Lipid-based nanocarriers for the oral administration of biopharmaceutics

Development of a novel squalene/α-tocopherol-based self-emulsified nanoemulsion incorporating Leishmania peptides for induction of antigen-specific immune responses

Vaccination has emerged as the most effective strategy to confront infectious diseases, among which is leishmaniasis, that threat public health. Despite laborious efforts there is still no vaccine for humans to confront leishmaniasis. Multi-epitope protein/peptide vaccines present a number of advantages, however their use along with appropriate adjuvants that may also act as antigen carriers is considered essential to overcome subunit vaccines' low immunogenicity. In the present study, a stable self-emulsified nanoemulsion was developed and double-adjuvanted with squalene and α-tocopherol. The prepared nanoemulsion droplets exhibited low cytotoxicity in a certain range of concentrations, while they were efficiently taken up by macrophages and dendritic cells in vitro as well as in vivo in secondary lymphoid organs. To further characterize nanoformulation's potent antigen delivery capability, three multi-epitope Leishmania peptides were incorporated into the nanoemulsion. Peptide encapsulation resulted in dendritic cells' functional differentiation characterized by elevated levels of maturation markers and intracellular cytokine production. Intramuscular administration of the nanoemulsion incorporating Leishmania peptides induced antigen-specific spleen cell proliferation as well as elicitation of CD4+ central memory cells, supporting the potential of the developed nanoformulation to successfully act also as an antigen delivery vehicle and thus encouraging further preclinical studies on its vaccine candidate potency.

Nanomaterials as a Potential Target for Infectious Parasitic Agents

Despite the technological advancement in the era of personalized medicine and therapeutics development, infectious parasitic causative agents remain one of the most challenging areas of research and development. The disadvantages of conventional parasitic prevention and control are the emergence of multiple drug resistance as well as the non-specific targeting of intracellular parasites, which results in high dose concentration needs and subsequently intolerable cytotoxicity. Nanotechnology has attracted extensive interest to reduce medication therapy adverse effects including poor bioavailability and drug selectivity. Numerous nanomaterials-based delivery systems have previously been shown in animal models to be effective in the treatment of various parasitic infections. This review discusses a variety of nanomaterials-based antiparasitic procedures and techniques as well as the processes that allow them to be targeted to different parasitic infections. This review focuses on the key prerequisites for creating novel nanotechnology-based carriers as a potential option in parasite management, specifically in the context of human-related pathogenic parasitic agents.

Nanocarriers transport across the gastrointestinal barriers: The contribution to oral bioavailability via blood circulation and lymphatic pathway

Oral administration is the preferred route of drug delivery in clinical practice due to its noninvasiveness, safety, convenience, and high patient compliance. The gastrointestinal tract (GIT) plays a crucial role in facilitating the targeted delivery of oral drugs. However, the GIT presents multiple barriers that impede drug absorption, including the gastric barrier in the stomach and the mucus and epithelial barriers in the intestine. In recent decades, nanotechnology has emerged as a promising approach for overcoming these challenges by utilizing nanocarrier-based drug delivery systems such as liposomes, micelles, polymeric nanoparticles, solid lipid nanoparticles, and inorganic nanoparticles. Encapsulating drugs within nanocarriers not only protects them from degradation but also enhances their transport and absorption across the GIT, ultimately improving oral bioavailability. The aim of this review is to elucidate the mechanisms underlying nanocarrier-mediated transportation across the GIT into systemic circulation via both the blood circulation and lymphatic pathway.

Formulation of Piperine-Loaded Nanoemulsion: In Vitro Characterization, Ex Vivo Evaluation, and Cell Viability Assessment

Piperine is an alkaloid, but its therapeutic efficacy is limited due to poor aqueous solubility. In this study, piperine nanoemulsions were prepared using oleic acid (oil), Cremophore EL (surfactant), and Tween 80 (co-surfactant) using the high-energy ultrasonication approach. The optimal nanoemulsion (N2) was further evaluated using transmission electron microscopy, release, permeation, antibacterial, and cell viability studies based on minimal droplet size and maximum encapsulation efficiency. The prepared nanoemulsions (N1-N6) showed a transmittance of more than 95%, a mean droplet size between 105 ± 4.11 and 250 ± 7.4 nm, a polydispersity index of 0.19 to 0.36, and a ζ potential of -19 to -39 mV. The optimized nanoemulsion (N2) showed significantly improved drug release and permeation compared with pure piperine dispersion. The nanoemulsions were stable in the tested media. The transmission electron microscopy image showed a spherical and dispersed nanoemulsion droplet. The antibacterial and cell line results of piperine nanoemulsions were significantly better than the pure piperine dispersion. The findings suggested that piperine nanoemulsions may be a more advanced nanodrug delivery system than conventional ones.

Chitosan-Coated Liposomes: The Strategy to Reduce Intestinal Toxicity and Improve Bioavailability of Oral Vinorelbine

In recent years, the oral administration of vinorelbine has gradually replaced intravenous administration in the treatment of several types of tumors. Even though the risk of phlebitis is avoided with oral administration, oral vinorelbine is still not a highly patient-compliant route due to the severe gastrointestinal toxicity. Vinorelbine-loaded liposomes with high encapsulation efficiency and suitable particle size were prepared using the ammonium sulfate gradient method. Chitosan-coated liposomes showed the slowest in vitro release compared to uncoated liposomes and vinorelbine solution. No damage was observed in the intestinal epithelial cells of mice orally administered with coated vinorelbine liposomes due to the low presence of the free drug in the gastrointestinal tract and the LD₅₀ was increased from 129.83 to 182.25 mg/kg compared to oral vinorelbine solution. In addition, the positive surface potential of chitosan-coating endowed liposomes with mucosal adhesive function, delaying the time to reach the peak plasma concentration of vinorelbine from 1 to 4 h after administration. And bioavailability was increased to 2.1-fold compared to vinorelbine solution. In short, a new strategy to address the severe gastrointestinal side effects of oral vinorelbine has been developed.

Targeted delivery and controlled released of essential oils using nanoencapsulation: A review

Essential oils (EOs) contain a complex mixture of volatile and non-volatile molecules with diverse biological activities, including flavoring, antioxidant, antimicrobial, and nutraceutical properties. As a result, EOs have numerous potential applications in the agriculture, food, and pharmaceutical industries. However, their hydrophobicity, chemical instability, and volatility pose a challenge for many of their applications. These challenges can often be overcome by encapsulation EOs in colloidal delivery systems. Over the last decade or so, nanoencapsulation and microencapsulation technologies have been widely explored for their potential to improve the handling, dispersibility, and stability of hydrophobic substances, as well as to control their release profiles (e.g., targeted, triggered, sustained, or burst release). These technologies include emulsification, coacervation, precipitation, spray-drying, spray-cooling, freeze-drying, fluidized bed coating, and extrusion. This article reviews some of the most important developments in EOs encapsulation, the physicochemical mechanisms underlying the behavior of encapsulated EOs, current challenges, and potential applications in the food and biomedical sciences. This review has found that nanoencapsulation has countless of potential advantages for the utilization of EOs in the food industry and can improve their water-dispersibility, food matrix compatibility, chemical stability, volatility, and bioactivity.

Development of Fluorescently Labeled Self-Emulsifying Drug Delivery Systems (SEDDS) for Prolonged Stability, In Vitro Sustained Release and Cellular Uptake

AIM

In this study, four fluorescein hydrophobic ionic complexes were formed with the cationic polymers Eudragit RS, Eudragit RL, Eudragit E, and polyethyleneimine (PEI) to provide fluorescein sustained release, sustained cellular uptake, and stability.

METHODS

Complexes were loaded in a self-emulsifying drug delivery system (SEDDS) composed of 40% Tween 80, 20% Kolliphor EL, 15% 2-n-Octyl-1-dodecanol, and 25% dipropylene glycol. SEDDS were investigated regarding their size, polydispersity index (PDI), zeta potential, and cytotoxicity. Fluorescein release from SEDDS was performed in phosphate buffer (pH 6.8 and pH 8) and the released fluorescein was evaluated for cellular uptake. Moreover, fluorescein from all of the SEDDS pre-concentrates was released at different time points to check its long-term stability over six months.

RESULTS

The average fluorescein load in SEDDS was 0.045%. SEDDS showed an average droplet size of 24.9 ± 1.6 nm with PDI ≤ 0.3. SEDDS complexes diluted 1:100 increased the zeta potential from -7.3 mV to +3.7 mV and provided > 85% cell viability. An 92.27 ± 3.18% fluorescein exhibited a few seconds of immediate release when used as control or PEI complex in SEDDS. On the contrary, Eudragit-fluorescein complexes in SEDDS showed sustained release of 87.01 ± 5.22% fluorescein in ≤ 70 min with 22.19 ± 14.56% and 59.27 ± 16.57% released at 10 min in pH 6.8 and pH 8 release media, respectively. Comparatively, the medium at pH 6.8 maintained a significantly improved sustained fluorescein release (p ≤ 0.001). Furthermore, Eudragit RS/RL compared to Eudragit E significantly exhibited a slower fluorescein release rate from SEDDS (p ≤ 0.01). The cellular uptake of the released fluorescein was 72.4 ± 8.2% for all SEDDS complexes after 3 h. Eudragit complexes compared to PEI complex in SEDDS significantly showed more sustained fluorescein cellular uptake at 1 h and 2 h (p ≤ 0.001). However, SEDDS complexes showed the longest fluorescein stability with PEI after six months, whereas fluorescein stability for SEDDS containing fluorescein as Eudragit complex and control showed 39.1% and 82.5% fluorescence decrease, respectively after three months.

CONCLUSION

In the developed SEDDS, the presence of hydrophobic ionic complexes can significantly promote longer stability and sustained cellular uptake of fluorescein while releasing in a sustained manner.

In-vitro and in-vivo evaluation of taste-masked ibuprofen formulated in oral dry emulsions

OBJECTIVE

The aim of this study was to develop a pediatric oral preparation for ibuprofen.

SIGNIFICANCE

Ibuprofen is widely used for defervescence in children, but medication compliance is poor due to its bitter taste. Dry emulsions possess good stability and can be transported and stored in solid form; they can be dispersed into liquid emulsions with water and easily administered to children.

METHODS

In this study, a dry emulsion excipient was prepared by spray drying: a mixture of orange peel and corn oils (3:7, w/w) was used as the oil phase and solvent for ibuprofen; gum arabic and gum tragacanth were chosen as emulsifiers; and maltodextrin was used as a solid carrier.

RESULTS

The particle sizes of the liquid and reconstituted emulsions were 5.75 µm and 6.11 µm, respectively; the average particle size distribution of the dry emulsion powder was 8.13 µm; scanning electron microscopy showed that the dry emulsion powder was composed of evenly distributed smooth spheres. At a drug loading of 36.52 ± 1.15 mg/g, 90% of ibuprofen was released from the dry emulsion excipient within 30 min. Sensory evaluations using human volunteers, rats, and an electronic tongue demonstrated that the emulsion had a taste-masking effect on ibuprofen. It was further corroborated by in vivo studies using a rat model that highlighted a 1.76-fold increase in ibuprofen absorption when the drug was administered as an emulsion compared with granules.

CONCLUSIONS

These results indicate that the dry emulsion for taste-masking is promising and valuable in the development of ibuprofen for pediatrics.

Dopamine-loaded lipid based nanocarriers for intranasal administration of the neurotransmitter: A comparative study

Both dopamine (DA) loaded Solid Lipid Nanoparticles (SLN) and liposomes (Lip), designed for intranasal administration of the neurotransmitter as an innovative Parkinson disease treatment, were already characterized in vitro in some extent by us (Trapani et al., 2018a and Cometa et al., 2020, respectively). Herein, to gain insight into the structure of SLN, X-ray Photoelectron Spectroscopy Analysis was carried out and DA-SLN (SLN 1) were found to exhibit high amounts of the neurotransmitter on the surface, whereas the external side of Glycol Chitosan (GCS) containing SLN (SLN 2) possessed only few amounts. However, SLN 2 were characterized by the highest encapsulation DA efficiency (i.e., 81%). Furthermore, in view of intranasal administration, mucoadhesion tests in vitro were also conducted for SLN and Lip formulations, evidencing high muchoadesive effect exerted by SLN 2. Concerning ex-vivo studies, SLN and Lip were found to be safe for Olfactory Ensheathing Cells and fluorescent SLN 2 were taken up in a dose-dependent manner reaching the 100% of positive cells, while Lip 2 (chitosan-glutathione-coated) were internalised by 70% OECs with six-times more lipid concentration. Hence, SLN 2 formulation containing DA and GCS may constitute interesting formulations for further studies and promising dosage form for non-invasive nose-to-brain neurotransmitter delivery.

Nanotechnology-aided diagnosis, treatment and prevention of leishmaniasis

Leishmaniasis is a prevalent parasitic infection belonging to neglected tropical diseases. It is caused by Leishmania protozoan parasites transmitted by sandflies and it is responsible for increased morbidity/mortality especially in low- and middle-income countries. The lack of cheap, portable, easy to use diagnostic tools exhibiting high efficiency and specificity impede the early diagnosis of the disease. Furthermore, the typical anti-leishmanial agents are cytotoxic, characterized by low patient compliance and require long-term regimen and usually hospitalization. In addition, due to the intracellular nature of the disease, the existing treatments exhibit low bioavailability resulting in low therapeutic efficacy. The above, combined with the common development of resistance against the anti-leishmanial agents, denote the urgent need for novel therapeutic strategies. Furthermore, the lack of effective prophylactic vaccines hinders the control of the disease. The development of nanoparticle-based biosensors and nanocarrier-aided treatment and vaccination strategies could advance the diagnosis, therapy and prevention of leishmaniasis. The present review intends to highlight the various nanotechnology-based approaches pursued until now to improve the detection of Leishmania species in biological samples, decrease the side effects and increase the efficacy of anti-leishmanial drugs, and induce enhanced immune responses, specifically focusing on the outcome of their preclinical and clinical evaluation.

Oral lipid nanomedicines: Current status and future perspectives in cancer treatment

Oral anticancer drugs have earned a seat at the table, as the need for homecare treatment in oncology has increased. Interest in this field is growing as a result of their proven efficacy, lower costs and positive patient uptake. However, the gastrointestinal barrier is still the main obstacle to surmount in chemotherapeutic oral delivery. Anticancer nanomedicines have been proposed to solve this quandary. Among these, lipid nanoparticles are described to be efficiently absorbed while protecting drugs from early degradation in hostile environments. Their intestinal lymphatic tropism or mucoadhesive/penetrative properties give them unique characteristics for oral administration. Considering that chronic cancer cases are increasing over time, it is important to be able to provide treatments with low toxicity and low prices. The challenges, opportunities and therapeutic perspectives of lipid nanoparticles in this area will be discussed in this review, taking into consideration the pre-clinical and clinical progress made in the last decade.

Lipid-nanopotentiated combinatorial delivery of tamoxifen and sulforaphane: ex vivo, in vivo and toxicity studies

Aim: This study aims to load tamoxifen (TAM) and sulforaphane (SFN) into nanostructured lipid carriers (NLCs) to enhance their oral delivery. Materials & methods: TAM-SFN-NLCs were prepared using Precirol® ATO5 and Transcutol® HP, characterized and evaluated in vitro and ex vivo to assess the drug release profile and intestinal permeability, respectively. In vivo pharmacokinetic and acute toxicity assessment was performed in Wistar rats. Results: Optimized TAM-SFN-NLCs exhibited a particle size of 121.9 ± 6.42 nm and zeta potential of -21.2 ± 2.91 mV. The NLCs enhanced intestinal permeability of TAM and SFN and augmented oral bioavailability of TAM and SFN 5.2-fold and 4.8-fold, respectively. SFN significantly reduced TAM-associated toxicity in vivo. Conclusion: This coencapsulation of a chemotherapeutic agent with a herbal bioactive in NLCs could pave a novel treatment approach against cancer.

Self-Emulsifying Drug Delivery Systems: Hydrophobic Drug Polymer Complexes Provide a Sustained Release in Vitro

The aim of this study was to develop hydrophobic ionic drug polymer complexes in order to provide sustained drug release from self-emulsifying drug delivery systems (SEDDS). Captopril (CTL) was used as an anionic model drug to form ionic complexes with the cationic polymers Eudragit RS, RL, and E. Complexes of polymer to CTL charge ratio 1:1, 2:1, and 4:1 were incorporated in two SEDDS, namely FA which was 40% Kolliphor RH 40, 20% Kolliphor EL, and 40% castor oil and FB, which was 40% Kolliphor RH 40, 30% glycerol, 15% Kolliphor EL, and 15% castor oil. Blank and complex loaded SEDDS were characterized regarding their droplet size, polydispersity index (PDI), and zeta potential. Resazurin assay was performed on Caco-2 cells to evaluate the biocompatibility of SEDDS. Release of CTL from SEDDS was determined in release medium containing 0.2 mg/mL of 5,5'-dithiobis(2-nitrobenzoic acid) (DNTB) allowing quantification of free drug released into solution via a thiol/disulfide exchange reaction between CTL and DNTB forming a yellow dye. The droplet size of SEDDS FA and SEDDS FB were in the range of 100 ± 20 nm and 40 ± 10 nm, respectively, with a PDI < 0.5. The zeta potential of SEDDS FA and SEDDS FB increased after the incorporation of complexes. Cell viability remained above 80% after incubation with SEDDS FA and SEDDS FB in a concentration of 1% and 3% for 4 h. Without any polymer, CTL was entirely released from both SEDDS within seconds. In contrast, the higher the cationic lipophilic polymer to CTL ratio in SEDDS, the more sustained was the release of CTL. Among the polymers which were evaluated, Eudragit RL provided the most sustained release. SEDDS FA containing Eudragit RL and CTL in a ratio of 1:1 released 64.78 ± 8.28% of CTL, whereas SEDDS FB containing the same complex showed a release of 91.85 ± 1.17% within 1 h. Due to the formation of lipophilic ionic polymer complexes a sustained drug release from oily droplets formed by SEDDS can be achieved. Taking into account that drugs are otherwise instantly released from SEDDS, results of this study might open the door for numerous additional applications of SEDDS for which a sustained drug release is essential.

Development and characterisation of ibuprofen-loaded nanoemulsion with enhanced oral bioavailability

Lipophilic compounds constitute a majority of therapeutics in the pipeline of drug discovery. Despite possessing enhanced efficacy and permeability, some of these drugs suffer poor solubility necessitating the need of a suitable drug delivery system. Nanoemulsion is a drug delivery system that provides enhanced solubility for poorly soluble drugs in an attempt to improve the oral bioavailability. The purpose of this study is to develop a nanoemulsion system using ibuprofen as a model drug in order to investigate the potential of this colloidal system to enhance the absorption of poorly water-soluble drugs. Ibuprofen loaded-nanoemulsion with different drug concentrations (1.5, 3 and 6% w/w) were formulated from olive oil, sucrose ester L-1695 and glycerol using D-phase emulsification technique. A pseudoternary phase diagram was utilised to identify the optimal excipient composition to formulate the nanoemulsion system. In vitro diffusion chamber studies using rodent intestinal linings highlighted improved absorption profile when ibuprofen was delivered as nanoemulsion in comparison to microemulsions and drug-in-oil systems. This was further corroborated by in vivo studies using rat model that highlighted a two-fold increase in ibuprofen absorption when the drug was administered as a nanoemulsion relative to drug-in-oil system. On the other hand, when ibuprofen was administered as microemulsions, only a 1.5-fold increase in absorption was observed relative to drug-in-oil system. Thus, this study highlights the potential of using nanoemulsion as a drug delivery system to enhance the oral bioavailability of hydrophobic drugs.

Recent Advances in Encapsulation, Protection, and Oral Delivery of Bioactive Proteins and Peptides using Colloidal Systems

There are many areas in medicine and industry where it would be advantageous to orally deliver bioactive proteins and peptides (BPPs), including ACE inhibitors, antimicrobials, antioxidants, hormones, enzymes, and vaccines. A major challenge in this area is that many BPPs degrade during storage of the product or during passage through the human gut, thereby losing their activity. Moreover, many BPPs have undesirable taste profiles (such as bitterness or astringency), which makes them unpleasant to consume. These challenges can often be overcome by encapsulating them within colloidal particles that protect them from any adverse conditions in their environment, but then release them at the desired site-of-action, which may be inside the gut or body. This article begins with a discussion of BPP characteristics and the hurdles involved in their delivery. It then highlights the characteristics of colloidal particles that can be manipulated to create effective BPP-delivery systems, including particle composition, size, and interfacial properties. The factors impacting the functional performance of colloidal delivery systems are then highlighted, including their loading capacity, encapsulation efficiency, protective properties, retention/release properties, and stability. Different kinds of colloidal delivery systems suitable for encapsulation of BPPs are then reviewed, such as microemulsions, emulsions, solid lipid particles, liposomes, and microgels. Finally, some examples of the use of colloidal delivery systems for delivery of specific BPPs are given, including hormones, enzymes, vaccines, antimicrobials, and ACE inhibitors. An emphasis is on the development of food-grade colloidal delivery systems, which could be used in functional or medical food applications. The knowledge presented should facilitate the design of more effective vehicles for the oral delivery of bioactive proteins and peptides.

Apoptotic induction and anti-metastatic activity of eugenol encapsulated chitosan nanopolymer on rat glioma C6 cells via alleviating the MMP signaling pathway

Glioma is the prime cause of cancer allied mortality in adolescent people and it accounts about 80% of all malignant tumours. Eugenol is a major bioactive constituent present in the essential oils with numerous pharmacological benefits including nueroprotective activity. The major drawback of eugenol is its extreme volatile property and oxygen sensitivity therefore we increased the efficacy of drug; eugenol by encapsulating with chitosan polymer. Eugenol loaded chitosan polymer (EuCs) was characterized using FTIR, XRD, SEM, HR-TEM analysis and the encapsulation, drug release efficacy was assessed at in vitro condition. The induction of autophagy and anticancer efficacy of EuCs on glioma cells was evaluated with rat C6 glioma cells using MTT assay, acridine orange staining, immunocytochemical analysis of NFκβ protein expression and FLOW cytometric analysis. The anti-metastatic property of Eu-CS was assessed by immunoblotting and RT-PCR analysis of epithelial mesenchymal transition protein expression in EuCs treated rat C6 glioma cells. Our characterization analysis proves that EuCs possess essential physical and functional properties of copolymer to be utilized as a drug. Further the MTT analysis and AO staining confirms even in the presence of oncogenic inducer and autophagic inhibitors, EuCs exhibits apoptotic potency on rat C6 glioma cells. The result of immunocytochemical studies depicts the inhibition of NFκβ protein expression and flow cytometry studies confirm apoptosis induction by EuCs. The inhibition of metastasis by EuCs was proven by the decrease in epithelial mesenchymal transition protein expression in Eu-Cs treated rat C6 glioma cells. Over all our results authentically confirms eugenol loaded chitosan nanopolymer persuasively induces apoptosis and inhibits metastasis in rat C6 glioma cells.

Physiological and Pharmaceutical Considerations for Rectal Drug Formulations

Although the oral route is the most convenient route for drug administration, there are a number of circumstances where this is not possible from either a clinical or pharmaceutical perspective. In these cases, the rectal route may represent a practical alternative and can be used to administer drugs for both local and systemic actions. The environment in the rectum is considered relatively constant and stable and has low enzymatic activity in comparison to other sections of the gastrointestinal tract. In addition, drugs can partially bypass the liver following systemic absorption, which reduces the hepatic first-pass effect. Therefore, rectal drug delivery can provide significant local and systemic levels for various drugs, despite the relatively small surface area of the rectal mucosa. Further development and optimization of rectal drug formulations have led to improvements in drug bioavailability, formulation retention, and drug release kinetics. However, despite the pharmaceutical advances in rectal drug delivery, very few of them have translated to the clinical phase. This review will address the physiological and pharmaceutical considerations influencing rectal drug delivery as well as the conventional and novel drug delivery approaches. The translational challenges and development aspects of novel formulations will also be discussed.

Pharmacokinetic Aspects of Nanoparticle-in-Matrix Drug Delivery Systems for Oral/Buccal Delivery

Oral route maintains its predominance among the ones used for drug delivery, especially when medicines are self-administered. If the dosage form is solid, therapy gains in dose precision and drug stability. Yet, some active pharmaceutical substances do not present the required solubility, permeability, or release profile for incorporation into traditional matrices. The combination of nanostructured drugs (nanoparticle [NP]) with these matrices is a new and little-explored alternative, which could bring several benefits. Therefore, this review focused on combined delivery systems based on nanostructures to administer drugs by the oral cavity, intended for buccal, sublingual, gastric, or intestinal absorption. We analyzed published NP-in-matrix systems and compared main formulation characteristics, pharmacokinetics, release profiles, and physicochemical stability improvements. The reported formulations are mainly semisolid or solid polymers, with polymeric or lipid NPs and one active pharmaceutical ingredient. Regarding drug specifics, most of them are poorly permeable or greatly metabolized. The few studies with pharmacokinetics showed increased drug bioavailability and, sometimes, a controlled release rate. From our knowledge, the gathered data make up the first focused review of these trendy systems, which we believe will help to gain scientific deepness and future advancements in the field.

Self-emulsifying drug delivery systems: Impact of stability of hydrophobic ion pairs on drug release

The aim of this study was to evaluate the impact of stability of hydrophobic ion pairs (HIPs) in gastrointestinal (GI) fluids on their release from self-emulsifying drug delivery systems (SEDDS). HIPs of leuprolide (LEU), insulin (INS) and bovine serum albumin (BSA) were formed using various mono- and di-carboxylate surfactants i.e. sodium deoxycholate (SDC), sodium dodecanoate (SDD), sodium stearoyl glutamate (SSG) and pamoic acid di-sodium salt (PAM). HIPs were evaluated regarding precipitation efficiency, log Pn-butanol/water and dissociation behavior at various pH and ionic strength. Solubility studies of these HIPs were accomplished to identify suitable solvents for the formulation of SEDDS. Subsequently, HIPs were incorporated into SEDDS followed by characterization regarding zeta potential, stability and log DSEDDS/release medium. Independent from the type of (poly)peptides, PAM showed most efficient HIP properties among tested surfactants. The highest encapsulation efficiency with PAM was achieved at molar ratios of 1:1 for LEU, 1:3 for INS and 1:50 for BSA and log Pn-butanol/water of HIPs were increased at least 2.5 units. Dissociation studies showed that LEU-PAM, INS-PAM, BSA-PAM complexes were dissociated within 6 h up to 25%, 60% and 85% in GI fluids, respectively. These HIPs were successfully incorporated into SEDDS exhibiting negative zeta potential and high stability for 4 h. Log DSEDDS/release medium of LEU-PAM, INS-PAM, BSA-PAM complexes were 2.4 ± 0.7, 2.1 ± 0.62 and 1.6 ± 0.45, respectively. Findings of this study showed that stability of HIPs has great impact on log DSEDDS/release medium and consequently on their release from SEDDS.

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.

Recent advances in carrier mediated nose-to-brain delivery of pharmaceutics

Central nervous system (CNS) disorders (e.g., multiple sclerosis, Alzheimer's disease, etc.) represent a growing public health issue, primarily due to the increased life expectancy and the aging population. The treatment of such disorders is notably elaborate and requires the delivery of therapeutics to the brain in appropriate amounts to elicit a pharmacological response. However, despite the major advances both in neuroscience and drug delivery research, the administration of drugs to the CNS still remains elusive. It is commonly accepted that effectiveness-related issues arise due to the inability of parenterally administered macromolecules to cross the Blood-Brain Barrier (BBB) in order to access the CNS, thus impeding their successful delivery to brain tissues. As a result, the direct Nose-to-Brain delivery has emerged as a powerful strategy to circumvent the BBB and deliver drugs to the brain. The present review article attempts to highlight the different experimental and computational approaches pursued so far to attain and enhance the direct delivery of therapeutic agents to the brain and shed some light on the underlying mechanisms involved in the pathogenesis and treatment of neurological disorders.

Encapsulation, protection, and delivery of bioactive proteins and peptides using nanoparticle and microparticle systems: A review

There are many examples of bioactive proteins and peptides that would benefit from oral delivery through functional foods, supplements, or medical foods, including hormones, enzymes, antimicrobials, vaccines, and ACE inhibitors. However, many of these bioactive proteins are highly susceptible to denaturation, aggregation or hydrolysis within commercial products or inside the human gastrointestinal tract (GIT). Moreover, many bioactive proteins have poor absorption characteristics within the GIT. Colloidal systems, which contain nanoparticles or microparticles, can be designed to encapsulate, retain, protect, and deliver bioactive proteins. For instance, a bioactive protein may have to remain encapsulated and stable during storage and passage through the mouth and stomach, but then be released within the small intestine where it can be absorbed. This article reviews the application of food-grade colloidal systems for oral delivery of bioactive proteins, including microemulsions, emulsions, nanoemulsions, solid lipid nanoparticles, multiple emulsions, liposomes, and microgels. It also provides a critical assessment of the characteristics of colloidal particles that impact the effectiveness of protein delivery systems, such as particle composition, size, permeability, interfacial properties, and stability. This information should be useful for the rational design of medical foods, functional foods, and supplements for effective oral delivery of bioactive proteins.

Development of rectal self-emulsifying suspension of a moisture-labile water-soluble drug

Self-emulsifying drug delivery systems, commonly used for oral delivery of poorly soluble compounds, were used to formulate water soluble but moisture labile compounds for rectal application. The objective was to use the oily phase of the system to formulate a liquid, non-aqueous product while obtaining the advantages of self-emulsification, rapid contact with the rectal mucosa and rapid absorption post-administration. Ceftriaxone was used as a model drug and the human bile salt sodium chenodeoxycholate was used as an absorption enhancer. After preliminary screening of 23 excipients, based on their emulsification ability and emulsion fineness in binary and ternary mixtures, a full factorial design was used to screen different formulations of three preselected excipients. The optimal formulation contained 60% of excipients, namely Capryol 90, Kolliphor EL and Kolliphor PS20 in 4 : 6 : 6 ratio and 40% of a powder blend that included 500 mg of ceftriaxone. Characterization of the system showed that it complied with the requirements for rectal administration, in particular rapid emulsification in a small quantity of liquid. Rabbit bioavailability showed rapid absorption of ceftriaxone, achieving 128% bioavailability compared to powder control formulation. These results demonstrated the potential of self-emulsifying formulations for rectal administration of Class 3 BCS drugs.

Crosstalk of Nanosystems Induced Extracellular Vesicles as Promising Tools in Biomedical Applications

Hybrid vesicles are considered as a bridge between natural nanosystems (NNSs) and artificial nanosystems (ANSs). NNSs are extracellular vesicles (EVs), membranous, bio-formed endogenously, which act as endogenous cargoes, and reflecting cellular dynamics. EVs have cellular tropism, permeate tight junctions, and are non-immunogenic. EVs are used as tools in the development of diagnostic and therapeutic agents. ANSs can induce biogenesis of hybrid vesicles as promising smart diagnostic agents, and innovative drug cargoes. EVs can encapsulate small molecules, macromolecules, and ANSs. The manipulation of EVs during biogenesis was suggested for engineering hybrid EVs. This review article highlights the role of ANSs in the biogenesis of NNSs, and introduces hybrid nanosystems research.

Thermoresponsive pegylated bubble liposome nanovectors for efficient siRNA delivery via endosomal escape

AIM

Improving the delivery of siRNA into cancer cells via bubble liposomes. Designing a thermoresponsive pegylated liposome through the introduction of ammonium bicarbonate salt into liposomes so as to control their endosomal escape for gene therapy.

METHODS

A sub-200 nm nanovector was fully characterized and examined for cellular uptake, cytotoxicity, endosomal escape and gene silencing.

RESULTS

The siRNA-liposomes were internalized into cancer cells within 5 min and then released siRNAs in the cytosol prior to lysosomal degradation upon external temperature elevation. This was confirmed by confocal bioimaging and gene silencing reaching up to 90% and further demonstrated by the protein inhibition of both target genes.

CONCLUSION

The thermoresponsiveness of ammonium bicarbonate containing liposomes enabled the rapid endosomal escape of the particles and resulted in an efficient gene silencing.

Recent developments in nanocarrier-aided mucosal vaccination

To date, most of the licensed vaccines for mucosal delivery are based on live-attenuated viruses which carry the risk of regaining their pathogenicity. Therefore, the development of efficient nonviral vectors allowing the induction of potent humoral and cell-mediated immunity is regarded as an imperative scientific challenge as well as a commercial breakthrough for the pharma industries. For a successful translation to the clinic, such nanocarriers should protect the antigens from mucosal enzymes, facilitate antigen uptake by microfold cells and allow the copresentation of robust, safe for human use, mucosal adjuvants to antigen-presenting cells. Finally, the developed formulations should exhibit accuracy regarding the administered dose, a major drawback of mucosal vaccines in comparison with parenteral ones.