Enhanced oral absorption of insulin-loaded liposomes containing bile salts: A mechanistic study

Lipid-based nanocarriers: an attractive approach for rheumatoid arthritis management

Lipid nanoparticles (LNPs) have emerged as transformative tools in modern drug delivery, offering unparalleled potential in enhancing the efficacy and safety of various therapeutics. In the context of rheumatoid arthritis (RA), a disabling autoimmune disorder characterized by chronic inflammation, joint damage, and limited patient mobility, LNPs hold significant promise for revolutionizing treatment strategies. LNPs offer several advantages over traditional drug delivery systems, including improved pharmacokinetics, enhanced tissue penetration, and reduced systemic toxicity. This article concisely summarizes the pathogenesis of RA, its associated risk factors, and therapeutic techniques and their challenges. Additionally, it highlights the noteworthy advancements made in managing RA through LNPs, including liposomes, niosomes, bilosomes, cubosomes, spanlastics, ethosomes, solid lipid nanoparticles, lipid micelles, lipid nanocapsules, nanostructured lipid carriers, etc. It also delves into the specific functional attributes of these nanocarrier systems, focusing on their role in treating and monitoring RA.

Nanostructured biloalbuminosomes loaded with berberine and berberrubine for Alleviating heavy Metal-Induced male infertility in rats

Despite the remarkable biological effects of berberine (BBR), particularly on fertility, its bioavailability is low. This study aims to test the effectiveness of novel nanostructured biloalbuminosomes (BILS) of BBR and its metabolite berberrubine (M1) in treatment of testicular and prostatic lesions. M1 was semi-synthesized from BBR using microwave-assisted reaction. The solvent evaporation method was used to prepare BBR-BILS and M1-BILS by three different concentrations of sodium cholate (SC) or glycocholate (SG), along with the incorporation of bovine serum albumin (BSA). The prepared BILS were fully characterized. Male infertility was induced by cadmium (Cd) at 5 mg/kg and lead (Pb) at 20 mg/kg contaminated water for 90 days, followed by treatment with BBR, M1, and their BILS (BBR-BILS and M1-BILS) for 45 days. Blood male infertility markers, testicular and prostatic oxidative stress status, autophagy, inflammation, along with testicular and prostatic concentrations of Cd and Pb, and histopathology of both tested tissues were determined using standardized protocols. The optimal BBR-BILS and M1-BILS nano-preparations, containing 30 mg SC, were chosen based on the best characterization properties of the preparations. Both nano-preparations improved heavy metals-induced testicular and prostatic deformities, as they reduced Bax and elevated Bcl-2 expressions in both tissues. Moreover, they activated the mTOR/PI3K pathway with a marked reduction in AMPK and activated LC-3II protein levels. Consequently, testicular and prostatic architecture and functions were improved. This study is the first to report the preparation of BBR and M1 BILS nano-preparations and proved their superior efficacy compared to free drugs against testicular and prostatic deformities by attenuating oxidative stress-induced excessive autophagy, offering a new hope to manage male infertility.

Nanotechnology-based drug delivery platforms for erectile dysfunction: addressing efficacy, safety, and bioavailability concerns

Erectile dysfunction (ED), is a common and multidimensional sexual disorder, which comprises changes among any of the processes of the erectile response such as organic, relational, and psychological. However, both endocrine and nonendocrine causes of ED produce substantial health implications including depression and anxiety due to poor sexual performance, eventually affecting man's life eminence. Marginally invasive interventions following ED consist of lifestyle modifications, oral drugs, injections, vacuum erection devices, etc. Nevertheless, these conventional treatment regimens follow certain drawbacks such as efficacy and safety issues, and navigate to the development of novel therapeutic approaches such as nanomedicine for ED management. Nanotechnology-centred drug delivery platforms are being explored to minimize these limitations with better in vitro and in vivo effectiveness. Moreover, nanomedicine and nanocarrier-linked approaches are rapidly developing science in the nanoscale range, which contributes to site-specific delivery in a controlled manner and has generated considerable interest prominent to their potential to enhance bioavailability, decrease side effects, and avoidance of first-pass metabolism. This review provides an overview of recent discoveries regarding various nanocarriers and nano-delivery methods, along with current trends in the clinical aspects of ED. Additionally, strategies for clinical translation have been incorporated.

Neuroprotective efficiency of celecoxib vesicular bilosomes for the management of lipopolysaccharide-induced Alzheimer in mice employing 23 full factorial design

The aim of this study was to develop and evaluate bilosomes loaded with Celecoxib (CXB) for the efficient treatment of Alzheimer. The thin-film hydration approach was utilized in the formulation of CXB bilosomes (CXB-BLs). The study used a 23-factorial design to investigate the impact of several formulation variables. Three separate parameters were investigated: bile salt type (X1), medication amount (X2), and lipid-bile salt ratio (X3). The dependent responses included entrapment efficiency (Y1: EE %), particle size (Y2: PS), and zeta potential (Y3: ZP). The formulation factors were statistically optimized using the Design-Expert® program. The vesicles demonstrated remarkable CXB encapsulation efficiency, ranging from 94.16 ± 1.91 to 98.38 ± 0.85%. The vesicle sizes ranged from 241.8 ± 6.74 to 352 ± 2.34 nm. The produced formulations have high negative zeta potential values, indicating strong stability. Transmission electron microscopy (TEM) revealed that the optimized vesicles had a spherical form. CXB release from BLs was biphasic, with the release pattern following Higuchi's model. In vivo studies confirmed the efficiency of CXB-BLs in management of lipopolysaccharide-induced Alzheimer as CXB-BLs ameliorated cognitive dysfunction, decreased acetylcholinesterase (AChE), and inhibited neuro-inflammation and neuro-degeneration through reducing Toll-like receptor (TLR4), and Interleukin-1β (IL-1β) levels. The findings suggested that the created CXB-BLs could be a potential drug delivery strategy for Alzheimer's treatment.

Impact of formulation parameters on self-assembled liposomes (LeciPlex® III): A detailed investigation

The present study investigated the feasibility of fabricating self-assembled liposomes, LeciPlex®, a phospholipid-based vesicular nanocarrier using cationic, anionic, and nonionic stabilizers. The phospholipid investigated was soy phosphatidylcholine and the nano-precipitation method based on solvent diffusion was applied as the fabrication technique of liposomes in this study. The effects of various formulation variables, such as lipid and stabilizer concentration, total solid concentration, and solvent type on the self-assembly of vesicles were studied for physical characterization including particle size analysis, differential scanning calorimetry, viscosity, optical transmittance, transmission electron microscopy, and small angle neutron scattering. All three LeciPlex® systems exhibited a direct relationship between particle size and phospholipid concentration. The two categoric variables, solvent, and stabilizer used to prepare LeciPlex® demonstrated a significant effect on particle size for all three LeciPlex® systems. Small angle neutron scattering, and optical transmittance confirmed the formation of micellar systems at a phospholipid: stabilizer ratio of 1:2 and vesicular systems at a ratio of 2:1 for the systems stabilized with anionic and nonionic surfactants. In contrast to this, the LeciPlex® formed with the cationic stabilizer Dioctadecyldimethylammonium bromide (DODAB), formed vesicles at both ratios. From these investigations, it was clear that the formulation space for LeciPlex® was diversified by the addition of cationic, anionic, and non-ionic stabilizers.

Emerging Trends in Bilosomes as Therapeutic Drug Delivery Systems

In recent years, there has been a notable surge in the utilization of stabilized bile acid liposomes, chemical conjugates, complexes, mixed micelles, and other drug delivery systems derived from bile acids, often referred to as bilosomes. The molecular structure and interactions of these amphiphilic compounds provide a distinctive and captivating subject for investigation. The enhanced stability of new generation bilosomes inside the gastrointestinal system results in the prevention of drug degradation and an improvement in mucosal penetration. These characteristics render bilosomes to be a prospective nanocarrier for pharmaceutical administration, prompting researchers to investigate their potential in other domains. This review paper discusses bilosomes that have emerged as a viable modality in the realm of drug delivery and have significant promise for use across several domains. Moreover, this underscores the need for additional investigation and advancement in order to comprehensively comprehend the prospective uses of bilosomes and their effectiveness in the field of pharmaceutical administration. This review study explores the current scholarly attention on bilosomes as prospective carriers for drug delivery. Therapeutic areas where bilosomes have shown outstanding performance in terms of drug delivery are outlined in the graphical abstract.

Engineering aspects of lipid-based delivery systems: In vivo gene delivery, safety criteria, and translation strategies

Defects in the genome cause genetic diseases and can be treated with gene therapy. Due to the limitations encountered in gene delivery, lipid-based supramolecular colloidal materials have emerged as promising gene carrier systems. In their non-functionalized form, lipid nanoparticles often demonstrate lower transgene expression efficiency, leading to suboptimal therapeutic outcomes, specifically through reduced percentages of cells expressing the transgene. Due to chemically active substituents, the engineering of delivery systems for genetic drugs with specific chemical ligands steps forward as an innovative strategy to tackle the drawbacks and enhance their therapeutic efficacy. Despite intense investigations into functionalization strategies, the clinical outcome of such therapies still needs to be improved. Here, we highlight and comprehensively review engineering aspects for functionalizing lipid-based delivery systems and their therapeutic efficacy for developing novel genetic cargoes to provide a full snapshot of the translation from the bench to the clinics. We outline existing challenges in the delivery and internalization processes and narrate recent advances in the functionalization of lipid-based delivery systems for nucleic acids to enhance their therapeutic efficacy and safety. Moreover, we address clinical trials using these vectors to expand their clinical use and principal safety concerns.

The Exploitation of Sodium Deoxycholate-Stabilized Nano-Vesicular Gel for Ameliorating the Antipsychotic Efficiency of Sulpiride

The present study explored the effectiveness of bile-salt-based nano-vesicular carriers (bilosomes) for delivering anti-psychotic medication, Sulpiride (Su), via the skin. A response surface methodology (RSM), using a 33 Box-Behnken design (BBD) in particular, was employed to develop and optimize drug-loaded bilosomal vesicles. The optimized bilosomes were assessed based on their vesicle size, entrapment efficiency (% EE), and the amount of Sulpiride released. The Sulpiride-loaded bilosomal gel was generated by incorporating the optimized Su-BLs into a hydroxypropyl methylcellulose polymer. The obtained gel was examined for its physical properties, ex vivo permeability, and in vivo pharmacokinetic performance. The optimum Su-BLs exhibited a vesicle size of 211.26 ± 10.84 nm, an encapsulation efficiency of 80.08 ± 1.88% and a drug loading capacity of 26.69 ± 0.63%. Furthermore, the use of bilosomal vesicles effectively prolonged the release of Su over a period of twelve hours. In addition, the bilosomal gel loaded with Su exhibited a three-fold increase in the rate at which Su transferred through the skin, in comparison to oral-free Sulpiride. The relative bioavailability of Su-BL gel was almost four times as high as that of the plain Su suspension and approximately two times as high as that of the Su gel. Overall, bilosomes could potentially serve as an effective technique for delivering drugs through the skin, specifically enhancing the anti-psychotic effects of Sulpiride by increasing its ability to penetrate the skin and its systemic bioavailability, with few adverse effects.

A novel approach to insulin delivery via oral route: Milk fat globule membrane derived liposomes as a delivery vehicle

The current research endeavor seeks to unlock the potential of orally administered insulin formulations by utilizing liposomes derived from the fat globule membrane (MFGM) of camel milk as carriers for insulin. This pursuit emerges as a result of the recognized limitations of subcutaneous insulin therapy. The liposomes were meticulously created using the thin film hydration method, followed by comprehensive chemical and morphological analyses. Additionally, comprehensive safety assessments were carried out in vitro and in vivo, revealing significant findings. The Fourier-transform infrared (FTIR) spectrum confirmed the presence of insulin within the liposomes, demonstrating changes in their size and charge. The in vitro cytotoxicity analysis, performed on HEK-293 cell lines through the MTT assay, yielded results indicating a cell viability of over 90%. In the in vivo investigation, diabetic rats induced by STZ were utilized to evaluate the effects of the liposomes, revealing substantial reductions in blood glucose levels, bilirubin, alkaline phosphatase (ALP), albumin, and alanine aminotransferase (ALT) levels. Hepatic histopathological assessments showed signs of recovery across all treatment groups, with no observable microscopic changes in renal tissue. This investigation highlights the significant hypoglycemic effects observed in insulin-loaded liposomes derived from MFGM obtained from camel milk when administered orally.

Bile salt-enriched vs. non-enriched nanoparticles: comparison of their physicochemical characteristics and release pattern

Bile salts were first used in the preparation of nanoparticles due to their stabilizing effects. As time went by, they attracted much attention and were increasingly employed in fabricating nanoparticles. It is well accepted that the physicochemical properties of nanoparticles are influential factors in their permeation, distribution, elimination and degree of effectiveness as well as toxicity. The review of articles shows that the use of bile salts in the structure of nanocarriers may cause significant changes in their physicochemical properties. Hence, having information about the effect of bile salts on the properties of nanoparticles could be valuable in the design of optimal carriers. Herein, we review studies in which bile salts were used in preparing liposomes, niosomes and other nanocarriers. Furthermore, the effects of bile salts on entrapment efficiency, particle size, polydispersity index, zeta potential, release profile and stability of nanoparticles are pointed out. Finally, we debate how to take advantage of bile salts potential for preparing desirable nanocarriers.

Non-Invasive Delivery of Insulin for Breaching Hindrances against Diabetes

Insulin is recognized as a crucial weapon in managing diabetes. Subcutaneous (s.c.) injections are the traditional approach for insulin administration, which usually have many limitations. Numerous alternative (non-invasive) slants through different routes have been explored by the researchers for making needle-free delivery of insulin for attaining its augmented absorption as well as bioavailability. The current review delineating numerous pros and cons of several novel approaches of non-invasive insulin delivery by overcoming many of their hurdles. Primary information on the topic was gathered by searching scholarly articles from PubMed added with extraction of data from auxiliary manuscripts. Many approaches (discussed in the article) are meant for the delivery of a safe, effective, stable, and patient friendly administration of insulin via buccal, oral, inhalational, transdermal, intranasal, ocular, vaginal and rectal routes. Few of them have proven their clinical efficacy for maintaining the glycemic levels, whereas others are under the investigational pipe line. The developed products are comprising of many advanced micro/nano composite technologies and few of them might be entering into the market in near future, thereby garnishing the hopes of millions of diabetics who are under the network of s.c. insulin injections.

Optimization, cellular uptake, and in vivo evaluation of Eudragit S100-coated bile salt-containing liposomes for oral colonic delivery of 5-aminosalicylic acid

Eudragit S100-coated bile salt-containing liposomes were prepared and optimized by experimenting with different variables, including bile salt type and concentration, and the method of incorporation into liposomes using a model hydrophilic compound, 5-aminosalicylic acid (5-ASA). After optimizing the formulation, cellular uptake, and animal pharmacokinetic experiments were performed. The inclusion of sodium glycocholate (SG) into liposomes decreased liposome particle size and entrapment efficiency significantly but had no effect on zeta potential. The method of incorporating SG into the lipid or aqueous phase of the liposome did not notably impact the characteristics of the liposomes but the hydration media had a substantial effect on the entrapment efficiency of 5-ASA. In vitro drug release in different fluids simulating distinct gastrointestinal tract sections, indicated pH-dependent disintegration of the coating layer of coated SG-containing liposomes. The majority of the drug was retained when subjected to simulated gastric fluid (SGF) and fed-state simulated intestinal fluid (FeSSIF) (≈ 37% release after 2 h in SGF pH 1.2, followed by 3 h in FeSSIF pH 5). The remaining drug was subsequently released in phosphate-buffered saline pH 7.4 (≈ 85% release within 24 h). Increasing SG concentration in the liposomes decreased the amount of drug released in FeSSIF. Similar results were observed when SG was replaced with sodium taurocholate. Cellular uptake studies in Caco-2 cells demonstrated that all liposomal formulations (conventional liposomes, bile salt-containing liposomes, and coated bile salt-containing liposomes) have shown to be equally effective at increasing the cellular uptake compared to free fluorescein solution. In the pharmacokinetic study, coated bile salt-containing liposomes showed a lower Cmax and prolonged residence in the gastrointestinal tract in comparison to conventional liposomes. Taken together, these findings suggest that the polymer-coated bile salt-containing liposomes have the potential to serve as a drug delivery system targeted at the colon.

Mesoporous silica nanoparticles: An emerging approach in overcoming the challenges with oral delivery of proteins and peptides

Proteins and peptides (PPs), as therapeutics are widely explored in the past few decades, by virtue of their inherent advantages like high specificity and biocompatibility with minimal side effects. However, owing to their macromolecular size, poor membrane permeability, and high enzymatic susceptibility, the effective delivery of PPs is often challenging. Moreover, their subjection to varying environmental conditions, when administered orally, results in PPs denaturation and structural conformation, thereby lowering their bioavailability. Hence, for effective delivery with enhanced bioavailability, protection of PPs using nanoparticle-based delivery system has gained a growing interest. Mesoporous silica nanoparticles (MSNs), with their tailored morphology and pore size, high surface area, easy surface modification, versatile loading capacity, excellent thermal stability, and good biocompatibility, are eligible candidates for the effective delivery of macromolecules to the target site. This review highlights the different barriers hindering the oral absorption of PPs and the various strategies available to overcome them. In addition, the potential benefits of MSNs, along with their diversifying role in controlling the loading of PPs and their release under the influence of specific stimuli, are also discussed in length. Further, the tuning of MSNs for enhanced gene transfection efficacy is also highlighted. Since extensive research is ongoing in this area, this review is concluded with an emphasis on the potential risks of MSNs that need to be addressed prior to their clinical translation.

A comprehensive review on recent nanosystems for enhancing antifungal activity of fenticonazole nitrate from different routes of administration

This review aims to comprehensively highlight the recent nanosystems enclosing Fenticonazole nitrate (FTN) and to compare between them regarding preparation techniques, studied factors and responses. Moreover, the optimum formulae were compared in terms of in vitro, ex vivo and in vivo studies in order to detect the best formula. FTN is a potent antifungal imidazole compound that had been used for treatment of many dangerous fungal infections affecting eye, skin or vagina. FTN had been incorporated in various innovative nanosystems in the recent years in order to achieve significant recovery such as olaminosomes, novasomes, cerosomes, terpesomes and trans-novasomes. These nanosystems were formulated by various techniques (ethanol injection or thin film hydration) utilizing different statistical designs (Box-Behnken, central composite, full factorial and D-optimal). Different factors were studied in each nanosystem regarding its composition as surfactant concentrations, surfactant type, amount of oleic acid, cholesterol, oleylamine, ceramide, sodium deoxycholate, terpene concentration and ethanol concentration. Numerous responses were studied such as percent entrapment efficiency (EE%), particle size (PS), poly-dispersity index (PDI), zeta potential (ZP), and in vitro drug release. Selection of the optimum formula was based on numerical optimization accomplished by Design-Expert® software taking in consideration the largest EE %, ZP (as absolute value) and in vitro drug release and lowest PS and PDI. In vitro comparisons were done employing different techniques such as Transmission electron microscopy, pH determination, effect of gamma sterilization, elasticity evaluation and docking study. In addition to, ex vivo permeation, in vivo irritancy test, histopathological, antifungal activity and Kinetic study.

Lactoferrin decorated bilosomes for the oral delivery of quercetin in type 2 diabetes: In vitro and in vivo appraisal

Despite its tremendous potential for type 2 diabetes management, quercetin (QRC) suffers poor gastric stability, poor bioavailability, and extensive first pass metabolism. Drug encapsulation into bilosomes (BSL) has proven enhanced properties in-vitro and in-vivo. Herein, this work endeavoured to evaluate efficacy of QRC-encapsulated bilosomes capped with lactoferrin (LF); a milk protein with antidiabetic potential, for type 2 diabetes oral treatment. The optimized formulation (LF-QRC-BSL) was evaluated in-vitro on α-amylase enzyme inhibition and insulin resistant HepG2 cell model and in vivo on streptozocin/high fat diet induced diabetes in rats. LF-QRC-BSL showed a small size (68.1 nm), a narrow PDI (0.18) and a -25.5 mV zeta potential. A high entrapment efficiency (94 %) with sustained release were also observed. LF-QRC-BSL displayed 100 % permeation through excised diabetic rat intestines after 6 h, 70.2 % inhibition of α-amylase enzyme in-vitro and an augmented recovery of glucose uptake in insulin resistant cells. In diabetic rats, LF-QRC-BSL resulted in significant decrease in blood glucose level, improved lipid profile and tissue injury markers with reduced oxidative stress and inflammatory markers. Further, histopathological examination of the kidneys, liver and pancreas revealed an almost restored normal condition comparable to the negative control. Overall, LF-QRC-BSL have proven to be a promising therapy for type 2 diabetes.

Unlocking the Potential of Bilosomes and Modified Bilosomes: a Comprehensive Journey into Advanced Drug Delivery Trends

Vesicular drug delivery systems have revolutionized the pharmaceutical field, offering a promising path for achieving targeted and sustained drug delivery. The oral, transdermal, and ocular routes of administration offer optimal ease in attaining desired therapeutic outcomes. However, conventional treatment strategies are all plagued with several challenges, such as poor skin permeability, ocular barriers, and gastrointestinal (GIT) degradation leading to vesicular disruption with the release of the encapsulated drug before reaching the targeted site of action. In recent years, bilosomes-stabilized nanovesicles containing bile salts have received considerable attention due to their versatility and adaptability for diverse applications. These bilayered vesicles enhance the solubility of lipophilic drugs and improve formulation stability in the gastrointestinal tract. They exhibit ultra-deformable properties, improving stratum corneum permeability, making them ideal candidates for oral and transdermal drug delivery. In addition, bilosomes find utility in topical drug delivery, making them applicable for ocular administration. Over the past decade, extensive research has highlighted bilosomes' potential as superior vesicular carriers surpassing liposomes and niosomes. Advances in this field have led to the development of modified bilosomes, such as probilosomes and surface-modified bilosomes, further enhancing their capabilities and therapeutic potential. Thus, the present review provides a comprehensive summary of bilosomes, modified bilosomes, surface modifications with their mechanism of action, formulation components, preparation methods, patents, and a wide array of recent pharmaceutical applications in oral, transdermal, and ocular drug delivery. The enhanced properties of bilosomes offer promising prospects for targeted and effective drug delivery, providing potential solutions for addressing various therapeutic challenges.

Physiologically Based Pharmacokinetic Modeling of Extracellular Vesicles

Extracellular vesicles (EVs) are lipid membrane bound-cell-derived structures that are a key player in intercellular communication and facilitate numerous cellular functions such as tumor growth, metastasis, immunosuppression, and angiogenesis. They can be used as a drug delivery platform because they can protect drugs from degradation and target specific cells or tissues. With the advancement in the technologies and methods in EV research, EV-therapeutics are one of the fast-growing domains in the human health sector. Therapeutic translation of EVs in clinics requires assessing the quality, safety, and efficacy of the EVs, in which pharmacokinetics is very crucial. We report here the application of physiologically based pharmacokinetic (PBPK) modeling as a principal tool for the prediction of absorption, distribution, metabolism, and excretion of EVs. To create a PBPK model of EVs, researchers would need to gather data on the size, shape, and composition of the EVs, as well as the physiological processes that affect their behavior in the body. The PBPK model would then be used to predict the pharmacokinetics of drugs delivered via EVs, such as the rate at which the drug is absorbed and distributed throughout the body, the rate at which it is metabolized and eliminated, and the maximum concentration of the drug in the body. This information can be used to optimize the design of EV-based drug delivery systems, including the size and composition of the EVs, the route of administration, and the dose of the drug. There has not been any dedicated review article that describes the PBPK modeling of EV. This review provides an overview of the absorption, distribution, metabolism, and excretion (ADME) phenomena of EVs. In addition, we will briefly describe the different computer-based modeling approaches that may help in the future of EV-based therapeutic research.

The crossroad of nanovesicles and oral delivery of insulin

INTRODUCTION

Diabetes mellitus is one of the challenging health problems worldwide. Multiple daily subcutaneous injection of insulin causes poor compliance in patients. Development of efficient oral formulations to improve the quality of life of such patients has been an important goal in pharmaceutical industry. However, due to serious issues such as low bioavailability and instability, it has not been achieved yet.

AREAS COVERED

Due to functional properties of the vesicles and the fact that hepatic-directed vesicles of insulin could reach the clinical phases, we focused on three main vesicular delivery systems for oral delivery of insulin: liposomes, niosomes, and polymersomes. Recent papers were thoroughly discussed to provide a broad overview of such oral delivery systems.

EXPERT OPINION

Although conventional liposomes are unstable in the presence of bile salts, their further modifications such as surface coating could increase their stability in the GI tract. Bilosomes showed good flexibility and stability in GI fluids. Also, niosomes were stable, but they could not induce significant hypoglycemia in animal studies. Although polymersomes were effective, they are expensive and there are some issues about their safety and industrial scale-up. Also, we believe that other modifications such as addition of a targeting agent or surface coating of the vesicles could significantly increase the bioavailability of insulin-loaded vesicles.

Self-assembled short peptides: Recent advances and strategies for potential pharmaceutical applications

Self-assembled short peptides have intrigued scientists due to the convenience of synthesis, good biocompatibility, low toxicity, inherent biodegradability and fast response to change in the physiological environment. Therefore, it is necessary to present a comprehensive summary of the recent advances in the last decade regarding the construction, route of administration and application of self-assembled short peptides based on the knowledge on their unique and specific ability of self-assembly. Herein, we firstly explored the molecular mechanisms of self-assembly of short peptides, such as non-modified amino acids, as well as Fmoc-modified, N-functionalized, and C-functionalized peptides. Next, cell penetration, fusion, and peptide targeting in peptide-based drug delivery were characterized. Then, the common administration routes and the potential pharmaceutical applications (drug delivery, antibacterial activity, stabilizers, imaging agents, and applications in bioengineering) of peptide drugs were respectively summarized. Last but not least, some general conclusions and future perspectives in the relevant fields were briefly listed. Although with certain challenges, great opportunities are offered by self-assembled short peptides to the fascinating area of drug development.

Oral insulin delivery: Barriers, strategies, and formulation approaches: A comprehensive review

Diabetes Mellitus is characterized by a hyperglycemic condition which can either be caused by the destruction of the beta cells or by the resistance developed against insulin in the cells. Insulin is a peptide hormone that regulates the metabolism of carbohydrates, proteins, and fats. Type 1 Diabetes Mellitus needs the use of Insulin for efficient management. However invasive methods of administration may lead to reduced adherence by the patients. Hence there is a need for a non-invasive method of administration. Oral Insulin has several merits over the conventional method including patient compliance, and reduced cost, and it also mimics endogenous insulin and hence reaches the liver by the portal vein at a higher concentration and thereby showing improved efficiency. However oral Insulin must pass through several barriers in the gastrointestinal tract. Some strategies that could be utilized to bypass these barriers include the use of permeation enhancers, absorption enhancers, use of suitable polymers, use of suitable carriers, and other agents. Several formulation types have been explored for the oral delivery of Insulin like hydrogels, capsules, tablets, and patches which have been described briefly by the article. A lot of attempts have been made for developing oral insulin delivery however none of them have been commercialized due to numerous shortcomings. Currently, there are several formulations from the companies that are still in the clinical phase, the success or failure of some is yet to be seen in the future.

Challenges and Opportunities in the Oral Delivery of Recombinant Biologics

Recombinant biological molecules are at the cutting-edge of biomedical research thanks to the significant progress made in biotechnology and a better understanding of subcellular processes implicated in several diseases. Given their ability to induce a potent response, these molecules are becoming the drugs of choice for multiple pathologies. However, unlike conventional drugs which are mostly ingested, the majority of biologics are currently administered parenterally. Therefore, to improve their limited bioavailability when delivered orally, the scientific community has devoted tremendous efforts to develop accurate cell- and tissue-based models that allow for the determination of their capacity to cross the intestinal mucosa. Furthermore, several promising approaches have been imagined to enhance the intestinal permeability and stability of recombinant biological molecules. This review summarizes the main physiological barriers to the oral delivery of biologics. Several preclinical in vitro and ex vivo models currently used to assess permeability are also presented. Finally, the multiple strategies explored to address the challenges of administering biotherapeutics orally are described.

Budesonide-Loaded Bilosomes as a Targeted Delivery Therapeutic Approach Against Acute Lung Injury in Rats

Budesonide (BUD), a glucocorticoids drug, inhibits all steps in the inflammatory response. It can reduce and treat inflammation and other symptoms associated with acute lung injury such as COVID-19. Loading BUD into bilosomes could boost its therapeutic activity, and lessen its frequent administration and side effects. Different bilosomal formulations were prepared where the independent variables were lipid type (Cholesterol, Phospholipon 80H, L-alpha phosphatidylcholine, and Lipoid S45), bile salt type (Na cholate and Na deoxycholate), and drug concentration (10, 20 mg). The measured responses were: vesicle size, entrapment efficiency, and release efficiency. One optimum formulation (composed of cholesterol, Na cholate, and 10 mg of BUD) was selected and investigated for its anti-inflammatory efficacy in vivo using Wistar albino male rats. Randomly allocated rats were distributed into four groups: The first: normal control group and received intranasal saline, the second one acted as the acute lung injury model received intranasal single dose of 2 mg/kg potassium dichromate (PD). Whereas the third and fourth groups received the market product (Pulmicort® nebulising suspension 0.5 mg/ml) and the optimized formulation (0.5 mg/kg; intranasal) for 7 days after PD instillation, respectively. Results showed that the optimized formulation decreased the pro-inflammatory cytokines TNF-α, and TGF-β contents as well as reduced PKC content in lung. These findings suggest the potentiality of BUD-loaded bilosomes for the treatment of acute lung injury with the ability of inhibiting the pro-inflammatory cytokines induced COVID-19.

Tailoring of Novel Bile Salt Stabilized Vesicles for Enhanced Transdermal Delivery of Simvastatin: A New Therapeutic Approach against Inflammation

Simvastatin (SMV), a cholesterol-lowering agent, has antioxidant and anti-inflammatory effects. Nevertheless, the oral use of SMV is linked with poor systemic bioavailability owing to its limited aqueous solubility and extensive first-pass metabolism. The aim of this study was to evaluate the feasibility of transdermal delivery of SMV using bile salt stabilized vesicles (bilosomes) for enhancing the anti-inflammatory potential of SMV. SMV-loaded bilosomes (SMV-BS) were prepared by the thin film hydration technique and optimized by 3³ Box-Behnken design. The fabricated SMV-BS were assessed for vesicle size, entrapment efficiency (% EE) and cumulative drug release. The optimized formula was incorporated into HPMC gel and investigated for physical properties, ex vivo permeation, in vivo pharmacokinetic study and anti-inflammatory potential in inflamed paw edema rat model. The optimized SMV-BS showed vesicle size of 172.1 ± 8.1 nm and % EE of 89.2 ± 1.8%. In addition, encapsulating SMV within bilosomal vesicles remarkably sustained drug release over 12 h, compared to plain drug suspension. Furthermore, SMV-loaded bilosomal gel showed a three-fold enhancement in SMV transdermal flux, compared to plain drug suspension. Most importantly, the relative bioavailability of SMV-BS gel was ~2-fold and ~3-fold higher than those of oral SMV suspension and SMV gel, respectively. In carrageenan-induced paw edema model, SMV-BS gel induced a potent anti-inflammatory effect, as evidenced by a remarkable reduction in paw edema, which was comparable to that of the standard anti-inflammatory drug, indomethacin. Collectively, bilosomes might represent a plausible transdermal drug delivery system that could enhance the anti-inflammatory activity of SMV by boosting its skin permeation and its systemic bioavailability.

Hyaluronic acid-enriched bilosomes: an approach to enhance ocular delivery of agomelatine via D-optimal design: formulation, in vitro characterization, and in vivo pharmacodynamic evaluation in rabbits

Agomelatine (AGO) is a dual-functional drug. It uses as an antidepressant when orally administrated and antiglaucomic when topically applied to the eye. This study aimed to formulate AGO into bilosomal vesicles for glaucoma treatment, as modern studies pointed out the effect of topical AGO on intraocular pressure for the treatment of glaucoma. A modified ethanol injection technique was used for the fabrication of AGO bilosomes according to a D-optimal design. Phosphatidylcholine (PC) to edge activator (EA) ratio, Hyaluronic acid percentage (HA%), and EA type were utilized as independent variables. The measured responses were percent entrapment efficiency (EE%), particle size (PS), polydispersity index, zeta potential, percentage of drug released after 2 h (Q_2h%), and 24 h (Q_24h%). The optimal bilosomal formula (OB), with the desirability of 0.814 and the composition of 2:1 PC: EA ratio, 0.26% w/v HA and sodium cholate as EA, was subjected to further in vitro characterizations and in vivo evaluation studies. The OB formula had EE% of 81.81 ± 0.23%, PS of 432.45 ± 0.85 nm, Q_2h% of 42.65 ± 0.52%, and Q_24h% of 75.14 ± 0.39%. It demonstrated a higher elasticity than their corresponding niosomes with a typical spherical shape of niosomes by using transmission electron microscope. It exhibited acceptable stability over three months. pH and Refractive index measurements together with the histopathological study ensured that the OB formula is safe for the eye and causes no ocular irritation or blurred vision. The OB formula showed superiority in the in vivo pharmacodynamics parameters over the AGO solution, so AGO-loaded bilosome could improve ocular delivery and the bioavailability of agomelatine.

Brain Targeting of Citicoline Sodium via Hyaluronic Acid-Decorated Novel Nano-Transbilosomes for Mitigation of Alzheimer's Disease in a Rat Model: Formulation, Optimization, in vitro and in vivo Assessment

BACKGROUND

Alzheimer's disease (AD) is one of the furthermost advanced neurodegenerative disorders resulting in cognitive and behavioral impairment. Citicoline sodium (CIT) boosts the brain's secretion of acetylcholine, which aids in membrane regeneration and repair. However, it suffers from poor blood-brain barrier (BBB) permeation, which results in lower levels of CIT in the brain.

PURPOSE

This study targeted to encapsulate CIT into novel nano-platform transbilosomes decorated with hyaluronic acid CIT-HA*TBLs to achieve enhanced drug delivery from the nose to the brain.

METHODS

A method of thin-film hydration was utilized to prepare different formulae of CIT-TBLs using the Box-Behnken design. The optimized formula was then hyuloranated via integration of HA to form the CIT-HA*TBLs formula. Furthermore, AD induction was performed by aluminum chloride (Alcl3), animals were allocated, and brain hippocampus tissue was isolated for ELISA and qRT-PCR analysis of malondialdehyde (MDA), nuclear factor kappa B (NF-kB), and microRNA-137 (miR-137) coupled with immunohistochemical amyloid-beta (Aβ1-42) expression and histopathological finding.

RESULTS

The hyuloranated CIT-HA*TBLs formula, which contained the following ingredients: PL (300 mg), Sp 60 (43.97 mg), and SDC (20 mg). They produced spherical droplets at the nanoscale (178.94 ±12.4 nm), had a high entrapment efficiency with 74.92± 5.54%, had a sustained release profile of CIT with 81.27 ±3.8% release, and had ex vivo permeation of CIT with 512.43±19.58 μg/cm2. In vivo tests showed that CIT-HA*TBL thermogel dramatically reduces the hippocampus expression of miR-137 and (Aβ1-42) expression, boosting cholinergic neurotransmission and decreasing MDA and NF-kB production. Furthermore, CIT-HA*TBLs thermogel mitigate histopathological damage in compared to the other groups.

CONCLUSION

Succinctly, the innovative loading of CIT-HA*TBLs thermogel is a prospectively invaluable intranasal drug delivery system that can raise the efficacy of CIT in Alzheimer's management.

Pitavastatin-loaded bilosomes for oral treatment of hepatocellular carcinoma: a repurposing approach

Albeit its established efficacy as an anti-hyperlipidemic agent, pitavastatin (PIT) has been shown to have other various therapeutic effects. One of these effects is the anti-cancer activity against hepatocellular carcinoma (HCC). This effect has been evaluated in this study for the first time via its oral delivery loaded in bilosomes both in vitro in hepatocellular carcinoma (HCC) cell line; HepG2 and in vivo in an Ehrlich ascites carcinoma (EAC) model. Moreover, the impact of surface modification of bilosomes with lactoferrin (LF) as an active targeting ligand for HCC was investigated. Bilosomes were prepared by thin-film hydration and different molar phospholipid to bile salt ratios were used to optimize the bilosomal formulation. The molar phospholipid to bile salt ratio was adjusted to 4:1 at pH 7.4. LF-coated bilosomes possessed a particle size, PDI, entrapment efficiency, and zeta potential of 112.28 nm ± 6.35, 0.229 ± 0.06, 90.56% ± 3.22, and −7.86 mV ± 1.13, respectively. LF-coated bilosomes also increased permeation of PIT when tested on Caco-2 cells by 3.1-folds (compared to uncoated ones or free PIT solution). It also improved the cytotoxicity of HepG2 spheroids 44-folds more than PIT-free solution. RT-PCR analysis showed that LF-coated PIT-loaded bilosomes caused an improvement (2-fold increase) in the apoptotic potential of PIT mediated by caspase-3. In conclusion, the optimized LF-coated PIT-loaded bilosomes were cytotoxic to HCC with improved hepatocytes permeation and cellular uptake. Thus, the proposed formula could be a promising treatment for HCC.

Development of surface modified bilosomes for the oral delivery of quercetin: optimization, characterization in-vitro antioxidant, antimicrobial, and cytotoxicity study

Quercetin (QT) is a flavonoid that exhibits anti-oxidant and chemo-preventive activity. This research work aimed to develop surface-modified bilosomes (BS) of QT. The BS was prepared by the solvent evaporation method and optimized by the Box-Behnken design. The optimized QT-BS (QT-BS3opt) displayed vesicle size (143.51 nm), PDI (0.256), zeta potential (-15.4 mV), and entrapment efficiency (89.52%). Further, the optimized QT-BS formulation was coated with chitosan (CS). The XRD diffractogram of CS-QT-BS3opt1 did not exhibit extensive peaks of QT, revealing that QT is properly encapsulated in the polymer matrix. The QT-BS3opt and CS-QT-BS3opt1 exhibited sustained-release (86.62 ± 3.23% and 69.32 ± 2.57%, respectively) up to 24 h with the Korsmeyer-Peppas kinetic model (R² =0.9089). CS-QT-BS3opt1 exhibited significantly (P < .05) high flux, i.e. 4.20-fold more than pure QT dispersion and 1.27-fold higher than QT-BS3opt. CS-QT-BS3opt1 showed significantly greater bio-adhesion (76.43 ± 2.42%) than QT-BS3opt (20.82 ± 1.45%). The antioxidant activity showed that QT from CS-QT-BS3opt1 has more remarkable (P < .05) antioxidant activity at each concentration than pure QT. The CS-QT-BS3opt1 exhibited 1.61-fold higher cytotoxicity against MFC7 and 1.44-fold higher cytotoxicity against MDA-MB-231 than pure QT. The CS-QT-BS3opt1 displayed a significantly greater antimicrobial potential against E. coli than against S. aureus. From all these findings, it could be concluded that surface-modified QT-BS might be an effective approach for increasing the efficacy of QT in the treatment of certain ailments.

Bilosomes as a promising nanoplatform for oral delivery of an alkaloid nutraceutical: improved pharmacokinetic profile and snowballed hypoglycemic effect in diabetic rats

Diabetes mellitus is a life-threatening metabolic disease. At the moment, there is no effective treatment available to combat it. In this study, we aimed to develop berberine-loaded bilosomes (BER-BLS) to boost the oral bioavailability and therapeutic efficacy of berberine, a natural antidiabetic medication. The BER-BLS was fabricated using a thin-film hydration strategy and optimized using a central composite design (face-centered). The average vesicle size, entrapment efficiency, and surface charge of the optimized BER-BLS preparation were 196.5 nm, 89.7%, (−) 36.4 mV, respectively. In addition, it exhibited higher stability and better-sustained release of berberine than the berberine solution (BER-SOL). BER-BLS and BER-SOL were administered to streptozocin-induced diabetic rats. The optimized BER-BLS formulation had a significant hypoglycemic impact, with a maximum blood glucose decrease of 41%, whereas BER-SOL only reduced blood glucose by 19%. Furthermore, the pharmacological effect of oral BER-BLS and BER-SOL corresponded to 99.3% and 31.7%, respectively, when compared to subcutaneous insulin (1 IU). A pharmacokinetic analysis found a 6.4-fold rise in the relative bioavailability of berberine in BER-BLS when compared to BER-SOL at a dosage of 100 mg/kg body weight. Histopathological investigation revealed that BER-BLS is suitable for oral administration. Our data demonstrate that BLS is a potential nanocarrier for berberine administration, enhancing its oral bioavailability and antidiabetic activity.

Advances in the stability challenges of bioactive peptides and improvement strategies

Bioactive peptides are widely used in functional foods due to their remarkable efficacy, selectivity, and low toxicity. However, commercially produced bioactive peptides lack quality stability between batches. Furthermore, the efficacies of bioactive peptides cannot be guaranteed in vivo due to gastrointestinal digestion and rapid plasma, liver, and kidney metabolism. The problem of poor stability has restricted the development of peptides. Bioactive peptide stability assessments use different stability assays, so the results of different studies are not always comparable. This review summarizes the quality stability challenges in the enzymatic hydrolysis production of bioactive peptides and the metabolism stability challenges after oral administration. Future directions on the strategies for improving their stability are provided. It was proposed that we use fingerprinting as a quality control measure using qualitative and quantitative characteristic functional peptide sequences. The chemical modification and encapsulation of bioactive peptides in microcapsules and liposomes are widely used to improve the digestive and metabolic stability of bioactive peptides. Additionally, the establishment of a universal stability test and a unified index would greatly improve uniformity and comparability in research into bioactive peptides. In summary, the reliable evaluation of stability is an essential component of peptide characterization, and these ideas may facilitate further development and utilization of bioactive peptides.

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Stability challenges encountered by bioactive peptides were summarized.

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Strategies to improve the stability of bioactive peptides were provided.

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A universal stability test and unified index would improve uniformity and comparability in research into bioactive peptides.

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It was proposed that we use a method of traditional Chinese medicine fingerprinting as a quality control measure.

Deformable Nanovesicle-Loaded Gel for Buccal Insulin Delivery

Deformable nanovesicles (DNVs) have been widely used in oral mucosal delivery studies of biomolecular drugs. However, their development for oral mucosal preparations has been limited by their physical and chemical instability, the need for small oral volumes, and the complexity of the oral microenvironment. This study aimed to develop a more suitable buccal delivery system for DNVs with improved storage stability. Preliminary stability studies investigated different gel types, the effects of different hydrophilic gel matrices, and matrix temperature sensitivity using DNVs loaded with insulin-phospholipid complex (IPC-DNVs). A temperature-sensitive gel encapsulating IPC-DNVs (IPC-DNV-TSG) prepared with 2% w/v gelatin was stable at 4 °C for three months and maintained an excellent hypoglycemic effect. The delivery efficiency of IPC-DNVs and IPC-DNV-TSG was compared using a TR146 cell model, revealing that cell viability remained high. Cellular uptake was slightly lower for IPC-DNV-TSG than for IPC-DNVs, but total transport did not differ significantly between the two groups, which may have been related to the viscosity of IPC-DNV-TSG and the hydrophilicity, cell adhesion properties, and biocompatibility of gelatin. Moreover, neither IPC-DNVs nor IPC-DNV-TSG induced significant mucosal irritation in rabbit tongue tissue sections. The study findings demonstrate a promising method for possible use as oral mucosal delivery of peptide drugs.

Novel Bile Salt Stabilized Vesicles-Mediated Effective Topical Delivery of Diclofenac Sodium: A New Therapeutic Approach for Pain and Inflammation

The oral delivery of diclofenac sodium (DNa), a non-steroidal analgesic, anti-inflammatory drug, is associated with various gastrointestinal side effects. The aim of the research was to appraise the potential of transdermal delivery of DNa using bilosomes as a vesicular carrier (BSVC) in inflamed paw edema. DNa-BSVCs were elaborated using a thin-film hydration technique and optimized using a 3¹.2² multilevel categoric design with Design Expert^® software 10 software (Stat-Ease, Inc., Minneapolis, MI, USA). The effect of formulation variables on the physicochemical properties of BSVC, as well as the optimal formulation selection, was investigated. The BSVCs were evaluated for various parameters including entrapment efficiency (EE%), vesicle size (VS), zeta potential (ZP) and permeation studies. The optimized BSVC was characterized for in vitro release, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and incorporated into hydrogel base. The optimized DNa-BSVC gel effectiveness was assessed in vivo using carrageenan-induced paw edema animal model via cyclooxygenase 2 (COX-2), interleukin 6 (IL-6), Hemooxygenase 1 (HO-1) and nuclear factor-erythroid factor2-related factor 2 (Nfr-2) that potentiate anti-inflammatory and anti-oxidant activity coupled with histopathological investigation. The resulting vesicles presented VS from 120.4 ± 0.65 to 780.4 ± 0.99 nm, EE% from 61.7 ± 3.44 to 93.2 ± 2.21%, ZP from −23.8 ± 2.65 to −82.1 ± 12.63 mV and permeation from 582.9 ± 32.14 to 1350.2 ± 45.41 µg/cm². The optimized BSVCs were nano-scaled spherical vesicles with non-overlapped bands of their constituents in the FTIR. Optimized formulation has superior skin permeability ex vivo approximately 2.5 times greater than DNa solution. Furthermore, histological investigation discovered that the formed BSVC had no skin irritating properties. It was found that DNa-BSVC gel suppressed changes in oxidative inflammatory mediators (COX-2), IL-6 and consequently enhanced Nrf2 and HO-1 levels. Moreover, reduction of percent of paw edema by about three-folds confirmed histopathological alterations. The results revealed that the optimized DNa-BSVC could be a promising transdermal drug delivery system to boost anti-inflammatory efficacy of DNa by enhancing the skin permeation of DNa and suppressing the inflammation of rat paw edema.

Recent Advances in Oral Peptide or Protein-Based Drug Liposomes

The high physiology and low toxicity of therapeutic peptides and proteins have made them a hot spot for drug development in recent years. However, their poor oral bioavailability and unstable metabolism make their clinical application difficult. The bilayer membrane of liposomes provides protection for the drug within the compartment, and their high biocompatibility makes the drug more easily absorbed by the body. However, phospholipids—which form the membranes—are subjected to various digestive enzymes and mucosal adhesion in the digestive tract and disintegrate before absorption. Improvements in the composition of liposomes or modifying their surface can enhance the stability of the liposomes in the gastrointestinal tract. This article reviews the basic strategies for liposome preparation and surface modification that promote the oral administration of therapeutic polypeptides.

Addressing the Superior Drug Delivery Performance of Bilosomes─A Microscopy and Fluorescence Study

The global health scenario in present times has raised human awareness about drug delivery strategies. Among colloidal drug delivery vehicles, vesicular nanocarriers such as liposomes and niosomes are popular. However, liposomes and niosomes get disrupted in the harsh environment of the gastrointestinal tract. In this context, the drug delivery community has reported the superior performance of vesicles containing bile salts, that is, bilosomes. The present work attempts to examine the structural/morphological aspects underlying the superior performance of bilosomes. Optical microscopy, electron microscopy, and light scattering give a definite proof of the enhanced stability of bilosomes compared to niosomes, both prepared from the same amphiphilic molecule. Fluorescence probing of the vesicles provides detailed insight into the bilayer characteristics and the differences between bilosomes and niosomes. Fluorescence resonance energy transfer studies lend further support to the findings that bilosomes have a more flexible bilayer structure than niosomes. The entrapment efficiency of the vesicles for the well-known antioxidant curcumin (whose bioavailability is a matter of concern due to low water solubility) was also studied. Bilosomes show higher curcumin entrapment efficiency than niosomes. For use in drug delivery, one needs to establish a trade-off between cargo/drug entrapment and release. Thus, a flexible bilayer structure is an advantage.

Bile acid-based advanced drug delivery systems, bilosomes and micelles as novel carriers for therapeutics

Diabetes mellitus affects almost half a billion patients worldwide and results from either destruction of β-cells responsible for insulin secretion or increased tissue resistance to insulin stimulation and the reduction of glycemic control. Novel drug delivery systems can improve treatment efficacy in diabetic patients. The low aqueous solubility of most oral antidiabetic drugs decreases drug bioavailability; therefore, there is a demand for the use of novel methods to overcome this issue. The application of bile acids mixed micelles and bilosomes can provide an enhancement in drug efficacy. Bile acids are amphiphilic steroidal molecules that contain a saturated tetracyclic hydrocarbon cyclopentanoperhydrophenanthrene ring, and consist of three 6-membered rings and a 5-membered ring, a short aliphatic side chain, and a tough steroid nucleus. This review offers a comprehensive and informative data focusing on the great potential of bile acid, their salts, and their derivatives for the development of new antidiabetic drug delivery system.

Formulation and Evaluation of Moxifloxacin Loaded Bilosomes In-Situ Gel: Optimization to Antibacterial Evaluation

In this study, moxifloxacin (MX)-loaded bilosome (BS) in situ gel was prepared to improve ocular residence time. MX-BSs were prepared using the thin-film hydration method. They were optimized using a Box−Behnken design (BBD) with bile salt (A, sodium deoxycholate), an edge activator (B, Cremophor EL), and a surfactant (C, Span 60) as process variables. Their effects were assessed based on hydrodynamic diameter (Y1), entrapment efficacy (Y2), and polydispersity index (Y3). The optimized formulation (MX-BSop) depicted a low hydrodynamic diameter (192 ± 4 nm) and high entrapment efficiency (76 ± 1%). Further, MX-BSop was successfully transformed into an in situ gel using chitosan and sodium alginate as carriers. The optimized MX-BSop in situ gel (MX-BSop-Ig4) was further evaluated for gelling capacity, clarity, pH, viscosity, in vitro release, bio-adhesiveness, ex vivo permeation, toxicity, and antimicrobial properties. MX-BSop-Ig4 exhibited an optimum viscosity of 65.4 ± 5.3 cps in sol and 287.5 ± 10.5 cps in gel states. The sustained release profile (82 ± 4% in 24 h) was achieved with a Korsmeyer−Peppas kinetic release model (R2 = 0.9466). Significant bio-adhesion (967.9 dyne/cm2) was achieved in tear film. It also exhibited 1.2-fold and 2.8-fold higher permeation than MX-Ig and a pure MX solution, respectively. It did not show any toxicity to the tested tissue, confirmed by corneal hydration (77.3%), cornea histopathology (no internal changes), and a HET-CAM test (zero score). MX-BSop-Ig4 exhibited a significantly (p < 0.05) higher antimicrobial effect than pure MX against Staphylococcus aureus and Escherichia coli. The findings suggest that bilosome in situ gel is a good alternative to increase corneal residence time, as well as to improve therapeutic activity.

Surface-Modified Bilosomes Nanogel Bearing a Natural Plant Alkaloid for Safe Management of Rheumatoid Arthritis Inflammation

Rheumatoid arthritis (RA) is a chronic inflammatory illness affecting the joints. The characteristic of RA is gradual joint deterioration. Current RA treatment alleviates signs such as inflammation and pain and substantially slows the progression of the disease. In this study, we aimed to boost the transdermal delivery of berberine (a natural product) by encapsulating it in chitosan, surface-modified bilosomes nanogel for better management of the inflammation of RA. The chitosan-coated bilosomes loaded with berberine (BER-CTS-BLS) were formulated according to the thin-film hydration approach and optimized for various causal variables, considering the effect of lipid, sodium deoxycholate, and chitosan concentrations on the size of the particles, entrapment, and the surface charge. The optimized BER-CTS-BLS has 202.3 nm mean diameter, 83.8% entrapment, and 30.8 mV surface charge. The optimized BER-CTS-BLS exhibited a delayed-release profile in vitro and increased skin permeability ex vivo. Additionally, histological examination revealed that the formulated BLS had no irritating effects on the skin. Furthermore, the optimized BER-CTS-BLS ability to reduce inflammation was evaluated in rats with carrageenan-induced paw edema. Our results demonstrate that the group treated with topical BER-CTS-BLS gel exhibited a dramatic reduction in rat paw edema swelling percentage to reach 24.4% after 12 h, which was substantially lower than other groups. Collectively, chitosan-coated bilosomes containing berberine have emerged as a promising therapeutic approach to control RA inflammation.

Oral delivery of therapeutic peptides and proteins: Technology landscape of lipid-based nanocarriers

The oral administration of therapeutic peptides and proteins is favoured from a patient and commercial point of view. In order to reach the systemic circulation after oral administration, these drugs have to overcome numerous barriers including the enzymatic, sulfhydryl, mucus and epithelial barrier. The development of oral formulations for therapeutic peptides and proteins is therefore necessary. Among the most promising formulation approaches are lipid-based nanocarriers such as oil-in-water nanoemulsions, self-emulsifying drug delivery systems (SEDDS), solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC), liposomes and micelles. As the lipophilic character of therapeutic peptides and proteins can be tremendously increased such as by the formation of hydrophobic ion pairs (HIP) with hydrophobic counter ions, they can be incorporated in the lipophilic phase of these carriers. Since gastrointestinal (GI) peptidases as well as sulfhydryl compounds such as glutathione and dietary proteins are too hydrophilic to enter the lipophilic phase of these carriers, the incorporated therapeutic peptide or protein is protected towards enzymatic degradation as well as unintended thiol/disulfide exchange reactions. Stability of lipid-based nanocarriers towards lipases can be provided by the use to excipients that are not or just poorly degraded by these enzymes. Nanocarriers with a size <200 nm and a mucoinert surface such as PEG or zwitterionic surfaces exhibit high mucus permeating properties. Having reached the underlying absorption membrane, lipid-based nanocarriers enable paracellular and lymphatic drug uptake, induce endocytosis and transcytosis or simply fuse with the cell membrane releasing their payload into the systemic circulation. Numerous in vivo studies provide evidence for the potential of these delivery systems. Within this review we provide an overview about the different barriers for oral peptide and protein delivery, highlight the progress made on lipid-based nanocarriers in order to overcome them and discuss strengths and weaknesses of these delivery systems in comparison to other technologies.

Recent progress in polymeric non-invasive insulin delivery

The design of carriers for insulin delivery has recently attracted major research attentions in the biomedical field. In general, the release of drug from polymers is driven via a variety of polymers. Several mechanisms such as matrix release, leaching of drug, swelling, and diffusion are usually adopted for the release of drug through polymers. Insulin is one of the most predominant therapeutic drugs for the treatment of both diabetes mellitus; type-I (insulin-dependent) and type II (insulin-independent). Currently, insulin is administered subcutaneously, which makes the patient feel discomfort, pain, hyperinsulinemia, allergic responses, lipodystrophy surrounding the injection area, and occurrence of miscarried glycemic control. Therefore, significant research interest has been focused on designing and developing new insulin delivery technologies to control blood glucose levels and time, which can enhance the patient compliance simultaneously through alternative routes as non-invasive insulin delivery. The aim of this review is to emphasize various non-invasive insulin delivery mechanisms including oral, transdermal, rectal, vaginal, ocular, and nasal. In addition, this review highlights different smart stimuli-responsive insulin delivery systems including glucose, pH, enzymes, near-infrared, ultrasound, magnetic and electric fields, and the application of various polymers as insulin carriers. Finally, the advantages, limitations, and the effect of each non-invasive route on insulin delivery are discussed in detail.

Lipid-based nano-formulation platform for eplerenone oral delivery as a potential treatment of chronic central serous chorioretinopathy: in-vitro optimization and ex-vivo assessment

PURPOSE

Eplerenone (EPL) is a selective mineralocorticoid receptor antagonist used for treatment of chronic central serous chorioretinopathy which characterized by accumulation of subretinal fluid causing a localized area of retinal detachment. unfortunately, EPL suffers from poor oral bioavailability due to poor aqueous solubility in addition to high hepatic first pass metabolism.

METHOD

Aiming to improve its oral bioavailability, EPL-loaded nanostructured lipid carriers (NLCs) were prepared by the emulsification solvent evaporation method and in-vitro evaluated for particle size (PS), polydispersity index (PDI), zeta potential (ZP), and entrapment efficiency (EE%). A D-optimal design was used for study the effect of liquid lipid to solid lipid ratio, surfactant type and percentage on PS, PDI, EE%, and for data optimization. The optimized EPL-loaded NLCs system was further evaluated using in-vitro drug release and ex-vivo permeation studies through rabbit intestine in comparison to EPL aqueous suspension. The physicochemical properties of the drug in the optimized system were further examined using FT-IR and X-ray diffraction studies.

RESULTS

The resultant NLCs showed small PS (100.85-346.60 nm), homogenous distribution (0.173-0.624), negatively charged particles (ZP -20.20 to -36.75 mV), in addition to EE% (34.31-70.64%). The optimized EPL-loaded NLCs system with a desirability value of 0.905 was suggested through the Design expert® software, containing liquid to solid lipid ratio (2:1) in presence of 0.43%w/v Pluronic® F127 as a surfactant. The optimized EPL-loaded NLCs system showed a PS of 134 nm and PDI of 0.31, in addition to high EE% (76 ± 6.56%w/w), and ZP (-32.37 mV). The ex-vivo permeation study showed two-fold higher drug permeation through rabbit intestine compared to that from the aqueous drug suspension after 24 h, confirming the ability of optimized EPL-loaded NLCs system as successful oral targeting delivery carrier.

CONCLUSION

Our results pave the way for a new oral nanotherapeutic approach toward CSCR treatment. In-vivo study is currently under investigation.

Engineering Nano- and Microparticles as Oral Delivery Vehicles to Promote Intestinal Lymphatic Drug Transport

Targeted oral delivery of a drug via the intestinal lymphatic system (ILS) has the advantages of protecting against hepatic first-pass metabolism of the drug and improving its pharmacokinetic performance. It is also a promising route for the oral delivery of vaccines and therapeutic agents to induce mucosal immune responses and treat lymphatic diseases, respectively. This article describes the anatomical structures and physiological characteristics of the ILS, with an emphasis on enterocytes and microfold (M) cells, which are the main gateways for the transport of particulate delivery vehicles across the intestinal epithelium into the lymphatics. A comprehensive overview of recent advances in the rational engineering of particulate vehicles, along with the challenges and opportunities that they present for improving ILS drug delivery, is provided, and the mechanisms by which such vehicles target and transport through enterocytes or M cells are discussed. The use of naturally sourced materials, such as yeast microcapsules and their derived polymeric β-glucans, as novel ILS-targeting delivery vehicles is also reviewed. Such use is the focus of an emerging field of research. Their potential use in the oral delivery of nucleic acids, such as mRNA vaccines, is proposed.

Harnessing of Doxylamine Succinate/Pyridoxine Hydrochloride-Dual Laden Bilosomes as a Novel Combinatorial Nanoparadigm for Intranasal Delivery: In Vitro Optimization and In Vivo Pharmacokinetic Appraisal

The present work is concerned with tailoring and appraisal of a novel nano-cargo; bilosomes (BLS) dual laded with doxylamine succinate (DAS) and pyridoxine hydrochloride (PDH), the first treatment option against gestational nausea and vomiting, for intranasal delivery. This bifunctional horizon could surmount constraints of orally-commercialized platforms both in dosage regimen and pharmacokinetic profile. For accomplishing this purpose, DAS/PDH-BLS were elaborated integrating phospholipid, sodium cholate and cholesterol applying thin-film hydration method based on Box-Behnken design. Utilizing Design-Expert® software, the effect of formulation variables on BLS physicochemical features alongside the optimal formulation selection were investigated. Then, the optimum DAS/PDH-BLS formulation was incorporated into a thermally-triggered in situ gelling base. The in vivo pharmacokinetic studies were explored in rats for intranasal DAS/PDH-BLS in situ gel compared with analogous intranasal free in situ gel and oral solution. The optimized BLS disclosed vesicle size of 243.23 nm, ζ potential of -31.33 mV, entrapment efficiency of 59.18 and 41.63%, accumulative % release within 8 h of 63.30 and 85.52% and accumulative permeated amount over 24 h of 347.92 and 195.4 µg/cm² for DAS/PDH, respectively. Following intranasal administration of the inspected BLS in situ gel, pharmacokinetic studies revealed a 1.64- and 2.3-fold increment in the relative bioavailability of DAS and a 1.7- and 3.73-fold increase for PDH compared to the intranasal free in situ gel and oral solution, respectively besides significantly extended mean residence times for both drugs. Thus, the intranasally exploited DAS/PDH-BLS could be deemed as a promising hybrid nanoplatform with fruitful pharmacokinetics and tolerability traits.

Rapid and improved oral absorption of N-butylphthalide by sodium cholate-appended liposomes for efficient ischemic stroke therapy

As a multi-target drug to treat ischemic stroke, N-butylphthalide (NBP) is extremely water-insoluble and exhibits limited oral bioavailability, impeding its wide oral application. Effective treatment of ischemic stroke by NBP requires timely and efficient drug exposure, necessitating the development of new oral formulations. Herein, liposomes containing biosurfactant sodium cholate (CA-liposomes) were systemically investigated as an oral NBP delivery platform because of its high biocompatibility and great potential for clinical applications. The optimized liposomes have a uniform hydrodynamic size of 104.30 ± 1.60 nm and excellent encapsulation efficiency (93.91 ± 1.10%). Intriguingly, NBP-loaded CA-liposomes produced rapid drug release and the cumulative release was up to 88.09 ± 4.04% during 12 h while that for NBP group was only 6.79 ± 0.99%. Caco-2 cell monolayer assay demonstrated the superior cell uptake and transport efficiency of NBP-loaded CA-liposomes than free NBP, which was mediated by passive diffusion via transcellular and paracellular routes. After oral administration to rats, NBP-loaded CA-liposomes exhibited rapid and almost complete drug absorption, with a t_max of 0.70 ± 0.14 h and an absolute bioavailability of 92.65% while NBP suspension demonstrated relatively low bioavailability (21.7%). Meanwhile, NBP-loaded CA-liposomes produced 18.30-fold drug concentration in the brain at 5 min compared with NBP suspension, and the brain bioavailability increased by 2.48-fold. As expected, NBP-loaded CA-liposomes demonstrated significant therapeutic efficacy in a middle cerebral artery occlusion rat model. Our study provides new insights for engineering oral formulations of NBP with fast and sufficient drug exposure against ischemic stroke in the clinic.

Lipid-Based Nanocarrier System for the Effective Delivery of Nutraceuticals

Nutraceuticals possess several health benefits and functions; however, most nutraceuticals are prone to degradation in the gastrointestinal environment and have poor bioavailability. Application of a novel carrier system is of increasing importance to overcome obstacles and provide efficient applicability. Lipid-based nanocarriers provide a large surface-to-mass ratio, enhanced intestinal absorption by solubilization in the intestinal milieu, intestinal lymphatic transport, and altering enterocyte-based transport. A critical overview of the current limitation, preparation, and application of lipid-based nanocarriers (liposomes and niosomes) and lipid nanoparticles (SLNs and NLCs) is discussed. Physical and gastrointestinal stability and bioavailability of nanoencapsulated nutraceuticals are considered as well.

Improving the ameliorative effects of berberine and curcumin combination via dextran-coated bilosomes on non-alcohol fatty liver disease in mice

Background

The combination of berberine (BER) and curcumin (CUR) has been verified with ameliorative effects on non-alcohol fatty liver disease (NAFLD). However, discrepant bioavailability and biodistribution of BER and CUR remained an obstacle to achieve synergistic effects. Multilayer nanovesicles have great potential for the protection and oral delivery of drug combinations. Therein lies bile salts inserted liposomes, named as bilosomes, that possesses long residence time in the gastrointestinal tract (GIT) and permeability across the small intestine. Diethylaminoethyl dextran (DEAE-DEX) is generally used as an outside layer on the nanovesicles to increase the mucinous stability and promote oral absorption. Herein, we developed a DEAE-DEX-coated bilosome with BER and CUR encapsulated (DEAE-DEX@LSDBC) for the treatment of NAFLD.

Results

DEAE-DEX@LSDBC with 150 nm size exhibited enhanced permeation across mucus and Caco-2 monolayer. In vivo pharmacokinetics study demonstrated that DEAE-DEX@LSDBC profoundly prolonged the circulation time and improved the oral absorption of both BER and CUR. Intriguingly, synchronized biodistribution of BER and CUR and highest biodistribution at liver was achieved by DEAE-DEX@LSDBC, which contributed to the optimal ameliorative effects on NAFLD. It was further verified to be mainly mediated by anti-oxidation and anti-inflammation related pathways

Conclusion

DEAE-DEX coated bilosome displayed promoted oral absorption, prolonged circulation and synchronized biodistribution of BER and CUR, leading to improved ameliorative effects on NAFLD in mice, which provided a promising strategy for oral administration of drug combinations.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-00979-1.

Oral delivery of proteins and peptides: Challenges, status quo and future perspectives

Proteins and peptides (PPs) have gradually become more attractive therapeutic molecules than small molecular drugs due to their high selectivity and efficacy, but fewer side effects. Owing to the poor stability and limited permeability through gastrointestinal (GI) tract and epithelia, the therapeutic PPs are usually administered by parenteral route. Given the big demand for oral administration in clinical use, a variety of researches focused on developing new technologies to overcome GI barriers of PPs, such as enteric coating, enzyme inhibitors, permeation enhancers, nanoparticles, as well as intestinal microdevices. Some new technologies have been developed under clinical trials and even on the market. This review summarizes the history, the physiological barriers and the overcoming approaches, current clinical and preclinical technologies, and future prospects of oral delivery of PPs.