Improved oral bioavailability and brain transport of Saquinavir upon administration in novel nanoemulsion formulations

Influence of Poloxamer 188 on Anti-Inflammatory and Analgesic Effects of Diclofenac-Loaded Nanoemulsion: Formulation, Optimization and in Vitro/in Vivo Evaluation

In this study, a polymer-stabilized nanoemulsion (PNE) was developed to improve the inflammatory and analgesic activities of diclofenac (DA). DA-PNEs were prepared from sesame oil and poloxamer 188 (P188), polysorbate 80, and span 80 as emulsifiers and optimized by a systematic multi-objective optimization method. The developed DA-PNEs exhibited thermodynamical stability with low viscosity. The mean diameter, PDI, surface charge, and entrapment efficiency of DA-PNEs were 122.49±3.42 nm, 0.226±0.08, -47.3 ± 3.6 mV, and 93.57±3.4 %, respectively. The cumulative in vitro release profile of DA-PNEs was significantly higher than the neat drug in simulated gastrointestinal fluids. The anti-inflammatory activities of DA-PNEs were evaluated in the λ-carrageenan-induced paw edema model. To investigate the effect of P188 on analgesic and anti-inflammatory activities, a formulation without P188 was also prepared and named DA-NEs. Following oral administration, DA-PNEs showed a significantly higher (p<0.05) effect in reducing pain and inflammation symptoms as compared to free diclofenac and DA-NEs. Moreover, histopathological examination confirmed that DA-PNEs meaningfully reduced the extent of paw edema, comparable to that of DA. Taken together, the findings of the in vitro and in vivo studies suggest that diclofenac-loaded P188-stabilized nanoemulsion can be considered a potential drug delivery system for treating and controlling inflammatory disorders and alleviating pains.

Nanoemulsion: An Emerging Novel Technology for Improving the Bioavailability of Drugs

The pharmaceutical sector has made considerable strides recently, emphasizing improving drug delivery methods to increase the bioavailability of various drugs. When used as a medication delivery method, nanoemulsions have multiple benefits. Their small droplet size, which is generally between 20 and 200 nanometers, creates a significant interfacial area for drug dissolution, improving the solubility and bioavailability of drugs that are weakly water-soluble. Additionally, nanoemulsions are a flexible platform for drug administration across various therapeutic areas since they can encapsulate hydrophilic and hydrophobic medicines. Nanoemulsion can be formulated in multiple dosage forms, for example, gels, creams, foams, aerosols, and sprays by using low-cost standard operative processes and also be taken orally, topically, topically, intravenously, intrapulmonary, intranasally, and intraocularly. The article explores nanoemulsion formulation and production methods, emphasizing the role of surfactants and cosurfactants in creating stable formulations. In order to customize nanoemulsions to particular medication delivery requirements, the choice of components and production techniques is crucial in assuring the stability and efficacy of the finished product. Nanoemulsions are a cutting-edge technology with a lot of potential for improving medication bioavailability in a variety of therapeutic contexts. They are a useful tool in the creation of innovative pharmaceutical formulations due to their capacity to enhance drug solubility, stability, and delivery. Nanoemulsions are positioned to play a crucial role in boosting medication delivery and enhancing patient outcomes as this field of study continues to advance.

Recent developments in industrial applications of nanoemulsions

Nanotechnology is being utilized in various industries to increase the quality, safety, shelf-life, and functional performance of commercial products. Nanoemulsions are thermodynamically unstable colloidal dispersions that consist of at least two immiscible liquids (typically oil and water), as well as various stabilizers (including emulsifiers, texture modifiers, ripening inhibitors, and weighting agents). They have unique properties that make them particularly suitable for some applications, including their small droplet size, high surface area, good physical stability, rapid digestibility, and high bioavailability. This article reviews recent developments in the formulation, fabrication, functional performance, and gastrointestinal fate of nanoemulsions suitable for use in the pharmaceutical, cosmetic, nutraceutical, and food industries, as well as providing an overview of regulatory and health concerns. Nanoemulsion-based delivery systems can enhance the water-dispersibility, stability, and bioavailability of hydrophobic bioactive compounds. Nevertheless, they must be carefully formulated to obtain the required functional attributes. In particular, the concentration, size, charge, and physical properties of the nano-droplets must be taken into consideration for each specific application. Before launching a nanoscale product onto the market, determination of physicochemical characteristics of nanoparticles and their potential health and environmental risks should be evaluated. In addition, legal, consumer, and economic factors must also be considered when creating these systems.

Oral drug delivery for immunoengineering

The systemic pharmacotherapeutic efficacy of immunomodulatory drugs is heavily influenced by its route of administration. A few common routes for the systemic delivery of immunotherapeutics are intravenous, intraperitoneal, and intramuscular injections. However, the development of novel biomaterials, in adjunct to current progress in immunoengineering, is providing an exciting area of interest for oral drug delivery for systemic targeting. Oral immunotherapeutic delivery is a highly preferred route of administration due to its ease of administration, higher patient compliance, and increased ability to generate specialized immune responses. However, the harsh environment and slow systemic absorption, due to various biological barriers, reduces the immunotherapeutic bioavailability, and in turn prevents widespread use of oral delivery. Nonetheless, cutting edge biomaterials are being synthesized to combat these biological barriers within the gastrointestinal (GI) tract for the enhancement of drug bioavailability and targeting the immune system. For example, advancements in biomaterials and synthesized drug agents have provided distinctive methods to promote localized drug absorption for the modulation of local or systemic immune responses. Additionally, novel breakthroughs in the immunoengineering field show promise in the development of vaccine delivery systems for disease prevention as well as combating autoimmune diseases, inflammatory diseases, and cancer. This review will discuss current progress made within the field of biomaterials and drug delivery systems to enhance oral immunotherapeutic availability, and how these new delivery platforms can be utilized to deliver immunotherapeutics for resolution of immune-related diseases.

Nanomedicine based approaches for combating viral infections

Millions of people die each year from viral infections across the globe. There is an urgent need to overcome the existing gap and pitfalls of the current antiviral therapy which include increased dose and dosing frequency, bioavailability challenges, non-specificity, incidences of resistance and so on. These stumbling blocks could be effectively managed by the advent of nanomedicine. Current review emphasizes over an enhanced understanding of how different lipid, polymer and elemental based nanoformulations could be potentially and precisely used to bridle the said drawbacks in antiviral therapy. The dawn of nanotechnology meeting vaccine delivery, role of RNAi therapeutics in antiviral treatment regimen, various regulatory concerns towards clinical translation of nanomedicine along with current trends and implications including unexplored research avenues for advancing the current drug delivery have been discussed in detail.

Nanotechnology Interventions in the Management of COVID-19: Prevention, Diagnosis and Virus-Like Particle Vaccines

SARS-CoV-2 claimed numerous lives and put nations on high alert. The lack of antiviral medications and the small number of approved vaccines, as well as the recurrence of adverse effects, necessitates the development of novel treatment ways to combat COVID-19. In this context, using databases such as PubMed, Google Scholar, and Science Direct, we gathered information about nanotechnology's involvement in the prevention, diagnosis and virus-like particle vaccine development. This review revealed that various nanomaterials like gold, polymeric, graphene and poly amino ester with carboxyl group coated magnetic nanoparticles have been explored for the fast detection of SARS-CoV-2. Personal protective equipment fabricated with nanoparticles, such as gloves, masks, clothes, surfactants, and Ag, TiO2 based disinfectants played an essential role in halting COVID-19 transmission. Nanoparticles are used not only in vaccine delivery, such as lipid nanoparticles mediated transport of mRNA-based Pfizer and Moderna vaccines, but also in the development of vaccine as the virus-like particles elicit an immune response. There are now 18 virus-like particle vaccines in pre-clinical development, with one of them, developed by Novavax, reported being in phase 3 trials. Due to the probability of upcoming COVID-19 waves, and the rise of new diseases, the future relevance of virus-like particles is imperative. Furthermore, psychosocial variables linked to vaccine reluctance constitute a critical problem that must be addressed immediately to avert pandemic.

Lipid Nanocarriers for Anti-HIV Therapeutics: A Focus on Physicochemical Properties and Biotechnological Advances

Since HIV was first identified, and in a relatively short period of time, AIDS has become one of the most devastating infectious diseases of the 21st century. Classical antiretroviral therapies were a major step forward in disease treatment options, significantly improving the survival rates of HIV-infected individuals. Even though these therapies have greatly improved HIV clinical outcomes, antiretrovirals (ARV) feature biopharmaceutic and pharmacokinetic problems such as poor aqueous solubility, short half-life, and poor penetration into HIV reservoir sites, which contribute to the suboptimal efficacy of these regimens. To overcome some of these issues, novel nanotechnology-based strategies for ARV delivery towards HIV viral reservoirs have been proposed. The current review is focused on the benefits of using lipid-based nanocarriers for tuning the physicochemical properties of ARV to overcome biological barriers upon administration. Furthermore, a correlation between these properties and the potential therapeutic outcomes has been established. Biotechnological advancements using lipid nanocarriers for RNA interference (RNAi) delivery for the treatment of HIV infections were also discussed.

Nanotechnology-based antiviral therapeutics

The host immune system is highly compromised in case of viral infections and relapses are very common. The capacity of the virus to destroy the host cell by liberating its own DNA or RNA and replicating inside the host cell poses challenges in the development of antiviral therapeutics. In recent years, many new technologies have been explored for diagnosis, prevention, and treatment of viral infections. Nanotechnology has emerged as one of the most promising technologies on account of its ability to deal with viral diseases in an effective manner, addressing the limitations of traditional antiviral medicines. It has not only helped us to overcome problems related to solubility and toxicity of drugs, but also imparted unique properties to drugs, which in turn has increased their potency and selectivity toward viral cells against the host cells. The initial part of the paper focuses on some important proteins of influenza, Ebola, HIV, herpes, Zika, dengue, and corona virus and those of the host cells important for their entry and replication into the host cells. This is followed by different types of nanomaterials which have served as delivery vehicles for the antiviral drugs. It includes various lipid-based, polymer-based, lipid-polymer hybrid-based, carbon-based, inorganic metal-based, surface-modified, and stimuli-sensitive nanomaterials and their application in antiviral therapeutics. The authors also highlight newer promising treatment approaches like nanotraps, nanorobots, nanobubbles, nanofibers, nanodiamonds, nanovaccines, and mathematical modeling for the future. The paper has been updated with the recent developments in nanotechnology-based approaches in view of the ongoing pandemic of COVID-19.Graphical abstract.

Nanoemulsion Improves the Neuroprotective Effects of Curcumin in an Experimental Model of Parkinson's Disease

Parkinson's disease (PD) is a neurodegenerative disorder characterized by motor dysfunction. Recent studies have shown that curcumin (CUR) has neuroprotective effects in PD experimental models. However, its efficacy is limited due to low water solubility, bioavailability, and access to the central nervous system. In this study, we compared the effects of new curcumin-loaded nanoemulsions (NC) and free CUR in an experimental model of PD. Adult Swiss mice received NC or CUR (25 and 50 mg/kg) or vehicle orally for 30 days. Starting on the eighth day, they were administered rotenone (1 mg/kg) intraperitoneally until the 30th day. At the end of the treatment, motor assessment was evaluated by open field, pole test, and beam walking tests. Oxidative stress markers and mitochondrial complex I activity were measured in the brain tissue. Both NC and CUR treatment significantly improved motor impairment, reduced lipoperoxidation, modified antioxidant defenses, and prevented inhibition of complex I. However, NC was more effective in preventing motor impairment and inhibition of complex I when compared to CUR in the free form. In conclusion, our results suggest that NC effectively enhances the neuroprotective potential of CUR and is a promising nanomedical application for PD.

Critical Review of Lipid-Based Nanoparticles as Carriers of Neuroprotective Drugs and Extracts

The biggest obstacle to the treatment of diseases that affect the central nervous system (CNS) is the passage of drugs across the blood-brain barrier (BBB), a physical barrier that regulates the entry of substances into the brain and ensures the homeostasis of the CNS. This review summarizes current research on lipid-based nanoparticles for the nanoencapsulation of neuroprotective compounds. A survey of studies on nanoemulsions (NEs), nanoliposomes/nanophytosomes and solid lipid nanoparticles (SLNs)/nanostructured lipid carriers (NLCs) was carried out and is discussed herein, with particular emphasis upon their unique characteristics, the most important parameters influencing the formulation of each one, and examples of neuroprotective compounds/extracts nanoencapsulated using these nanoparticles. Gastrointestinal absorption is also discussed, as it may pose some obstacles for the absorption of free and nanoencapsulated neuroprotective compounds into the bloodstream, consequently hampering drug concentration in the brain. The transport mechanisms through which compounds or nanoparticles may cross BBB into the brain parenchyma, and the potential to increase drug bioavailability, are also discussed. Additionally, factors contributing to BBB disruption and neurodegeneration are described. Finally, the advantages of, and obstacles to, conventional and unconventional routes of administration to deliver nanoencapsulated neuroprotective drugs to the brain are also discussed, taking into account the avoidance of first-pass metabolism, onset of action, ability to bypass the BBB and concentration of the drug in the brain.

Nanomedicine for COVID-19: the role of nanotechnology in the treatment and diagnosis of COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the recent outbreak of coronavirus 2019 (COVID-19). Although nearly two decades have passed since the emergence of pandemics such as SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV), no effective drug against the CoV family has yet been approved, so there is a need to find newer therapeutic targets. Currently, simultaneous research across the globe is being performed to discover efficient vaccines or drugs, including both conventional therapies used to treat previous similar diseases and emerging therapies like nanomedicine. Nanomedicine has already proven its value through its application drug delivery and nanosensors in other diseases. Nanomedicine and its components can play an important role in various stages of prevention, diagnosis, treatment, vaccination, and research related to COVID-19. Nano-based antimicrobial technology can be integrated into personal equipment for the greater safety of healthcare workers and people. Various nanomaterials such as quantum dots can be used as biosensors to diagnose COVID-19. Nanotechnology offers benefits from the use of nanosystems, such as liposomes, polymeric and lipid nanoparticles, metallic nanoparticles, and micelles, for drug encapsulation, and facilitates the improvement of pharmacological drug properties. Antiviral functions for nanoparticles can target the binding, entry, replication, and budding of COVID-19. The toxicity-related inorganic nanoparticles are one of the limiting factors of its use that should be further investigated and modified. In this review, we are going to discuss nanomedicine options for COVID-19 management, similar applications for related viral diseases, and their gap of knowledge.

Dye-Loaded Nanoemulsions: Biomimetic Fluorescent Nanocarriers for Bioimaging and Nanomedicine

Lipid nanoemulsions (NEs), owing to their controllable size (20 to 500 nm), stability and biocompatibility, are now frequently used in various fields, such as food, cosmetics, pharmaceuticals, drug delivery, and even as nanoreactors for chemical synthesis. Moreover, being composed of components generally recognized as safe (GRAS), they can be considered as "green" nanoparticles that mimic closely lipoproteins and intracellular lipid droplets. Therefore, they attracted attention as carriers of drugs and fluorescent dyes for both bioimaging and studying the fate of nanoemulsions in cells and small animals. In this review, the composition of dye-loaded NEs, methods for their preparation, and emerging biological applications are described. The design of bright fluorescent NEs with high dye loading and minimal aggregation-caused quenching (ACQ) is focused on. Common issues including dye leakage and NEs stability are discussed, highlighting advanced techniques for their characterization, such as Förster resonance energy transfer (FRET) and fluorescence correlation spectroscopy (FCS). Attempts to functionalize NEs surface are also discussed. Thereafter, biological applications for bioimaging and single-particle tracking in cells and small animals as well as biomedical applications for photodynamic therapy are described. Finally, challenges and future perspectives of fluorescent NEs are discussed.

The influence of nanodelivery systems on the antioxidant activity of natural bioactive compounds

Bioactive compounds may lose their antioxidant activity (e.g., phenolic compounds) at elevated temperatures, enhanced oxidative conditions and severe light exposures so they should be protected by various strategies such as nano/microencapsulation methods. Encapsulation technology has been employed as a proper method for using antioxidant ingredients and to provide easy dispersibility of antioxidants in all matrices including food and pharmaceutical products. It can improve the food fortification processes, release of antioxidant ingredients, and extending the shelf-life and bioavailability of them when ingested in the intestine. In this study, our main goal is to have an overview of the influence of nanoencapsulation on the bioactivity and bioavailability, and cellular activities of antioxidant ingredients in different delivery systems. Also, the effect of encapsulation process conditions, storage conditions, carrier wall materials, and release profile on the antioxidant activity of different natural bioactives are explained. Finally, analytical techniques for measuring antioxidant activity of nanoencapsulated ingredients will be covered.

Incorporation of docosahexaenoic acid (DHA) enhances nanodelivery of antiretroviral across the blood-brain barrier for treatment of HIV reservoir in brain

Although the newer antiretroviral (ARV) drugs are highly active against the human immunodeficiency virus (HIV) in the body compartment, they often fail to effectively tackle the HIV reservoir in the brain because of inefficient penetration to the blood-brain barrier (BBB). In this study, we investigated the potential benefits of incorporating docosahexaenoic acid (DHA), an omega-3 fatty acid essential for brain development, in lipid nanocarriers for facilitating the BBB passage of an ARV darunavir. The resulting nanocarriers (nanoARVs) containing 5-15% DHA were 90-140 nm in size, had high darunavir payload (~11-13% w/w), good stability and minimal cellular toxicity, and could be further decorated with transferrin (Tf) for Tf-receptor targeting. In BBB models of hCMEC/d3 cells, nanoARVs with higher DHA content achieved increased nanocarrier uptake and up to 8.99-fold higher darunavir permeation than free darunavir. In animals, nanoARVs were able to achieve 3.38-5.93-fold increase in brain darunavir level over free darunavir. Tf-conjugated nanoARVs also achieved significantly higher anti-HIV activity than free darunavir (viral titer 2 to 2.6-fold higher in latter group). Comparison of DHA incorporation and Tf-receptor targeting showed that while both strategies could enhance the cellular uptake and brain accumulation of the nanocarriers, DHA was more effective (P < 0.05) for improving BBB permeation and brain accumulation of the darunavir payload. Substituting DHA with another oil noticeably reduced the cellular uptake of nanoARVs. Overall, this proof-of-concept study has supported the development of DHA-based nanoARVs as an effective, safe yet technically simple strategy to enhance brain delivery of darunavir and potentially other lipophilic ARVs for treatment of HIV reservoir.

Preparation, optimization and preliminary pharmacokinetic study of curcumin encapsulated turmeric oil microemulsion in zebra fish

The present investigation aimed to develop curcumin loaded turmeric oil microemulsion for brain targeting. An effort has been made to investigate the role of functional components in developing brain targeted formulation which could enhance the bioavailability and uptake of drug in the brain upon oral administration. Preliminary studies like solubility study, emulsification study and construction of the pseudo ternary phase diagram were performed for screening components. The formulation was optimized by using extreme vertices mixture design. The optimized formulation was characterized for appearance, stability to centrifugation, dilution potential, globule size, zeta potential and drug content. Furthermore, ex-vivo permeation in chicken gut sac non everted technique and pharmacokinetic study in adult zebra fishes were carried out. The optimized formulation was found to clear, yellow-colored with the absence of phase separation and precipitation denoted the stability of formulation to centrifugation and dilution. The mean globule size, polydispersity index, zeta potential and drug content was observed as 29.13± 0.12 nm, 0.23 ± 0.01,-12.33 ± 1.37 mV and 99.10±3.91 %, respectively. Ex vivo permeation study revealed 2.41 fold enhancement in the steady-state flux when compared to curcumin solution. Furthermore, optimized formulation showed shorter T_max (5 min) and higher AUC_(0-∞) (7.93 μg/brain*min) compared to the curcumin solution which showed similar T_max and AUC_(0-∞) of 2.78 μg/brain*min after oral administration to zebra fishes revealing 3.97 fold enhancement. The results revealed enhanced ex vivo oral absorption and enhanced in vivo brain pharmacokinetics of curcumin via functional microemulsion in the zebra fish model.

Nanosized Cubosomal Thermogelling Dispersion Loaded with Saquinavir Mesylate to Improve Its Bioavailability: Preparation, Optimization, in vitro and in vivo Evaluation

Background

Low bioavailability and poor permeability of the blood-brain barrier are problematic when delivering therapeutic agents and particularly anti-human immunodeficiency virus therapy to the central nervous system. The intranasal route offers an alternative for central nervous system delivery. Cubosomes have been reported as helpful vehicles for intranasal delivery of therapeutics to enable brain targeting.

Objective

In this study, we aimed to develop the intranasal cubosomal thermogelling dispersion of saquinavir mesylate for central nervous system delivery.

Methods

The Box-Behnken design was applied to study the effect of monoolein, Poloxamer 407, and polyvinyl alcohol as independent factors and the particle size, entrapment efficiency, gelation temperature, and stability index as responses. The optimized cubosomes were evaluated using transmission electron microscopy, ex vivo permeation, and in vivo pharmacokinetics.

Results

The optimized formula consisting of monoolein (8.96%), Poloxamer 407 (17.45%), and polyvinyl alcohol (7.5%) was prepared and evaluated. Higher values for the steady-state flux, permeability coefficient, and enhancement factor were observed for the cubosomal thermogelling dispersion of saquinavir during ex vivo permeation in comparison with an aqueous suspension of saquinavir. From the pharmacokinetic profile, the relative bioavailability for the intranasal optimized formula was approximately 12-fold higher when compared with oral aqueous suspension and 2.5-fold greater when compared to the intranasal aqueous suspension of saquinavir.

Conclusion

Overall, the saquinavir-loaded cubosomal thermogelling formulation is promising for central nervous system delivery by intranasal administration.

Drug Delivery and Targeting to the Brain Through Nasal Route: Mechanisms, Applications and Challenges

Blood-brain barrier (BBB) provides restrictions for the transportation of various therapeutic agents to the brain. Efforts to directly target the brain by olfactory as well as trigeminal nerve pathway, bypassing BBB, have grown significantly in recent times. The intranasal route of transportation of the drug encompasses ability for the delivery of drug directly to the brain, improves site-specificity in the brain and avoids systemic side effects. In the current era, novel drug delivery systems are useful tools for targeting the brain without providing any harmful effects in nasal mucosa as well as the central nervous system. The complex structure of nasal cavity, mucociliary clearance, degradation by the enzymes present in nasal cavity and pathological conditions like rhinitis, common cold, etc. are the major disputes for nasal drug delivery. The use of nanotechnological approaches like solid lipid nanoparticles, polymeric nanoparticles, nanoemulsions, liposomes and polymeric micelles provides the ability to overcome these barriers. There are several emerging nasal drug delivery technologies produced by various pharmaceutical companies to conquer these hurdles. This review tries to address the recent developments in the area of direct drug delivery to the brain through the nasal route.

Optimization of composition and obtainment parameters of biocompatible nanoemulsions intended for intraductal administration of piplartine (piperlongumine) and mammary tissue targeting

As a new strategy for treatment of ductal carcinoma in situ, biocompatible and bioadhesive nanoemulsions for intraductal administration of the cytotoxic agent piplartine (piperlongumine) were optimized in this study. To confer bioadhesive properties, the nanoemulsion was modified with chitosan or hyaluronic acid. Tricaprylin was selected as the nanoemulsion non-polar phase due to its ability to dissolve larger drug amounts compared to isopropyl myristate and monocaprylin. Use of phosphatidylcholine as sole surfactant did not result in a homogeneous nanoemulsion, while its association with polysorbate 80 and glycerol (in a surfactant blend) led to the formation of nanoemulsions with droplet size of 76.5 ± 1.2 nm. Heating the aqueous phase to 50 °C enabled sonication time reduction from 20 to 10 min. Inclusion of either chitosan or hyaluronic acid resulted in nanoemulsions with similar in vitro bioadhesive potential, and comparable ability to prolong mammary tissue retention (to 120 h) in vivo without causing undesirable histological alterations. Piplartine was stable in both nanoemulsions for 60 days; however, the size of loaded NE-HA was maintained at a similar range for longer periods of time, suggesting that this nanoemulsion may be a stronger candidate for intraductal delivery.

Nanotechnology approaches for delivery of cytochrome P450 substrates in HIV treatment

Introduction: Antiretroviral therapy (ART) has led to a significant reduction in HIV-1 morbidity and mortality. Many antiretroviral drugs (ARVs) are metabolized by cytochrome P450 (CYP) pathway, and the majority of these drugs are also either CYP inhibitors or inducers and few possess both activities. These CYP substrates, when used for HIV treatment in the conventional dosage form, have limitations such as low systemic bioavailability, potential drug-drug interactions, and short half-lives. Thus, an alternative mode of delivery is needed in contrast to conventional ARVs. Areas covered: In this review, we summarized the limitations of conventional ARVs in HIV treatment, especially for ARVs which are CYP substrates. We also discussed the preclinical and clinical studies using the nanotechnology strategy to overcome the limitations of these CYP substrates. The preclinical studies and clinical studies published from 2000 to February 2019 were discussed. Expert opinion: Since preclinical and clinical studies for prevention and treatment of HIV using nanotechnology approaches have shown considerable promise in recent years, nanotechnology could become an alternative strategy for daily oral therapy as a future treatment.

Enhanced Oral Bioavailability of Ibrutinib Encapsulated Poly (Lactic-co- Glycolic Acid) Nanoparticles: Pharmacokinetic Evaluation in Rats

Background:

The poor oral bioavailability of newly discovered chemical entities and marketed formulations are usually related to poor aqueous solubility or poor permeability, leading to drug failure in the development phases or therapeutic failure in a clinical setting. However, advancement in drug formulations and delivery technologies have enabled scientists to improve the bioavailability of formulations by enhancing solubility or permeability.

Objective:

This study reports the enhancement of the oral bioavailability of ibrutinib (IBR), a poorly soluble anticancer drug in Wistar albino rats.

Methods:

IBR loaded nanoparticles were formulated through the nanoprecipitation method by utilizing poly lactide-co-glycolide (PLGA) as a safe, biodegradable and biocompatible polymer, and poloxamer or pluronic 127 as a stabilizer. Animals were administered with a dose of 10 mg/kg of IBR suspension or an equivalent amount of IBR loaded nanoparticles. Plasma samples were extracted and analyzed by state of the art UPLC-MS/MS technique. Pharmacokinetic (PK) parameters and bioavailability were calculated by non-compartmental analysis.

Results:

There was an approximately 4.2-fold enhancement in the oral bioavailability of IBR-loaded nanoparticles, as compared to the pure IBR suspension. The maximum plasma concentration (Cmax; 574.31 ± 56.20 Vs 146.34 ± 5.37 ng/mL) and exposure (AUC; 2291.65 ± 263.83 vs 544.75 ± 48.33 ng* h/mL) of IBR loaded nanoparticles were significantly higher than those exhibited through pure IBR suspension.

Conclusion:

The outcomes of the present study suggested the potential of PLGA nanoparticles in the enhancement of bioavailability and the therapeutic efficacy of IBR.

Improved oral bioavailability of repaglinide, a typical BCS Class II drug, with a chitosan-coated nanoemulsion

The aim of the present study was to develop modified nanoemulsions to improve the oral bioavailability and pharmacokinetics of a poor water-soluble drug, repaglinide (RPG). The repaglinide-loaded nanoemulsions (RPG-NEs) were prepared from olive oil as internal phase, span 80, tween 80, and poloxamer 188 as emulsifiers, using homogenization technique. The mean droplet size, zeta potential, and entrapment efficiency of RPG-NEs were 86.5 ± 3.4 nm, -33.8 ± 2.1 mV, and 96.3 ± 2.3%, respectively. The chitosan-coated RPG-NEs (Cs-RPG-NEs) showed an average droplet size of 149.3 ± 3.9 nm and a positive zeta-potential of +31.5 ± 2.8 mV. Drug release profile of RPG-NEs was significantly higher than free drug in the simulated gastrointestinal fluids (p < .005). The in vivo study revealed 3.51- and 1.78-fold increase in the AUC_0-12h and C_max of the drug, respectively, in RPG-NEs-receiving animals in comparison to the free drug. The pharmacokinetic analysis confirmed that Cs-RPG-NEs were more efficient than uncoated ones for the oral delivery of RPG. Cs-RPG-NEs showed a longer t_1/2 and higher AUC_0-∞ compared to control group. The relative bioavailability of Cs-RPG-NEs was higher than that of uncoated RPG-NEs and free drug. Collectively, these findings suggest that chitosan-coated nanoemulsions are promising carrier for improving the oral bioavailability of RPG.

Nanoemulsions in CNS drug delivery: recent developments, impacts and challenges

Despite enormous efforts, treatment of CNS diseases remains challenging. One of the main issues causing this situation is limited CNS access for the majority of drugs used as part of the therapeutic regimens against life-threatening CNS diseases. Regarding the inarguable position of the nanocarrier systems in neuropharmacokinetic enhancement of the CNS drugs, this review discusses the latest findings on nanoemulsions (NEs) as one of the most promising candidates of this type, to overcome the challenges of CNS drug delivery. Future development of NE-based CNS drug delivery needs to consider so many aspects not only from a physicochemical point of view but also related to the biointerface of these very small droplets before achieving clinical value.

Nanoemulsions for "Nose-to-Brain" Drug Delivery

The blood–brain barrier (BBB) plays a fundamental role in protecting the brain from toxic substances and therefore also controls and restricts the entry of therapeutic agents. The nasal administration of drugs using the nose-to-brain pathway allows direct drug targeting into the brain, avoiding the first-pass effect and bypassing the BBB. Through the nasal route, the drug can access the brain directly along the trigeminal and olfactory nerves, which are located in the upper part of the nasal cavity. Nanoemulsions are formulations belonging to the field of nanomedicine. They consist of emulsions (commonly oil in water) stabilized by one or more surfactants—and eventually co-surfactants—delivered in droplets of small dimensions (sizes of 100–300 nm or less) with a high surface area. A mucoadhesive polymer such as chitosan can be added to the formulation to impair rapid nasal clearance. Nanoemulsions represent promising formulations to deliver drugs directly into the brain through the intranasal route. Therefore, they can be used as a possible alternative to oral administration, avoiding problems such as low solubility in water, poor bioavailability, enzymatic degradation and slow onset of action. This review focuses the present situation in literature regarding the use of nanoemulsions for nose-to-brain targeting, with particular attention to recent publications. Nasal nanoemulsions appear to be effective, non-invasive and safe drug delivery systems to achieve brain targeting for the treatment of neurological diseases.

Insights on Oral Drug Delivery of Lipid Nanocarriers: a Win-Win Solution for Augmenting Bioavailability of Antiretroviral Drugs

The therapeutic functionality of innumerable antiretroviral drugs is supposedly obscured owing to their low metabolic stability in the gastrointestinal tract and poor solubilization property leading to poor oral bioavailability. Dictated by such needs, lipid-based formulations could be tailored using nanotechnology which would be instrumental in ameliorating the attributes of such drugs. The stupendous advantages which lipid nanocarriers offer including improved drug stability and peroral bioavailability coupled with sustained drug release profile and feasibility to incorporate wide array of drugs makes it a potential candidate for pharmaceutical formulations. Furthermore, they also impart targeted drug delivery thereby widening their arena for use. Therefore, the review will encompass the details pertaining to numerous lipid nanocarriers such as nanoemulsion, solid lipid nanoparticle, nanostructured lipid carriers, and so on. These nanocarriers bear the prospective of improving the mucosal adhesion property of the drugs which ultimately upgrades its pharmacokinetic profile. The biodegradable and physiological nature of the lipid excipients used in the formulation is the key parameter and advocates for their safe use. Nevertheless, these lipid-based nanocarriers are amenable to alterations which could be rightly achieved by changing the excipients used or by modifying the process parameters. Thus, the review will systematically envisage the impending benefits and future perspectives of different lipid nanocarriers used in oral delivery of antiretroviral drugs.

Basic principles of drug delivery systems - the case of paclitaxel

Cancer is the second cause of death worldwide, exceeded only by cardiovascular diseases. The prevalent treatment currently used against metastatic cancer is chemotherapy. Among the most studied drugs that inhibit neoplastic cells from acquiring unlimited replicative ability (a hallmark of cancer) are the taxanes. They operate via a unique molecular mechanism affecting mitosis. In this review, we show this mechanism for one of them, paclitaxel, and for other (non-taxanes) anti-mitotic drugs. However, the use of paclitaxel is seriously limited (its bioavailability is <10%) due to several long-standing challenges: its poor water solubility (0.3 μg/mL), its being a substrate for the efflux multidrug transporter P-gp, and, in the case of oral delivery, its first-pass metabolism by certain enzymes. Adequate delivery methods are therefore required to enhance the anti-tumor activity of paclitaxel. Thus, we have also reviewed drug delivery strategies in light of the various physical, chemical, and enzymatic obstacles facing the (especially oral) delivery of drugs in general and paclitaxel in particular. Among the powerful and versatile platforms that have been developed and achieved unprecedented opportunities as drug carriers, microemulsions might have great potential for this aim. This is due to properties such as thermodynamic stability (leading to long shelf-life), increased drug solubilization, and ease of preparation and administration. In this review, we define microemulsions and nanoemulsions, analyze their pertinent properties, and review the results of several drug delivery carriers based on these systems.

Enhancement of saquinavir absorption and accumulation through the formation of solid drug nanoparticles

Background

Nanotechnology is now considered a promising drug delivery method for orally administered hydrophobic drugs to their sites of action. The effect of nanodispersion on cellular transport and accumulation of saquinavir (SQV) was investigated.

Methods

The transport of five solid drug nanoparticle (SDN) SQV formulations along Caco-2 cell monolayers (CCM) was compared to that of standard SQV. The SDNs were prepared using SQV mesylate (20%), Pluronic F127 (10%) plus five other excipients (HPMC, PVP, PVA, Lecithin S75 and Span 80) in different proportions. Cellular accumulation in CEM parental and CEMVBL (P-gp overexpressing) cells was conducted to ascertain the effect of nanodispersion on P-gp mediated efflux of SQV. All SDN formulations were dissolved in water, whereas SQV in DMSO to improve solubility. Quantification was via HPLC.

Results

From transport results, an SDN sample composed of SQV mesylate/Pluronic F127 plus HPMC (70%) and had a 24% increase in apparent absorption compared to standard SQV, largely driven by a 38% reduction in basolateral to apical permeation. Additionally, the formulation and two others (SQV mesylate/Pluronic F127 alone; and + HPMC (65%)/Lecithin [5%]) accumulated more significantly in CEM cells, suggesting enhanced delivery to these cells. Moreover, accumulation and transport of the three SDNs compared well to that of SQV despite being dissolved in water, suggestive of improved dissolution. The inclusion of PVA resulted in increased efflux.

Conclusion

The use of HPMC and Pluronic F127 produced SQV SDNs with improved permeation in Caco-2 cells and improved accumulation in CEM cells, but negative effects with PVA.

N,N,N‑trimethyl chitosan modified flaxseed oil based mucoadhesive neuronanoemulsions for direct nose to brain drug delivery

Here we fabricated flaxseed oil-based neuronanoemulsions (NNEs) which were further surface-modified with a mucoadhesive polymer, N,N,N‑trimethyl chitosan (TMC) to form mucoadhesive neuronanoemulsions (mNNEs). The NNEs were loaded with high partitioning ropinirole-dextran sulfate (ROPI-DS) nanoplex and fabricated using hot high-pressure homogenization (HPH) technique. NNEs were optimized using Central Composite experimental design. TMC modified mNNE have not been prepared yet for direct nose to brain drug delivery. Here, an objective to provide controlled drug release with prolonged residence on the nasal mucosa for the treatment of Parkinson's disease (PD) is at prime consideration. Enhanced brain targeting through BBB bypass drug delivery, improved therapeutic efficacy through enhanced retention of mNNE formulation over nasal mucosal membrane, reduced dose and frequency of administration, and safety were further expected outcomes of this experiment. The mNNE formulation was subjected to 6 month stability assessment. The mNNE formulation was administered to the Swiss albino mice model via intranasal route and both, the plasma and brain pharmacokinetics were estimated. The in vivo studies performed on mice exhibited high brain targeting efficiency of mNNE formulation through nose to brain delivery via olfactory pathway. The prepared intranasal mNNEs could be on the clinics, if investigated more for behavioral and neurotoxicity studies.

Soft- and hard-lipid nanoparticles: a novel approach to lymphatic drug delivery

With the current advance in nanotechnology, the development has accelerated of a number of nanoparticle-type drugs such as nano-emulsions, lipid emulsions, liposomes, and cell therapeutics. With these developments, attempts are being made to apply these new drugs to healing many intractable diseases related to antibody production, autoimmune disorders, cancer, and organ transplantation in both clinical and nonclinical trials. Drug delivery to the lymphatic system is indispensable for treating these diseases, but the core technologies related to the in vivo distribution characteristics and lymphatic delivery evaluation of these particle-type drugs have not yet been established. Additionally, the core technologies for setting up the pharmacotherapeutic aspects such as their usage and dosages in the development of new drugs do not meet the needs of the market. Therefore, it is necessary to consider dividing these particle-type drugs into soft-lipid nanoparticles that can change size in the process of body distribution and hard-lipid nanoparticles whose surfaces are hardened and whose sizes do not easily change in vivo; these soft- and hard-lipid nanoparticles likely possess different biodistribution characteristics including delivery to the lymphatic system. In this review, we summarize the different types, advantages, limitations, possible remedies, and body distribution characteristics of soft- and hard-lipid nanoparticles based on their administration routes. We also emphasize that it will be necessary to fully understand the differences in distribution between these soft- and hard-lipid nanoparticle-type drugs and to establish pharmacokinetic models for their more ideal lymphatic delivery.

Chemical Characterization, Analgesic, Antioxidant, and Anticholinesterase Potentials of Essential Oils From Isodon rugosus Wall. ex. Benth

Isodon rugosus Wall. ex. Benth is an important species and is used in folk medicine for different types of pains such as abdominal pain, earache, toothache, gastric, and generalized body pain. Recently, we also have reported the antinociceptive potential of chloroform fraction of I. rugosus. In this research, we have investigated the antinociceptive, antioxidant and anti-cholinesterase potentials of essential oils from I. rugosus (Ir.EO), and have determined a possible mechanism of anti-nociception. The Ir.EO was subjected to gas chromatography-mass spectroscopy analysis to find out its chemical constituents. The Ir.EO was assayed for analgesic potential following acetic acid induced writhing, formalin test and hot plate method in animal models. The antioxidant activity was conducted against DPPH and ABTS free radicals following spectroscopic analysis. The cholinesterase inhibitory assays were performed using Ellman's assay. The GC-MS analysis of Ir.EO revealed the identification of 141 compounds. Ir.EO demonstrated strong antinociceptive potential in all three in-vivo models. With the use of nalaxone, it was confirmed that the essential oil was acting on the central pathway of nociception. The Ir.EO also exhibited strong free radicals scavenging potential, exhibiting IC₅₀ values of 338 and 118 μg/ml for DPPH and ABTS free radicals respectively. In AChE and BChE inhibitory assays, the observed IC₅₀ values were 93.56 and 284.19 μg/ml respectively. The encouraging antinociceptive, antioxidant and anticholinesterase results revealed that Ir.EO is a rich source of bioactive compounds as obvious from the GC-MS results.

Nanotechnology approaches to eradicating HIV reservoirs

The advent of combination antiretroviral therapy (cART) has transformed HIV-1 infection into a controllable chronic disease, but these therapies are incapable of eradicating the virus to bring about an HIV cure. Multiple strategies have been proposed and investigated to eradicate latent viral reservoirs from various biological sanctuaries. However, due to the complexity of HIV infection and latency maintenance, a single drug is unlikely to eliminate all HIV reservoirs and novel strategies may be needed to achieve better efficacy while limiting systemic toxicity. In this review, we describe HIV latency in cellular and anatomical reservoirs, and present an overview of current strategies for HIV cure with a focus on their challenges for clinical translation. Then we provide a summary of nanotechnology solutions that have been used to address challenges in HIV cure by delivering physicochemically diverse agents for combination therapy or targeting HIV reservoir sites. We also review nanocarrier-based gene delivery and immunotherapy used in cancer treatment but may have potential applications in HIV cure.

Enhanced brain penetration of pretomanid by intranasal administration of an oil-in-water nanoemulsion

AIM

To enhance the drug delivery to the brain with an oil-in-water nanoemulsion of pretomanid via intranasal (IN) administration.

MATERIALS & METHODS

The study involved 70 male Sprague-Dawley rats (160-180 g) that received either 20 mg/kg body weight (b.w.) a nanoemulsion or a 20 mg/kg b.w. of pretomanid in solution via the IN route. The drug was quantified by liquid chromatography-tandem mass spectrometry to investigate whole tissue-drug concentrations, and mass spectrometric imaging to visualize drug localization in the brain.

RESULTS

Nanoemulsion delivery concentrations of pretomanid in the brain reached peak concentrations (C_max) of 12,062.3 ng/g that is significantly higher than the required therapeutic level. The mass spectrometric imaging analysis clearly showed a time dependent and uniform distribution in the brain.

CONCLUSION

The results of this study show that IN delivery of oil-in-water nanoemulsion may be very promising for targeting anatomical tuberculosis reservoirs, such as the brain.

Nanoemulsion as a strategy for improving the oral bioavailability and anti-inflammatory activity of andrographolide

Background

Andrographolide (AG), a compound with low water solubility, possesses various pharmacological activities, particularly anti-inflammatory activity. However, its low oral bioavailability is a major obstacle to its potential use. This study developed and optimized an AG-loaded nanoemulsion (AG-NE) formulation to improve AG oral bioavailability and its protective effects against inflammatory bowel disease.

Methods

A high-pressure homogenization technique was used to prepare the AG-NE and solubility, viscosity, and droplet size tests were conducted to develop the optimized AG-NE composed of α-tocopherol, ethanol, Cremophor EL, and water. The permeability was assessed using everted rat gut sac method and in vivo absorption and anti-inflammatory effect in rats was also evaluated. The plasma concentration of AG was determined using our validated high performance liquid chromatography method, which was used to generate a linear calibration curve over the concentration range of 0.1–25 μg/mL in rat plasma (R²>0.999).

Results

The optimized AG-NE had a droplet size of 122±11 nm confirmed using transmission electron microscopy and a viscosity of 28 centipoise (cps). It was stable at 4 and 25°C for 90 days. An ex vitro intestinal permeability study indicated that the jejunum was the optimal site for AG absorption from the optimized AG-NE, which was 8.21 and 1.40 times higher than that from an AG suspension and AG ethanol solution, respectively. The pharmacokinetic results indicate that the absorption of AG from AG-NE was significantly enhanced in comparison with that from the AG suspension, with a relative bioavailability of 594.3%. Moreover, the ulcer index and histological damage score of mice with indomethacin-induced intestinal lesions were significantly reduced by AG-NE pretreatment.

Conclusion

We conclude that the developed AG-NE not only enhanced the oral bioavailability of AG in this study but may also prove to be an effective formulation of AG for preventing gastrointestinal inflammatory disorders.

Rapamycin-Loaded, CapryolTM 90 and Oleic Acid Mediated Nanoemulsions: Formulation Development, Characterization and Toxicity Assessment

This study was planned to explore the capability of nanoemulsions (NEs) consisting of CapryolTM 90 and oleic acid for the delivery of rapamycin (RAP). Permeability and cytotoxicity of RAP-loaded NEs were also inspected. Pseudo-ternary phase diagrams were created with oleic acid and CapryolTM 90 (as oil phase) and four surfactants and co-surfactants at various weight ratios (Rsm). Selected NEs from O/W region on the phase diagrams with the drug concentration of 1 mg/mL, were prepared via the spontaneous emulsification technique, characterized for particle size and subjected to stability tests at various temperatures over 9-12 months. Cumulative drug release was determined for a period of 48 h using a dialysis sac. The assay of RAP was determined using HPLC technique. Cytotoxicity of NEs was evaluated by MTT assay on breast cancer cell line, namely SKBR-3. The permeability of RAP-loaded NEs across Caco-2 monolayers was assessed by measurement of TEER (transepithelial electrical resistance) value. The intracellular uptake of coumarin 6-loaded NEs by SKBR-3 cells was also investigated using florescence microscopy. NEs containing oleic acid/Tween 20/propylene glycol, CapryolTM 90/Tween 20/iso-propanol, and CapryolTM 90/Cremophor® RH40/Transcutol® P showed more cytotoxicity and permeability compared with the RAP methanolic solution. The minimum toxic concentration of RAP in NE formulations was found to be 7.5 µg/mL. The highest intracellular uptake was observed for the NE composed of CapryolTM 90/Tween 20/iso-propanol which was in consistent with the results obtained from cytotoxicity and permeability tests. The overall results implicated that this novel carrier was effective for enhancing RAP permeation in Caco-2 cell membrane along with enhancement of cytotoxicity.

Nano-ART and NeuroAIDS

Human immunodeficiency virus (HIV) is a neurotropic virus that enters the central nervous system (CNS) early in the course of infection. Although highly active antiretroviral therapy (HAART) has resulted in remarkable decline in the morbidity and mortality in AIDS patients, controlling HIV infections still remains a global health priority. HIV access to the CNS serves as the natural viral preserve because most antiretroviral (ARV) drugs possess inadequate or zero delivery across the brain barriers. The structure of the blood-brain barrier (BBB), the presence of efflux pumps, and the expression of metabolic enzymes pose hurdles for ARV drug-brain entry. Thus, development of target-specific, effective, safe, and controllable drug delivery approach is an important health priority for global elimination of AIDS progression. Nanoformulations can circumvent the BBB to improve CNS-directed drug delivery by affecting such pumps and enzymes. Alternatively, they can be optimized to affect their size, shape, and protein and lipid coatings to facilitate drug uptake, release, and ingress across the barrier. Improved drug delivery to the CNS would affect pharmacokinetic and drug biodistribution properties. This review focuses on how nanotechnology can serve to improve the delivery of antiretroviral medicines, termed NanoART, across the BBB and affect the biodistribution and clinical benefit for NeuroAIDS.

Polyunsaturated fatty acid-based targeted nanotherapeutics to enhance the therapeutic efficacy of docetaxel

Since breast cancer is one of the most lethal malignancies, targeted strategies are urgently needed. In this study, we report the enhanced therapeutic efficacy of docetaxel (DTX) when combined with polyunsaturated fatty acids (PUFA) for effective treatment of multi-resistant breast cancers. Folic acid (FA)-conjugated PUFA-based lipid nanoparticles (FA-PLN/DTX) was developed. The physicochemical properties, in vitro uptake, in vitro cytotoxicity, and in vivo anticancer activity of FA-PLN/DTX were evaluated. FA-PLN/DTX could efficiently target and treat human breast tumor xenografts in vivo. They showed high payload carrying capacity with controlled release characteristics and selective endocytic uptake in folate receptor-overexpressing MCF-7 and MDA-MB-231 cells. PUFA synergistically improved the anticancer efficacy of DTX in both tested cancer cell lines by inducing a G2/M phase arrest and cell apoptosis. Combination of PUFA and DTX remarkably downregulated the expression levels of pro-apoptotic and anti-apoptotic markers, and blocked the phosphorylation of AKT signaling pathways. Compared to DTX alone, FA-PLN/DTX showed superior antitumor efficacy, with no signs of toxic effects in cancer xenograft animal models. We propose that PUFA could improve the therapeutic efficacy of anticancer agents in cancer therapy. Further studies are necessary to fully understand these findings and achieve clinical translation.