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Background: The TrialNet Oral Insulin (OI) prevention trial showed no overall treatment effect, using the diagnosis of type 1 diabetes as an endpoint. A significant delay in onset was only found in a high‐risk stratum (termed secondary stratum 1) of participants with low first‐phase insulin release (FPIR). Methods: Since trials with an endpoint of type 1 diabetes take years to complete, in this post hoc analysis, we assessed whether a novel combination of glucose and C‐peptide markers could identify a therapeutic benefit after 1 year of follow‐up (trial participants followed for a median 2.7 years). Results: Participants were relatives with multiple islet autoantibodies and low FPIR (n = 40). Glucose rose, and C‐peptide declined in the placebo group, whereas glucose rose minimally, and C‐peptide increased in the OI group. When glucose and C‐peptide were plotted on two‐dimensional grids using 30–120‐min oral glucose tolerance test (OGTT) time points, changes in ratios of their central points (centroid ratio) differed between groups (p = 0.037 adjusted for age, BMI, and baseline C‐peptide and glucose). Conclusions: These findings support a favorable early effect of OI on combined glucose and C‐peptide endpoints in high‐risk individuals, indicating metabolic benefit. With further study, these measures may allow for shorter trials compared to the standard endpoint of type 1 diabetes diagnosis. [ABSTRACT FROM AUTHOR]

The advancements in nanoscience have brought attention to the potential of utilizing nanoparticles as carriers for oral insulin administration. This study aims to investigate the effectiveness of synthesized polymeric mesoporous silica nanoparticles (MSN) as carriers for oral insulin and their interactions with insulin and IR through in-silico docking. Diabetic rats were treated with various MSN samples, including pure MSN, Amin-grafted MSN/PEG/Insulin (AMPI), Al-grafted MSN/PEG/Insulin (AlMPI), Zinc-grafted MSN/PEG/Insulin (ZNPI), and Co-grafted MSN/PEG/Insulin (CMPI). The nanocomposites were synthesized using a hybrid organic-inorganic method involving MSNs, graphene oxide, and insulin. Characterization of the nanocomposites was conducted using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). In vivo tests included the examination of blood glucose levels and histopathological parameters of the liver and pancreas in type 1 diabetic rats. The MSN family demonstrated a significant reduction in blood glucose levels compared to the diabetic control group (p

Virus-capsid mimicking mucus-permeable nanoparticles are promising oral insulin carriers which surmount intestinal mucus barrier. However, the impact of different viruscapsid mimicking structure remains unexplored. In this study, utilizing biotin grafted chitosan as the main skeleton, virus-mimicking nanoparticles endowed with biologicshell (streptavidin coverage) and polymeric-shell (hyaluronic acid/alginate coating) were designed with insulin as a model drug by self-assembly processes. It was demonstrated that biologic-shell mimicking nanoparticles exhibited a higher intestinal trans-mucus (> 80%, 10 min) and transmucosal penetration efficiency (1.6-2.2-fold improvement) than polymeric-shell counterparts. Uptake mechanism studies revealed caveolae-mediated endocytosis was responsible for the absorption of biologic-shell mimicking nanoparticles whereas polymeric-shell mimicking nanoparticles were characterized by clathrin-mediated pathway with anticipated lysosomal insulin digestion. Further, in vivo hypoglycemic study indicated that the improved effect of regulating blood sugar levels was virus-capsid structure dependent out of which biologic-shell mimicking nanoparticles presented the best performance (5.1%). Although the findings of this study are encouraging, much more work is required to meet the standards of clinical translation. Taken together, we highlight the external structural dependence of virus-capsid mimicking nanoparticles on the mucopenetrating and uptake mechanism of enterocytes that in turn affecting their in vivo absorption, which should be pondered when engineering virus-mimicking nanoparticles for oral insulin delivery. [ABSTRACT FROM AUTHOR]

Aims: To verify whether the oral insulin N11005 is administered as a prandial insulin by assessing the pharmacokinetics (PK), pharmacodynamics (PD), and safety profiles of N11005 with a short-acting biosynthetic human insulin (Novolin R) as reference. Methods: This was a randomized, open-label, single-dose, crossover hyperinsulinemic-euglycemic clamp study in healthy Chinese male subjects. A total of 12 subjects were enrolled in the test (T) group (N11005, 300 IU, p.o.) and the reference (R) group (Novolin R, 0.1 IU/Kg, i.h.) with a washout period of 14 days. All subjects were administered on the same day of the clamp study. Glucose Infusion Rates (GIR), serum insulin, and C-peptide concentration were determined during every 8-hour clamp cycle. Trial registration: Clinicaltrials.gov identifier NCT04975022. Results: After administration, the ratios of mean serum C-peptide concentration to baseline concentration in both T and R groups were lower than 50%, which confirmed the stability of the clamp platform. T group (N11005) showed a more rapid onset of action (tGIR10%max?11 min) and a comparable duration of action to the R group, which was basically in line with the characteristics of prandial insulins. No adverse events (AEs) occurred throughout the study, which demonstrated that N11005 and Novolin R are safe and well-tolerated. Conclusions: The PD profiles of the single-dose N11005 in the human body are similar to those of prandial insulins, with an excellent safety profile. [ABSTRACT FROM AUTHOR]

A large number of people are suffering with one or the other type of diabetes around the globe. Insulin has proven to be beneficial for the treatment of both types of diabetes. Due to the drawbacks (injection pain, needle phobia, lipodystrophy, noncompliance peripheral hyperinsulinemia, failure to deliver physiological pattern of insulin, and daily metabolic variability in glycemic control) associated with a conventional delivery system that is, the subcutaneous injection, a need to develop new insulin delivery system was felt strongly. A few noninvasive methods which are under process to deliver insulin include per-oral (enteric gastrointestinal route), intrapulmonary, buccal, intranasal, oropharyngeal, rectal, intrauterine, ocular, transdermal, oral, and vaginal. Intranasal insulin is fetching tons of importance as it provides multiple reasons to choose this method of delivery over other delivery systems. Certain factors are responsible for limiting the use of intranasal insulin for which various methods have been studied to overcome it. Many clinical trials are going on for launching intranasal insulin into the market.

A large number of people are suffering with one or the other type of diabetes around the globe. Insulin has proven to be beneficial for the treatment of both types of diabetes. Due to the drawbacks (injection pain, needle phobia, lipodystrophy, noncompliance peripheral hyperinsulinemia, failure to deliver physiological pattern of insulin, and daily metabolic variability in glycemic control) associated with a conventional delivery system that is, the subcutaneous injection, a need to develop new insulin delivery system was felt strongly. A few noninvasive methods which are under process to deliver insulin include per-oral (enteric gastrointestinal route), intrapulmonary, buccal, intranasal, oropharyngeal, rectal, intrauterine, ocular, transdermal, oral, and vaginal. Intranasal insulin is fetching tons of importance as it provides multiple reasons to choose this method of delivery over other delivery systems. Certain factors are responsible for limiting the use of intranasal insulin for which various methods have been studied to overcome it. Many clinical trials are going on for launching intranasal insulin into the market. [ABSTRACT FROM AUTHOR]

Abstract Background Oral administration of insulin (INS) could be absorbed into systemic circulation only if the carrier protected it from the hostile gastrointestinal conditions. However, traditional macromolecular carriers have not totally overcome challenges in addressing these biological barriers. Result In this study, inspired by small molecule natural products (SMNPs), we demonstrate the multi-functional self-assembly nanoparticles (BA-Al NPs) originating from baicalin (BA) and AlCl3 through coordination bonds and hydrogen bonds. As a novel carrier for oral insulin delivery (INS@BA-Al NPs), it displayed effective capacity in pH stimuli-responsive insulin release, intestinal mucoadhesion and transepithelial absorption enhance. Meanwhile, BA improved the paracellular permeability for insulin absorption, because of its downregulation at both mRNA and protein level on internal tight junction proteins. In vivo experiments exhibited remarkable bioavailability of INS and an ideal glucose homeostasis in the type I diabetic rat model. Conclusion This study offers a novel frontier of multi-functional carriers based on SMNPs with self-assembly character and bioactivity, which could be a promising strategy for diabetes therapy. Graphical Abstract

OBJECTIVE: Compliance to insulin injections is poor due to difficulty in subcutaneous administration. Hence, there is a need of an oral formulation of insulin. Oral insulin is currently under investigation. The present analysis aimed to evaluate oral insulin versus placebo for patients with diabetes mellitus (type-1 and type-2). MATERIALS AND METHODS: Results from PUBMED and MEDLINE were searched and compiled from January 1, 2000 to January 9, 2020. Postprandial blood glucose excursions (2PPG), glycated hemoglobin (HbA1c), C-peptide levels, and immune antibody (IAA) levels were compared between the arms. In addition, time to diabetes and safety of oral insulin were discussed. RESULTS: Thirteen out of 1778 trials were included to the analysis. Oral insulin was found to induce significant reduction in mean 2PPG excursion (standardized mean difference [SMD]: −1.94, 95% CI: −3.20 to −0.68, I2 = 91.81, P < 0.005) and mean IAA levels (SMD:-0.49, 95% CI: −0.82 to -0.16, I2 = 27.12, P < 0.005) compared with placebo. Mean C-peptide levels were notably lower in the oral insulin arm. However, the difference was not statistically significant. No significant difference was observed in mean HbA1c levels. The rate of development of type-1 diabetes was not significantly influenced by oral insulin. No deaths or treatment-related serious adverse events were reported. CONCLUSION: Oral insulin provided significant benefits for acute maintenance of diabetes mellitus. It elicited lower immune response and was well tolerated. This new formulation has potential to augment the management of diabetes mellitus. More studies are required to assess its long-term effects. [ABSTRACT FROM AUTHOR]

Type 1 diabetes (T1D) is a chronic autoimmune condition that affects millions of people worldwide. Insulin pumps or injections are the standard treatment options for this condition. This article provides a comprehensive overview of the several type 1 diabetes treatment options, focusing on oral insulin. The article is divided into parts that include immune-focused treatments, antigen vaccination, cell-directed interventions, cytokine-directed interventions, and non-immunomodulatory adjuvant therapy. Under the section on non-immunomodulatory adjunctive treatment, the benefits and drawbacks of medications such as metformin, amylin, sodium-glucose cotransporter inhibitors, glucagon-like peptide-1 receptor agonists (GLP-1 Ras), and verapamil are discussed. The article also discusses the advantages of oral insulin, including increased patient compliance and more dependable and regular blood sugar control. However, several variables, including the enzymatic and physical barriers of the digestive system, impair the administration of insulin via the mouth. Researchers have looked at a few ways to get over these challenges, such as changing the structure of the insulin molecule, improving absorption with the use of absorption enhancers or nanoparticles, and taking oral insulin together with other medications. Even with great advancements in the use of these treatment strategies, T1D still needs improvement in the therapeutic difficulties. Future studies in these areas should focus on creating tailored immunological treatments, looking into combination medications, and refining oral insulin formulations in an attempt to better control Type 1 Diabetes. The ultimate objective is to create accurate, customized strategies that will enhance glycemic management and the quality of life for individuals with the condition. [ABSTRACT FROM AUTHOR]

Diabetes is a chronic metabolic disease characterized by lack of insulin in the body leading to failure of blood glucose regulation. Diabetes patients usually need frequent insulin injections to maintain normal blood glucose levels, which is a painful administration manner. Long-term drug injection brings great physical and psychological burden to diabetic patients. In order to improve the adaptability of patients to use insulin and reduce the pain caused by injection, the development of oral insulin formulations is currently a hot and difficult topic in the field of medicine and pharmacy. Thus, oral insulin delivery is a promising and convenient administration method to relieve the patients. However, insulin as a peptide drug is prone to be degraded by digestive enzymes. In addition, insulin has strong hydrophilicity and large molecular weight and extremely low oral bioavailability. To solve these problems in clinical practice, the oral insulin delivery nanosystems were designed and constructed by rational combination of various nanomaterials and nanotechnology. Such oral nanosystems have the advantages of strong adaptability, small size, convenient processing, long-lasting pharmaceutical activity, and drug controlled-release, so it can effectively improve the oral bioavailability and efficacy of insulin. This review summarizes the basic principles and recent progress in oral delivery nanosystems for insulin, including physiological absorption barrier of oral insulin and the development of materials to nanostructures for oral insulin delivery nanosystems. [ABSTRACT FROM AUTHOR]

Background: Oral administration of insulin (INS) could be absorbed into systemic circulation only if the carrier protected it from the hostile gastrointestinal conditions. However, traditional macromolecular carriers have not totally overcome challenges in addressing these biological barriers. Result: In this study, inspired by small molecule natural products (SMNPs), we demonstrate the multi-functional self-assembly nanoparticles (BA-Al NPs) originating from baicalin (BA) and AlCl3 through coordination bonds and hydrogen bonds. As a novel carrier for oral insulin delivery (INS@BA-Al NPs), it displayed effective capacity in pH stimuli-responsive insulin release, intestinal mucoadhesion and transepithelial absorption enhance. Meanwhile, BA improved the paracellular permeability for insulin absorption, because of its downregulation at both mRNA and protein level on internal tight junction proteins. In vivo experiments exhibited remarkable bioavailability of INS and an ideal glucose homeostasis in the type I diabetic rat model. Conclusion: This study offers a novel frontier of multi-functional carriers based on SMNPs with self-assembly character and bioactivity, which could be a promising strategy for diabetes therapy. [ABSTRACT FROM AUTHOR]

Nanopartikel insulin telah dikembangkan sebagai alternatif penghantaran insulin oral. Sistem penghantaran obat dengan nanopartikel dapat diperoleh dari polimer sambungsilang gom xantan dan gom akasia dengan natrium trimetafosfat. Tujuan penelitian ini untuk mendapatkan nanopartikel insulin dengan menggunakan gom xantan dan gom akasia tersambungsilang untuk penghantaran oral. Pada penelitian ini nanopartikel insulin diperoleh dengan mencampur koloid gom xantan dan gom akasia dengan perbandingan 1:1 yang kemudian direaksikan dengan natrium trimetafosfat dalam suasana basa. Kemudian insulin dalam larutan HCl dimasukkan ke dalam koloid dan dikeringkan sehingga diperoleh serbuk nanopartikel insulin. Serbuk nanopartikel insulin dikarakterisasi meliputi penentuan data derajat substitusi (DS), efisiensi penjerapan, Dv90, daya mengembang, uji pelepasan obat in vitro, dan uji stabilitas. Hasil penelitian menunjukkan bahwa nanopartikel insulin yang terbentuk memiliki DS: 0,08 – 0,10 dengan efisiensi penjerapan 26,11% - 48,73%. Selain itu, nanopartikel insulin yang diperoleh memiliki nilai Dv90: 547 nm - 726 nm, dan daya mengembang sebesar 1,1 - 2,9 kali di dalam HCl pH 1,2 dan 2,5 - 3,4 kali di dalam dapar fosfat pH 6,8. Uji pelepasan in vitro menunjukkan bahwa dalam 3 jam telah dilepaskan insulin sebanyak 78,42% - 85,09%. Hasil uji stabilitas pada suhu 4 oC menunjukkan bahwa kadar insulin dalam nanopartikel adalah 74,46% - 85,09% pada minggu ke-9. Sebagai kesimpulan, penelitian ini menunjukkan bahwa nanopartikel gom xantan dan gom akasia tersambungsilang berpotensi untuk digunakan sebagai sistem penghantaran insulin oral. The insulin nanoparticles has been developed as an alternative to oral insulin delivery. Nanoparticle drug delivery system could be prepared by a cross-linked polymer, which was composed of xanthan gum and acacia gum, and cross-linked by sodium trimetaphosphate. The aim of the present study was to produce insulin nanoparticles using the cross-linked polymer of xanthan gum and acacia gum for oral delivery. In this study, insulin nanoparticles was prepared by mixing xanthan gum and acacia gum colloid with the ratio 1:1 and using sodium trimetaphosphate as a cross-linking agent in bases condition. Afterwards, insulin solution in HCl was added into the colloid, and then dried to produce the insulin nanoparticles. Insulin nanoparticle powders were characterized in terms of degree of substitution (DS), entrapment efficiency, Dv90, swelling ability, in vitro release study, and stability test. The results showed that the substitution degree of the insulin nanoparticles was 0.08 – 0.10 and the entrapment efficiency was 26.11% - 48.73%. Moreover, the insulin nanoparticles had Dv90 value 547 nm - 726 nm and swelling index of 1.1 - 2.9 in HCl pH 1.2 and 2.5 - 3.4 in phosphate buffer pH 6.8, respectively. According to the dissolution study, the insulin nanoparticles provided the insulin release of 78.42% - 85.67% within 3 hours. Furthermore, stability testing showed insulin content after 9 weeks incubation at 4oC was 74.46% - 85.09%. Therefore, this work demonstrated that a cross-linked polymer of xanthan gum and acasia gum nanoparticle could be potential for could be potential for oral insulin delivery system.

Surfactin, a lipopeptide produced by Bacillus species, has been used for the oral delivery of insulin. In this study, another lipopeptide of iturin was tested for its ability to orally delivery insulin alone or plus surfactin. Iturin could form co-precipitate with insulin at acidic pH values. After treatment by ultrasonification, the structure of coprecipitate was destroyed that led to a significant decrease in hypoglycemic effect after oral administration. Iturin weakly binds to (Kd = 257 μM) and induce insulin structure more compact that is favorable for insulin uptake by the intestine. After being coated with Acryl-Eze by lyophilization, the coprecipitate formed the spherical enteric-coated insulin microparticles delivered by iturin with a relative oral bioavailability of 6.84% in diabetic mice. For further improving oral hypoglycemic effect, surfactin was added to form the spherical enteric-coated insulin microparticles in a formulation containing insulin, Acryl-Eze, iturin and surfactin at a ratio of 1:1:0.5: 0.5 (w/w), with an insulin encapsulation efficiency of 66.22%. The enteric-coated insulin microparticles delivered by iturin plus surfactin showed a classical profile for controlled release in the intestine with a relative bioavailability of 7.67% after oral administration, which could effectively control the postprandial blood glucose at a level about 50% of the initial one just like the subcutaneous injection. Collectively, iturin plus surfactin is more efficient for oral delivering insulin than the sole one, and the resultant enteric-coated insulin microparticles are potential for the development of oral insulin to control postprandial blood glucose in diabetic patients.

Ghullam Reza Barbari,1 Farid Abedin Dorkoosh,1 Mohsen Amini,2 Mohammad Sharifzadeh,3 Fateme Atyabi,1 Saeed Balalaie,4 Niyousha Rafiee Tehrani,5 Morteza Rafiee Tehrani1 1Department of Pharmaceutics, 2Department of Medicinal Chemistry, 3Department of Pharmacology, School of Pharmacy, Tehran University of Medical Sciences, 4Department of Chemistry, Khaje Nasiroddin University, 5Department of Biochemistry, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Abstract: A simple and reproducible water-in-oil (W/O) nanoemulsion technique for making ultrasmall (

Surfactin, a lipopeptide produced by Bacillus species, has been used for the oral delivery of insulin. In this study, another lipopeptide of iturin was tested for its ability to orally delivery insulin alone or plus surfactin. Iturin could form co-precipitate with insulin at acidic pH values. After treatment by ultrasonification, the structure of coprecipitate was destroyed that led to a significant decrease in hypoglycemic effect after oral administration. Iturin weakly binds to (Kd = 257 μM) and induce insulin structure more compact that is favorable for insulin uptake by the intestine. After being coated with Acryl-Eze by lyophilization, the coprecipitate formed the spherical enteric-coated insulin microparticles delivered by iturin with a relative oral bioavailability of 6.84% in diabetic mice. For further improving oral hypoglycemic effect, surfactin was added to form the spherical enteric-coated insulin microparticles in a formulation containing insulin, Acryl-Eze, iturin and surfactin at a ratio of 1:1:0.5: 0.5 (w/w), with an insulin encapsulation efficiency of 66.22%. The enteric-coated insulin microparticles delivered by iturin plus surfactin showed a classical profile for controlled release in the intestine with a relative bioavailability of 7.67% after oral administration, which could effectively control the postprandial blood glucose at a level about 50% of the initial one just like the subcutaneous injection. Collectively, iturin plus surfactin is more efficient for oral delivering insulin than the sole one, and the resultant enteric-coated insulin microparticles are potential for the development of oral insulin to control postprandial blood glucose in diabetic patients. [ABSTRACT FROM AUTHOR]

ABSTRACT Introduction/Aim: The gut has shown to have a pivotal role on the pathophysiology of metabolic disease. Food stimulation of distal intestinal segments promotes enterohormones secretion influencing insulin metabolism. In diabetic rats, oral insulin has potential to change intestinal epithelium behavior. This macromolecule promotes positive effects on laboratorial metabolic parameters and decreases diabetic intestinal hypertrophy. This study aims to test if oral insulin can influence metabolic parameters and intestinal weight in obese non-diabetic rats. Methods: Twelve weeks old Wistar rats were divided in 3 groups: control (CTRL) standard chow group; high fat diet low carbohydrates group (HFD) and HFD plus daily oral 20U insulin gavage (HFD+INS). Weight and food consumption were weekly obtained. After eight weeks, fasting blood samples were collected for laboratorial analysis. After euthanasia gut samples were isolated. Results: Rat oral insulin treatment decreased body weight gain (p

Oral delivery of macromolecules requires permeation enhancers (PEs) adaptable to formulation. Sucrose laurate (SL) (D1216), a food grade surfactant, was assessed in Caco-2 monolayers, isolated rat intestinal tissue mucosae, and rat intestinal instillations. Accordingly, 1 mM SL increased the apparent permeability coefficient (Papp) of [14C]-mannitol and reduced transepithelial electrical resistance (TEER) across monolayers. It altered expression of the tight junction protein, ZO-1, increased plasma membrane potential, and decreased mitochondrial membrane potential in Caco-2 cells. The concentrations that increased flux were of the same order as those that induced cytotoxicity. In rat colonic tissue mucosae, the same patterns emerged in respect to the concentration-dependent increases in paracellular marker fluxes and TEER reductions with 5 mM being the key concentration. While the histology revealed some perturbation, ion transport capacity was retained. In rat jejunal and colonic instillations, 50 and 100 mM SL co-administered with insulin induced blood glucose reductions and achieved relative bioavailability values of 2.4% and 8.9%, respectively, on a par with the gold standard PE, sodium caprate (C10). The histology of the intestinal loops revealed little damage. In conclusion, SL is a candidate PE with high potential for emulsion-based systems. The primary action is plasma membrane perturbation, leading to tight junction openings and a predominant paracellular flux.

The objective of the present investigation was to formulate and characterize the human insulin entrapped Eudragit S100 microspheres containing protease inhibitors and to develop an optimized formulation with desirable features. A w/o/w multiple emulsion solvent evaporation technique was employed to produce microspheres of human insulin using Eudragit S-100 as coating material and polyvinyl alcohol as a stabilizer. The resultant microspheres were evaluated for drug-excipient compatibility, encapsulation efficiency, particle size, surface morphology, micromeritic properties, enteric nature, and in vitro drug release studies. Micromeritic properties indicated good flow properties and compressibility. In present investigation formulation F6 with drug/polymer ratio (1:100) was found to be optimal in terms of evaluated parameters where it showed a significantly higher percentage of encapsulation efficiency (76.84%) with minimal drug release (3.25%) in an acidic environment. The optimized formulation (F6) also possessed good spherical shape and particle size (57.42 µm) required to achieve the desired in vitro drug release profile at pH 7.4. The results confirmed that human insulin-loaded Eudragit S-100 microspheres containing protease inhibitor possessed good encapsulation efficiency, pH dependant controlled release carrying encapsulated insulin to its optimum site of absorption. This ultimately resulted in enhanced insulin absorption and biological response. Graphical Abstract: [ABSTRACT FROM AUTHOR]

The only effective treatment for type 1 and advanced insulin-dependent type 2 diabetes mellitus is frequent subcutaneous insulin injections, which are physiologically different from endogenous insulin secretion and can result in hyperinsulinemia, pain, infection and patients' low compliance. Thus, efforts were devoted to changing the management of insulin-dependent diabetes through oral insulin delivery. Although the oral route is the most convenient way of drug delivery, insulin is vulnerable to rapid degradation in the stomach. Polymeric nanocarriers have recently attracted considerable attention as oral delivery vehicles that can be used to protect insulin from degradation and facilitate insulin absorption. This study aims to fabricate cationic β-cyclodextrin (CβCD)-insulin-loaded alginate nanoparticles and evaluate their potential as an oral insulin delivery system. CβCD were prepared from β-cyclodextrin (β-CD) through a onestep polycondensation using choline chloride (CC) to provide an ammonium group and epichlorohydrin (EP) to form polymeric chains. Insulin was complexed with CβCD to enhance the release profile, then encapsulated into calcium alginate nanoparticles via the ionic gelation method. The size, zeta potential, encapsulation efficiency (EE), surface morphology and cumulative drug release of the nanoparticles were recorded. In-vitro cytotoxicity of the nanoparticles against HT-29 cells was evaluated by MTT assay. CβCDinsulin-loaded alginate nanoparticles were characterized by reduced particle size, improved encapsulation efficiency and controlled insulin release in the simulated gastric fluid (SGF). The optimised nanoparticles exhibited a suitable particle size, with high encapsulation efficiency >80% and a controlled cumulative insulin release profile in simulated gastric fluid. MTT assay revealed that all formulations were non-toxic. The present study advocates that CβCD-insulin-loaded alginate nanoparticles is a promising system for enhancing oral insulin delivery. [ABSTRACT FROM AUTHOR]

The advancements in nanoscience have brought attention to the potential of utilizing nanoparticles as carriers for oral insulin administration. This study aims to investigate the effectiveness of synthesized polymeric mesoporous silica nanoparticles (MSN) as carriers for oral insulin and their interactions with insulin and IR through in-silico docking. Diabetic rats were treated with various MSN samples, including pure MSN, Amin-grafted MSN/PEG/Insulin (AMPI), Al-grafted MSN/PEG/Insulin (AlMPI), Zinc-grafted MSN/PEG/Insulin (ZNPI), and Co-grafted MSN/PEG/Insulin (CMPI). The nanocomposites were synthesized using a hybrid organic-inorganic method involving MSNs, graphene oxide, and insulin. Characterization of the nanocomposites was conducted using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). In vivo tests included the examination of blood glucose levels and histopathological parameters of the liver and pancreas in type 1 diabetic rats. The MSN family demonstrated a significant reduction in blood glucose levels compared to the diabetic control group (p < 0.001). The synthesized nanocomposites exhibited safety, non-toxicity, fast operation, self-repairing pancreas, cost-effectiveness, and high efficiency in the oral insulin delivery system. In the in-silico study, Zn-grafted MSN, Co-grafted MSN, and Al-grafted MSN were selected. Docking results revealed strong interactions between MSN compounds and insulin and IR, characterized by the formation of hydrogen bonds and high binding energy. Notably, Co-grafted MSN showed the highest docking scores of -308.171 kcal/mol and -337.608 kcal/mol to insulin and IR, respectively. These findings demonstrate the potential of polymeric MSN as effective carriers for oral insulin, offering promising prospects for diabetes treatment., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors. Published by Elsevier Ltd.)

Virus-capsid mimicking mucus-permeable nanoparticles are promising oral insulin carriers which surmount intestinal mucus barrier. However, the impact of different virus-capsid mimicking structure remains unexplored. In this study, utilizing biotin grafted chitosan as the main skeleton, virus-mimicking nanoparticles endowed with biologic-shell (streptavidin coverage) and polymeric-shell (hyaluronic acid/alginate coating) were designed with insulin as a model drug by self-assembly processes. It was demonstrated that biologic-shell mimicking nanoparticles exhibited a higher intestinal trans-mucus (>80%, 10 min) and transmucosal penetration efficiency (1.6-2.2-fold improvement) than polymeric-shell counterparts. Uptake mechanism studies revealed caveolae-mediated endocytosis was responsible for the absorption of biologic-shell mimicking nanoparticles whereas polymeric-shell mimicking nanoparticles were characterized by clathrin-mediated pathway with anticipated lysosomal insulin digestion. Further, in vivo hypoglycemic study indicated that the improved effect of regulating blood sugar levels was virus-capsid structure dependent out of which biologic-shell mimicking nanoparticles presented the best performance (5.1%). Although the findings of this study are encouraging, much more work is required to meet the standards of clinical translation. Taken together, we highlight the external structural dependence of virus-capsid mimicking nanoparticles on the muco-penetrating and uptake mechanism of enterocytes that in turn affecting their in vivo absorption, which should be pondered when engineering virus-mimicking nanoparticles for oral insulin delivery., Competing Interests: The authors declare no conflict of interest., (© 2023 Shenyang Pharmaceutical University. Published by Elsevier B.V.)

Aims: To verify whether the oral insulin N11005 is administered as a prandial insulin by assessing the pharmacokinetics (PK), pharmacodynamics (PD), and safety profiles of N11005 with a short-acting biosynthetic human insulin (Novolin R) as reference., Methods: This was a randomized, open-label, single-dose, crossover hyperinsulinemic-euglycemic clamp study in healthy Chinese male subjects. A total of 12 subjects were enrolled in the test (T) group (N11005, 300 IU, p.o.) and the reference (R) group (Novolin R, 0.1 IU/Kg, i.h.) with a washout period of 14 days. All subjects were administered on the same day of the clamp study. Glucose Infusion Rates (GIR), serum insulin, and C-peptide concentration were determined during every 8-hour clamp cycle. Trial registration: Clinicaltrials.gov identifier NCT04975022., Results: After administration, the ratios of mean serum C-peptide concentration to baseline concentration in both T and R groups were lower than 50%, which confirmed the stability of the clamp platform. T group (N11005) showed a more rapid onset of action (tGIR 10%max ≈11 min) and a comparable duration of action to the R group, which was basically in line with the characteristics of prandial insulins. No adverse events (AEs) occurred throughout the study, which demonstrated that N11005 and Novolin R are safe and well-tolerated., Conclusions: The PD profiles of the single-dose N11005 in the human body are similar to those of prandial insulins, with an excellent safety profile., Clinical Trial Registration: Clinicaltrials.gov, identifier NCT04975022., Competing Interests: Authors WL, XC, YLZ, QZ, YH, YJZ, LL, ZW, WW, and JH were employed by the company Sunshine Lake Pharma Co., Ltd. Authors W-HH and Y-TY were employed by the company INNOPHARMAX, INC. The authors declare that this study received funding from Sunshine Lake Pharma Co., Ltd. The funder had the following involvement in the study: experiment development, data research, statistical support, and animal studies. W.H., and Y.Y. from INNOPHARMAX, INC. also contributed to animal studies. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Pan, Wang, Li, Chen, Zhuang, Zhou, Huang, Zhou, Lan, Wang, Wang, Hong, Hao, Yang and Guo.)

Many patients with advanced type 2 diabetes mellitus (T2DM) and all patients with T1DM require insulin to keep blood glucose levels in the target range. The most common route of insulin administration is subcutaneous insulin injections. There are many ways to deliver insulin subcutaneously such as vials and syringes, insulin pens, and insulin pumps. Though subcutaneous insulin delivery is the standard route of insulin administration, it is associated with injection pain, needle phobia, lipodystrophy, noncompliance and peripheral hyperinsulinemia. Therefore, the need exists for delivering insulin in a minimally invasive or noninvasive and in most physiological way. Inhaled insulin was the first approved noninvasive and alternative way to deliver insulin, but it has been withdrawn from the market. Technologies are being explored to make the noninvasive delivery of insulin possible. Some of the routes of insulin administration that are under investigation are oral, buccal, nasal, peritoneal and transdermal. This review article focuses on the past, present and future of various insulin delivery techniques. This article has focused on different possible routes of insulin administration with its advantages and limitation and possible scope for the new drug development. [ABSTRACT FROM AUTHOR]

The use of intelligent insulin delivery systems has become more important for treating diabetes. In this study, a dual-responsive oral insulin delivery nanocarrier that responds to glucose and pH has been developed. First, the oleic acid hydrophobic modified guar gum (GG) was synthesized by the esterification reaction, and the γ-polyglutamic acid (γ-PGA) was coupled with GG by the amidation reaction. The obtained pH-responsive copolymer (γ-PGA-GG) was cross-linked by concanavalin A to obtain pH/glucose dual-responsive nanocarriers, and insulin was effectively loaded into the dual-responsive nanocarriers. The insulin-loaded nanoparticles can achieve effective pH and glucose responses, releasing insulin on demand. In vitro and in vivo studies demonstrated the dual-responsive nanoparticles can protect insulin against the pH changes in the digestive tract and deliver insulin into the body to exert a hypoglycemic effect. Moreover, the dual-responsive nanoparticles have significant potential to be employed for oral insulin delivery. [Display omitted] • γ-PGA-GG copolymer was used as a oral insulin carrier material. • Concanavalin A was used as functional molecule, assisted nanoparticles achieving blood glucose response. • Nanoparticles could significantly improve the delivery efficiency of oral insulin. • Nanoparticle provided long-term glycemic control in T1D mice without any toxicity. [ABSTRACT FROM AUTHOR]

Abstract: In this study, we report the biodistribution of aspart-insulin, a rapid-acting insulin analogue, following oral or subcutaneous (SC) administration to rats using the single-photon emission computed tomography (SPECT)/computed tomography (CT). Oral delivery of aspart-insulin was achieved using a pH-responsive nanoparticle (NP) system composed of chitosan (CS) and poly(γ-glutamic acid). The results obtained in the SPECT/CT study indicate that the orally administered aspart-insulin was absorbed into the systemic circulation, while the drug carrier (CS) was mainly retained in the gastrointestinal tract.Via the SC route, the peak aspart-insulin concentration in the peripheral tissue/plasma was observed at 20 min after injection. Within 3 h, half of the initial dose (ID) of aspart-insulin was degraded and excreted into the urinary bladder. In contrast, via oral delivery, there was constantly circulating aspart-insulin in the peripheral tissue/plasma during the course of the study, while 20% of the ID of aspart-insulin was metabolized and excreted into the urinary bladder. In the pharmacodynamic (PD) and pharmacokinetic (PK) evaluation in a diabetic rat model, the orally administered aspart-insulin loaded NPs produced a slower hypoglycemic response for a prolonged period of time, whereas the SC injection of aspart-insulin produced a more pronounced hypoglycemic effect for a relatively shorter duration. Finally, comparison of the PD/PK profiles of the orally administered aspart-insulin with those of the SC injection of NPH-insulin, an intermediate-acting insulin preparation, suggests the suitability of our NP system to be used as a non-invasive alternative for the basal insulin therapy. [Copyright &y& Elsevier]

Abstract: In the present study thiol functionalized polymethacrylic acid–polyethylene glycol–chitosan (PCP)-based hydrogel microparticles were utilized to develop an oral insulin delivery system. Thiol modification was achieved by grafting cysteine to the activated surface carboxyl groups of PCP hydrogels (Cys-PCP). Swelling and insulin loading/release experiments were conducted on these particles. The ability of these particles to inhibit protease enzymes was evaluated under in vitro experimental conditions. Insulin transport experiments were performed on Caco-2 cell monolayers and excised intestinal tissue with an Ussing chamber set-up. Finally, the efficacy of insulin-loaded particles in reducing the blood glucose level in streptozotocin-induced diabetic rats was investigated. Thiolated hydrogel microparticles showed less swelling and had a lower insulin encapsulation efficiency as compared with unmodified PCP particles. PCP and Cys-PCP microparticles were able to inhibit protease enzymes under in vitro conditions. Thiolation was an effective strategy to improve insulin absorption across Caco-2 cell monolayers, however, the effect was reduced in the experiments using excised rat intestinal tissue. Nevertheless, functionalized microparticles were more effective in eliciting a pharmacological response in diabetic animal, as compared with unmodified PCP microparticles. From these studies thiolation of hydrogel microparticles seems to be a promising approach to improve oral delivery of proteins/peptides. [Copyright &y& Elsevier]

Many challenges are associated with the oral delivery of insulin, relating to the physical and chemical stability of the hormone, and its absorption and metabolism in the human body. The present study aims to demonstrate the oral delivery of insulin in both normal and steptozotocin (STZ)–induced diabetic rats with the help of the aqueous extract of Desmodium gangeticum (DG) root. Human insulin was mixed with the aqueous extract of DG root (0.1 mg⁄ml) with human insulin (40 IU⁄ml) in ratio 1:1(v⁄v), to prepare oral insulin drug. Decreased plasma glucose level and increased plasma insulin in normal and STZ–induced diabetic rat suggested the probable absorption of insulin through GI tract when insulin was administered by mixing with DG extract. Indeed, insulin mixed DG potentially stimulates the release of insulin in STZ–induced diabetic rat rather than in normal animal. In vivo insulin secretaguage action of oral insulin drug was determined by isolated rat heart model and the results showed a significant cardio protection in STZ rat. The finding of this study suggests that insulin mixed with DG extract can be a promising vehicle for oral delivery of insulin. However, further studies are required to explore the exact compound(s) responsible for the protective delivery of insulin orally. Increased plasma insulin level by insulin mixed DG extract administration in STZ–treated diabetic rat indicates not only insulin secretaguage action of the mixture but also a probable altered insulin release mechanism in diabetic condition. [ABSTRACT FROM AUTHOR]

For many decades, rigorous efforts have been made worldwide to develop a successful oral insulin-delivery system, which still remains an elusive goal. However, over the past few years, tremendous understanding has evolved in the development of biocompatible and biodegradable polymers, synthesis of nanopeptide delivery systems, bicompatibility and its cellular uptake mechanisms. With these advancements, efforts are being directed toward nanoparticle-based oral peptide-delivery systems. It is established that nanoparticles enhance oral bioavailability by facilitating insulin uptake via a transcellular or paracellular pathway. In this process, the particle also reaches the systemic circulation. Hence, biocompatibility and the half-life of the particles in the systemic circulation is an important aspect that needs to be looked into. In this review, the various approaches adopted for nanoparticle-based oral insulin delivery, uptake mechanisms, biocompatibility and bioavailability of the nanoparticle are discussed. INSETS: Examples of organic/inorganic materials used in …;Key issues. [ABSTRACT FROM AUTHOR]

Although most protein pharmaceuticals are usually formulated as a solution or suspension and delivered by invasive routes such as subcutaneous injections, major efforts in both academic and industrial laboratories have been directed towards developing effective oral formulations and increasing the oral absorption of intact protein through the use of formulations that protect the macromolecule and/or enhance it's uptake into the intestinal mucosa. However, in spite of these major attempts, relatively little progress has been made. For the efficient delivery of peptides and proteins by non-parenteral route, in particular via the gastrointestinal tract, novel concepts are needed to overcome significant enzymatic and diffusion barriers. The properties of protein and peptides, which are of major interest in oral delivery, are highlighted in the article. This article reviews the various problems associated and novel approaches for formulation and development of oral protein and peptide drug delivery systems. [ABSTRACT FROM AUTHOR]

Our aim was to evaluate insulin autoantibody (IAA) levels over time in the Diabetes Prevention Trial Type 1 (DPT-1) oral insulin study to determine the effect of oral insulin compared with placebo on IAA levels. The DPT-1 trial randomised 372 relatives of subjects with type 1 diabetes, positive for IAA and with normal IVGTTs and OGTTs, to oral insulin 7.5 mg daily or placebo. Subjects were followed with IVGTTs, OGTTs and serial IAA measurements. The change in IAA level over time was modelled statistically using mixed model longitudinal data analysis with spatial exponential law for unevenly spaced data. In a separate analysis, subjects were divided into four groups by treatment and diabetes status at the end of the study. IAA levels were compared amongst the groups at randomisation, last sampling and at the maximum level. Longitudinal data analysis showed that treatment did not affect levels of IAA over time. After controlling for age, the IAA levels at randomisation and the last visit and the maximum values were different in the four groups. Significantly higher levels were noted in groups that developed diabetes compared with those that did not, with no significant difference by treatment group. This suggests that IAA levels over time were not influenced by oral insulin in subjects already positive for IAA at the start of treatment. ClinicalTrials.gov ID no.: NCT00004984. [ABSTRACT FROM AUTHOR]

Aims/hypothesis. Tolerance to orally administered antigens may he generated through the induction of T helper cell type 2 and 3 (Th2/Th3) regulatory cells. We previously reported that treatment of recent onset Type 1 diabetes with oral insulin had no effect on residual beta cell function. The aim of this study was to evaluate whether this treatment produces a deviation in the immune response, with polarisation of the cytokine pattern and the induction of a Th2-like antibody response. Methods. Mononuclear cells were collected from a total of 20 patients with Type 1 diabetes before and after 12 months of treatment with oral insulin (n=11) or placebo (n=9). Following stimulation of the cells with insulin or phytohaemagglutinin, levels of Th2 and Th3 cytokines (including TGF-β, IFN-γ, IL-4 and IL-5) in the culture supernatants were assessed by ELISA. In addition, levels of total and specific insulin antibody IgG subclasses were measured by radioimmunoassay in serum samples drawn from 33 patients with Type 1 diabetes before and after 3, 6 and 12 months of therapy with oral insulin (n=18) or placebo (n=I5). Results. After 12 months of treatment, the release of TGF-β was significantly higher in patients who received oral insulin compared with those who received placebo (p=0.025 and p=0.006 for lymphocytes challenged with insulin and phytohaemagglutinin respectively). The two groups had similar levels of IL-4 and IL-S both at baseline and after 12 months of treatment. The release of IFN-γ was markedly reduced in patients treated with oral insulin compared with those who received placebo at the 12-month follow-up. Circulating levels of IgG 1 and IgG 3 subclasses directed against insulin were significantly lower in the oral insulin group than in the placebo group after 12 months of treatment (p=0.05 for IgG 1 and p=0.014 !br IgG 3). Conclusions/interpretation. The increased TG F-β release observed in patients treated with oral insulin suggests that a regulatory response can he induced in vivo by this treatment. The lower levels of insulin antibody IgG 1 and IgG 3 subclasses present in patients exposed to oral insulin are consistent with a Th2 deviation of the immune response. The failure of oral insulin treatment to provide any measurable clinical benefit may he due to the timing of treatment initiation. [ABSTRACT FROM AUTHOR]

SUMMARY Our earlier investigations have demonstrated a critical difference in the efficacy of orally administered porcine compared to human or mouse insulin (no effect) in preventing type I diabetes in two distinct experimental models. Based on these findings one has to assume that certain insulins might not be suitable for the induction of oral ‘tolerance’/bystander suppression, which might be one cause for recent failures in human oral antigen trials. Here we demonstrate that coupling to the non-toxic subunit of cholera toxin (CTB) can abolish these differences in efficacy between human and porcine insulin. As expected, an added benefit was the much smaller oral antigen dose required to induce CD4[sup +] insulin-B specific regulatory cells that bystander-suppress autoaggressive responses. Mechanistically we found that uptake or transport of insulin–CTB conjugates in the gut occurs at least partially via binding to GM-1, which would explain the enhanced clinical efficacy. Both B chains bound well to major histocompatibility complex (MHC) class II, indicating comparable immunological potential once uptake and processing has occurred. Thus, our findings delineate a pathway to overcome issues in oral antigen choice for prevention of type I diabetes. [ABSTRACT FROM AUTHOR]

Aims/hypothesis. Induction of tolerance to insulin is achievable in animal models of Type I (insulin-dependent) Diabetes mellitus by oral treatment with this hormone, which can lead to prevention of the disease. In the Diabetes Prevention Trial of Type I diabetes (DPT-1), oral insulin is given with the aim of preventing disease insurgence. We investigated whether if given at diagnosis of Type I diabetes in humans, oral insulin can still act as a tolerogen and therefore preserve residual beta-cell function, which is known to be substantial at diagnosis. Methods. A double-blind trial was carried out in patients (mean age ± SD: 14 ± 8 years) with recent-onset Type I diabetes to whom oral insulin (5 mg daily) or placebo was given for 12 months in addition to intensive subcutaneous insulin therapy. A total of 82 patients with clinical Type I diabetes ( < 4 weeks duration) were studied. Basal C peptide and glycated haemoglobin were measured and the insulin requirement monitored every 3 months up to 1 year. Insulin antibodies were also measured in 27 patients treated with oral insulin and in 18 patients receiving placebo at the beginning of the trial and after 3, 6 and 12 months of treatment. Results. The trial was completed by 80 patients. Overall and without distinction between age at diagnosis, at 3, 6, 9 and 12 months baseline mean C-peptide secretion in patients treated with oral insulin did not differ from that of those patients treated with placebo. In patients younger than 15 years a tendency for lower C-peptide values at 9 and 12 months was observed in the oral insulin group. Insulin requirement at 1 year was similar between the two groups as well as the percentage of glycated haemoglobin. Finally, IgG insulin antibodies were similar in the two groups at each time point. Conclusion/interpretation. The results of this study indicate that the addition of 5 mg of oral insulin does not modify the course of the disease in the first year after diagnosis and probably does not statistically affect the humoral immune response against insulin. [Diabetologia (2000) 43: 1000–1004] [ABSTRACT FROM AUTHOR]

The impact of oral treatment with insulin on disease development was studied in diabetes prone BB rats. Because of the positive outcome of a prior study in non obese diabetic (NOD) mice, BB rats received insulin in combination with a bacterial adjuvant. Porcine insulin was given orally twice weekly from 35–100 days of age, the E. coli preparation OM-89 was fed on alternate days. Other groups received vehicle, the bacterial adjuvant, or insulin alone. Both insulin containing oral dosing regimens induced a transient non significant delay in diabetes onset. Insulin alone, however did not decrease the final diabetes incidence. Oral dosing with insulin plus adjuvant caused exacerbation of disease development as judged from the decreased survival rate in comparison with the insulin treated group ( p < 0.05). Intra-islet infiltration also increased ( p < 0.005) compared with the insulin or vehicle treated groups. The effect correlated with enhanced interferon gamma (IFN γ) and decreased interleukin 10 (IL-10) gene expression in the gut suggesting a shift towards proinflammatory T helper 1 (Th1) reactivity ( p < 0.01). Although treatment with adjuvant alone also increased the degree of insulitis, an enhanced incidence of diabetes and a shift in cytokine expression was only seen in the group receiving insulin plus adjuvant. Taken together, the data suggest that treatment with a bacterial adjuvant and oral insulin may alter the gut immunoregulatory state such that disease promoting rather than protective immune responses are induced. [Diabetologia (1998) 41: 844–847] [ABSTRACT FROM AUTHOR]

A combined biochemical and morpho-cytochemical investigation was carried out in order to assess insulin absorption by the duodenal and colon epithelium. Insulin was introduced in the lumen of the rat duodenum or colon in combination with sodium cholate and aprotinin. Blood analysis made at several time points has demonstrated a rapid increase in circulating levels of insulin followed by significant and consistent decreases in blood glucose. This indicates that biologically active insulin is absorbed by the intestinal mucosa and transferred to the circulation. Because of the initial high blood glucose levels, the lowering of the glycaemic values was more significant in diabetic animals. Also, levels of circulating insulin remained higher for longer time when the administration was performed in the colon. The integrity of the intestinal wall after insulin administration, evaluated morphologically, was retained. Application of protein A-gold immunocytochemistry has established the pathway for insulin absorption. In both duodenal and colon epithelial cells the labelling for insulin was detected in the endosomal compartment, in the Golgi apparatus and in association with the baso-lateral plasma membrane interdigitations. Some labelling was also present in the interstitial space and in capillary endothelial plasmalemmal vesicles. Insulin introduced in the lumen of the rat duodenum and colon appears thus to be rapidly internalized by the epithelial cells and transferred through a transcytotic pathway to the interstitial space from which it reaches the blood circulation. This exogenous insulin then induces significant decreases in plasma glucose levels which lasts for several hours. The results obtained support the possibility for the clinical development of an oral preparation of insulin. [ABSTRACT FROM AUTHOR]

Aim: As injection is not an ideal means for insulin delivery, various attempts have been made to administer insulin orally until now. The development of an oral dosage form of insulin would help diabetic patients and make the treatment more convenient. The aim of the present study is to evaluate the effectiveness of an oral insulin formulation containing polar and non-polar ingredients. Materials and Methods: New excipient for oral insulin administration in normal and diabetic rats was evaluated by measuring blood glucose concentrations in two groups (10 rats each) of normal and streptozotocin-induced diabetic rats. Oral insulin was administrated and blood glucose was measured by glucometer at 0, 1, 2, 3 and 4 h post-feeding. The data was compared by Student's t test. Results: Oral insulin formulation significantly (P<0.05) reduced blood glucose from 100 mg/dl to 33.73 mg/dl and 451.66 mg/dl to 200.83 mg/dl at 4 h in normal and diabetic rats, respectively. Conclusion: The novel excipient used could protect insulin from gastric and pancreatic enzymes and reduce blood glucose concentration in both healthy and diabetic rats suggesting that oral delivery of insulin is feasible in a near future. [ABSTRACT FROM AUTHOR]