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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]

Oral insulin (INS) is predicted to have the most therapeutic advantages in treating diabetes to repress hepatic glucose production through its potential to mimic the endogenous insulin pathway. Many oral insulin delivery systems have been investigated. Layered double hydroxide (LDH) as an inorganic material has been widely used in drug delivery thanks to its appealing features such as good biocompatibility, low toxicity, and excellent loading capability. However, when used in oral drug delivery, the effectiveness of LDH is limited due to the acidic degradation in the stomach. In this study, to overcome these challenges, chitosan (Chi) and alginate (Alg) dual-coated LDH nanocomposites with the loading of insulin (Alg-Chi-LDH@INS) were developed by the layered-by-layered method for oral insulin delivery with dynamic size of ~ 350.8 nm, negative charge of ~ − 13.0 mV, and dispersity index 0.228. The insulin release profile was evaluated by ultraviolet–visible spectroscopy. The drug release profiles evidenced that alginate and chitosan coating partially protect insulin release from a burst release in acidic conditions. The analysis using flow cytometry showed that chitosan coating significantly enhanced the uptake of LDH@INS by Caco-2 cells compared to unmodified LDH and free insulin. Further in the in vivo study in streptozocin-induced diabetic mice, a significant hypoglycemic effect was maintained following oral administration with great biocompatibility (~ 50% blood glucose level reduction at 4 h). This research has thus provided a potential nanocomposite system for oral delivery of insulin. [ABSTRACT FROM AUTHOR]

Subcutaneous insulin injection is mainly used to treat diabetes, but it has limitations, such as hyperinsulinemia, adipose tissue atrophy and hypoglycemia. As a simple way of administration, oral insulin can reduce side effects and improve patients ’ compliance. However, protein drugs can be inactivated by gastrointestinal enzymes after oral administration. In recent years, with the rapid development of nanotechnology, targeted nano-delivery systems have been widely used in the study of oral insulin. Compared with unmodified nanocarriers, targeted nano delivery system has obvious advantages. Insulin can not only be loaded by it, but also smoothly pass through the gastrointestinal barrier and be successfully transported to the site of action. At the same time, the structural stability of insulin can also be protected, so as to maintain its biological activity and finally achieve mild hypoglycemic effect. Therefore, targeted oral delivery of insulin is promising to replace the common subcutaneous injection of insulin and provide painless treatment for diabetic patients. The ligand-modified targeting nanocarriers enhance the intestinal absorption and transport of insulin by specifically binding to receptors on the surface of intestinal cells and play a mild hypoglycemic effect. The main characteristics, targeting mechanism and main factors affecting the targeting effect of targeting nanocarriers are discussed. The main factors include the size, shape and ligand density of nanoparticles. The design ideas, research methods and oral bioavailability of nano-carriers modified with different surface ligands are reviewed in detail. These targeting ligands are folic acid (FA), fragment crystallizable (Fc), biotin, polypeptide, transferrin and VB12. The existing problems and future development directions of targeting nanocarriers for oral insulin are also put forward. [ABSTRACT FROM AUTHOR]

Objective: Oral administration of insulin is a potential candidate for managing diabetes. However, it is obstructed by the gastrointestinal tract barriers resulting in negligible oral bioavailability. Methods: This investigation presents a novel nanocarrier platform designed to address these challenges. In this regard, the process involved amination of sodium alginate by ethylene diamine, followed by its conjugation with deoxycholic acid. Results: The resulting DCA@Alg@INS nanocarrier revealed a significantly high insulin loading content of 63.6 ± 1.03% and encapsulation efficiency of 87.6 ± 3.84%, with a particle size of 206 nm and zeta potentials of -3 mV. In vitro studies showed sustained and pH-dependent release profiles of insulin from nanoparticles. In vitro cellular studies, confocal laser scanning microscopy and flow cytometry analysis confirmed the successful attachment and internalization of DCA@Alg@INS nanoparticles in Caco-2 cells. Furthermore, the DCA@Alg@INS demonstrated a superior capacity for cellular uptake and permeability coefficient relative to the insulin solution, exhibiting sixfold and 4.94-fold enhancement, respectively. According to the uptake mechanism studies, the results indicated that DCA@Alg@INS was mostly transported through an energy-dependent active pathway since the uptake of DCA@Alg@INS by cells was significantly reduced in the presence of NaN3 by ~ 92% and at a low temperature of 4°C by ~ 94%. Conclusions: Given the significance of administering insulin through oral route, deoxycholic acid-modified alginate nanoparticles present a viable option to surmount various obstacles presented by the gastrointestinal. [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]

Oral delivery of macromolecules remains highly challenging due to their rapid degradation in the gastrointestinal tract and poor absorption across the tight junctions of the epithelium. In the last decade, researchers have investigated several medical devices to overcome these challenges using various approaches, some of which involve piercing through the intestine using micro and macro needles. We have developed a new generation of medical devices called self-unfolding proximity enabling devices, which makes it possible to orally deliver macromolecules without perforating the intestine. These devices protect macromolecules from the harsh conditions in the stomach and release their active pharmaceutical ingredients in the vicinity of the intestinal epithelium. One device version is a self-unfolding foil that we have used to deliver insulin and nisin to rats and pigs respectively. In our study, this device has shown a great potential for delivering peptides, with a significant increase in the absorption of solid dosage of insulin by ∼12 times and nisin by ∼4 times in rats and pigs, respectively. With the ability to load solid dosage forms, our devices can facilitate enhanced absorption of minimally invasive oral macromolecule formulations. [Display omitted] • Advancing oral delivery: optimizing self-unfolding foil (SUF) as an effective oral delivery device for macromolecules • Enhanced visualization: incorporating contrast materials for in vivo tracking of SUFs • Boosting insulin bioavailability in rats: achieving 12-fold increase using SUFs • Scaling up success: optimizing SUFs for efficient oral delivery device in large animals • Maximizing nisin bioavailability: a 4-fold increase was achieved by oral administration of SUFs in pigs [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]

The objective of this research was to optimize the composition and performance of chitosan-coated solid lipid nanoparticles carrying insulin (Ch-In-SLNs) and to assess the potential of piperine in enhancing the intestinal permeability of insulin from these SLNs in vitro. The SLNs were formulated from glyceryl behenate (GB), soya lecithin, and poloxamer® 407, and then coated with a combination of chitosan and piperine to facilitate insulin penetration across the gastrointestinal (GI) mucosa. A Box-Behnken Design (BBD) was utilized to optimize the Ch-In-SLNs formulations, with PDI, particle size, zeta potential, and association efficiency (AE) serving as the response variables. The resulting Ch-In-SLNs exhibited excellent monodispersity (PDI = 0.4), optimal particle size (654.43 nm), positive zeta potential (+36.87 mV), and low AE values. The Ch-In-SLNs demonstrated sustained release of insulin for 12 h in simulated gastric fluid (SGF) and intestinal fluid (SIF), with increased release in the latter. After incubation in SGF and SIF for 12 h, the insulin SLNs retained 54 and 41 % of their initial insulin load, respectively, indicating effective protection from gastric enzymes. Permeation studies using goat intestine and Caco-2 cell lines indicated improved insulin permeation in the presence of piperine. Additionally, cell uptake studies confirmed the role of piperine in enhancing insulin permeation. [Display omitted] • The Chitosan coated In-SLNs demonstrated sustained release in in vitro. • Chitosan coating was effective in protecting the entrapped insulin from degradation in gastrointestinal conditions. • Cellular uptake studies confirmed enhanced insulin permeation in the presence of piperine. • The SLNs formulation showed promising scalability for potential commercial applications. [ABSTRACT FROM AUTHOR]

Sodium alginate has good biocompatibility and is widely used in the study of drug carriers. In this paper, a method to prepare calcium alginate microspheres with high sphericity based on double emulsion droplets was proposed, in which sodium alginate is used as the innermost phase. By adjusting the density of the system, the double-emulsion droplets could be suspended in the collecting solution, leading to the homogeneous reaction between the sodium alginate droplets and the calcium ions. By changing the flow rate, the size of the droplets could be changed, and by changing the concentration of calcium ions in the collecting solution, the sphericity of the calcium alginate microspheres could be changed. Then the swelling properties and drug release properties of calcium alginate microspheres were determined. The drug delivery study revealed that the insulin-loaded Ca-Alginate microspheres were able to decrease blood glucose by 41.4 % after oral administration to mice. Thus, the Ca-Alginate microsphere is a suitable candidate for controlled pH-sensitive drug delivery. [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

Regardless of age, diabetes is one of the most prevalent diseases that people deal with. There are several various types of diabetes medications available, but metformin is the most popular. This primary purpose of this article is to provide a comparison of various dosage forms used for treatment of diabetes. However, oral insulin therapy has a number of potential advantages and would be practical for patients. The study and development of oral insulin is a fascinating subject in the study of diabetes. We are making progress toward creating an insulin formulation that won't require injections before to meals, which will enhance the quality of life and mental health of more than nine million type 1 diabetics worldwide. Despite the fact that it is only currently available in injectable form, insulin is nevertheless crucial for the management of diabetes. The ultimate goal for improving simplicity of use and providing therapeutic benefits stemming from its direct distribution to the portal vein and liver is the development of an oral insulin. [ABSTRACT FROM AUTHOR]

Insulin therapy is essential for regulating blood sugar levels. Conventional subcutaneous injection is prone to psychological stress, local tissue damage and severe blood glucose fluctuations, and thus the development of oral insulin technology has become an alternative therapy. However, oral insulin faces challenges such as difficult absorption, poor adhesion, low bioavailability, and short duration of action, due to the large molecular weight, low permeability, and easily degradable by enzymes and gastric acids. In this study, oral insulin nanocapsule delivery systems (Orl-Ins-NPs) were developed by using polylactic acid-co-glycolic acid (PLGA) as the encapsulation material for insulin loading. After preparation, optimization and characterization, the mean size of Orl-Ins-NPs was 140.08 nm, the encapsulation efficiency of the system was 54.3 %, and the loading capacity of insulin was 2.2 %. In addition, cationic modification with chitosan/ polyethyleneimine promoted adhesion and permeation of the intestinal mucus layer, and surface coating with pH-responsive methyl methacrylate trimethylamine ethyl chloride copolymer achieved 100 % gastric protection. The results of rat blood glucose test showed that, subcutaneous injection of the control group reduced blood glucose concentrations within 1 h and returned to initial levels within 4 h, while Orl-Ins-NPs slowly reduced blood glucose concentration to 51.3 % of the initial level and maintains stability within 10 h. Orl-Ins-NPs exhibited good physicochemical stabilities, sustained release property, improved in vitro acid resistance, as well as long-term in vivo hypoglycemic effect. This system demonstrates its potential clinical application in oral insulin and other protein drugs delivery., Competing Interests: Declaration of competing interest 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., (Copyright © 2024. Published by Elsevier B.V.)

Oral insulin delivery is considered a revolutionary alternative to daily subcutaneous injections in terms of compliance and convenience. However, significant challenges remain in terms of inactivation in gastrointestinal environment and limited permeation across the intestinal epithelium. Herein, we used acid-resistant metal-organic framework (PCN-222) to load insulin and modified the exterior with sodium dodecyl sulfate (SDS) to achieve efficient oral insulin delivery. The PCN-222 nanocarrier with ordered mesoporous cage structure and suitable pore size achieved a high insulin loading of 75 %. The SDS on the surface of nanocarrier reduces its hydrophilicity while reversibly altering cell morphology and increasing epithelial cell permeability, thereby promoting intestinal epithelial absorption. The constructed particle (I@P@S) was encapsulated in sodium alginate (SA) microspheres to protect it from gastric acid degradation and releases it upon entry into the intestinal tract. Through an uptake pathway dominated by clathrin-mediated endocytosis, the released I@P@S realized efficient intestinal permeability and controlled insulin release under physiological conditions due to the phosphate sensitivity of PCN-222, leading to an in vivo bioavailability of 12.9 %. This work provides a valuable reference for the design of oral insulin delivery systems., Competing Interests: Declaration of competing interest 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., (Copyright © 2024 Elsevier B.V. All rights reserved.)

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]

Despite tremendous efforts, the world continues its fight against the common chronic disease-diabetes. Diabetes is caused by elevated glucose levels in the blood, which can lead to several complications like glaucoma, cataract, kidney failure, diabetic ketoacidosis, heart attack, and stroke. According to recent statistics, China, India, and the US rank at the top three positions with regards to the number of patients affected by diabetes. Ever since its discovery, insulin is one of the major therapeutic molecules that is used to control the disease in the diabetic population, worldwide. The most common route of insulin administration has been the subcutaneous route. However, the limitations associated with this route have motivated global efforts to explore alternative strategies to deliver insulin, including pulmonary, transdermal, nasal, rectal, buccal, and oral routes. Oral insulin delivery is the most convenient and patient-centered route. However, the oral route is also associated with numerous drawbacks that present significant challenges to the scientific fraternity. The human physiological system acts as a formidable barrier to insulin, limiting its bioavailability. The present review covers the major barriers against oral insulin delivery and explains formulation strategies that have been adopted to overcome these barriers. The review focuses on oral insulin delivery strategies (OIDS) for increasing the bioavailability of oral insulin, including nanoparticles, microparticles, nano-in-microparticles, hydrogels, tablets, capsules, intestinal patches, and use of ionic liquids. It also highlights some of the notable recent advancements and clinical trials in oral insulin delivery. This formulation based OIDS may significantly improve patient compliance in the treatment of diabetes. [Display omitted] [ABSTRACT FROM AUTHOR]

Oral delivery is an ideal method of insulin administration and is currently a promising research field. Here, we evaluated the safety, pharmacokinetic, and pharmacodynamic characteristics of oral administration of an insulin capsule (ORMD‐0801) with 2 different sources of recombinant human insulin. This was a single‐center, randomized, double‐blind, placebo‐controlled, dose‐escalating phase 1 trial. Single dosing of the oral insulin capsule was administered in 70 healthy Chinese subjects. In stage 1, four dose groups (8, 16, 32, and 48 mg) for capsules containing Sanofi insulin and in stage 2, three dose groups (8, 32, and 48 mg) containing Hefei Tianmai insulin were evaluated consequently. The results showed that the oral insulin formulations with either source in the dose range 8 to 48 mg were safe, and no serious adverse events were observed. After a standard breakfast 45 minutes after dosing, the area under the concentration‐time curve (AUC) from time 0 to time t and AUC from time 0 to infinity for insulin in the 8‐mg and 48‐mg dose groups in stage 1 and for 8‐ to 48‐mg groups in stage 2 were slightly increased compared with placebo, but no significant dose‐related changes in the pharmacokinetic parameters were observed for either stage. The peak‐valley difference and the change in value of the AUC for glucose from baseline showed a dose‐related increase in the dose range from 8 to 48 mg in both stages. Together, this study indicated that in healthy Chinese subjects, this oral capsule containing 2 different insulin formulations was safe and well tolerated after a single‐dose administration. [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]

Aim: To assess the safety and efficacy of oral insulin (ORMD‐0801) in patients with type 2 diabetes (T2D). Materials and Methods: After a 2‐week washout of other medications, adult metformin‐treated patients with T2D were randomized to receive placebo or 16 or 24 mg ORMD‐0801, once daily, at bedtime, for 28 days. The mean change from baseline weighted mean night‐time glucose levels was determined from 2 nights of continuous glucose monitoring (CGM) recordings during the placebo run‐in and last week of treatment. Results: In total, 188 patients (HbA1c: 7.82% ± 0.88% [placebo] and 8.08% ± 1.11% [pooled ORMD‐0801 group]) were enrolled. In the placebo group, mean night‐time CGM increased from baseline by 13.7 ± 26.1 mg/dL, whereas the increase was significantly smaller in the pooled ORMD‐0801 group (1.7 ± 23.5 mg/dL, P =.0120). Glycaemic control variables (24‐hour, fasting and daytime CGM glucose) also displayed smaller increases with ORMD‐0801 versus placebo. Change from baseline HbA1c was −0.01% in the pooled ORMD‐0801 group versus +0.20% in the placebo group (P =.0149). ORMD‐0801 was well tolerated, with similar adverse event and hypoglycaemia rates as placebo. Conclusions: In patients with T2D, bedtime ORMD‐0801 curbed increases in night‐time glycaemia, 24‐hour glycaemia and HbA1c, without increasing the risk of hypoglycaemia or safety events compared with the control arm. [ABSTRACT FROM AUTHOR]

Schematic diagram of a glucose-responsive nanodrug delivery system. (a) Schematic diagram of the synthesis of VB12-FU-ConA@Ins nanocarriers. (b) Mechanism of Insulin release by VB12-FU-ConA stimulated by glucose. [Display omitted] The smart oral administration Insulin device has the potential to improve glycemic management. It can reduce the risk of hypoglycemia associated with exogenous Insulin (INS) therapy while also avoiding many of the disadvantages associated with subcutaneous injections. Furthermore, diabetes mellitus (DM) is an endocrine illness characterized by inflammation, and it is critical to minimize the amount of inflammatory markers in diabetic patients while maintaining average blood glucose. In this study, a responsive nanosystem vitamin B12-Fucoidan-Concanavalin A (VB12-FU-ConA NPs) with anti-inflammatory action was developed for smart oral delivery of Insulin. Con A has high sensitivity and strong specificity as a glucose-responsive material. Fucoidan has anti-inflammatory, immunomodulatory, and hypoglycemic functions, and it can bind to Con A to form a reversible complex. Under high glucose conditions, free glucose competitively binds to Con A, which swells the nanocarrier and promotes Insulin release. Furthermore, in the low pH environment of the gastrointestinal tract, positively charged VB12 and anionic fucoidan bind tightly to protect the Insulin wrapped in the carrier, and VB12 can also bind to intestinal epithelial factors to improve transit rate, thereby promoting INS absorption. In vitro tests showed that the release of nanoparticles in hyperglycemic solutions was significantly higher than the drug release in normoglycemic conditions. Oral delivery of the nanosystems dramatically lowered blood glucose levels in type I diabetic mice (T1DM) during in vivo pharmacodynamics, minimizing the risk of hypoglycemia. Blood glucose levels reached a minimum of 8.1 ± 0.4 mmol/L after 8 h. Administering the nanosystem orally notably decreased the serum levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in diabetic mice. The nano delivery system can be degraded and metabolized in the intestinal tract after being taken orally, demonstrating good biodegradability and biosafety. In conclusion, the present study showed that VB12-FU-ConA nanocarriers are expected to be a novel system for rationalizing blood glucose. [ABSTRACT FROM AUTHOR]

The effect of the structure of a mucoadhesive, insulin-containing, polymeric hydrogel on the rate of hormone release was studied. It has been shown that a decrease in the pore size of the hydrogel leads to an increase in the rate of insulin release, which contributes to a reduction in the time to achieve a positive effect upon oral administration of the drug while maintaining the physiological pathway of hormone penetration of the blood through the liver. [ABSTRACT FROM AUTHOR]

Delivering macromolecular drugs, e.g. peptides, to the systemic circulation by oral administration is challenging due to their degradation in the gastrointestinal tract and low transmucosal permeation. In this study, the concept of an oral delivery device utilizing an elastomeric material is presented with the potential of increasing the absorption of peptides, e.g. insulin. Absorption enhancement in the intestine is proposed as a result of self-unfolding of a polydimethylsiloxane foil upon release from enteric coated capsules. A pH-sensitive polymer coating prevents capsule disintegration until arrival in the small intestine where complete unfolding of the elastomeric foil ensures close contact with the intestinal mucosa. Foils with close-packed hexagonal compartments for optimal drug loading are produced by casting against a deep-etched silicon master. Complete unfolding of the foil upon capsule disintegration is verified in vitro and the insulin release profile of the final delivery device confirms insulin protection at gastric pH. In vivo performance is evaluated with the outcome of quantifiable plasma insulin concentrations in all rats receiving duodenal administration of the novel delivery device. By taking advantage of elastomeric material properties for drug delivery, this approach might serve as inspiration for further development of commercially viable biocompatible devices for oral delivery of macromolecules. Unlabelled Image • A new oral delivery device prototype was designed comprising a self-unfolding elastomeric foil in an enteric coated capsule. • An alternative in vivo approach was established to ensure gastric emptying of enteric coated capsules in rats. • All the rats receiving duodenal placement of the oral device prototype showed quantitative insulin plasma concentrations. [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.

Insulin therapy has advanced remarkably over the past few decades. Ultra-rapid-acting and ultra-long-acting insulin analogs are now commercially available. Many additional insulin formulations are in development. This review outlines recent advances in insulin therapy and novel therapies in development. [ABSTRACT FROM AUTHOR]

We evaluated the pharmacokinetics and pharmacodynamics of oral insulin tregopil in relation to premeal dosing time, between‐meal interval, and meal composition type in type 2 diabetes mellitus patients in a randomized, placebo‐controlled, crossover study consisting of 3 sequential cohorts. In Cohort 1, insulin tregopil administered 10 to 20 minutes before a meal resulted in optimal postmeal exposure and demonstrated better postprandial glucose‐lowering effect (glucose area under concentration‐time curve [AUC]) compared to the 30‐minute group. In Cohort 2, insulin tregopil pharmacokinetic exposure (plasma AUC) showed a progressive increase through 4, 5, and 6 hours of between‐meal interval. The 6‐hour between‐meal interval resulted in better absorption of insulin tregopil in comparison to 4‐ and 5‐hour intervals. However, no significant differences were observed in pharmacodynamic parameters except for higher glucose AUC0‐180min in the insulin tregopil 4‐hour group during the afternoon meal as compared to the morning meal. In Cohort 3, a high‐fiber meal had the least impact on insulin tregopil absorption and resulted in the highest reduction in plasma glucose levels in the afternoon. A high‐fat meal reduced insulin tregopil absorption in the afternoon meal; however, pharmacodynamic response was not diminished significantly. Insulin tregopil has a rapid onset of action of approximately 10 minutes and, when administered 10 to 20 minutes before a meal, demonstrated up to 13% to 18% reduction in blood glucose levels compared to baseline. A 5‐hour between‐meal interval minimizes the impact of a meal on absorption of subsequent (afternoon) insulin tregopil dose, and the pharmacodynamic response of insulin tregopil is not altered by meal composition. Insulin tregopil was well tolerated in patients with type 2 diabetes mellitus. [ABSTRACT FROM AUTHOR]

Diabetes mellitus is a chronic metabolic disease that affects >500 million patients worldwide. Subcutaneous injection of insulin is the most effective treatment at present. However, regular needle injections will cause pain, inflammation, and other adverse consequences. In recent years, significant progress has been made in non-injectable insulin preparations. Oral administration is the best way of administration due to its simplicity, convenience, and good patient compliance. However, oral insulin delivery is hindered by many physiological barriers in the gastrointestinal tract, resulting in the low relative bioavailability of direct oral insulin delivery. To improve the relative bioavailability, a variety of insulin delivery vectors have been developed. Polysaccharides are used to achieve safe and effective insulin loading due to their excellent biocompatibility and protein affinity. The functional characteristics of polysaccharide-based delivery carriers, such as pH responsiveness, mucosal adhesion, and further functionalization modifications, enhance the gastrointestinal absorption and bioavailability of insulin. This paper reviews the materials and structures of oral insulin polysaccharide-based carriers, providing ideas for further improving the relative bioavailability of oral insulin. [Display omitted] [ABSTRACT FROM AUTHOR]

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 (

Aims: Current therapy fails to emulate rapid (first‐phase) insulin release in relation to a meal, a key defect in types 1 and 2 diabetes. We aimed to quantify the pharmacokinetic (PK) and pharmacodynamic (PD) profile of insulin tregopil, an enterically‐absorbed insulin analog that restores the normal distribution of insulin between the hepatic portal and peripheral circulations. Materials and methods: The PK and PD profiles of insulin tregopil were studied in overnight‐fasted, catheterized, conscious canines using four approaches: (1) equimolar intraportal infusions of tregopil vs human insulin; (2) escalating doses of oral tregopil; (3) identical, consecutive enteric doses of tregopil; and (4) comparison of oral tregopil to inhaled and subcutaneous human insulin administration. Results: Equimolar intraportal infusions of tregopil and human insulin resulted in very similar PK profiles and PD profiles were nearly identical. Enteric delivery of tregopil brought about rapid absorption with tmax = 20 minutes in most cases. Median tmax was 20 minutes for oral tregopil and inhaled insulin and 88 minutes for subcutaneous human insulin. The time required for arterial plasma insulin levels to return to baseline was approximately 90, 210 and 360 minutes for oral tregopil, inhaled insulin and subcutaneous insulin, respectively. Conclusions: Enterically delivered tregopil is rapidly absorbed and restores a portal‐to‐peripheral vascular distribution. These characteristics should improve postprandial hyperglycaemia in types 1 and 2 diabetes. [ABSTRACT FROM AUTHOR]

The objective of this study was to enhance the convenience and effectiveness of diabetes treatment by developing hydrogel microparticles as an oral insulin delivery system, aiming to reduce the necessity for frequent treatments. The hydrogel microparticles were prepared with polysaccharides through a combination of physical and chemical crosslinking method, they achieved good results in insulin loading efficiency (70 %), insulin release efficiency (98 %) and sustained release time (>20 h). The effective transmembrane transport was validated using an intestinal epithelial cell model, which demonstrated a continuous hypoglycemic effect lasting from 6 to 26 h in a type 2 diabetes mouse model. Additionally, the relative bioavailability of insulin reached 30.14 ± 2.62 %, representing a significant breakthrough in the field of oral insulin delivery carriers. Furthermore, oral insulin hydrogel exhibited a substantial improvement in insulin resistance, organ damage, and diabetes-related complications stemming from hyperglycemia. These compelling findings underscore the potential of hydrogel microparticles as a cost-effective and valuable strategy for oral drug delivery in diabetes treatment. [ABSTRACT FROM AUTHOR]

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]

Tight junction (TJ) structures restrict the movement of solutes between adjacent epithelial cells to maintain homeostatic conditions. A peptide, termed PIP 640, with the capacity to regulate the transient opening of intestinal TJ structures through an endogenous mechanism involving the induction of myosin light chain (MLC) phosphorylation at serine 19 (MLC-pS 19 ) has provided a promising new method to enhance the in vivo oral bioavailability of peptide therapeutics. PIP 640 is a decapeptide composed of all D-amino acids (rrdykvevrr-NH 2 ) that contains a central sequence designed to emulates a specific domain of C-kinase potentiated protein phosphatase-1 inhibitor-17 kDa (CPI-17) surrounded by positively-charged amino acids that provide a cell penetrating peptide (CPP)-like character. Here, we examine compositional requirements of PIP 640 with regard to its actions on MLC phosphorylation, its intracellular localization to TJ structures, and its interactions with MLC phosphatase (MLCP) elements that correlate with enhanced solute uptake. These studies showed that a glutamic acid and tyrosine within this peptide are critical for PIP 640 to retain its ability to increase MLC-pS 19 levels and enhance the permeability of macromolecular solutes of the size range of therapeutic peptides without detectable cytotoxicity. On the other hand, exchange of the aspartic acid for alanine and then arginine resulted in an increasingly greater bias toward protein phosphatase-1 (PP1) relative to MLCP inhibition, an outcome that resulted in increased paracellular permeability for solutes in the size range of therapeutic peptides, but with a significant increase in cytotoxicity. Together, these data further our understanding of the composition requirements of PIP 640 with respect to the desired goal of transiently altering the intestinal epithelial cell paracellular barrier properties through an endogenous mechanism, providing a novel approach to enhance the oral bioavailability of poorly absorbed therapeutic agents of < ~ 5 kDa. [ABSTRACT FROM AUTHOR]

Chitosan is an abundant natural cationic polysaccharide with excellent biodegradability, bioadhesion, and biocompatibility. Chitosan is extensively researched for various particulate oral insulin drug delivery systems. Oral insulin is economically efficient and more convenient than injections, with greater patient compliance. Electrostatic ionic interaction between cationic chitosan and anionic polymer or insulin leads to the formation of spontaneously self-assembled nanoparticles. This simple technique attracted many researchers as it can be carried out quickly in mild conditions without harmful solvents, such as surfactants or chemical cross-linkers that might degrade the insulin structure. The formulated chitosan nanoparticles help to protect the core insulin from enzymatic degradation in the digestive system and improve paracellular intestinal uptake from the enterocytes due to mucoadhesion and reversible tight junction opening. Moreover, functionalized chitosan nanoparticles create newer avenues for targeted and prolonged delivery. This review focuses on modified chitosan-insulin nanoparticles and their implications on oral insulin delivery. Dependent variables and their optimal concentration ranges used in self-assembly techniques for chitosan-insulin nanoparticular synthesis are summarized. This review provides a comprehensive guide to fine-tune the essential factors to formulate stable insulin-chitosan nanoparticles using mild ionic interactions. [Display omitted] [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.