Insulin Formulations Research Articles

Insulin Stabilization Designs for Enhanced Therapeutic Efficacy and Accessibility.

ConspectusInsulin has remained indispensable in the treatment of diabetes since it was first discovered in 1921. Unlike small molecular drugs, insulin and other protein drugs are prone to degradation when exposed to elevated temperatures, mechanical agitation during transportation, and prolonged storage periods. Therefore, strict cold-chain management is crucial for the insulin supply, requiring significant resources, which can limit the access to insulin, particularly in low-income areas. Moreover, although insulin formulations have advanced tremendously in the last century, insulin treatment still imposes a challenging regimen and provides suboptimal outcomes for the majority of patients. There is an increasing focus on pursuing improved pharmacology, specifically on safer, more user-friendly insulin therapies that minimize the self-management burden. These challenges underscore the need for developing novel insulin formulations with improved stability that are compatible with advanced insulin therapy.Insulin stabilization can be achieved through either chemical modification of insulin or formulation component design. Inspired by insulin-like peptides from invertebrates, we have developed novel stable insulin analogs based on a fundamental understanding of the insulin receptor engagement for insulin bioactivity. We created a novel four-disulfide insulin analog with high aggregation stability and potency by introducing a fourth disulfide bond between a C-terminal extended insulin A-chain and residues near the C-terminus of the B-chain. In an effort to stabilize insulin in its monomeric state to develop ultrafast-acting insulin with rapid absorption upon injection, we have developed a series of structurally miniaturized yet fully active insulin analogs that do not form dimers due to the lack of the canonical B-chain C-terminal octapeptide. Additionally, our study provided strategies for expanding the scope of cucurbit[7]uril (CB[7])-assisted insulin stabilization by engineering safe and biodegradable CB[7]-zwitterionic polypeptide excipients. We also explored insulin N-terminal substitution methods to achieve pH-dependent insulin stabilization without prolonging the duration of action.This Account describes our exploration of engineering stable insulin analogs and formulation design strategies for stabilizing insulin in aqueous solutions. Beyond conventional stabilization strategies for insulin injections, the unmet challenges and recent innovations in insulin stabilization are discussed, addressing the growing demand for alternative, less invasive routes of insulin administration. Additionally, we aim to provide a thorough overview of insulin stabilization from the perspective of commercially available insulin drugs and common pharmaceutical engineering practices in the industry. We also highlight unresolved insulin stabilization challenges and ongoing research strategies. We anticipate that further emphasis on collective efforts of protein engineering, pharmaceutical formulation design, and drug delivery will inform the development of stable and advanced insulin therapy.

Microneedling With Topical Insulin Versus Microneedling With Placebo in the Treatment of Postacne Atrophic Scars: A Randomized Control Trial.

Among the treatment modalities for post-acne scars, microneedling is considered a safe and effective method. To compare the efficacy and safety of combined microneedling with topical insulin versus microneedling with placebo (topical saline) in treating atrophic acne scars. Twenty-one patients with atrophic post-acne scars were randomized and treated in a split face manner with 4 sessions at 3-week intervals of microneedling using dermapen, followed by application of insulin on one side of the face and saline (placebo) on the other side. Evaluation of response was done before the sessions and after 1 month of the last session using the Global Scarring Grading System of Goodman & Baron and Lipper & Perez scores, Patient reported acne scar improvement using a 4-point scale, patient satisfaction, and the facial acne scar quality of life tools. Both therapeutic modalities yielded a statistically significant improvement of atrophic acne scars. By comparing both modalities, there was no statistical significance regarding clinical improvement and side effects. Using topical insulin combined with microneedling may have a value in improving atrophic acne scars, suggesting further evaluation using different delivery systems, insulin formulations, and assessment modalities.

Exploring the “New World”: weekly basal insulins

therapeutic option today, especially in specific clinical conditions, even in type 2 diabetes. Our country is approaching a new era in the history of insulin. We are indeed close to the availability of the first weekly basal insulin formulations. The AMD annals present a unique chance to evaluate the evolution of pharmacological therapies for diabetes in recent years. The AMD annals confirm that in 2023 still more than 32% of the population with type 2 diabetes in Italy was treated with insulin, and more than 97% of subjects were treated with basal insulin. The appropriate prescription of insulin is hindered by numerous obstacles, resulting in therapeutic inertia. Among these, the non-acceptance of daily injection therapy and the difficulty in adherence justify the rationale for developing weekly basal insulin Among the weekly basal insulins in development, icodec and efsitora are the closest to being introduced into our clinical practice. The development of new biotechnological approaches has resulted in the development of insulins with a half-life of 8 and 17 days for icodec and efsitora, respectively. Icodec and efsitora, in the QWINT and ONWARDS phase 3 programs, have been shown to be effective in achieving primary and secondary efficacy endpoints. The two weekly basal insulins have shown that in the context of an oral basal regimen for people with type 2 diabetes, the risk of hypoglycemia is not different from that of daily basal insulins In studies in type 1 diabetes and in people with type 2 diabetes on basal bolus insulin therapy, the risk of hypoglycemia was found to be higher for new weekly basal insulins than for daily basal insulins, bringing up the need for more research and possibly a different prescribing approach for basal weekly insulins in this population. The reduction in the number of injections results in patients being more satisfied with the treatment, this could result in a significant improvement in quality of life and an increase in acceptance and adherence to prescribed treatment, and finally, it responds to the urgent need to counter therapeutic inertia in the care of people with diabetes.

Pioneering Oral Insulin Formulations and Delivery Techniques: A Review

The development of oral insulin presents significant promise for diabetes treatment, mitigating peripheral hyperinsulinemia, weight gain, and hypoglycemia while enhancing patient convenience and facilitating rapid insulinization of the liver. Effective oral insulin products are crucial for early intensive insulin therapy, which ensures tight glycaemic control and delays diabetes complications. However, despite the need, oral insulin has faced many challenges, and past technologies have had limited success. Repeated insulin injections can result in local hypertrophy over time generating attention to user-friendly oral insulin delivery systems that are not invasive to the body and copy the natural pathway. This review article examines New methods for oral insulin delivery that have shown promise, using techniques like complexation, hydrogels, and nanoparticles to boost effectiveness, though they still trail injectable insulin. Further studies will help determine how well oral insulin works at various doses and inform the development of competing formulations.

Improved Glycemic Control using Oral Semaglutide in a Patient with Type 2 Diabetes with Insulin Allergy

AbstractWe present a unique clinical scenario of a patient with type 2 diabetes mellitus (T2DM) who exhibited an allergic reaction to all forms of insulin. The patient had previously maintained good glycemic control with maximum-dose metformin. However, her glycemic control deteriorated once she became pregnant. Trials with various types of insulin resulted in allergic reactions, but this was managed successfully using insulin pump therapy, which was discontinued postpartum. Upon reassessment, her HbA1c had deteriorated to 80 mmol/mol. After re-attempting various insulin formulations without success, she was trialed again using the closed-loop Omnipod system. Initial management with the closed-loop system failed to achieve optimal glycemic control. Therefore, oral semaglutide was added. The introduction of oral semaglutide to her treatment regimen led to a significant improvement in her glycemic status. This report compares the patient's glycemic control while on the closed-loop Omnipod system alone versus in combination with oral semaglutide. The findings suggest that oral semaglutide, in conjunction with a closed-loop system, may offer a viable alternative for patients with insulin-dependent type 2 diabetes who cannot tolerate insulin.

Insulin-Loaded Chitosan-Cellulose-Derivative Hydrogels: In Vitro Permeation of Hormone through Strat-M® Membrane and Rheological and Textural Analysis.

This work is part of the current research trend to develop a hydrogel carrier of insulin to promote wound healing. Topically applied insulin promotes keratinocyte proliferation and migration, increases collagen synthesis, reduces inflammation and oxidative stress, and exhibits antimicrobial activity. The aim of this study was to design an insulin hydrogel matrix based on selected cellulose derivatives (methylcellulose, hydroxyethylcellulose, and hydroxypropylmethylcellulose) and chitosan. Rheological parameters of the formulations were evaluated using rotational rheometry and an oscillation test. Textural tests were performed. In vitro pharmaceutical insulin availability studies were carried out using the innovative Strat-M® membrane to imitate the skin barrier. It was found that the pharmaceutical formulation of insulin based on chitosan and methylcellulose showed an acceptable balance between rheological and textural parameters and ease of application. The API was released from the carrier in a prolonged manner, eliminating the need to apply the formulation several times per day. The developed hydrogel shows potential for use in clinical practice.

An orally administered glucose-responsive polymeric complex for high-efficiency and safe delivery of insulin in mice and pigs.

Contrary to current insulin formulations, endogenous insulin has direct access to the portal vein, regulating glucose metabolism in the liver with minimal hypoglycaemia. Here we report the synthesis of an amphiphilic diblock copolymer comprising a glucose-responsive positively charged segment and polycarboxybetaine. The mixing of this polymer with insulin facilitates the formation of worm-like micelles, achieving highly efficient absorption by the gastrointestinal tract and the creation of a glucose-responsive reservoir in the liver. Under hyperglycaemic conditions, the polymer triggers a rapid release of insulin, establishing a portal-to-peripheral insulin gradient-similarly to endogenous insulin-for the safe regulation of blood glucose. This insulin formulation exhibits a dose-dependent blood-glucose-regulating effect in a streptozotocin-induced mouse model of type 1 diabetes and controls the blood glucose at normoglycaemia for one day in non-obese diabetic mice. In addition, the formulation demonstrates a blood-glucose-lowering effect for one day in a pig model of type 1 diabetes without observable hypoglycaemia, showing promise for the safe and effective management of type 1 diabetes.

COMPARATIVE ANALYSIS OF INSULIN VARIETIES IN THE MANAGEMENT OF OBESITY: A COMPREHENSIVE SYSTEMATIC REVIEW

Obesity remains a critical global health issue, closely intertwined with metabolic conditions such as type 2 diabetes. The prevalence of obesity continues to surge, and the need for effective strategies to manage both obesity and its associated comorbidities has become increasingly pressing. Traditionally, insulin therapy has been associated with weight gain, posing additional challenges for obese individuals with diabetes. However, recent advancements in insulin formulations, particularly GLP-1 receptor agonists and amylin agonists, have opened new pathways for dual managing obesity and glycemic control. This systematic review examines the relationship between insulin formulations and obesity control, focusing on injectable medications such as Victoza®, Saxenda®, Ozempic®, and Mounjaro®. These drugs belong to the GLP-1 receptor agonist class and have shown significant promise in promoting weight loss, enhancing glycemic control, and managing obesity-related comorbidities. Additionally, the overall effectiveness of these treatments is incorporated in a meta-analysis of relevant clinical trials in the management of obesity.

Advances in Nanomedicine for Precision Insulin Delivery.

Diabetes mellitus, which comprises a group of metabolic disorders affecting carbohydrate metabolism, is characterized by improper glucose utilization and excessive production, leading to hyperglycemia. The global prevalence of diabetes is rising, with projections indicating it will affect 783.2 million people by 2045. Insulin treatment is crucial, especially for type 1 diabetes, due to the lack of β-cell function. Intensive insulin therapy, involving multiple daily injections or continuous subcutaneous insulin infusion, has proven effective in reducing microvascular complications but poses a higher risk of severe hypoglycemia. Recent advancements in insulin formulations and delivery methods, such as ultra-rapid-acting analogs and inhaled insulin, offer potential benefits in terms of reducing hypoglycemia and improving glycemic control. However, the traditional subcutaneous injection method has drawbacks, including patient compliance issues and associated complications. Nanomedicine presents innovative solutions to these challenges, offering promising avenues for overcoming current drug limitations, enhancing cellular uptake, and improving pharmacokinetics and pharmacodynamics. Various nanocarriers, including liposomes, chitosan, and PLGA, provide protection against enzymatic degradation, improving drug stability and controlled release. These nanocarriers offer unique advantages, ranging from enhanced bioavailability and sustained release to specific targeting capabilities. While oral insulin delivery is being explored for better patient adherence and cost-effectiveness, other nanomedicine-based methods also show promise in improving delivery efficiency and patient outcomes. Safety concerns, including potential toxicity and immunogenicity issues, must be addressed, with the FDA providing guidance for the safe development of nanotechnology-based products. Future directions in nanomedicine will focus on creating next-generation nanocarriers with precise targeting, real-time monitoring, and stimuli-responsive features to optimize diabetes treatment outcomes and patient safety. This review delves into the current state of nanomedicine for insulin delivery, examining various types of nanocarriers and their mechanisms of action, and discussing the challenges and future directions in developing safe and effective nanomedicine-based therapies for diabetes management.

The complications of long time treatment of insulin therapy in type-2 diabetes patients: A Review

Diabetes is a chronic metabolic disease characterized by elevated blood sugar levels. It can also mean long-term problems with the metabolism of carbohydrates caused by insulin deficiency, which leads to hyperglycemia and glycosuria. Weight gain is a common side effect of insulin therapy and other oral antidiabetic medications for diabetic patients, which can hinder their ability to meet strict glycemic targets and potentially reduce treatment success. Insulin-related weight gain is attributed to anabolic effects, appetite increases, and reduced glycosuria. Insulin therapy has been linked to increased cardiovascular risk and mortality in type 2 diabetes patients, as well as inflammation, atherosclerosis, hypertension, dyslipidemia, heart failure, and arrhythmias. Large-scale evaluations suggest that insulin therapy has a poorer short- and long-term safety profile than other anti-T2D therapies. To treat diabetes, a variety of insulin formulations are available, each acting at a distinct pace. Whether they are long-acting, intermediate-acting, or rapid-acting, there are similar adverse effects to be mindful of. Weight gain, injection site responses, and hypoglycemia (low blood glucose) are common side effects of insulin. Lipodystrophy, or improper fat distribution, and limb edema are uncommon adverse effects of insulin. When it comes to insulin introduction, titration, and follow-up treatment, doctors can manage patients with type 2 diabetes mellitus more effectively by employing simple algorithms. Primary care doctors and other medical professionals can manage patients with type 2 diabetes mellitus more easily by using streamlined insulin introduction and titration protocols.

Insulin amyloid fibril formation reduction by tripeptide stereoisomers.

Insulin fibrillation is a problem for diabetic patients that can occur during storage and transport, as well as at the subcutaneous injection site, with loss of bioactivity, inflammation, and various adverse effects. Tripeptides are ideal additives to stabilise insulin formulations, thanks to their low cost of production and inherent cytocompatibility. In this work, we analysed the ability of eight tripeptide stereoisomers to inhibit the fibrillation of human insulin in vitro. The sequences contain proline as β-breaker and Phe-Phe as binding motif for the amyloid-prone aromatic triplet found in insulin. Experimental data based on spectroscopy, fluorescence, microscopy, and calorimetric techniques reveal that one stereoisomer is a more effective inhibitor than the others, and cell live/dead assays confirmed its high cytocompatibility. Importantly, in silico data revealed the key regions of insulin engaged in the interaction with this tripeptide, rationalising the molecular mechanism behind insulin fibril formation reduction.

A dose titration protocol for once-daily insulin glargine 300 U/mL for the treatment of diabetes mellitus in dogs.

In purpose-bred dogs, insulin glargine 300 U/mL (IGla300) has long duration of action, peakless time-action profile, and low potency, making it suitable for use as a basal insulin. To evaluate IGla300 in client-owned diabetic dogs monitored using a flash glucose monitoring system (FGMS). Ninety-five client-owned diabetic dogs, newly diagnosed or previously treated with other insulin formulations, with or without concurrent diseases. Prospective multi-institutional study. Clinical signs and standardized assessment of FGMS data, using treatment and monitoring guidelines established a priori, guided dose adjustments and categorization into levels of glycemic control. The initial IGla300 dose was 0.5 U/Kg q24h for newly diagnosed dogs and (median dose [range]) 0.8 U/Kg (0.2-2.5) q24h for all dogs. Glycemic control was classified as good or excellent in 87/95 (92%) dogs. The IGla300 was administered q24h (1.9 U/kg [0.2-5.2]) and q12h (1.9 U/kg/day [0.6-5.0]) in 56/95 (59%) and 39/95 (41%) dogs, respectively. Meal-time bolus injections were added in 5 dogs (0.5 U/kg/injection [0.3-1.0]). Clinical hypoglycemia occurred in 6/95 (6%) dogs. Dogs without concurrent diseases were more likely to receive IGla300 q24h than dogs with concurrent diseases (72% vs 50%, respectively; P = .04). Insulin glargine 300 U/mL can be considered a suitable therapeutic option for once-daily administration in diabetic dogs. Clinicians should be aware of the low potency and wide dose range of IGla300. In some dogs, twice-daily administration with or without meal-time bolus injections may be necessary to achieve glycemic control. Monitoring with FGMS is essential for dose titration of IGla300.

Muco-Adhesive and Muco-Penetrative Formulations for the Oral Delivery of Insulin.

Insulin, a pivotal anabolic hormone, regulates glucose homeostasis by facilitating the conversion of blood glucose to energy or storage. Dysfunction in insulin activity, often associated with pancreatic β cells impairment, leads to hyperglycemia, a hallmark of diabetes. Type 1 diabetes (T1D) results from autoimmune destruction of β cells, while type 2 diabetes (T2D) stems from genetic, environmental, and lifestyle factors causing β cell dysfunction and insulin resistance. Currently, insulin therapy is used for most of the cases of T1D, while it is used only in a few persistent cases of T2D, often supplemented with dietary and lifestyle changes. The key challenge in oral insulin delivery lies in overcoming gastrointestinal (GI) barriers, including enzymatic degradation, low permeability, food interactions, low bioavailability, and long-term safety concerns. The muco-adhesive (MA) and muco-penetrative (MP) formulations aim to enhance oral insulin delivery by addressing these challenges. The mucus layer, a hydrogel matrix covering epithelial cells in the GI tract, poses significant barriers to oral insulin absorption. Its structure, composition, and turnover rate influence interactions with insulin and other drug carriers. Some of the few factors that influence mucoadhesion and mucopenetration are particle size, surface charge distribution, and surface modifications. This review discusses the challenges associated with oral insulin delivery, explores the properties of mucus, and evaluates the strategies for achieving excellent MA and MP formulations, focusing on nanotechnology-based approaches. The development of effective oral insulin formulations holds the potential to revolutionize diabetes management, providing patients with a more convenient and patient-friendly alternative to traditional insulin administration methods.

Insulin therapy in type 2 diabetes: Insights into clinical efficacy, patient-reported outcomes, and adherence challenges.

Insulin therapy plays a crucial role in the management of type 2 diabetes as the disease progresses. Over the past century, insulin formulations have undergone significant modifications and bioengineering, resulting in a diverse range of available insulin products. These products show distinct pharmacokinetic and pharmacodynamic profiles. Consequently, various insulin regimens have em-erged for the management of type 2 diabetes, including premixed formulations and combinations of basal and bolus insulins. The utilization of different insulin regimens yields disparate clinical outcomes, adverse events, and, notably, patient-reported outcomes (PROs). PROs provide valuable insights from the patient's perspective, serving as a valuable mine of information for enhancing healthcare and informing clinical decisions. Adherence to insulin therapy, a critical patient-reported outcome, significantly affects clinical outcomes and is influenced by multiple factors. This review provides insights into the clinical effectiveness of various insulin preparations, PROs, and factors impacting insulin therapy adherence, with the aim of enhancing healthcare practices and informing clinical decisions for individuals with type 2 diabetes.

Natural lipopeptide surfactin inhibits insulin aggregation and prevents amyloid-induced cytotoxicity and inflammation

Despite the centennial of the pioneering discovery of insulin, challenges regarding insulin aggregation at the site of repeated injection, as well as during industrial production, storage, and transportation, have cast a gloom over this remarkable success story. Aggregation substantially impacts the quality, potency, and effectiveness of insulin formulation, decreasing bioavailability, intensifying the risk of immunogenicity, and endangering patient health. Herein, the suitability of Bacillus-derived amphiphilic biosurfactant surfactin was demonstrated to evade temperature-induced fibrillation of insulin. Fluorometric assessment employing thioflavin-T and intrinsic tyrosine fluorescence indicated the dose-dependent reduction in insulin unfolding and subsequent formation of fibrils. Decreased thioflavin fluorescence at the plateau stage and about a 79% increase in fibrillation lag time was observed for samples containing an equimolar ratio of insulin to surfactin. Circular dichroism analysis further indicated about a 30% increase in α-helix content in samples containing an equimolar ratio of insulin and surfactin, as compared to controls. The findings were further bolstered by dynamic light scattering, electron microscopic analysis, and native polyacrylamide gel electrophoresis. Molecular docking and simulation studies did not indicate any structural destabilization of insulin with surfactin, having major interactions at the hydrophobic and potential amyloidogenic regions of insulin B-chain: B12-B19 (VEALYLVC) and B23-B27 (GFFYT) through hydrophobic and hydrogen bonds. Notably, an almost 22% increase in cell viability was observed for cells incubated with aggregated insulin containing equimolar concentrations of SFN. Surfactin also subdued insulin amyloid-induced upregulation of the pro-inflammatory genes. Thus, surfactin may be contemplated as an additive in biopharmaceutical formulations to imbue stability and may also be evaluated as anti-amyloid therapeutics for other pathological proteinopathies.

Frequency of hypoglycaemia with basal insulin treatments in adults with type 1 diabetes treated with basal-bolus insulin regimens in treat-to-target trials: A narrative review.

To summarise, in a narrative review, published data on hypoglycaemia occurrence with basal insulin therapy in adults with type 1 diabetes treated with basal-bolus insulin regimens in treat-to-target randomised controlled trials. Data were included from 21 eligible trials, which mainly used self-measured blood glucose or plasma glucose to detect hypoglycaemia. All-day self-measured blood glucose or plasma glucose level 2 (glucose threshold of 3.1 or 3.0 mmol/L) and level 3 (severe, requiring assistance) hypoglycaemic events were reported, respectively, by a range of 69.0%-97.5% and 0%-13.4% adults when receiving basal-bolus insulin therapy, with rates of 10.6-68.1 and 0.0-0.4 events per patient-year of exposure, respectively. Hypoglycaemia rates measured using continuous glucose monitoring (three studies) were numerically, yet consistently, higher than with either other method, except when limiting to symptomatic events. Nocturnal hypoglycaemia rates were generally less than 30% of the equivalent all-day rates. Differences across the studies in design (e.g., titration targets) and participant characteristics hindered comparison of hypoglycaemia rates by insulin formulation. Consequently, few trends were identified by insulin formulation, study methodology or individuals' characteristics, suggesting that further research is required to identify treatment strategies that facilitate development of individualised recommendations to lower hypoglycaemia risk. These findings are useful to understand hypoglycaemia risk with available basal insulin therapies when used in a multiple daily injection regimen, as well as to provide context for the results of ongoing and future clinical trials, including those for two once-weekly basal insulins, insulin icodec and basal insulin Fc.

Glycaemic outcomes in hospital with IDegAsp versus BIAsp30 premixed insulins.

IDegAsp (Ryzodeg70/30), a unique premixed formulation of long-acting insulin degludec and rapid-acting insulin aspart, is increasing in use. Management of IDegAsp during hospitalisation is challenging because of degludec's ultra-long duration of action. We investigated inpatient glycaemia in patients treated with IDegAsp compared to biphasic insulin aspart (BIAsp30; Novomix30). We performed a retrospective observational study at two hospitals assessing inpatients with type 2 diabetes treated with IDegAsp or BIAsp30 prior to and during hospital admission. Standard inpatient glycaemic outcomes were analysed based on capillary blood glucose (BG) measurements. We assessed 88 individuals treated with IDegAsp and 88 HbA1c-matched individuals treated with BIAsp30. Patient characteristics, including insulin dose at admission, were well matched, but the IDegAsp group had less frequent twice-daily insulin dosing than the BIAsp30 group (49% vs 87%, P < 0.001). Patient-days with BG <4 mmol/L were not different (10.6% vs 9.9%, P = 0.7); however, the IDegAsp group had a higher patient-day mean BG (10.4 (SD 3.4) vs 10.0 (3.4) mmol/L, P < 0.001), and more patient-days with mean BG >10 mmol/L (48% vs 38%, P < 0.001) compared to the BIAsp30 group. Glucose was higher in the IDegAsp group in the evening (4 PM to midnight) (11.6 (SD 4.0) vs 10.9 (4.6) mmol/L, P = 0.004), but not different at other times during the day. Inpatients treated with IDegAsp compared to BIAsp30 had similar hypoglycaemia incidence, but higher hyperglycaemia incidence, potentially related to less frequent twice-daily dosing. With the increasing use of IDegAsp in the community, development of hospital management guidelines for this insulin formulation is needed.

Insulin Analogs and the Mode of Insulin Delivery: Recent Advances and Challenges.

Diabetes is a medical condition associated with impaired glucose regulation caused either due to insufficient insulin production or resistance to insulin (Type 2 diabetes, gestational diabetes) or the absence of insulin through the selective killing of beta cells in the pancreas (Type 1 diabetes). Irregular insulin production leads to various health complications. To prevent such complications, patients must adhere to medical recommendations before availing of any advanced insulin therapy(ies), considered productive for the treatment. Natural insulin, although highly effective in controlling blood glucose levels, patients are often at risk of developing hypoglycemia and many other complications. This has led to the development of insulin analogs, the modified variants of natural insulin having a minimal risk of causing hypoglycemia. Besides the development of analogs, the mode of insulin delivery is also considered critical in achieving better glycemic control in diabetic patients. Until recently, various exogenous insulin delivery methods were practiced, but effective glycemic control without any associated risk and ease of delivery remains a subject of paramount concern. It countered attenuation or delayed onset of diabetes-associated complications without a permanent cure, raising an unmet demand for insulin formulations and delivery methods that offer stability, biocompatibility, reproducibility, precision dosing, non-immunogenicity, and safety. The current practice utilizes non-physiological delivery methods with less invasive administration routes, offering glycemic stability and therapeutic effectiveness. This review focuses on the recent advances made and future perspectives envisioned about newer insulin therapies and delivery methods that tend to improve the management of diabetes by inculcating ideas to reduce the disease's severity and improve the quality of life.

Less is more: Validating a single method for comprehensive rh-insulin analysis

The objective of this current study is to establish a single method for potency and related proteins analysis of human insulin formulations using reverse-phase high performance liquid (RP-HPLC) chromatography technique which was validated and verified for the potency analysis in insulin formulations. Chromatographic separation was achieved using an octadecylsilane (C-18) stationary phase and a mobile phase composed of 55% (v/v) buffer (0.2 M sodium sulfate in water, {pH 2.3}) and 45% (v/v) acetonitrile. Detection was performed by UV detector at 214 nm with a flow rate of 1 ml/min and an injection volume of 20 µL, at 40°C. Currently there are separate methods available in Indian Pharmacopoeia for analysis of Potency and Related proteins in human insulin. We have validated a single method where quantitation of potency and related proteins can be performed in the same run. The method validation exhibited linearity over the concentration range of 0.08–4.5 mg/ml (r2=0.999) with limit of detection of 0.094 mg/ml The accuracy of the method was 99–102.8%. Thus, it is proposed that both potency and related proteins in insulin formulations can be precisely evaluated using a single run thus saving the time and cost for quality analysis of insulin preparations both at manufacturing and regulatory laboratories which in turn will increase the market availability of such standard quality insulin preparations for public health use.

Biorelevant subcutaneous in vitro test predicts the release of human and fast acting insulin formulations

The administration of insulins by subcutaneous injection is nowadays widely prevalent. The injection site is located below the dermis and composed of cells and the extracellular matrix formed of a network of macromolecules such as hyaluronic acid and collagen. Following an injection, the insulins from the formulated products are timely released as drug molecules from the injection site into systemic circulation. In this publication, we show the development of an in vitro setup utilizing a hydrogel composed of a special collagen-hyaluronic acid mixture that mimics the extracellular matrix. Another setup was used for differentiation of the commercially available and research insulin formulations by determining the in vitro permeation characteristics with the results that were correlated with the human in vivo data. Significant differentiation was achieved at 90 % confidence level between the permeation curves of insulin glulisine containing formulations (U100 and a concentrated research formulation), while in case of the insulin lispro containing formulations (U100 and U200) the permeation curves showed similarity. These results demonstrated that the in vitro setup may be used as a tool for formulation development and drug candidate profiling as it is able to differentiate or show similarities between the agglomeration states and concentration of the active pharmaceutical ingredients.