersion, the significantly (P < 0.05) higher flux (26.7 μg/cm²/h), enhancement ratio (11.9), C_max (118.23 ng/mL), and relative bioavailability (≈ 8.6 folds) could elucidate the potential of N13-LFU-C4 system in improving transdermal drug permeability and bioavailability.

Design, formulation and optimization of topical ethosomes using full factorial design: in-vitro and ex-vivo characterization

The present study aimed to develop lomefloxacin-loaded ethosomal vesicles intended to be applied topically for treating skin infections. Ethosomes were prepared using the cold method. The formulation variables were optimized using 2² factorial design and Design Expert^® software for analyzing the data statistically and graphically using response surface plots. Phosphatidylcholine (X1) and ethanol (X2) were chosen as the independent variables, while the dependent variables comprised entrapment efficiency (Y1), vesicles size (Y2) and zeta potential (Y3). The optimized ethosomes were subsequently incorporated into Carbopol^® 940 gel and characterized for rheological behaviour, in-vitro release, ex-vivo skin permeation and deposition. The ex-vivo permeation and skin deposition studies showed better results compared to drug solutions. In a nutshell, the ethosomal vesicles were found to be a promising carrier demonstrating enhanced topical delivery of lomefloxacin.

Polysorbate-Based Drug Formulations for Brain-Targeted Drug Delivery and Anticancer Therapy

Polysorbates (PSs) are synthetic nonionic surfactants consisting of polyethoxy sorbitan fatty acid esters. PSs have been widely employed as emulsifiers and stabilizers in various drug formulations and food additives. Recently, various PS-based formulations have been developed for safe and efficient drug delivery. This review introduces the general features of PSs and PS-based drug carriers, summarizes recent progress in the development of PS-based drug formulations, and discusses the physicochemical properties, biological safety, P-glycoprotein inhibitory properties, and therapeutic applications of PS-based drug formulations. Additionally, recent advances in brain-targeted drug delivery using PS-based drug formulations have been highlighted. This review will help researchers understand the potential of PSs as effective drug formulation agents.

A pilot study evaluating the efficacy and safety of retinaldehyde-loaded niosomes against mild-to-moderate acne

BACKGROUND

Retinoids are the mainstay of topical therapy for acne. To improve the efficacy and minimize the side effects of retinoids, various novel drug delivery mechanisms, including nanoparticles, have been developed.

AIM

To evaluate the efficacy and safety of a retinaldehyde-loaded niosome (RA-N) nanoemulsion against sebum secretion and keratinization on mild-to-moderate acne.

PATIENTS/METHODS

Twenty-three participants exhibiting mild-to-moderate acne with both closed and open comedones were included. They applied a 0.05% RA-N nanoemulsion daily for 4 weeks, did not to use any other emollient or topical pharmaceutical, and were asked to report any symptoms and treatment satisfaction.

RESULTS

The participants demonstrated significantly fewer closed and open comedones after 2 and 4 weeks of treatment than at baseline (*p < 0.05). The mean sebum secretion, measured using Sebumeter®, was 327.95 ± 90.20 μg cm^-2 at baseline and reduced to 282.60 ± 99.70 and 250.65 ± 97.6 μg cm^-2 , respectively, after 2 and 4 weeks of treatment (*p < 0.05). The mean desquamation index, determined using Visioscan®, was 10.99 ± 1.69 at baseline and decreased to 9.81 ± 1.10 and 8.89 ± 1.32, respectively, after 2 and 4 weeks of treatment (*p < 0.05). The application of the RA-N nanoemulsion resulted in a significantly lower desquamation level, suggesting that the RA-N nanoemulsion was well-tolerated without any skin irritation. None of the participants reported a serious adverse event during this study.

CONCLUSION

Our findings suggest that the RA-N nanoemulsion was effective in improving comedones in acne-prone skin and safe for long-term application. Further studies are necessary to investigate the long-term effects of the application of the RA-N nanoemulsion in participants with inflammatory acne and acne scars.

Liposomes: Structure, Biomedical Applications, and Stability Parameters With Emphasis on Cholesterol

Liposomes are essentially a subtype of nanoparticles comprising a hydrophobic tail and a hydrophilic head constituting a phospholipid membrane. The spherical or multilayered spherical structures of liposomes are highly rich in lipid contents with numerous criteria for their classification, including structural features, structural parameters, and size, synthesis methods, preparation, and drug loading. Despite various liposomal applications, such as drug, vaccine/gene delivery, biosensors fabrication, diagnosis, and food products applications, their use encounters many limitations due to physico-chemical instability as their stability is vigorously affected by the constituting ingredients wherein cholesterol performs a vital role in the stability of the liposomal membrane. It has well established that cholesterol exerts its impact by controlling fluidity, permeability, membrane strength, elasticity and stiffness, transition temperature (Tm), drug retention, phospholipid packing, and plasma stability. Although the undetermined optimum amount of cholesterol for preparing a stable and controlled release vehicle has been the downside, but researchers are still focused on cholesterol as a promising material for the stability of liposomes necessitating explanation for the stability promotion of liposomes. Herein, the prior art pertaining to the liposomal appliances, especially for drug delivery in cancer therapy, and their stability emphasizing the roles of cholesterol.

Nanotechnology-based delivery of CRISPR/Cas9 for cancer treatment

CRISPR/Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats-associated protein 9) is a potent technology for gene-editing. Owing to its high specificity and efficiency, CRISPR/Cas9 is extensity used for human diseases treatment, especially for cancer, which involves multiple genetic alterations. Different concepts of cancer treatment by CRISPR/Cas9 are established. However, significant challenges remain for its clinical applications. The greatest challenge for CRISPR/Cas9 therapy is how to safely and efficiently deliver it to target sites in vivo. Nanotechnology has greatly contributed to cancer drug delivery. Here, we present the action mechanisms of CRISPR/Cas9, its application in cancer therapy and especially focus on the nanotechnology-based delivery of CRISPR/Cas9 for cancer gene editing and immunotherapy to pave the way for its clinical translation. We detail the difficult barriers for CRISIR/Cas9 delivery in vivo and discuss the relative solutions for encapsulation, target delivery, controlled release, cellular internalization, and endosomal escape.

Optically Manipulated Microtools to Measure Adhesion of the Nanoparticle-Targeting Ligand Glutathione to Brain Endothelial Cells

Targeting nanoparticles as drug delivery platforms is crucial to facilitate their cellular entry. Docking of nanoparticles by targeting ligands on cell membranes is the first step for the initiation of cellular uptake. As a model system, we studied brain microvascular endothelial cells, which form the anatomical basis of the blood-brain barrier, and the tripeptide glutathione, one of the most effective targeting ligands of nanoparticles to cross the blood-brain barrier. To investigate this initial docking step between glutathione and the membrane of living brain endothelial cells, we applied our recently developed innovative optical method. We present a microtool, with a task-specific geometry used as a probe, actuated by multifocus optical tweezers to characterize the adhesion probability and strength of glutathione-coated surfaces to the cell membrane of endothelial cells. The binding probability of the glutathione-coated surface and the adhesion force between the microtool and cell membrane was measured in a novel arrangement: cells were cultured on a vertical polymer wall and the mechanical forces were generated laterally and at the same time, perpendicularly to the plasma membrane. The adhesion force values were also determined with more conventional atomic force microscopy (AFM) measurements using functionalized colloidal probes. The optical trapping-based method was found to be suitable to measure very low adhesion forces (≤ 20 pN) without a high level of noise, which is characteristic for AFM measurements in this range. The holographic optical tweezers-directed functionalized microtools may help characterize the adhesion step of nanoparticles initiating transcytosis and select ligands to target nanoparticles.

Altering the intra-liver distribution of phospholipid-free small unilamellar vesicles using temperature-dependent size-tunability

We demonstrated that phospholipid-free small unilamellar vesicles (PFSUVs) composed of TWEEN 80 and cholesterol (25/75, mol%) could be fabricated using a staggered herringbone micromixer with precise controlling of their mean size between 54 nm and 147 nm. Increasing the temperature or decreasing the flow rate led to an increase in the resulting particle diameter. In zebrafish embryos, 120-nm PFSUVs showed 3-fold higher macrophage clearance compared to the 60-nm particles, which exhibited prolonged blood circulation. In mice, the 60-nm particles showed dominant accumulation in the liver hepatocytes (66% hepatocytes positive), while the 120-nm particles were delivered equally to the liver and spleen macrophages. Accordingly, in a murine model of acetaminophen-induced hepatotoxicity the 60-nm particles loaded with chlorpromazine reduced the serum alanine aminotransferase level and liver necrosis 2- to 4-fold more efficiently than their 120-nm counterparts and the free drug, respectively. This work showed that the intra-liver distribution of PFSUVs was largely determined by the size. Most other nanoparticles published to date are predominantly cleared by the liver Kupffer cells. The 60-nm PFSUVs, on the other hand, focused the delivery to the hepatocytes with significant advantages for the therapy of liver diseases.

Identifying Underlying Issues Related to the Inactive Excipients of Transfersomes based Drug Delivery System

Transfersomes are bilayer vesicles composed of phospholipid and edge activators, which are mostly surfactant. Transfersomes based drug delivery system has gained a lot of interest of the pharmaceutical researchers for their ability to improve drug penetration and permeation through the skin. Transdermal drug delivery via transfersomes has the potential to overcome the challenge of low systemic availability. However, this complex vesicular system has different issues to consider for developing a successful transdermal delivery system. One of the major ingredients, phospholipid, has versatile sources and variable effect on the vesicle size and drug entrapment in transfersomes. The other one, termed as edge activators or surfactant, has some crucial consideration of skin damage and toxicity depending upon its type and concentration. A complex interaction between type and concentration of phospholipid and surfactant was observed, which affect the physicochemical properties of transfersomes. This review focuses on the practical factors related to these two major ingredients, such as phospholipid and surfactant. The origin, purity, desired concentration, the susceptibility of degradation, etc. are the important factors for selecting phospholipid. Regarding surfactants, the major aspects are type and desired concentration. A successful development of transfersomes based drug delivery system depends on the proper considerations of these factors and practical aspects.

Lipid nanovesicles for biomedical applications: 'What is in a name'?

Vesicles, generally defined as self-assembled structures formed by single or multiple concentric bilayers that surround an aqueous core, have been widely used for biomedical applications. They can either occur naturally (e.g. exosomes) or be produced artificially and range from the micrometric scale to the nanoscale. One the most well-known vesicle is the liposome, largely employed as a drug delivery nanocarrier. Liposomes have been modified along the years to improve physicochemical and biological features, resulting in long-circulating, ligand-targeted and stimuli-responsive liposomes, among others. In this process, new nomenclatures were reported in an extensive literature. In many instances, the new names suggest the emergence of a new nanocarrier, which have caused confusion as to whether the vesicles are indeed new entities or could simply be considered modified liposomes. Herein, we discussed the extensive nomenclature of vesicles based on the suffix "some" that are employed for drug delivery and composed of various types and proportions of lipids and others amphiphilic compounds. New names have most often been selected based on changes of vesicle lipid composition, but the payload, structural complexity (e.g. multicompartment) and new/improved proprieties (e.g. elasticity) have also inspired new vesicle names. Based on this discussion, we suggested a rational classification for vesicles.

Facile design of gemini surfactant-like peptide for hydrophobic drug delivery and antimicrobial activity

Recently, many kinds of gemini-type amphiphilic peptides have been designed and shown their advantage as self-assembling nanomaterials. In this study, we proposed a simple strategy to design gemini surfactant-like peptides, which are only composed of natural amino acids and can be easily obtained by conventional peptide sythnesis. Taking two prolines as the turn-forming units, a peptide named APK was designed. The petide has a linear sequence but naturally takes the conformation like a gemini surfactant. Compared with a single-tailed surfactant-like peptide A6K, APK showed much stronger ability to undergo self-assembly and to encapsulate hydrophobic pyrene. Several hydrophobic drugs including paclitaxel, doxorubicin, etomidate and propofol were encapsulated by APK, and the corresponding formulations showed anti-tumor or anesthetic efficacy comparable to their respective clinical formulations. Furthermore, APK could inhibit the growth of different microorganisms including E. coli, S. aureus and C. albicans. Etomidate and propofol formulations encapsulated by APK also showed strong antimicrobial activity. Taking APK as an example, our study indicated a straightforward strategy to design gemini surfactant-like peptides, which could be potential nanomaterials for exploring hydrophobic drug formulations with efficacy, safety and self-antimicrobial activity.

Optimization of propofol loaded niosomal gel for transdermal delivery

Propofol is an oily liquid widely used for rapid onset of anaesthesia via intravenous route, which shows major limitations of hypersensitivity, anaphylactic reactions and pain. The aim of the present work was to bypass the above issues by formulating tailored niosomal gel to deliver propofol via non-invasive transdermal route. The niosomes were prepared by film hydration method and sonication using cholesterol and Span 80. The Box Behnken design (BBD) was applied to optimize the size (93.5 nm) and the entrapment efficacy (81.5%) of the niosomes by selecting cholesterol at 139 mg, Span 80 at 0.525% and sonication time at 5.13 min. The scanning electron microscopy image showed spherical shape niosomes with smooth surface without aggregation. The ex vivo release data showed significant improvement in the propofol release (92.2% after 10 h) using niosomes in comparison to the control propofol gel (with 30% methanol) without niosomes (25.3% after 10 h). The in vivo pharmacokinetic parameters in the rat model confirmed the improvement in the relative bioavailability with optimized niosomal gel (relative bioavailability = 12.12) in comparison to the control propofol gel. In conclusion, the niosomal gel offered a potential alternative non-invasive route to deliver propofol for procedural sedation especially in pediatric population.

Enhancement strategies for transdermal drug delivery systems: current trends and applications

Transdermal drug delivery systems have become an intriguing research topic in pharmaceutical technology area and one of the most frequently developed pharmaceutical products in global market. The use of these systems can overcome associated drawbacks of other delivery routes, such as oral and parenteral. The authors will review current trends, and future applications of transdermal technologies, with specific focus on providing a comprehensive understanding of transdermal drug delivery systems and enhancement strategies. This article will initially discuss each transdermal enhancement method used in the development of first-generation transdermal products. These methods include drug/vehicle interactions, vesicles and particles, stratum corneum modification, energy-driven methods and stratum corneum bypassing techniques. Through suitable design and implementation of active stratum corneum bypassing methods, notably microneedle technology, transdermal delivery systems have been shown to deliver both low and high molecular weight drugs. Microneedle technology platforms have proven themselves to be more versatile than other transdermal systems with opportunities for intradermal delivery of drugs/biotherapeutics and therapeutic drug monitoring. These have shown that microneedles have been a prospective strategy for improving transdermal delivery systems.

Monoolein-based nanoparticles containing indinavir: a taste-masked drug delivery system

OBJECTIVE

This study developed a novel child-friendly drug delivery system for pediatric HIV treatment: a liquid, taste-masked, and solvent-free monoolein-based nanoparticles formulation containing indinavir (0.1%).

SIGNIFICANCE

Adherence to antiretroviral therapy by pediatric patients is difficult because of the lack of dosage forms adequate for children.

METHODS

Monoolein-based nanoparticles were developed. The particle size, zeta potential, pH, drug content, small angle X-ray scattering, stability, in vitro drug release profile, biocompatibility, toxicity, and taste-masking properties were evaluated.

RESULTS

Monoolein-based formulations containing indinavir had nanosized particles with 155 ± 7 nm, unimodal particle size distribution, and polydispersity index of 0.16 ± 0.03. The zeta potential was negative (-31.3 ± 0.3 mV) and pH was neutral (7.78 ± 0.01). A 96% drug incorporation efficiency was achieved, and the indinavir concentration remained constant for 30 days. Polarized light microscopy revealed isotropic characteristics. Transmission electron microscopy images showed spherical shaped morphology. Small-angle X-ray scattering displayed a form factor broad peak. Indinavir had a sustained release from the nanoparticles. The system was nonirritant and was able to mask drug bitter taste.

CONCLUSIONS

Monoolein-based nanoparticles represent a suitable therapeutic strategy for antiretroviral treatment with the potential to reduce the frequency of drug administration and promote pediatric adherence.

Vesicular systems for dermal and transdermal drug delivery

Dermal/transdermal drug delivery continues to grow in importance as a means of enhancing treatment activity while reducing toxicity by avoiding the systemic absorption of the drug. At the same time, this has led to the adjustment of a wide diversity of drug carriers. This paper begins with a review of the skin, including its structure and the parameters that influence drug diffusion, followed by strategies to improve dermal drug delivery. Of the multitude of existing carriers, we will focus on the most advanced vectors in dermal/transdermal delivery, and in particular, on vesicular systems. This review will present the state of the art as well as the new trends in this domain. Through the description of these systems, we will try to obtain information on the ideal properties that the carrier must have in order to improve the cutaneous and transcutaneous penetration of the drug.

The Challenge of Nanovesicles for Selective Topical Delivery for Acne Treatment: Enhancing Absorption Whilst Avoiding Toxicity

Acne is a common skin disease that affect over 80% of adolescents. It is characterized by inflammation of the hair bulb and the attached sebaceous gland. To date, many strategies have been used to treat acne as a function of the disease severity. However, common treatments for acne seem to show several side effects, from local irritation to more serious collateral effects. The use of topical vesicular carriers able to deliver active compounds is currently considered as an excellent approach in the treatment of different skin diseases. Many results in the literature have proven that drug delivery systems are useful in overcoming the toxicity induced by common drug therapies, while maintaining their therapeutic efficacy. Starting from these assumptions, the authors reviewed drug delivery systems already realized for the topical treatment of acne, with a focus on their limitations and advantages over conventional treatment strategies. Although their exact mechanism of permeation is not often completely clear, deformable vesicles seem to be the best solution for obtaining a specific delivery of drugs into the deeper skin layers, with consequent increased local action and minimized collateral effects.

Emerging potential of niosomes in ocular delivery

INTRODUCTION

Niosomes have recently grabbed attention as one of the best tools for various site-specific drug delivery systems, including ophthalmic drug delivery. Surfactants (nonionic; tweens and spans) of different HLB values and cholesterol are the fundamental components for these formulations. It is an alternative controlled ocular drug delivery system to liposomes to overcome the problems associated with sterilization, large-scale production, and stability. It also enhances the adhesion or retention ability of drug at the ocular site. Hydrophilic or lipophilic or amphoteric drugs can be easily encapsulated in niosomes. Besides, niosomes are a leading vesicular system compatible with most of the drugs for site-specific delivery.

AREAS COVERED

This article reveals challenges and barriers for ocular drug delivery, various transporters and receptors present in the ocular region for the transportation of therapeutics as well as nutrients, and various method of preparations, loading methods and application potential of niosomes in ocular drug delivery.

EXPERT OPINION

Niosomes, a vesicular system offers numerous advantages and applicability because of its good stability, non-immunogenicity, permeation potential, and controlled release ability etc. This drug delivery system has been efficiently used in the treatment of many ocular diseases.

Preparation and Evaluation of Cubosomes/Cubosomal Gels for Ocular Delivery of Beclomethasone Dipropionate for Management of Uveitis

PURPOSE

Topical corticosteroids administration is commonly used for management of various ocular conditions especially those affecting the anterior segment of the eye. Poor solubility and limited pre-corneal residence time result in insufficient drug penetration to the outer (cornea and conjunctival-scleral) coats of the eye. This study aimed to prepare and evaluate cubosomes for prolonging residence time and enhancing ocular bioavailability of BDP.

METHODS

GMO-cubosomes were prepared using the top-down technique. Two stabilizers were investigated: poloxamer 407 and solulan C24. Particle size, EE %, polarized-light microscopy, TEM, in vitro release, transcorneal permeation, BCOP, histopathology and in vivo evaluation for treatment of uveitis in a rabbits' model were studied.

RESULTS

The prepared cubosomes were of nano-sizes (100 nm - 278 nm); EE% was around 94%. The cubosomes were confirmed by visualizing the "Maltese crosses" textures. Transcorneal permeation was significantly (p < 0.05) improved, compared to BDP-suspension (the control formulation). The optimized cubosomes F1P was incorporated in CMC gel (Cubo-gel). The prepared Cubo-gel formulations showed better rheological characteristics and high ocular tolerability. Superior anti-inflammatory properties were recorded for the Cubo-gel for treatment of endotoxin-induced uveitis in the rabbit model when compared to the control BDP-suspension.

CONCLUSIONS

Transcorneal permeation parameters P_app and flux and AUC_0-10h markedly enhanced by up to 4-, 5.8-and 5.5-fold respectively, compared to the control BDP-suspension formulation. This study suggested that cubosomes/Cubo-gel could be an auspicious ocular delivery system for BDP that was able to effectively treat uveitis (a disease of the posterior segment of the eye).

Curcumin-loaded proniosomal gel as a biofreindly alternative for treatment of ocular inflammation: In-vitro and in-vivo assessment

Ocular inflammation is a natural defensive phenomenon, but, it results in discomfort in the eye; as well as makes the eye vulnerable to other diseases. The aim of this work is to investigate that Curcumin (CUR) could be an effective safer biofreindly alternative for treatment of ocular inflammation. Complete in-vitro characterization of proniosomal gel loading-CUR using different surfactants was studied. A comparative in-vivo evaluation of selected formulation to a marketed corticosteroid drops in induced-eye inflammation model in rabbits was assessed. The selected formulation (F_{Cr 300}) composed of Cremophore RH surfactant, lecithin and cholesterol (9:9:1) loading CUR (1.2% w/w). The formulation showed mean PS(212.0 ± 0.1)nm, PDI (0.3 ± 0.1) , ZP(-5.1 ± 0.2)mV and % EE (96.0 ± 0.1). TEM showed multilamellar circular shaped niosomes with smooth surface. SEM showed ruptured vesicles for the lyophilized formula. Selected proniosomal gel showed enhanced permeability 3.22-fold and 1.76-fold higher than CUR dispersion and its lyophilized form respectively. Both proniosomal gel (F_Cr300) and corticosteroid drops reduced the induced inflammatory signs effectively by 40% on day-one and complete recovery on day-four. This anti-inflammatory result was confirmed by histopathological analysis after treatment. Assessment of cumulative IOP as a predicted side effect verified the goal of this work. In conclusion, the use of CUR as a natural biofreindly alternative to the current chemical conventional ocular anti-inflammatory treatment protocols is comparable as an anti-inflammatory drug with much less side effects.

Therapeutic potential of phenylethanoid glycosides: A systematic review

Phenylethanoid glycosides (PhGs) are generally water-soluble phenolic compounds that occur in many medicinal plants. Until June 2020, more than 572 PhGs have been isolated and identified. PhGs possess antibacterial, anticancer, antidiabetic, anti-inflammatory, antiobesity, antioxidant, antiviral, and neuroprotective properties. Despite these promising benefits, PhGs have failed to fulfill their therapeutic applications due to their poor bioavailability. The attempts to understand their metabolic pathways to improve their bioavailability are investigated. In this review article, we will first summarize the number of PhGs compounds which is not accurate in the literature. The latest information on the biological activities, structure-activity relationships, mechanisms, and especially the clinical applications of PhGs will be reviewed. The bioavailability of PhGs will be summarized and factors leading to the low bioavailability will be analyzed. Recent advances in methods such as bioenhancers and nanotechnology to improve the bioavailability of PhGs are also summarized. The existing scientific gaps of PhGs in knowledge are also discussed, highlighting research directions in the future.

Lipid vesicles: A versatile drug delivery platform for dermal and transdermal applications

Topical and transdermal application of active pharmaceutical ingredients to the skin is an attractive strategy being explored by formulation scientists to treat disease conditions rather than the oral drug delivery. Several approaches have been attempted, and many of them have emerged with significant clinical potential. However, the delivery of drugs across the skin is an arduous task due to permeation limiting barriers. It, therefore, requires the aid of external agents or carrier systems for efficient permeation. Lipid-based vesicular systems are carriers for the transport of drugs through the stratum corneum (dermal drug delivery) and into the bloodstream for systemic action (transdermal drug delivery) overcoming the barrier properties. This review article describes the various vesicular systems reported for skin delivery of actives with relevant case studies. The vesicular systems presented here are in the order of their advent from conventional systems to the advanced lipid vesicles. The design and development of drugs in vesicular systems have brought a new dimension to the treatment of disease conditions overcoming the permeation limiting barriers, thus improving its efficacy.

Combination of Alanine and Glutathione as Targeting Ligands of Nanoparticles Enhances Cargo Delivery into the Cells of the Neurovascular Unit

Inefficient drug delivery across the blood–brain barrier (BBB) and into target cells in the brain hinders the treatment of neurological diseases. One strategy to increase the brain penetration of drugs is to use vesicular nanoparticles functionalized with multiple ligands of BBB transporters as vehicles. Once within the brain, however, drugs must also be able to reach their therapeutic targets in the different cell types. It is, therefore, favorable if such nanocarriers are designed that can deliver their cargo not only to brain endothelial cells, but to other cell types as well. Here, we show that alanine-glutathione dual-targeting of niosomes enhances the delivery of a large protein cargo into cultured cells of the neurovascular unit, namely brain endothelial cells, pericytes, astrocytes and neurons. Furthermore, using metabolic and endocytic inhibitors, we show that the cellular uptake of niosomes is energy-dependent and is partially mediated by endocytosis. Finally, we demonstate the ability of our targeted nanovesicles to deliver their cargo into astroglial cells after crossing the BBB in vitro. These data indicate that dual-labeling of nanoparticles with alanine and glutathione can potentially be exploited to deliver drugs, even biopharmacons, across the BBB and into multiple cell types in the brain.

Glucosamine-NISV delivers antibody across the blood-brain barrier: Optimization for treatment of encephalitic viruses

The field of brain drug delivery faces many challenges that hinder development and testing of novel therapies for clinically important central nervous system disorders. Chief among them is how to deliver large biologics across the highly restrictive blood-brain barrier. Non-ionic surfactant vesicles (NISV) have long been used as a drug delivery platform for cutaneous applications and have benefits over comparable liposomes in terms of greater stability, lower cost and suitability for large scale production. Here we describe a glucosamine-coated NISV, for blood-brain barrier GLUT1 targeting, capable of traversing the barrier and delivering active antibody to cells within the brain. In vitro, we show glucosamine vesicle transcytosis across the blood-brain barrier with intact cargo, which is partially dynamin-dependent, but is clathrin-independent and does not associate with sorting endosome marker EEA1. Uptake of vesicles into astrocytes follows a more classical pathway involving dynamin, clathrin, sorting endosomes and Golgi trafficking where the cargo is released intracellularly. In vivo, glucosamine-coated vesicles are superior to uncoated or transferrin-coated vesicles for delivering cargo to the mouse brain. Finally, mice infected with Venezuelan equine encephalitis virus (VEEV) were successfully treated with anti-VEEV monoclonal antibody Hu1A3B-7 delivered in glucosamine-coated vesicles and had improved survival and reduced brain tissue virus levels. An additional benefit was that the treatment also reduced viral load in peripheral tissues. The data generated highlights the huge potential of glucosamine-decorated NISV as a drug delivery platform with wider potential applications.

Niosomes of active Fumaria officinalis phytochemicals: antidiabetic, antineuropathic, anti-inflammatory, and possible mechanisms of action

Background

Fumaria officinalis (F. officinalis, FO) has been used in many inflammatory and painful-ailments. The main aim of this work is to perform an in-depth bio-guided phytochemical investigation of F. officinalis by identifying its main-active ingredients. Optimizing pharmacokinetics via niosomal-preparation will also be done to enhance their in vivo antineuropathic and anti-inflammatory potentials, and to explore their possible-mechanism of actions.

Methods

Bio-guided phytochemical-investigations including fractionation, isolation, chromatographic-standardization, and identification of the most active compound(s) were done. Optimized niosomal formulations of F. officinalis most active compound(s) were prepared and characterized. An in vivo biological-evaluation was done exploring acute, subchronic, and chronic alloxan-induced diabetes and diabetic-neuropathy, and carrageenan-induced acute inflammatory-pain and chronic-inflammatory edema.

Results

In-vivo bio-guided fractionation and chromatographic phytochemical-analysis showed that the alkaloid-rich fraction (ARF) is the most-active fraction. ARF contained two major alkaloids; Stylopine 48.3%, and Sanguinarine 51.6%. In-vitro optimization, analytical, and in vivo biological-investigations showed that the optimized-niosome, Nio-2, was the most optimized niosomal formulation. Nio-2 had particle size 96.56 ± 1.87 nm and worked by improving the pharmacokinetic-properties of ARF developing adequate entrapment-efficiency, rapid-degradation, and acceptable stability in simulated GI conditions. FO, ARF, and Nio 2 were the most potent antidiabetic and anti-inflammatory compounds. The reduction of the pro-inflammatory tumor necrosis factor-alpha (TNF-alpha) and Interleukin 6 (IL-6), and elevation the anti-inflammatory factor IL-10 levels and amelioration of the in vivo oxidative-stress might be the main-mechanism responsible for their antinociceptive and anti-inflammatory activities.

Conclusions

Fumaria officinalis most-active fraction was identified as ARF. This study offers an efficient and novel practical oral formulation ameliorating various inflammatory conditions and diabetic complications especially neuropathic-pain.

Nanoformulation strategies for improving intestinal permeability of drugs: A more precise look at permeability assessment methods and pharmacokinetic properties changes

The therapeutic efficacy of orally administered drugs is often restricted by their inherent limited oral bioavailability. Low water solubility, limited permeability through the intestinal barrier, instability in harsh environment of the gastrointestinal (GI) tract and being substrate of the efflux pumps and the cytochrome P450 (CYP) can impair oral drug bioavailability resulting in erratic and variable plasma drug profile. As more drugs with low membrane permeability are developed, new interest is growing to enhance their intestinal permeability and bioavailability. A wide variety of nanosystems have been developed to improve drug transport and absorption. Sufficient evidence exists to suggest that nanoparticles are able to increase the transepithelial transport of drug molecules. However, key questions remained unanswered. What types of nanoparticles are more efficient? What are preclinical (or clinical) achievements of each type of nanoformulation in terms of pharmacokinetic (PK) parameters? Addressing this issue in this paper, we have reviewed the current literature regarding permeability enhancement, permeability assessment methods and changes in PK parameters following administration of various nanoformulations. Although permeability enhancement by various nanoformulations holds great promise for oral drug delivery, many challenges still need to be addressed before development of more clinically successful nanoproducts.

Formulation, Characterization and In-vitro and In-vivo Evaluation of Capecitabine Loaded Niosomes

BACKGROUND

Nanocarriers improve the efficacy of drugs by facilitating their specific delivery and protecting them from external environment resulting in a better performance against diseases.

OBJECTIVE

In this study, it was aimed to improve the efficacy of capecitabine against colorectal cancer by its entrapment in niosomes. Ether injection method was used to prepare niosomes composed of span 20 and cholesterol.

METHODS

Niosomes were evaluated by evaluating the entrapment efficiency, in-vitro drug release and cytotoxicity of capecitabine loaded niosomes. Niosomes were characterized by particle size analysis, transmission electron microscopy, Fourier transform infrared spectroscopy and differential scanning calorimetry for surface morphology and drug excipient interactions.

RESULTS

High encapsulation efficiency (90.55%) was observed, which is anticipated to resolve the multi-drug resistance problem. Reported particle size was 180.9 + 5 nm with a negative zeta potential - 21 + 0.5 mV and the kinetic study showed a concentration-dependent release of the drug from the niosome. DSC study proved entrapment of the entire drug and its non-covalent bonding with the excipients. Cytotoxicity study of niosomes on CaCO2 cell line showed an improved IC₅₀ value as compared to the free drug.

CONCLUSION

Enhanced cytotoxicity observed in the results further supports the suitability of niosome as a nanocarrier for pharmaceutical drug delivery.

Development and Investigation of Vitamin C-Enriched Adapalene-Loaded Transfersome Gel: a Collegial Approach for the Treatment of Acne Vulgaris

Adapalene-loaded transfersome gel containing vitamin C as a combination therapy for the management of acne vulgaris was developed in the present study. The transfersome was prepared by reverse-phase evaporation, and the effect of various process parameters were investigated by the Design of Experiment (DOE) approach and optimized based on the particle size (PS), polydispersity index (PDI), zeta potential (ZP), and entrapment efficiency (EE). The selected tranfersomes were further evaluated for their thermal behavior and morphology by transmission electron microscopy and turbidity measurements and incorporated into a gel with/without vitamin C. The gel was evaluated and compared with the marketed product (Adiff gel) for various physicochemical parameters, and in vivo studies in testosterone-induced rat models of acne. The prepared transfersomes had PS in the range of 280 to 400 nm, PDI values of 0.416 to 0.8, ZP of - 38 to - 20 mV, and % EE of 32 to 70%. DSC studies confirmed a positive interaction of the components in the transfersome. Surface morphology confirmed that the vesicles were spherical, unilamellar, and discrete. A relative deformability study showed higher elasticity of the transfersomes compared with Adiff aqs gel. Ascorbyl-6-palmitate in adapalene-loaded transfersome gel containing vitamin C (ADVTG) was found to have a good antioxidant free radical-scavenging activity. An in vitro drug release study showed that the sustained release of the transfersomal formulations was attributed to the flexibility of the vesicles by which penetration was increased. ADVTG was found to be promising in treating acne compared with the marketed product. Graphical Abstract.