Factors Affecting the Absorption of Subcutaneously Administered Insulin: Effect on Variability

Hydrogel formats to model potential drug interactions occurring at the subcutaneous injection site

We have previously developed an in vitro instrument, termed subcutaneous injection site simulator (SCISSOR), that can be used to monitor release properties of an active pharmaceutical ingredient (API) and formulation components of a medicine designed for SC injection. Initial studies to validate the SCISSOR instrument applications used a simple hyaluronic acid (HA) hydrogel to monitor early release events. We now report a type of cross-linked HA that can, when combined with HA, provide a hydrogel (HA-XR) with optical clarity and rheological properties that remain stable for at least 6 days. Incorporation of 0.05-0.1 mg/mL of collagens isolated from human fibroblasts (Col F), bovine type I collagen (Col I), chicken collagen type II (Col II), or chondroitin sulphate (CS) produced HA or HA-XR hydrogel formats with optical clarity and rheological properties comparable to HA or HA-XR alone. HA + Col F hydrogel had a much greater effect on release rates of 70 kDa compared to 4 kDa dextran, while Col F incorporated into the HA-XR hydrogel accentuated differences in release rates of prandial and basal forms of insulin as well as decreased the release rate of denosumab. A hydrogel format of HA + Col I was used to examine the complex events for bevacizumab release under conditions where a target ligand (vascular endothelial growth factor) can interact with extracellular matrix (ECM). Together, these data have demonstrated the feasibility of using a cross-linked HA format to examine API release over multiple days and incorporation of specific ECM elements to prepare more biomimetic hydrogels that allow for tractable examination of their potential impact of API release.

Prandial Insulins: A Person-Centered Choice

PURPOSE OF REVIEW

Postprandial hyperglycemia, or elevated blood glucose after meals, is associated with the development and progression of various diabetes-related complications. Prandial insulins are designed to replicate the natural insulin release after meals and are highly effective in managing post-meal glucose spikes. Currently, different types of prandial insulins are available such as human regular insulin, rapid-acting analogs, ultra-rapid-acting analogs, and inhaled insulins. Knowledge about diverse landscape of prandial insulin will optimize glycemic management.

RECENT FINDINGS

Human regular insulin, identical to insulin produced by the human pancreas, has a slower onset and extended duration, potentially leading to post-meal hyperglycemia and later hypoglycemia. In contrast, rapid-acting analogs, such as lispro, aspart, and glulisine, are new insulin types with amino acid modifications that enhance their subcutaneous absorption, resulting in a faster onset and shorter action duration. Ultra-rapid analogs, like faster aspart and ultra-rapid lispro, offer even shorter onset of action, providing better meal-time flexibility. The Technosphere insulin offers an inhaled route for prandial insulin delivery. The prandial insulins can be incorporated into basal-bolus, basal plus, or prandial-only regimens or delivered through insulin pumps. Human regular insulin, aspart, lispro, and faster aspart are recommended for management of hyperglycemia during pregnancy. Ongoing research is focused on refining prandial insulin replacement and exploring newer delivery methods. The article provides a comprehensive overview of various prandial insulin options and their clinical applications in the management of diabetes.

The Basis for Weekly Insulin Therapy: Evolving Evidence With Insulin Icodec and Insulin Efsitora Alfa

Basal insulin continues to be a vital part of therapy for many people with diabetes. First attempts to prolong the duration of insulin formulations were through the development of suspensions that required homogenization prior to injection. These insulins, which required once- or twice-daily injections, introduced wide variations in insulin exposure contributing to unpredictable effects on glycemia. Advances over the last 2 decades have resulted in long-acting, soluble basal insulin analogues with prolonged and less variable pharmacokinetic exposure, improving their efficacy and safety, notably by reducing nocturnal hypoglycemia. However, adherence and persistence with once-daily basal insulin treatment remains low for many reasons including hypoglycemia concerns and treatment burden. A soluble basal insulin with a longer and flatter exposure profile could reduce pharmacodynamic variability, potentially reducing hypoglycemia, have similar efficacy to once-daily basal insulins, simplify dosing regimens, and improve treatment adherence. Insulin icodec (Novo Nordisk) and insulin efsitora alfa (basal insulin Fc [BIF], Eli Lilly and Company) are 2 such insulins designed for once-weekly administration, which have the potential to provide a further advance in basal insulin replacement. Icodec and efsitora phase 2 clinical trials, as well as data from the phase 3 icodec program indicate that once-weekly insulins provide comparable glycemic control to once-daily analogues, with a similar risk of hypoglycemia. This manuscript details the technology used in the development of once-weekly basal insulins. It highlights the clinical rationale and potential benefits of these weekly insulins while also discussing the limitations and challenges these molecules could pose in clinical practice.

Assessing glycemic variability in critically ill patients: A prospective cohort study comparing insulin infusion therapy with insulin sliding scale

Glycemic variability (GV) has been associated with an increased mortality rate among critically ill patients. The clinical outcomes of having less GV even with slight hyperglycemia are better than those having tight glycemic control but higher GV. Insulin infusion remains the preferred method to control stress hyperglycemia in critically ill patients. However, its impacts on GV and clinical outcomes in critically ill patients still need further investigation. This study intended to evaluate the impact of insulin infusion therapy (IIT) compared to the insulin sliding scale (ISS) on the extent of GV and explore its impact on the clinical outcomes for critically ill patients. A prospective, single-center observational cohort study was conducted at a tertiary academic hospital in Saudi Arabia between March 2021 and November 2021. The study included adult patients admitted to ICUs who received insulin for stress hyperglycemia management. Patients were categorized into two groups based on the regimen of insulin therapy during ICU stay (IIT versus ISS). The primary outcome was the GV between the two groups. Secondary outcomes were ICU mortality, the incidence of hypoglycemia, and ICU length of stay (LOS). A total of 381 patients were screened; out of them, eighty patients met the eligibility criteria. The distribution of patients having diabetes and a history of insulin use was similar between the two groups. The GV was lower in the IIT group compared to the ISS group using CONGA (- 0.65, 95% CI [- 1.16, - 0.14], p-value = 0.01). Compared with ISS, patients who received IIT had a lower incidence of hypoglycemia that required correction (6.8% vs 2.77%; p-value = 0.38). In contrast, there were no significant differences in ICU LOS and ICU mortality between the two groups. Our study demonstrated that the IIT is associated with decreased GV significantly in critically ill patients without increasing the incidence of severe hypoglycemia. There is no survival benefit with the use of the IIT. Further studies with larger sample size are required to confirm our findings and elaborate on IIT's potential effect in reducing ICU complications in critically ill patients.

Learning Difference Equations With Structured Grammatical Evolution for Postprandial Glycaemia Prediction

People with diabetes must carefully monitor their blood glucose levels, especially after eating. Blood glucose management requires a proper combination of food intake and insulin boluses. Glucose prediction is vital to avoid dangerous post-meal complications in treating individuals with diabetes. Although traditional methods, and also artificial neural networks, have shown high accuracy rates, sometimes they are not suitable for developing personalised treatments by physicians due to their lack of interpretability. This study proposes a novel glucose prediction method emphasising interpretability: Interpretable Sparse Identification by Grammatical Evolution. Combined with a previous clustering stage, our approach provides finite difference equations to predict postprandial glucose levels up to two hours after meals. We divide the dataset into four-hour segments and perform clustering based on blood glucose values for the two-hour window before the meal. Prediction models are trained for each cluster for the two-hour windows after meals, allowing predictions in 15-minute steps, yielding up to eight predictions at different time horizons. Prediction safety was evaluated based on Parkes Error Grid regions. Our technique produces safe predictions through explainable expressions, avoiding zones D (0.2% average) and E (0%) and reducing predictions on zone C (6.2%). In addition, our proposal has slightly better accuracy than other techniques, including sparse identification of non-linear dynamics and artificial neural networks. The results demonstrate that our proposal provides interpretable solutions without sacrificing prediction accuracy, offering a promising approach to glucose prediction in diabetes management that balances accuracy, interpretability, and computational efficiency.

Development of a Weight-Band Dosing Approach for Vosoritide in Children with Achondroplasia Using a Population Pharmacokinetic Model

BACKGROUND AND OBJECTIVE

Vosoritide is a recently approved therapy for achondroplasia, the most common form of disproportionate short stature, that has been shown to be well tolerated and effective in increasing linear growth. This study aimed to develop a population pharmacokinetic (PPK) model to characterize pharmacokinetics (PK) of vosoritide and establish a weight-band dosing regimen.

METHODS

A PPK model was developed using data from five clinical trials in children with achondroplasia (aged 0.95-15 years) who received daily per-kg doses of vosoritide. The model was used to simulate expected exposures in children with a refined weight-band dosing regimen. Simulated exposure was compared with the observed exposure from the pivotal clinical trial to evaluate appropriateness of the weight-band dosing regimen.

RESULTS

A one-compartment model with a change-point first-order absorption and first-order elimination accurately described PK of vosoritide in children with achondroplasia. Body weight was found to be a predictor of vosoritide's clearance and volume of distribution. Additionally, it was observed that dosing solution concentration and duration of treatment influenced bioavailability. The weight-band dosing regimen resulted in simulated exposures that were within the range demonstrated to be well tolerated and effective in the pivotal clinical trial and showed improved consistency in drug exposure across the achondroplasia population.

CONCLUSIONS

The weight-band dosing regimen reduced the number of recommended dose levels by body weight and is expected to simplify dosing for children with achondroplasia and their caregivers.

CLINICAL TRIAL REGISTRATION

NCT02055157, NCT02724228, NCT03197766, NCT03424018, and NCT03583697.

Society of Critical Care Medicine Guidelines on Glycemic Control for Critically Ill Children and Adults 2024

RATIONALE

Maintaining glycemic control of critically ill patients may impact outcomes such as survival, infection, and neuromuscular recovery, but there is equipoise on the target blood levels, monitoring frequency, and methods.

OBJECTIVES

The purpose was to update the 2012 Society of Critical Care Medicine and American College of Critical Care Medicine (ACCM) guidelines with a new systematic review of the literature and provide actionable guidance for clinicians.

PANEL DESIGN

The total multiprofessional task force of 22, consisting of clinicians and patient/family advocates, and a methodologist applied the processes described in the ACCM guidelines standard operating procedure manual to develop evidence-based recommendations in alignment with the Grading of Recommendations Assessment, Development, and Evaluation Approach (GRADE) methodology. Conflict of interest policies were strictly followed in all phases of the guidelines, including panel selection and voting.

METHODS

We conducted a systematic review for each Population, Intervention, Comparator, and Outcomes question related to glycemic management in critically ill children (≥ 42 wk old adjusted gestational age to 18 yr old) and adults, including triggers for initiation of insulin therapy, route of administration, monitoring frequency, role of an explicit decision support tool for protocol maintenance, and methodology for glucose testing. We identified the best available evidence, statistically summarized the evidence, and then assessed the quality of evidence using the GRADE approach. We used the evidence-to-decision framework to formulate recommendations as strong or weak or as a good practice statement. In addition, "In our practice" statements were included when the available evidence was insufficient to support a recommendation, but the panel felt that describing their practice patterns may be appropriate. Additional topics were identified for future research.

RESULTS

This guideline is an update of the guidelines for the use of an insulin infusion for the management of hyperglycemia in critically ill patients. It is intended for adult and pediatric practitioners to reassess current practices and direct research into areas with inadequate literature. The panel issued seven statements related to glycemic control in unselected adults (two good practice statements, four conditional recommendations, one research statement) and seven statements for pediatric patients (two good practice statements, one strong recommendation, one conditional recommendation, two "In our practice" statements, and one research statement), with additional detail on specific subset populations where available.

CONCLUSIONS

The guidelines panel achieved consensus for adults and children regarding a preference for an insulin infusion for the acute management of hyperglycemia with titration guided by an explicit clinical decision support tool and frequent (≤ 1 hr) monitoring intervals during glycemic instability to minimize hypoglycemia and against targeting intensive glucose levels. These recommendations are intended for consideration within the framework of the patient's existing clinical status. Further research is required to evaluate the role of individualized glycemic targets, continuous glucose monitoring systems, explicit decision support tools, and standardized glycemic control metrics.

The artificial pancreas: two alternative approaches to achieve a fully closed-loop system with optimal glucose control

INTRODUCTION

Diabetes mellitus type 1 is a chronic disease that implies mandatory external insulin delivery. The patients must monitor their blood glucose levels and administer appropriate insulin boluses to keep their blood glucose within the desired range. It requires a lot of time and endeavour, and many patients struggle with suboptimal glucose control despite all their efforts.

MATERIALS AND METHODS

This narrative review combines existing knowledge with new discoveries from animal experiments.

DISCUSSION

In the last decade, artificial pancreas (AP) devices have been developed to improve glucose control and relieve patients of the constant burden of managing their disease. However, a feasible and fully automated AP is yet to be developed. The main challenges preventing the development of a true, subcutaneous (SC) AP system are the slow dynamics of SC glucose sensing and particularly the delay in effect on glucose levels after SC insulin infusions. We have previously published studies on using the intraperitoneal space for an AP; however, we further propose a novel and potentially disruptive way to utilize the vasodilative properties of glucagon in SC AP systems.

CONCLUSION

This narrative review presents two lesser-explored viable solutions for AP systems and discusses the potential for improvement toward a fully automated system: A) using the intraperitoneal approach for more rapid insulin absorption, and B) besides using glucagon to treat and prevent hypoglycemia, also administering micro-boluses of glucagon to increase the local SC blood flow, thereby accelerating SC insulin absorption and SC glucose sensor site dynamics.

A Mechanistic Physiologically-Based Pharmacokinetic Platform Model to Guide Adult and Pediatric Intravenous and Subcutaneous Dosing for Bispecific T Cell Engagers

Bispecific T cell engagers (Bi-TCEs) have revolutionized the treatment of oncology indications across both liquid and solid tumors. Bi-TCEs are rapidly evolving from conventional intravenous (i.v.) to more convenient subcutaneous (s.c.) administrations and extending beyond adults to also benefit pediatric patients. Leveraging clinical development experience across three generations of Bi-TCE molecules across both liquid and solid tumor indications from i.v./s.c. dosing in adults and pediatric subjects, we developed a mechanistic-physiologically-based pharmacokinetic (PBPK) platform model for Bi-TCEs. The model utilizes a full PBPK model framework and was successfully validated for PK predictions following i.v. and s.c. dosing across both liquid and solid tumor space in adults for eight Bi-TCEs. After refinement to incorporate physiological ontogeny, the model was successfully validated to predict pediatric PKs in 1 month - < 2 years, 2-11 years, and 12-17 years old subjects following i.v. dosing. Following s.c. dosing in pediatric subjects, the model predicted similar bioavailability, however, a shorter time to maximum concentration (Tmax ) for the three age groups compared with adults. The model was also applied to guide the dosing strategy for first generation of Bi-TCEs for organ impairment, specifically renal impairment, and was able to accurately predict the impact of renal impairment on PK for these relatively small-size Bi-TCEs. This work highlights a novel mechanistic platform model for accurately predicting the PK in adult and pediatric patients across liquid and solid tumor indications from i.v./s.c. dosing and can be used to guide optimal dose and dosing regimen selection and accelerating the clinical development for Bi-TCEs.

Exercising Safely with the MiniMed™ 780G Automated Insulin Delivery System

The physical and psychological benefits of exercise are particularly pertinent to people with type 1 diabetes (T1D). The variability in subcutaneous insulin absorption and the delay in offset and onset in glucose lowering action impose limitations, given the rapidly varying insulin requirements with exercise. Simultaneously, there are challenges to glucose monitoring. Consequently, those with T1D are less likely to exercise because of concerns regarding glucose instability. While glucose control with exercise can be enhanced using automated insulin delivery (AID), all commercially available AID systems remain limited by the pharmacokinetics of subcutaneous insulin delivery. Although glycemic responses may vary with exercises of differing intensities and durations, the principles providing the foundation for guidelines include minimization of insulin on board before exercise commencement, judicious and timely carbohydrate supplementation, and when possible, a reduction in insulin delivered in anticipation of planned exercise. There is an increasing body of evidence in support of superior glucose control with AID over manual insulin dosing in people in T1D who wish to exercise. The MiniMed™ 780G AID system varies basal insulin delivery with superimposed automated correction boluses. It incorporates a temporary (elevated glucose) target of 8.3 mmol/L (150 mg/dL) and when it is functioning, the autocorrection boluses are stopped. As the device has recently become commercially available, there are limited data assessing glucose control with the MiniMed™ 780G under exercise conditions. Importantly, when exercise was planned and implemented within consensus guidelines, %time in range and %time below range targets were met. A practical approach to exercising with the device is provided with illustrative case studies. While there are limitations to spontaneity imposed on any AID device due to the pharmacokinetics associated with the subcutaneous delivery of current insulin formulations, the MiniMed™ 780G system provides people with T1D an excellent option for exercising safely if the appropriate strategies are implemented.

Functionalisation of brush polyethylene glycol polymers with specific lipids extends their elimination half-life through association with natural lipid trafficking pathways

Polymeric prodrugs have been applied to control the delivery of various types of therapeutics. Similarly, conjugation of peptide therapeutics to lipids has been used to prolong systemic exposure. Here, we extend on these two approaches by conjugating brush polyethylene glycol (PEG) polymers with different lipid components including short-chain (1C2) or medium-chain (1C12) monoalkyl hydrocarbon tails, cholesterol (Cho), and diacylglycerols composed of two medium-chain (2C12) or long-chain (2C18) fatty acids. We uniquely evaluate the integration of these lipid-polymers into endogenous lipid trafficking pathways (albumin and lipoproteins) and the impact of lipid conjugation on plasma pharmacokinetics after intravenous (IV) and subcutaneous (SC) dosing to cannulated rats. The IV and SC elimination half-lives of Cho-PEG (13 and 22 h, respectively), 2C12-PEG (11 and 17 h, respectively) and 2C18-PEG (12 h for both) were prolonged compared to 1C2-PEG (3 h for both) and 1C12-PEG (4 h for both). Interestingly, 1C2-PEG and 1C12-PEG had higher SC bioavailability (40 % and 52 %, respectively) compared to Cho-PEG, 2C12-PEG and 2C18-PEG (25 %, 24 % and 23 %, respectively). These differences in pharmacokinetics may be explained by the different association patterns of the polymers with rat serum albumin (RSA), bovine serum albumin (BSA) and lipoproteins. For example, in pooled plasma (from IV pharmacokinetic studies), 2C18-PEG had the highest recovery in the high-density lipoprotein (HDL) fraction. In conclusion, the pharmacokinetics of brush PEG polymers can be tuned via conjugation with different lipids, which can be utilised to tune the elimination half-life, biodistribution and effect of therapeutics for a range of medical applications. STATEMENT OF SIGNIFICANCE: Lipidation of therapeutics such as peptides has been employed to extend their plasma half-life by promoting binding to serum albumin, providing protection against rapid clearance. Here we design and evaluate innovative biomaterials consisting of brush polyethylene glycol polymers conjugated with different lipids. Importantly, we show for the first time that lipidated polymeric materials associate with endogenous lipoprotein trafficking pathways and this, in addition to albumin binding, controls their plasma pharmacokinetics. We find that conjugation to dialkyl lipids and cholesterol leads to higher association with lipid trafficking pathways, and more sustained plasma exposure, compared to conjugation to short and monoalkyl lipids. Our lipidated polymers can thus be utilised as delivery platforms to tune the plasma half-life of various pharmaceuticals.

Nanoparticle technology for mRNA: Delivery strategy, clinical application and developmental landscape

The mRNA vaccine, a groundbreaking advancement in the field of immunology, has garnered international recognition by being awarded the prestigious Nobel Prize, which has emerged as a promising prophylactic and therapeutic modality for various diseases, especially in cancer, rare disease, and infectious disease such as COVID-19, wherein successful mRNA treatment can be achieved by improving the stability of mRNA and introducing a safe and effective delivery system. Nanotechnology-based delivery systems, such as lipid nanoparticles, lipoplexes, polyplexes, lipid-polymer hybrid nanoparticles and others, have attracted great interest and have been explored for mRNA delivery. Nanoscale platforms can protect mRNA from extracellular degradation while promoting endosome escape after endocytosis, hence improving the efficacy. This review provides an overview of diverse nanoplatforms utilized for mRNA delivery in preclinical and clinical stages, including formulation, preparation process, transfection efficiency, and administration route. Furthermore, the market situation and prospects of mRNA vaccines are discussed here.

Non-Invasive Delivery of Insulin for Breaching Hindrances against Diabetes

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

Unveiling Diabetes: Categories, Genetics, Diagnostics, Treatments, and Future Horizons

Diabetes mellitus is a global epidemic affecting millions of individuals worldwide. This comprehensive review aims to provide a thorough understanding of the categorization, disease identity, genetic architecture, diagnosis, and treatment of diabetes. The categorization of diabetes is discussed, with a focus on type 1 and type 2 diabetes, as well as the lesser-known types, type 3 and type 4 diabetes. The geographical variation, age, gender, and ethnic differences in the prevalence of type 1 and type 2 diabetes are explored. The impact of disease identity on disease management and the role of autoimmunity in diabetes are examined. The genetic architecture of diabetes, including the interplay between genotype and phenotype, is discussed to enhance our understanding of the underlying mechanisms. The importance of insulin injection sites and the insulin signalling pathway in diabetes management are highlighted. The diagnostic techniques for diabetes are reviewed, along with advancements for improved differentiation between types. Treatment and management approaches, including medications used in diabetes management are presented. Finally, future perspectives are discussed, emphasizing the need for further research and interventions to address the global burden of diabetes. This review serves as a valuable resource for healthcare professionals, researchers, and policymakers, providing insights to develop targeted strategies for the prevention, diagnosis, and management of this complex disease.

(Hybrid) Closed-Loop Systems: From Announced to Unannounced Exercise

Physical activity and exercise have many beneficial effects on general and type 1 diabetes (T1D) specific health and are recommended for individuals with T1D. Despite these health benefits, many people with T1D still avoid exercise since glycemic management during physical activity poses substantial glycemic and psychological challenges - which hold particularly true for unannounced exercise when using an AID system. Automated insulin delivery (AID) systems have demonstrated their efficacy in improving overall glycemia and in managing announced exercise in numerous studies. They are proven to increase time in range (70-180 mg/dL) and can especially counteract nocturnal hypoglycemia, even when evening exercise was performed. AID-systems consist of a pump administering insulin as well as a CGM sensor (plus transmitter), both communicating with a control algorithm integrated into a device (insulin pump, mobile phone/smart watch). Nevertheless, without manual pre-exercise adaptions, these systems still face a significant challenge around physical activity. Automatically adapting to the rapidly changing insulin requirements during unannounced exercise and physical activity is still the Achilles' heel of current AID systems. There is an urgent need for improving current AID-systems to safely and automatically maintain glucose management without causing derailments - so that going forward, exercise announcements will not be necessary in the future. Therefore, this narrative literature review aimed to discuss technological strategies to how current AID-systems can be improved in the future and become more proficient in overcoming the hurdle of unannounced exercise. For this purpose, the current state-of-the-art therapy recommendations for AID and exercise as well as novel research approaches are presented along with potential future solutions - in order to rectify their deficiencies in the endeavor to achieve fully automated AID-systems even around unannounced exercise.

Delivery of biologics: Topical administration

Biologics are unaffordable to a large majority of the global population because of prohibitively expensive fermentation systems, purification and the requirement for cold chain for storage and transportation. Limitations of current production and delivery systems of biologics were evident during the recent pandemic when <2.5% of vaccines produced were available to low-income countries and ∼19 million doses were discarded in Africa due to lack of cold-chain infrastructure. Among FDA-approved biologics since 2015, >90% are delivered using invasive methods. While oral or topical drugs are highly preferred by patients because of their affordability and convenience, only two oral drugs have been approved by FDA since 2015. A newly launched oral biologic costs only ∼3% of the average cost of injectable biologics because of the simplified regulatory approval process by elimination of prohibitively expensive fermentation, purification, cold storage/transportation. In addition, the cost of developing a new biologic injectable product (∼$2.5 billion) has been dramatically reduced through oral or topical delivery. Topical delivery has the unique advantage of targeted delivery of high concentration protein drugs, without getting diluted in circulating blood. However, only very few topical drugs have been approved by the FDA. Therefore, this review highlights recent advances in oral or topical delivery of proteins at early or advanced stages of human clinical trials using chewing gums, patches or sprays, or nucleic acid drugs directly, or in combination with, nanoparticles and offers future directions.

Physiologically based pharmacokinetic modelling of semaglutide in children and adolescents with healthy and obese body weights

AIMS

To develop paediatric physiologically based pharmacokinetic modelling (PBPK) models of semaglutide to estimate the pharmacokinetic profile for subcutaneous injections in children and adolescents with healthy and obese body weights.

METHODS

Pharmacokinetic modelling and simulations of semaglutide subcutaneous injections were performed using the Transdermal Compartmental Absorption & Transit model implemented in GastroPlus v.9.5 modules. A PBPK model of semaglutide was developed and verified in the adult population, by comparing the simulated plasma exposure with the observed data, and further scaled to the paediatric populations with normal and obese body weight.

RESULTS

The semaglutide PBPK model was successfully developed in adults and scaled to the paediatric population. Our paediatric PBPK simulations indicated a significant increase in maximum plasma concentrations for the 10-14 years' paediatric population with healthy body weights, which was higher than the observed values in adults at the reference dose. Since gastrointestinal adverse events are related to increased semaglutide concentrations, peak concentrations outside the target range may represent a safety risk for this paediatric age group. Besides, paediatric PBPK models indicated that body weight was inversely related to semaglutide maximum plasma concentration, corroborating the consensus on the influence of body weight on semaglutide PK in adults.

CONCLUSION

Paediatric PBPK was successfully achieved using a top-down approach and drug-related parameters. The development of unprecedented PBPK models will support paediatric clinical therapy for applying aid-safe dosing regimens for the paediatric population in diabetes treatment.

Impact of the Number of Needle Tip Bevels on the Exerted Forces and Energy in Insulin Pen Injections

Patients affected with type 1 diabetes and a non-negligible number of patients with type 2 diabetes are insulin dependent. Both the injection technique and the choice of the most suitable needle are fundamental for allowing them to have a good injection experience. The needles may differ in several parameters, from the length and diameter, up to the forces required to perform the injection and to some geometrical parameters of the needle tip (e.g., number of facets or bevels). The aim of the research is to investigate whether an increased number of bevels could decrease forces and energy involved in the insertion-extraction cycle, thus potentially allowing patients to experience lower pain. Two needle variants, namely, 31 G × 5 mm and 32 G × 4 mm, are considered, and experimental tests are carried out to compare 3-bevels with 5-bevels needles for both the variants. The analysis of the forces and energy for both variants show that the needles with 5 bevels require a statistically significant lower drag or sliding force (p-value = 0.040 for the 31 G × 5 mm needle and p-value < 0.001 for 32 G × 4 mm), extraction force (p-value < 0.001 for both variants), and energy (p-value < 0.001 for both variants) during the insertion-extraction cycle. As a result, 3-bevels needles do not have the same functionality of 5-bevels needles, show lower capacity of drag and extraction, and can potentially be related to more painful injection experience for patients.

Insulin-induced lipodystrophy and predisposing factors in children and adolescents with type 1 diabetes mellitus (T1DM) in a tertiary care Egyptian center

BACKGROUND

Lipodystrophy (LH) is one of the most common complications of subcutaneous insulin injection. Many factors are incriminated in the evolution of LH in children with diabetes type 1 (T1DM). LH may affect insulin absorption in the skin areas involved, resulting in a negative impact on blood glucose levels and glycemic variability.

PATIENTS AND METHODS

We calculated and evaluated the prevalence of LH in relation to possible clinical factors associated with the development of LH in a cohort of children (n =115) with T1DM using insulin pens or syringes and we studied possible predisposing factors including their age, duration of T1DM, injection technique, insulin dose/kg, degree of pain perception, and HbA1c level.

RESULTS

In our cross-sectional study, 84% of patients were using pens for insulin injection and 52.2 % of them were rotating the site of injection on daily basis. 27 % did not experience pain during an injection while 6 % had the worst hurt. 49.5 % had clinically detectable LH. Those with LH had higher HbA1c levels and more unexplained hypoglycemic events compared to those without LH (P: 0.058). The hypertrophied site was related to the preferred site of injection which was the arms in 71.9 % of the cases. Children who had LH were older with a longer duration of T1DM, rotating sites of injection less frequently, and were more frequently reusing needles compared to children without LH (P: < 0.05).

CONCLUSION

Improper insulin injection technique, older age, and longer duration of T1DM were associated with LH. Proper education of patients and their parents must include correct injection techniques, rotating injection sites, and minimal reuse of needles.

Subcutaneous injections: A cross-sectional study of knowledge and practice preferences of nurses

BACKGROUND

Widespread use of subcutaneous injection for parenteral medications is likely to be related to high medication bioavailability and rapid onset of action. Correct subcutaneous injection technique and site selection are essential for nursing care quality and patient safety.

AIM

The study aimed to determine nurses' knowledge and practice preferences regarding subcutaneous injection technique and administration site selection.

DESIGN

This cross-sectional study took place between March and June 2021.

METHODS

This study included 289 nurses, willing to participate who worked in units performing subcutaneous injections in a university hospital in Turkey.

RESULTS

Most nurses reported their preferred administration site for subcutaneous injections was the lateral aspects of the upper arm. More than half of the nurses did not use a rotation chart, they swabbed the skin before a subcutaneous injection, and they always pinched the skin at the injection site; 50% of nurses reported always administering subcutaneous injections at an angle of either 90 or 45 degrees. Most nurses performed an injection in less than 30 s and waited for 10 s before withdrawing the needle. They did not apply massage onto the site following the injection. Nurses' knowledge of subcutaneous injection was at a moderate level.

CONCLUSIONS

Nurse knowledge of best practice subcutaneous injection administration and site selection could be improved in line with current evidence to improve personcentred and quality and safe care delivery. Future research should involve developing and evaluating educational strategies and practice standards to enhance nurse understanding of best practice evidence to meet patient safety goals.

An Engineered Nanosugar Enables Rapid and Sustained Glucose-Responsive Insulin Delivery in Diabetic Mice

Glucose-responsive insulin-delivery platforms that are sensitive to dynamic glucose concentration fluctuations and provide both rapid and prolonged insulin release have great potential to control hyperglycemia and avoid hypoglycemia diabetes. Here, biodegradable and charge-switchable phytoglycogen nanoparticles capable of glucose-stimulated insulin release are engineered. The nanoparticles are "nanosugars" bearing glucose-sensitive phenylboronic acid groups and amine moieties that allow effective complexation with insulin (≈95% loading capacity) to form nanocomplexes. A single subcutaneous injection of nanocomplexes shows a rapid and efficient response to a glucose challenge in two distinct diabetic mouse models, resulting in optimal blood glucose levels (below 200 mg dL^-1 ) for up to 13 h. The morphology of the nanocomplexes is found to be key to controlling rapid and extended glucose-regulated insulin delivery in vivo. These studies reveal that the injected nanocomplexes enabled efficient insulin release in the mouse, with optimal bioavailability, pharmacokinetics, and safety profiles. These results highlight a promising strategy for the development of a glucose-responsive insulin delivery system based on a natural and biodegradable nanosugar.

Factors influencing bioequivalence evaluation of insulin biosimilars based on a structural equation model

Objective: This study aimed to explore the factors affecting the bioequivalence of test and reference insulin preparations so as to provide a scientific basis for the consistency evaluation of the quality and efficacy of insulin biosimilars.

Methods: A randomized, open, two-sequence, single-dose, crossover design was used in this study. Subjects were randomly divided into TR or RT groups in equal proportion. The glucose infusion rate and blood glucose were measured by a 24-h glucose clamp test to evaluate the pharmacodynamic parameters of the preparation. The plasma insulin concentration was determined by liquid chromatography–mass spectrometry (LC-MS/MS) to evaluate pharmacokinetic parameters. WinNonlin 8.1 and SPSS 23.0 were applied for PK/PD parameter calculation and statistical analysis. The structural equation model (SEM) was constructed to analyze the influencing factors of bioequivalence by using Amos 24.0.

Results: A total of 177 healthy male subjects aged 18–45 years were analyzed. Subjects were assigned to the equivalent group (N = 55) and the non-equivalent group (N = 122) by bioequivalence results, according to the EMA guideline. Univariate analysis showed statistical differences in albumin, creatinine, Tmax, bioactive substance content, and adverse events between the two groups. In the structural equation model, adverse events (β = 0.342; p &lt; 0.001) and bioactive substance content (β = −0.189; p = 0.007) had significant impacts on the bioequivalence of two preparations, and the bioactive substance content significantly affected adverse events (β = 0.200; p = 0.007).

Conclusion: A multivariate statistical model was used to explore the influencing factors for the bioequivalence of two preparations. According to the result of the structural equation model, we proposed that adverse events and bioactive substance content should be optimized for consistency evaluation of the quality and efficacy of insulin biosimilars. Furthermore, bioequivalence trials of insulin biosimilars should strictly obey inclusion and exclusion criteria to ensure the consistency of subjects and avoid confounding factors affecting the equivalence evaluation.

Design of a randomized cross-over study evaluating effects of carbohydrate intake on glycemic control in persons with type 1 diabetes

Introduction

Diet is an important factor in managing glycemic control in type 1 diabetes (T1D). Reducing carbohydrate intake may be important for stabilizing blood glucose levels in certain groups of patients with T1D. There are few studies examining the effects of a low carbohydrate diet in patients with T1D. The aim of this study is to investigate the effects of carbohydrate intake on glucose control in adults with T1D.

Materials and methods

Adults with T1D (N = 54) and inadequate glycemic control (HbA1c ≥ 7.5%; 58 mmol/mol) were randomized in a cross-over design to a moderate carbohydrate diet (30 percent of total energy from carbohydrates) versus a traditional diabetes diet (50 percent of total energy from carbohydrates) for 4 weeks with a between wash-out period of 4 weeks. Masked continuous glucose monitoring was used throughout the study to evaluate effects on mean blood glucose levels, time-in-range, hypoglycemia, hyperglycemia, and glycemic variability. Diabetes treatment satisfaction, hypoglycemic confidence, and physical activity were measured using questionnaires during different phases of the trial. HbA1c, blood lipids, blood pressure, and ketone levels were also measured. The primary endpoint is the difference in mean blood glucose level between the diet periods. Study completion is anticipated during winter 2022.

Discussion

The study seeks to increase knowledge about the effects of dietary carbohydrate intake on glycemic control and other health parameters in patients with T1D. If beneficial effects on mean blood glucose level without elevated risk of hypoglycemia or ketoacidosis are shown, a moderate carbohydrate diet may be a treatment option for people with T1D that have unsatisfactory blood glucose levels.

Clinical Trials Registration:www.clinicaltrials.gov, ID: NCT03400618.

The subtleties of insulin treatment in patients with lipodystrophy

In the treatment of Diabetes Mellitus (DM), which develops on the basis of insulin resistance in patients with lipodystrophy (LD) often require high doses of insulin. Traditionally in practice is to gradually increase the insulin doses to achieve blood glucose normalization. The fact that high insulin doses require a larger injection volume, which causes impairment in the absorption of insulin from the subcutaneous tissue to the circulation. In this article, we discussed the clinical approach to insulin practice in the treatment of DM in patients with LD and reviewed systematically the literature.

Improvements in Glycemic Outcomes in 4738 Children, Adolescents, and Adults with Type 1 Diabetes Initiating a Tubeless Insulin Management System

INTRODUCTION

Despite recent advances in diabetes technology, most people living with type 1 diabetes mellitus (T1D) are unable to meet glycemic targets. Real-world evidence can provide insight into outcomes achieved with specific treatment devices when used in clinical practice. The aim of this study was to analyze real-world outcomes collected from a large cohort of people living with T1D and initiating treatment with the Omnipod DASH System.

METHODS

In this retrospective observational study, real-world outcomes were analyzed from a database of information collected from people with T1D initiating the Omnipod DASH System. Information in the database was either taken directly from the patient's medical record or self-reported if medical records were unavailable. The primary outcome was change in glycated hemoglobin (HbA1c) from baseline (before initiation) to 3 months after initiation. Secondary outcomes were changes in total daily dose of insulin (TDD) and self-reported frequency of hypoglycemic events (< 70 mg/dL). Results are separated for the adult (≥ 18 years, N = 3341) and pediatric (< 18 years, N = 1397) cohorts.

RESULTS

The change in HbA1c from baseline was  - 0.9 ± 1.6% ( - 10 ± 18 mmol/mol; p < 0.0001) in adults and   - 0.9 ± 2.0% ( - 10 ± 22 mmol/mol; p < 0.0001) in the pediatric cohort. For those previously using multiple daily injections, HbA1c decreased by  - 1.0 ± 1.7% ( - 11 ± 19 mmol/mol) in adults and   - 1.0 ± 2.1% ( - 11 ± 23 mmol/mol) in the pediatric cohort (both p < 0.0001). Hypoglycemic events decreased in adults from 2.9 to 1.3 episodes per week ( - 1.6 ± 3.2 events/week; p < 0.0001), and in the pediatric cohort from 2.8 to 1.5 episodes per week ( - 1.3 ± 2.7 events/week; p < 0.0001). In adults, TDD decreased by 19.9% (p < 0.0001), and it remained stable in the pediatric cohort (p > 0.05).

CONCLUSIONS

Real-world outcomes from this large cohort of people initiating therapy with the Omnipod DASH System showed significant improvement in HbA1c and a substantial reduction in hypoglycemic events after 3 months of use.

Formulation and characterization of insulin nanoclusters for a controlled release

The growing interest in biopharmaceuticals combined with the challenges regarding formulation and delivery continues to encourage the development of new and improved formulations of this class of therapeutics. Nanoclusters (NCs) represent a type of formulation strategy where the biopharmaceutical is clustered in a reversible manner to function as both the therapeutic and the vehicle. In this study, insulin NCs (INCs) were formulated by a new methodology of first crosslinking proteins followed by desolvation. Crosslinking of the protein with the reducible DTSSP crosslinker improved control of the INC synthesis process to give INCs with a mean size of 198 ± 7 nm and a mean zeta potential of -39 ± 1 mV. Crosslinking and clustering of insulin did not induce cytotoxicity or major differences in the biological activity compared to the free unmodified protein. The potency of the crosslinked insulin and the INCs appeared slightly lower than that of the unmodified protein, and significantly higher doses of the INCs compared to the free protein were applied to achieve similar blood sugar lowering effects in vivo. Interestingly, the INCs allowed for high doses to be subcutaneously delivered with prolonged efficacy without being lethal in rats.

Pharmacokinetics and tolerability of prefilled syringe and auto-injector presentations of MSB11456: results of a randomized, single-dose study in healthy adults

BACKGROUND

Tocilizumab is a monoclonal immunoglobulin G interleukin-6 receptor antagonist. MSB11456 is a proposed tocilizumab biosimilar.

OBJECTIVE

To determine the pharmacokinetic equivalence of a single subcutaneous injection of MSB11456, when delivered via autoinjector (AI) and prefilled syringe (PFS), in healthy adult subjects.

RESEARCH DESIGN AND METHODS

In this randomized, open-label, single fixed-dose, crossover study, 91 subjects received subcutaneous administration of tocilizumab 162 mg via AI and PFS presentations. The primary endpoint pharmacokinetic parameters were analyzed using analysis of variance. Safety data were summarized descriptively.

RESULTS

There were no differences in pharmacokinetic parameters between presentations, and safety parameters were comparable. The 90% confidence intervals for the geometric least squares mean ratios of all primary pharmacokinetic parameters were contained within the predefined 80.00% to 125.00% bioequivalence limits, indicating pharmacokinetic equivalence between the AI and PFS.

CONCLUSIONS

MSB11456 administration via AI was bioequivalent to administration via PFS. MSB11456 can be administered by AI or PFS, increasing the available range of self-injection devices.

TRIAL REGISTRATION

The trial is registered at EudraCT, number 2020-003419-86.

Enhanced hexamerization of insulin via assembly pathway rerouting revealed by single particle studies

Insulin formulations with diverse oligomerization states are the hallmark of interventions for the treatment of diabetes. Here using single-molecule recordings we firstly reveal that insulin oligomerization can operate via monomeric additions and secondly quantify the existence, abundance and kinetic characterization of diverse insulin assembly and disassembly pathways involving addition of monomeric, dimeric or tetrameric insulin species. We propose and experimentally validate a model where the insulin self-assembly pathway is rerouted, favoring monomeric or oligomeric assembly, by solution concentration, additives and formulations. Combining our practically complete kinetic characterization with rate simulations, we calculate the abundance of each oligomeric species from nM to mM offering mechanistic insights and the relative abundance of all oligomeric forms at concentrations relevant both for secreted and administrated insulin. These reveal a high abundance of all oligomers and a significant fraction of hexamer resulting in practically halved bioavailable monomer concentration. In addition to providing fundamental new insights, the results and toolbox presented here can be universally applied, contributing to the development of optimal insulin formulations and the deciphering of oligomerization mechanisms for additional proteins.

The Effect of BMI on Pharmacokinetic and Pharmacodynamic Parameters of Insulin Degludec: Results from an Euglycemic Glucose Clamp Study

PURPOSE

This study evaluated the effect of body mass index (BMI) on pharmacokinetic (PK) and pharmacodynamic (PD) parameters of insulin degludec in healthy Chinese males, depending on an euglycemic glucose clamp study.

METHODS

Sixty-five healthy male subjects were divided into four groups according to quartile of BMI value. Group A: BMI ≤ 20.7 kg/m²; group B: 20.7 < BMI ≤ 22.5 kg/m²; group C: 22.5 < BMI ≤ 23.6 kg/m²; group D: BMI > 23.6 kg/m². Each volunteer received a single subcutaneous dose (0.4 U/kg) of insulin degludec and accepted a 24-h euglycemic glucose clamp study. The primary PK parameters were maximum observed drug concentration (C_max) and the area under the curve (AUC_INS) for the specified time intervals. The primary PD parameters were the time to the start of glucose infusion (T_onset), maximal glucose infusion rate (GIR_max) and area under the curve (AUC_GIR) for the specified time intervals. The differences of these PK/PD parameters were compared among groups.

RESULTS

C_max and the AUC of insulin (0-6 h, 6-12 h and 0-24 h) were more than onefold higher in group A than those in groups B, C, D, and the concentration-time curve of group A was significantly shifted to the left compared with the other three groups. The GIR_max, total AUC_GIR, and AUC_GIR for each time interval were significantly higher in group A than those in other three groups. The proportion of AUC_GIR in group A was the lowest proportion among four groups seen in the late stage. Multiple linear regression analysis showed that BMI was negatively correlated with AUC_GIR,_{0-24 h}.

CONCLUSIONS

Insulin degludec in healthy Chinese male subjects with BMI ≤ 20.7 kg/m² had a faster absorption, clearance, and a stronger glucose-lowering effect, but a steeper decrease of insulin action in the late stage after dosing.

Progressive Acceleration of Insulin Exposure Over 7 Days of Infusion Set Wear

Insulin exposure varies over 3 days of insulin infusion set (IIS) wear making day-to-day insulin dosing challenging for people with diabetes (PWD). Here we report insulin pharmacodynamic (PD) and pharmacokinetic (PK) data extending these observations to 7 days of IIS wear. PWD (A1C ≤8.5%, C-peptide <0.6 nmol/L, ≥6 months pump use) were enrolled in a crossover euglycemic clamp pilot study comparing conventional Teflon angled IISs with an investigational extended-wear IIS. PK/PD data from six participants were obtained for 5 h postbolus. Although PD data were unstable, PK profiles (pooled data from both groups) of insulin lispro (0.15 U/kg bolus) showed statistically significant progressive decreases from days 0 to 7 for t_max (P < 0.001), C_max (P < 0.05), and mean residence time (P < 0.0001). Area under the insulin concentration curve (AUC_0-300) declined by ∼24% from days 0 to 7 (P < 0.05). These results confirm/extend previous observations showing progressive acceleration of insulin exposure over IIS wear time. This may have implications for PWD and designers of closed-loop algorithms, although larger studies are necessary to confirm this. The study was registered in clinicaltrials.gov (NCT04398030).

Derivatization with fatty acids in peptide and protein drug discovery

Peptides and proteins are widely used to treat a range of medical conditions; however, they often have to be injected and their effects are short-lived. These shortcomings of the native structure can be addressed by molecular engineering, but this is a complex undertaking. A molecular engineering technology initially applied to insulin - and which has now been successfully applied to several biopharmaceuticals - entails the derivatization of peptides and proteins with fatty acids. Various protraction mechanisms are enabled by the specific characteristics and positions of the attached fatty acid. Furthermore, the technology can ensure a long half-life following oral administration of peptide drugs, can alter the distribution of peptides and may hold potential for tissue targeting. Due to the inherent safety and well-defined chemical nature of the fatty acids, this technology provides a versatile approach to peptide and protein drug discovery.

Transforming Evidence Generation for Drug Label Changes: A Case Study

Computer Modeling and Simulation (CM&S) provides the opportunity to drastically reduce clinical trial patient burden and advance regulatory decision making. At the suggestion of the US Food and Drug Administration (FDA), MannKind Corporation and Nudge BG submitted an application to the FDA Model-Informed Drug Development (MIDD) pilot program to support a label change for the initial dose of Afrezza® (insulin human), a novel inhalable insulin with a rapid pharmacokinetic and pharmacodynamic profile. The MIDD pilot program demonstrates the FDA's commitment to advancing regulatory science through the adoption of evidence generated by CM&S. A simulation framework was developed based on empirical data. It was used to generate evidence to support the label change. Briefing packages and presentations were prepared for two meetings with the FDA, over a period of four months. The model was thoroughly characterized, determined to be low risk for the question of interest, and submitted along with additional clinical evidence for validation. The FDA found the simulation framework to be helpful in providing insights into the question of interest and provides reasonable glycemic outcome predictions. At the conclusion of the MIDD paired meetings, FDA personnel from the Center for Drug Evaluation and Research review team accepted the simulation and requested additional, traditional clinical evidence to support the proposed label change. In the post-meeting comments, the FDA invited MannKind to submit a proposal for a data package including the CM&S evidence in a Type C meeting for further discussion on the label change. This MIDD pilot experience suggests that CM&S is a credible method for evidence generation. Collaboration between sponsor organizations as well as all stakeholders in the FDA, including proponents of CM&S, can further support regulatory decision-making. The learnings from early participants will allow the program to reach its full potential and thereby ultimately benefit patients, sponsors, and FDA.

From islet of Langerhans transplantation to the bioartificial pancreas

Type 1 diabetes is a disease resulting from autoimmune destruction of the insulin-producing beta cells in the pancreas. When type 1 diabetes develops into severe secondary complications, in particular end-stage nephropathy, or life-threatening severe hypoglycemia, the best therapeutic approach is pancreas transplantation, or more recently transplantation of the pancreatic islets of Langerhans. Islet transplantation is a cell therapy procedure, that is minimally invasive and has a low morbidity, but does not display the same rate of functional success as the more invasive pancreas transplantation because of suboptimal engraftment and survival. Another issue is that pancreas or islet transplantation (collectively known as beta cell replacement therapy) is limited by the shortage of organ donors and by the need for lifelong immunosuppression to prevent immune rejection and recurrence of autoimmunity. A bioartificial pancreas is a construct made of functional, insulin-producing tissue, embedded in an anti-inflammatory, immunomodulatory microenvironment and encapsulated in a perm-selective membrane allowing glucose sensing and insulin release, but isolating from attacks by cells of the immune system. A successful bioartificial pancreas would address the issues of engraftment, survival and rejection. Inclusion of unlimited sources of insulin-producing cells, such as xenogeneic porcine islets or stem cell-derived beta cells would further solve the problem of organ shortage. This article reviews the current status of clinical islet transplantation, the strategies aiming at developing a bioartificial pancreas, the clinical trials conducted in the field and the perspectives for further progress.

Insulin edema after initiation of hybrid closed-loop insulin pump therapy with continuous glucose monitoring: a case report

BACKGROUND

Insulin edema is a rare complication which can present after initiation or intensification of insulin therapy in people with diabetes. Initiation of closed-loop hybrid insulin pump therapy can result in rapid improvement in glycemic control for people with diabetes. We present a case in which transition to a closed-loop hybrid insulin pump system, followed by significant improvement in glycemic control, led to development of insulin edema in a person with type 1 diabetes.

CASE PRESENTATION

We present a 51-year-old woman with type 1 diabetes of 16 years duration, on insulin pump therapy for more than 10 years, who presented for follow-up 7 weeks after transitioning to a hybrid closed-loop insulin pump system with continuous glucose monitoring (CGM). She complained of weight gain and bilateral lower extremity edema which had started two weeks after the change in pump modality. Laboratory studies and echocardiogram did not reveal any etiology of the acute edema. HbA1c was 3.3% lower than the previous measurement 15 weeks earlier, and there was a significant increase in the daily total insulin dose. With exclusion of other causes of acute edema, the patient was diagnosed with insulin edema and started on hydrochlorothiazide. On follow up, her lower extremity edema significantly improved although her weight did not return to baseline.

CONCLUSION

To our knowledge, this is the first case of insulin edema reported in a person with type 1 diabetes using CGM and a hybrid closed-loop insulin pump system. The increase in total daily insulin dose, rapid improvement of glycemic control, and lack of hypoglycemic episodes were important factors to consider in evaluation of this case. Use of hybrid closed-loop systems can help achieve rapid improvement in glycemic control in people with diabetes. This case suggests that consideration should be given to adjusting initial blood glucose targets when starting these remarkable new technologies in people with baseline poor glycemic control.

Vasodilatory effects of glucagon: A possible new approach to enhanced subcutaneous insulin absorption in artificial pancreas devices

Patients with diabetes mellitus type 1 depend on exogenous insulin to keep their blood glucose concentrations within the desired range. Subcutaneous bihormonal artificial pancreas devices that can measure glucose concentrations continuously and autonomously calculate and deliver insulin and glucagon infusions is a promising new treatment option for these patients. The slow absorption rate of insulin from subcutaneous tissue is perhaps the most important factor preventing the development of a fully automated artificial pancreas using subcutaneous insulin delivery. Subcutaneous insulin absorption is influenced by several factors, among which local subcutaneous blood flow is one of the most prominent. We have discovered that micro-doses of glucagon may cause a substantial increase in local subcutaneous blood flow. This paper discusses how the local vasodilative effects of micro-doses of glucagon might be utilised to improve the performance of subcutaneous bihormonal artificial pancreas devices. We map out the early stages of our hypothesis as a disruptive novel approach, where we propose to use glucagon as a vasodilator to accelerate the absorption of meal boluses of insulin, besides using it conventionally to treat hypoglycaemia.

Enabling faster subcutaneous delivery of larger volume, high viscosity fluids

OBJECTIVES

Many current subcutaneous (SC) biologic therapies may require >1 mL volume or have increased viscosity, necessitating new delivery system approaches. This study evaluated 2-mL large-volume autoinjector (LVAI) delivery performance across varying solution viscosities and design inputs to assess the design space and identify configurations that produce practical injection times.

METHODS

Investigational LVAI delivery duration and volume, depot location, and tissue effects were examined in both air and in vivo models across various pre-filled syringe (PFS) cannula types (27 G Ultra-thin wall [UTW], 27 G special thin wall [STW], or 29 G thin-wall [TW]), drive spring forces (SF_LOW or SF_HIGH), and Newtonian solutions (2.3-50 centipoise [cP]).

RESULTS

Within each design configuration, increasing PFS internal diameters and spring forces reduced delivery times, while increasing viscosity increased times. The 27 G UTW PFS/SF_HIGH combination achieved shorter delivery times across all injection conditions, with 2 mL in vivo durations <15 seconds at ≤31 cP and routinely <20 seconds at 39 and 51 cP, with nominal and transitory tissue effects.

CONCLUSION

PFS cannula and spring force combinations can be tailored to achieve various injection durations across viscosities, while UTW PFS enables faster rates to potentially better accommodate human factors during LVAI injection, especially at high viscosity.

Subcutaneous Catabolism of Peptide Therapeutics: Bioanalytical Approaches and ADME Considerations

Many peptide drugs such as insulin and glucagon-like peptide (GLP-1) analogues are successfully administered subcutaneously (SC). Following SC injection, peptides may undergo catabolism in the SC compartment before entering systemic circulation, which could compromise their bioavailability and in turn affect their efficacy.This review will discuss how both technology and strategy have evolved over the past years to further elucidate peptide SC catabolism.Modern bioanalytical technologies (particularly liquid chromatography-high-resolution mass spectrometry) and bioinformatics platforms for data mining has prompted the development of in silico, in vitro and in vivo tools for characterizing peptide SC catabolism to rapidly address proteolytic liabilities and, ultimately, guide the design of peptides with improved SC bioavailability.More predictive models able to recapitulate the interplay between SC catabolism and other factors driving SC absorption are highly desirable to improve in vitro/in vivo correlations.We envision the routine incorporation of in vitro and in vivo SC catabolism studies in ADME screening funnels to develop more effective peptide drugs for SC delivery.

Comparison of the Impact of Insulin Degludec U100 and Insulin Glargine U300 on Glycemic Variability and Oxidative Stress in Insulin-Naive Patients With Type 2 Diabetes Mellitus: Pilot Study for a Randomized Trial

Background

There is an ongoing discussion about possible differences between insulin degludec (IDeg-100) and glargine U300 (IGlar-300). There is little data and head-to-head comparison of IDeg-100 and IGlar-300 regarding their simultaneous impact on glycemic variability and oxidative stress in patients with type 2 diabetes mellitus (T2DM).

Objective

In our randomized, open-label, crossover study, we compared the impact of IDeg-100 and IGlar-300 on glycemic variability and oxidative stress in insulin-naive patients with T2DM.

Methods

We recruited a total of 25 adult patients with T2DM (7 females) whose diabetes was uncontrolled (HbA1c ≥7.5%) on two or more oral glucose-lowering drugs; a total of 22 completed the study. Mean age was 57.3 (SD 6.99) years and duration of diabetes was 9.94 (SD 5.01) years. After the washout period, they were randomized alternately to first receive either IDeg-100 or IGlar-300 along with metformin. Each insulin was administered for 12 weeks and then switched. At the beginning and end of each phase, biochemical and oxidative stress parameters were analyzed. On 3 consecutive days prior to each control point, patients performed a 7-point self-monitoring of blood glucose profile. Oxidative stress was assessed by measuring thiol groups and hydroperoxides (determination of reactive oxygen metabolites test) in serum.

Results

IGlar-300 reduced mean glucose by 0.02-0.13 mmol/L, and IDeg-100 reduced glucose by 0.10-0.16 mmol/L, with no significant difference. The reduction of the coefficient of glucose variation also did not show a statistically significant difference. IGlar-300 increased thiols by 0.08 µmol/L and IDeg-100 increased thiols by 0.15 µmol/L, with no significant difference (P=.07) between them. IGlar-300 reduced hydroperoxides by 0.040 CARR U and IDeg-100 increased hydroperoxides by 0.034 CARR U, but the difference was not significant (P=.12).

Conclusions

The results of our study do not show a significant difference regarding glycemic variability between patients receiving either insulin IDeg-100 or IGlar-300, although IGlar-300 showed greater dispersion of data. No significant difference in oxidative stress was observed. In a larger study, doses of insulins should be higher to achieve significant impact on glycemic parameters and consequently on glycemic variability and oxidative stress.

Trial Registration

ClinicalTrials.gov, NCT04692415; https://clinicaltrials.gov/ct2/show/NCT04692415

A Comprehensive Review of the Evolution of Insulin Development and Its Delivery Method

The year 2021 marks the 100th anniversary of the momentous discovery of insulin. Through years of research and discovery, insulin has evolved from poorly defined crude extracts of animal pancreas to recombinant human insulin and analogues that can be prescribed and administered with high accuracy and efficacy. However, there are still many challenges ahead in clinical settings, particularly with respect to maintaining optimal glycemic control whilst minimizing the treatment-related side effects of hypoglycemia and weight gain. In this review, the chronology of the development of rapid-acting, short-acting, intermediate-acting, and long-acting insulin analogues, as well as mixtures and concentrated formulations that offer the potential to meet this challenge, are summarized. In addition, we also summarize the latest advancements in insulin delivery methods, along with advancement to clinical trials. This review provides insights on the development of insulin treatment for diabetes mellitus that may be useful for clinicians in meeting the needs of their individual patients. However, it is important to note that as of now, none of the new technologies mentioned have superseded the existing method of subcutaneous administration of insulin.

Hyperinsulinemia: beneficial or harmful or both on glucose homeostasis

Insulin, a principal anabolic hormone produced by pancreatic β-cells, has a primary function of storage of nutrients following excessive energy intake. Pre- or early type 2 diabetes stages present hyperinsulinemia (β-cell dysfunction) and insulin resistance. Initiation of hyperinsulinemia is triggered by a loss of first-phase glucose-stimulated insulin secretion with altered membrane ion channel distribution. More factors, including insulin resistance and excessive proliferation of β-cells, deteriorate the hyperinsulinemia, whereas the hyperinsulinemia contributes to further development of insulin resistance and type 2 diabetes; to develop eventually late-stage diabetes with absolute insulin deficiency. In this mini-review, the major focus was put on the causes and pathophysiology of hyperinsulinemia, and the metabolic consequences and current treatment of hyperinsulinemia were discussed. The data used in this narrative review were collected mainly from relevant discoveries in the past 3 years.

Unconventional insulins from predators and pathogens

Insulin and its related peptides are found throughout the animal kingdom, in which they serve diverse functions. This includes regulation of glucose homeostasis, neuronal development and cognition. The surprising recent discovery that venomous snails evolved specialized insulins to capture fish demonstrated the nefarious use of this hormone in nature. Because of their streamlined role in predation, these repurposed insulins exhibit unique characteristics that have unraveled new aspects of the chemical ecology and structural biology of this important hormone. Recently, insulins were also reported in other venomous predators and pathogenic viruses, demonstrating the broader use of insulin by one organism to manipulate the physiology of another. In this Review, we provide an overview of the discovery and biomedical application of repurposed insulins and other hormones found in nature and highlight several unique insights gained from these unusual compounds.

Feasibility study of a prototype extended-wear insulin infusion set in adults with type 1 diabetes

AIM

To assess the feasibility of a prototype insulin infusion set (IIS) for extended wear in adults with type 1 diabetes.

MATERIALS AND METHODS

The prototype Capillary Biomedical investigational extended-wear IIS (CBX IIS) incorporates a soft, flexible, reinforced kink-resistant angled nylon-derivative cannula with one distal and three proximal ports to optimize insulin delivery. Twenty adult participants with type 1 diabetes established on insulin pump therapy used the CBX IIS for two 7-day test periods while wearing a Dexcom G5 continuous glucose monitor.

RESULTS

Participants were able to wear the CBX IIS for an average of 6.6 ± 1.4 days. Eighty-eight percent (36 of 41) of sets were worn for 7 days. No serious adverse events were reported. Five infusion sets failed prematurely because of: unresolvable hyperglycaemia (three); hyperglycaemia with elevated ketones (one); or infection (one). Median time in range (3.9-10.0 mmol/L) was 62% (54-76). Average glucose levels per day of infusion set wear showed a statistically significant increase over time (p < .001).

CONCLUSIONS

Our preliminary observations confirm the tolerability of the prototype CBX IIS for extended wear, albeit with a deterioration in glucose control after the third day.

J. Schreiber L, Wallace EJ, Wylie R, O'Sullivan J, Dolan EB, Duffy GP. Medical devices, smart drug delivery, wearables and technology for the treatment of Diabetes Mellitus

Diabetes mellitus refers to a group of metabolic disorders which affect how the body uses glucose impacting approximately 9% of the population worldwide. This review covers the most recent technological advances envisioned to control and/or reverse Type 1 diabetes mellitus (T1DM), many of which will also prove effective in treating the other forms of diabetes mellitus. Current standard therapy for T1DM involves multiple daily glucose measurements and insulin injections. Advances in glucose monitors, hormone delivery systems, and control algorithms generate more autonomous and personalised treatments through hybrid and fully automated closed-loop systems, which significantly reduce hypo- and hyperglycaemic episodes and their subsequent complications. Bi-hormonal systems that co-deliver glucagon or amylin with insulin aim to reduce hypoglycaemic events or increase time spent in target glycaemic range, respectively. Stimuli responsive materials for the controlled delivery of insulin or glucagon are a promising alternative to glucose monitors and insulin pumps. By their self-regulated mechanism, these "smart" drugs modulate their potency, pharmacokinetics and dosing depending on patients' glucose levels. Islet transplantation is a potential cure for T1DM as it restores endogenous insulin and glucagon production, but its use is not yet widespread due to limited islet sources and risks of chronic immunosuppression. New encapsulation strategies that promote angiogenesis and oxygen delivery while protecting islets from recipients' immune response may overcome current limiting factors.

Evaluation of Outcomes Following Hospital-Wide Implementation of a Subcutaneous Insulin Protocol for Diabetic Ketoacidosis

IMPORTANCE

Standard diabetic ketoacidosis care in the US includes intravenous insulin treatment in the intensive care unit. Subcutaneous (SQ) insulin could decrease intensive care unit need, but the data are limited.

OBJECTIVE

To assess outcomes after implementation of an SQ insulin protocol for treating diabetic ketoacidosis.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study is a retrospective evaluation of a prospectively implemented SQ insulin protocol. The study was conducted at an integrated health care system in Northern California. Participants included hospitalized patients with diabetic ketoacidosis at 21 hospitals between January 1, 2010, and December 31, 2019. The preimplementation phase was 2010 to 2015, and the postimplementation phase was 2017 to 2019. Data analysis was performed from October 2020 to January 2022.

EXPOSURE

An SQ insulin treatment protocol for diabetic ketoacidosis.

MAIN OUTCOMES AND MEASURES

Difference-in-differences evaluation of the need for intensive care, mortality, readmission, and length of stay at a single intervention site using an SQ insulin protocol from 2017 onward compared with 20 control hospitals using standard care.

RESULTS

A total of 7989 hospitalizations for diabetic ketoacidosis occurred, with 4739 (59.3%) occurring before and 3250 (40.7%) occurring after implementation. The overall mean (SD) age was 42.3 (17.7) years, with 4137 hospitalizations (51.8%) occurring among female patients. Before implementation, SQ insulin was the first insulin used in 40 intervention (13.4%) and 651 control (14.7%) hospitalizations. After implementation, 98 hospitalizations (80.3%) received SQ insulin first at the intervention site compared with 402 hospitalizations (12.8%) at control sites. The adjusted rate ratio for intensive care unit admission was 0.43 (95% CI, 0.33-0.56) at the intervention sites, a 57% reduction compared with control sites, and was 0.50 (95% CI, 0.25-0.99) for 30-day hospital readmission, a 50% reduction. There were no significant changes in hospital length of stay and rates of death.

CONCLUSIONS AND RELEVANCE

These findings suggest that a protocol based on SQ insulin for diabetic ketoacidosis treatment was associated with significant decreases in intensive care unit need and readmission, with no evidence of increases in adverse events.

Effective Overall Glycaemic Control with Fast-Acting Insulin Aspart Across Patients with Different Baseline Characteristics: A Post Hoc Analysis of the Onset 9 Trial

AIMS

To investigate the efficacy and safety of fast-acting insulin aspart (faster aspart) compared with insulin aspart (IAsp) in participants with type 2 diabetes (T2D) across different subgroups.

METHODS

We report on a post hoc analysis of onset 9, a 16-week trial of participants with T2D randomised to faster aspart (n = 546) or IAsp (n = 545). Participants were grouped by baseline HbA1c (< 7.0%, ≥ 7.0%), meal test bolus insulin dose (≤ 10 units [U], > 10 U to ≤ 20 U, > 20 U), body mass index (< 30 kg/m², ≥ 30 to < 35 kg/m², ≥ 35 kg/m²), and age (< 65 years, ≥ 65 years). Outcomes assessed were change from baseline in HbA1c and in 1-h postprandial glucose (PPG) increment, and severe or blood glucose (BG)-confirmed hypoglycaemia.

RESULTS

Faster aspart provided reductions in HbA1c comparable to IAsp across all subgroups, with improved 1-h PPG control compared with IAsp in several subgroups. Faster aspart had comparable or improved rates of severe or BG-confirmed hypoglycaemia versus IAsp, particularly in participants with good glycaemic control (HbA1c < 7.0%), the elderly (≥ 65 years old), and those with insulin resistance (> 20 U meal test bolus insulin dose).

CONCLUSIONS

Faster aspart provides effective overall glycaemic control, with improved early PPG control compared with IAsp across a range of patient characteristics.

CLINICAL TRIAL REGISTRATION

NCT03268005.

Symmetric and asymmetric receptor conformation continuum induced by a new insulin

Cone snail venoms contain a wide variety of bioactive peptides, including insulin-like molecules with distinct structural features, binding modes and biochemical properties. Here, we report an active humanized cone snail venom insulin with an elongated A chain and a truncated B chain, and use cryo-electron microscopy (cryo-EM) and protein engineering to elucidate its interactions with the human insulin receptor (IR) ectodomain. We reveal how an extended A chain can compensate for deletion of B-chain residues, which are essential for activity of human insulin but also compromise therapeutic utility by delaying dissolution from the site of subcutaneous injection. This finding suggests approaches to developing improved therapeutic insulins. Curiously, the receptor displays a continuum of conformations from the symmetric state to a highly asymmetric low-abundance structure that displays coordination of a single humanized venom insulin using elements from both of the previously characterized site 1 and site 2 interactions.