Practical aspects of usage of insulin in India: Descriptive review and key recommendations

BACKGROUND AND AIMS

Insulin therapy is an integral part of diabetes management. However, reliable and easily accessible information on a number of basic facts concerning insulin therapy, including storage of insulin, managing insulin therapy during travel, nuances of insulin use while driving, and dose adjustments during sick days is lacking. This document aims to make readily available, reliable, and easy to implement information on these essential but relatively less discussed aspects of insulin therapy.

METHOD

Literature search was performed using PubMed and Cochrane Library from inception till 1^st of July 2019. The relevant topics were reviewed by a panel of 5 specialists and 23 contributing physicians and endocrinologists, who had assembled at Bengaluru, India for the 13th National Insulin Summit. After a thorough review of the literature, and following detailed discussions, the committee arrived at these recommendations.

RESULTS

Unopened vials and cartridges of insulin should be stored at 2 °C-8 °C in a refrigerator and protected from direct sunlight. For opened vials and in-use cartridges, manufacturer's instructions must be followed at all times. While traveling by air, dose adjustments are required only when flying across more than five time zones in the east or west directions. Insulin therapy should not be omitted or stopped during an acute illness; rather the doses need careful adjustments based on self-monitoring of blood glucose.

CONCLUSION

Recommendations and guidelines, covering many common aspects of insulin therapy are readily available. This consensus document aims to make recommendations for those essential aspects of insulin therapy that are crucial for its success but are relatively less known and less discussed.

A standardized glucose-insulin-potassium infusion protocol in surgical patients: Use of real clinical data from a clinical data warehouse

AIMS

We evaluated the clinical usefulness of a new unified glucose-insulin-potassium (GIK) regimen in a general surgical department.

METHODS

Surgical patients treated under the previous diverse GIK regimens (September 2016 to August 2017) and the new unified GIK regimen (September 2017 to August 2018) were identified in records of the Clinical Data Warehouse of Seoul National University Bundang Hospital. Serial and area under the curve (AUC) glucose levels, and percentages of time within the target glucose levels were compared in propensity score matched patients in the diverse GIK regimen and in the unified GIK regimen (n = 227 in each group).

RESULTS

The AUC of glucose at 6 h and 12 h was lower under the unified GIK regimen than the diverse GIK regimen. The percentage of target glucose levels was higher in the unified GIK regimen compared to the diverse GIK regimen (81.5% vs. 75.0%, P = 0.026), but the occurrence of hypoglycaemia did not differ significantly between groups.

CONCLUSIONS

The unified GIK regimen was more effective than the diverse GIK regimen for glycaemic control and did not increase the number of patients developing hypoglycaemia. This validated written GIK regimen can be safely used in a general surgical department.

A Case for Expanding Thermochromic Vial Monitor Technology to Insulin and Other Biologics

Insulin quality and efficacy determine glycemic control, which determines quality of life for people with diabetes. Insulin efficacy is reduced by heat exposure, especially in tropical climates, remote areas, and with improper handling. Insulin doses can be adjusted based on blood glucose monitoring, which may compensate for lack of viability. However, a measured response may be difficult with other biopharmaceuticals. Thermochromic vial monitor technology developed for oral polio vaccines (vaccine vial monitors) is an inexpensive, easily available, visible modality which can be used for insulin and other biopharmaceuticals to detect excessive heat exposure and thus reduced potency at any point in the cold-chain, till the end-users, thus improving patient care. Regulatory authorities must urgently consider the need to impose mandatory use of this technology for all biopharmaceuticals, including insulin, to ensure efficacy till end usage.

Assessment of optimal insulin administration timing for standard carbohydrates-rich meals using continuous glucose monitoring in children with type 1 diabetes: A cross-over randomized study

AIMS/INTRODUCTION

The present study was an assessment of postprandial glucose concentration after carbohydrates-rich meals using continuous glucose monitoring in 30 children with type 1 diabetes treated using continuous subcutaneous insulin infusion with a rapid-acting insulin analog.

MATERIALS AND METHODS

Over a period of 3 days, participants administered simple boluses with different delay times between insulin administration and the beginning of carbohydrates-rich meal consumption (meal no. 1 containing 197 kcal, no. 2 containing 247 kcal and meal no. 3 containing 323 kcal; containing practically no protein and fat). In the present cross-over randomized study, we analyzed the average glucose concentration profiles in 5-min intervals, mean glucose at insulin administration, mean glucose after 120 and 180 min, mean and peak glucose, glucose peak time, areas under the glucose and glucose increase curves, and time period lengths with glucose <50, 70 mg/dL, and >140 and 200 mg/dL.

RESULTS

For test meals at 20-min versus 0-min delay time, the study exposed a longer median time period to reach peak glucose (95 vs 65 min, P = 0.01) after meals. A tendency to the lowest peak and mean glucose, and the longest time with glucose within a normal range was observed in patients who administered bolus insulin 20 min before a meal.

CONCLUSIONS

For carbohydrates-rich meals, administration of a proper dose of a rapid-acting insulin analog is crucial. The influence of rapid-acting insulin analog administration timing seems to be of minor importance in comparison with correct insulin dose adjustment; however, a tendency to achieve more balanced glucose profiles was found in a group who administered insulin 20 min before a meal.

How often patients on insulin therapy measure postprandial glycemia and modify insulin doses accordingly? From an on-line survey in insulin-treated diabetes patients in Spain

INTRODUCTION

Controlling postprandial glycemia (PPG) is important to achieve optimal glycemic control, but few studies have evaluated how often is measured and evaluated.

OBJECTIVES

To evaluate how often patients on insulin therapy measure PPG and modify insulin doses accordantly. As secondary objectives, we evaluated the factors conditioning elevated PPG and associated issues.

MATERIAL AND METHODS

Cross-sectional observational study based on a web-based survey from an unselected sample of adult insulin-treated patients. A p-value of < 0.05 was significant.

RESULTS

1251 patients (68% women, 38.9 ± 13 years [mean ± SD], body mass index (BMI) 24.2 ± 4.2 kg/m², diabetes duration 17.4 ± 12.8 years, insulin dose 38 ± 18 IU) participated, 1104 with autoinmmune disease (AD) and 147 with non-autoinmmune diabetes (NAD). 59% of patients had HbA1c ≤ 7%, 92.7% of patients with AD and 55.8% with NAD were attended by specialists (p < 0.001). People with AD did more often blood glucose monitoring (BGM) (p < 0.0001) and used continuous glucose monitoring systems (CGMS) (p < 0.0001). 90.1% with AD and 68.0% with NAD received instructions on measuring PPG (p < 0.001), and more with AD received specific training to change the treatment (87% vs. 61.2%, p < 0.0001) and were more proactive. However, more with NAD discussed their postprandial glucose levels with their healthcare team during clinical visits (92.5% vs. 74.1%, p < 0.0001). Regarding bolus administration, 88.6% with AD and 68.7% with NAD injected the insulin bolus before meals (p < 0.001).

CONCLUSIONS

Patients with AD determine PPG more frequently. Diabetes type, follow-up setting, number of injections and CGMS use were the most important predictive factors for PPG measurement. Diabetes education programs should address how to best monitor PPG and appropriate corrective actions.

The association of basal insulin treatment versus standard care with outcomes in anti-GAD positive and negative subjects: A post-hoc analysis of the ORIGIN trial

We compared cardiovascular and other outcomes in patients with dysglycaemia with or without anti-glutamic acid dehydrogenase (GAD) antibodies participating in the Outcome Reduction with Initial Glargine Intervention (ORIGIN) trial. Of the 12 537 participants, 8162 had anti-GAD measured at baseline and 267 were anti-GAD positive. The effects of insulin glargine versus standard care and of n-3 fatty acids supplements versus placebo were compared by testing the interaction of the treatment effects and anti-GAD status. The effect of glargine on development of new diabetes was assessed in participants without previous diabetes at baseline. The overall incidence of outcomes did not differ between anti-GAD positive and anti-GAD negative subjects. The incidence of the composite of cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke did not differ between anti-GAD positive participants randomized to insulin glargine or to standard care, with a hazard ratio (HR) (95% confidence interval [CI]) of 0.80 (0.44-1.44) or in anti-GAD negative participants with a HR of 1.07 (0.96-1.20) (P for interaction = 0.20).

Concentrations of Intact Insulin Concurs With FDA and EMA Standards When Measured by HPLC in Different Parts of the Distribution Cold Chain

BACKGROUND

The article by Carter and Heinemann raised serious concerns about the concentrations of insulin in vials being sold in US pharmacies. To study the claims made in the manuscript, we reviewed Novo Nordisk data on insulin concentration.

METHODS

Insulin concentrations within vials from three different sources along the distribution chain were evaluated utilizing currently accepted US Pharmacopeia methodology: (1) insulin content and stability based on production batches covering 7 years of insulin production, (2) insulin content in samples returned to Novo Nordisk over the last three years in the United States, and (3) data from eight years of independent EMA testing.

RESULTS

The data demonstrated that without exception (1) insulin quality based on stability data was maintained, even in scenarios that stressed the normal recommendations for temperature storage conditions, (2) insulin content from the last three years of samples returned to Novo Nordisk from patients in the United States (233 vials) was within USP requirements recognized by FDA, and (3) ten years of independent EMA sampling of products obtained at wholesalers and pharmacies across the EU confirmed compliance (n = 43).

CONCLUSIONS

The study by Carter and Heinemann utilized an LC-MS technique, which has not been validated for the quantification of insulin in pharmaceutical preparations. It appears likely that their findings are the result of the method utilized and not due to decreased insulin content in samples. However, recognizing the importance of maintaining Insulin content from production to the patient, Novo Nordisk supports continued evaluation of insulin distributed to pharmacies and patients utilizing validated techniques compliant with international pharmacopeias.

Management of hyperglycemia in the neurosurgery patient

Hyperglycemia is associated with adverse outcomes in patients who are candidates for or underwent neurosurgical procedures. Specific concerns and settings that relate to these patients are preoperative glycemic control, intraoperative control, management in the neurological intensive care unit (NICU), and postoperative control. In each of these settings, physicians have to ensure appropriate glycemic control to prevent or minimize adverse events. The glycemic control is usually managed by a neurohospitalist in co-management with the neurosurgery team pre- and post-operatively, and by the neurocritical care team in the setting of NICU. In this review article, we outline current standards of care for neurosurgery patients with diabetes mellitus and/or and hyperglycemia and discuss results of most recent clinical trials. We highlight specific concerns with regards to glycemic controls in these patients including enteral tube feeding and parenteral nutrition, the issues of the transition to the outpatient care, and management of steroid-induced hyperglycemia. We also note lack of evidence in some important areas, and the need for more research addressing these gaps. Where possible, we provide suggestions how to manage these patients when there is no underlying guideline.

In the Biosimilar Marketplace Will There Be 50 Ways to Leave Your Insulin?

The future biosimilar insulin marketplace could be a bane, benefit, or something in between, to patients under our care in the United States. Formulary preferred product status, with or without FDA interchangeability designation, coupled with current and proposed state pharmacy substitution laws may lead to an environment with as many as 50 different substitution guidelines depending on in which state a patient presents his or her prescription to be filled. If online global prescription supply options, often referred to as "Canada Drug," are utilized, other country substitution guidelines come into play, which may yield a recipe for confusion, if not disaster.

How long can a vial of insulin be used after it is started: where are we 10 years later?

In August 2003, I wrote a commentary entitled "How Long Can a Vial of Insulin be Used After It Is Started." The commentary included comments from each of the 3 insulin manufacturers, as well as the American Diabetes Association. Anyone reading the article quickly realized that there was little agreement among the insulin manufacturers and just as little clarity to this question. Over the ensuing 10 years, there has been little or no effort made by either the Food and Drug Administration (FDA) or the insulin manufacturers to clarify this issue of insulin storage after a bottle is started. Current package inserts list varying times from 28 to 42 days, while the latest recommendation from the American Diabetes Association gives a uniform 1-month time limit. I would therefore propose that insulin manufacturers begin putting on every insulin vial and pen, in addition to the expiration date, the amount of time that particular insulin should be used after it is started. In addition there should be a box for the patient to write the starting date directly onto the vial or pen. This would eliminate the need for uniformity of recommendations; all the patient would have to do is read the instructions written on the insulin vial or pen.

Design of experiments-based monitoring of critical quality attributes for the spray-drying process of insulin by NIR spectroscopy

Moisture content and aerodynamic particle size are critical quality attributes for spray-dried protein formulations. In this study, spray-dried insulin powders intended for pulmonary delivery were produced applying design of experiments methodology. Near infrared spectroscopy (NIR) in combination with preprocessing and multivariate analysis in the form of partial least squares projections to latent structures (PLS) were used to correlate the spectral data with moisture content and aerodynamic particle size measured by a time of flight principle. PLS models predicting the moisture content were based on the chemical information of the water molecules in the NIR spectrum. Models yielded prediction errors (RMSEP) between 0.39% and 0.48% with thermal gravimetric analysis used as reference method. The PLS models predicting the aerodynamic particle size were based on baseline offset in the NIR spectra and yielded prediction errors between 0.27 and 0.48 μm. The morphology of the spray-dried particles had a significant impact on the predictive ability of the models. Good predictive models could be obtained for spherical particles with a calibration error (RMSECV) of 0.22 μm, whereas wrinkled particles resulted in much less robust models with a Q (2) of 0.69. Based on the results in this study, NIR is a suitable tool for process analysis of the spray-drying process and for control of moisture content and particle size, in particular for smooth and spherical particles.

Impact of improvement efforts on glycemic control and hypoglycemia at a university medical center

BACKGROUND

Great emphasis is placed on optimizing treatment of hospitalized patients with diabetes and hyperglycemia.

OBJECTIVE

This study was conducted to determine if the application of hospital-wide insulin order sets improved inpatient safety by reducing the number of actual hypoglycemic and hyperglycemic events and increasing at-target blood glucose.

DESIGN

A retrospective chart review was conducted of hypoglycemic and hyperglycemic events and at-target blood glucose occurring before and after institution of the insulin order sets and blood glucose protocols.

SETTING

The Medical University of South Carolina (MUSC) Medical Center is a 709-bed hospital and tertiary referral center for partnering hospitals in the southeastern United States.

PATIENTS

All patients were evaluated who had a documented history of diabetes or who had at least 1 finger-stick blood glucose above 180 mg/dL who were admitted for care to the MUSC adult main hospital (minimum of 18 years-of-age; maximum 100 years-of-age) during June 2004, June 2005, June 2006, and June 2007.

INTERVENTION

The intervention involved institution of hospital-wide hypoglycemia, hyperglycemia, subcutaneous insulin, and intravenous insulin treatment protocols.

MEASUREMENTS

Retrospective data on hypoglycemia, hyperglycemia, and at-target blood glucose incidence and frequency were collected via a computerized repository for all inpatients.

RESULTS

The percent time in range improved by 10% with no increase in the amount of severe hypoglycemic episodes for the blood glucose results.

CONCLUSIONS

Implementing standardized insulin order sets including hypoglycemia and hyperglycemia treatment protocols at MUSC produced expected benefits for patient safety for this patient population.

[Basic Review Committee for Clinical Laboratory Standardization. Column 1. Activity report of 2007. Group items of authentic sample, Working Group J2]

(1) Concerning measurement of serum levels of insulin, C-peptide, and cortisol, a joint experiment in 2006 suggested that a reference material derived from authentic samples was effective for the convergence of data. (2) To reconfirm the convergence of data using a candidate reference material derived from authentic sample, we generated pooled serum samples of patients as candidate materials, and the levels of insulin and C-peptide in the sera of healthy subjects and the level of cortisol in panel serum IRMM ERM-DA45I-1-DA45I-3 were measured. (3) The serum levels measured with commercially available reagents were reconfirmed to lead to data convergence. (4) We employed reagents which were traceable in reference materials of authentic samples, calibrated each reagent, and confirmed the convergence of data, as verified in the previous examination. (5) The prototype reference material of authentic sample was proven to be effective as a standard reference material.

Insulin pumps and insulin quality--requirements and problems

In developing insulin solution suitable for delivery devices the chemical and biological stability, as well as the physical stability, must be taken into consideration. Addition of certain mono- and disaccharides increases the physical stability of neutral insulin solutions, but concurrently the chemical and biological stability decrease to an unacceptable degree. Addition of Ca-ions in low concentrations offers a physiologically acceptable method for stabilizing neutral insulin solutions against heat precipitation without affecting the quality, including the chemical and biological stability.

A study of the effects of column porosity on gradient separations of proteins

The type of the stationary phase for reversed-phase liquid chromatography significantly affects the sample elution. Hydrodynamic properties, efficiency and gradient elution of proteins were investigated on five commercial C18 columns with wide-pore totally porous particles, with superficially porous layer particles, non-porous particles and a silica-based monolithic bed. The efficiency in the terms of reduced plate height is higher for low-molecular ethylbenzene than for proteins, but depends on the character of the pores in the individual columns tested. The superficially porous Poroshell and the non-porous Micra columns provide the best efficiency for proteins at high mobile phase flow rates, probably because of similar pore architecture in the stationary phase. The Zorbax column with similar pore architecture as the Poroshell active layer, i.e. narrow pore distribution of wider pores shows better efficiency than the packed column with narrow pores and broad pore distribution. The monolithic column shows lower efficiency for proteins at high flow rates, but it performs better than the broad-pore distribution totally porous particulate columns. Different pore architecture affects also the retention and selectivity for proteins on the individual columns. The retention times on all columns can be predicted using the model for reversed-phase gradient elution developed originally for low-molecular compounds. Consideration of the limited pore volume accessible to the biopolymers has negligible effect on the prediction of retention on the columns packed with non-porous or superficially porous particles, but improves the accuracy of the predicted data for the totally porous columns with broad pore distribution.

[Application of HPLC-ESI-ITMS in the quality control of carboxyterminal sequence confirmation for insulin and insulin chain B]

Application of HPLC-ESI-ITMS in the quality control of carboxyterminal sequence confirmation for insulin and insulin chain B was studied. The solution of intact insulin or insulin chain B was added to the solution of carboxypeptidase P (CPP) and carboxypeptidase Y (CPY). Fractions of appropriate volume were removed at some appointed time points, acidified with the same amount of 1% formic acid to stop the digestion, and then briefly vortexed for HPLC-ESI-ITMS analysis. Mobile phase A consisted of 0.02% TFA in 98% ultra-pure water and 2% acetonitrile. Mobile phase B consisted of 0.02% TFA in 98% acetonitrile and 2% ultra-pure water. The solution used for post-column fix consisted of propionic acid and isopropyl alcohol (20 : 80, v/v). Chromatographic separation was carried out on a reversed-phase column (Zorbax Prosphere C18, 300A, 5 microm, 2.1 mm ID x 150 mm length). The molecular weights of the multiply charged ions representing consecutive truncated losses of carboxyterminal amino acids were determined by the use of HPLC-ESI-ITMS. The differences between the consecutive truncated peptides are the experimental weights of the carboxyterminal amino acid residues. The carboxyterminal amino acid residue Ala, which released from chain B of intact insulin, was confirmed in the nanomolar concentration range by analyzing the molecular weight of the truncated peptides. Another one carboxyterminal amino acid Ala was confirmed in the nanomolar concentration range of insulin chain B. In the quality control for recombinant DNA product or natural protein, the confirmation of 1 - 3 carboxyterminal amino acid residues is regarded to be up to standard. One amino acid residue of insulin or insulin chain B could be confirmed accurately in the nanomolar concentration range. The results showed that intact insulin could be directly sequenced in the quality control without separating chain B from chain A. There would be no need to separate chain A from chain B to identify carboxyterminal of intact insulin. Furthermore, the method saved us a lot of trouble from the preparation and purification of insulin chain A and chain B.

When basal insulin therapy in type 2 diabetes mellitus is not enough--what next?

Type 2 diabetes mellitus (T2DM) is a progressive disease characterized by co-existing insulin deficiency (relative) and insulin insensitivity. Both fasting and post-prandial blood glucose are elevated, exposing the patient to acute and chronic complications due to micro- and macro-vascular angiopathy. Improving glycaemic control has been demonstrated to lower the risk of these complications. Owing to the progressive nature of the disease, an evolving treatment strategy is necessary to maintain glycaemic control. Insulin therapy is required when dietary and lifestyle modifications combined with oral hypoglycaemic agents fail to provide adequate glycaemic control. Adding an optimized dose of basal insulin to the existing oral therapy is a simple and widely used method for initiating insulin therapy. However, despite an effective control of fasting hyperglycaemia, further intervention to control post-prandial hyperglycaemia may become necessary to achieve HbA1c targets. Strategies for the addition of prandial insulin include administering short-acting (or rapid-acting) insulin analogues before each meal or twice-daily administration of pre-mixed insulin. As a single large meal often contributes to the greatest part of daytime hyperglycaemia, an alternative strategy is emerging with the addition of a single injection of prandial insulin prior to the meal that induces the largest post-prandial blood glucose excursion measured 2 h after the start of the meal. Over time, additional prandial boluses of insulin may be required to sustain daytime glycaemic control. This strategy offers a simple, stepwise approach to progress from basal insulin to a basal-bolus regimen. Studies are needed to validate this method and better define specific titration tactics.

Standardization of biological medicines: the first hundred years, 1900-2000

The use of materials of biological origin in medicine has a long history. These materials, including tissue, organ and microbial extracts, blood and its derivatives, antibodies and hormones, share the feature that for much of the last century the ability to characterize and quantify the active substance was limited. Quantification of these substances depends on biological standardization, a discipline that was refined to a science by the Medical Research Council from the 1920s onwards, and which, with contributions from several prominent Fellows of the Royal Society, including principally Sir Henry Dale, the UK has led the world to the present date.

Intensive insulin therapy to non-cardiac ICU patients

OBJECTIVE

Intensive insulin therapy reduced mortality in patients admitted to an intensive care unit following mainly cardiac surgery. The aim of this prospective study was to evaluate, if intensive insulin therapy could reduce mortality in medical and non-cardiac surgical patients admitted to a multidisciplinary intensive care unit.

PATIENTS AND METHODS

For 6 months all adult patients, admitted to the intensive care unit, were included. Insulin was administered, if blood glucose 12 mmol L-1. For the next 6 months blood glucose level was reduced with intensive insulin therapy (aim 4.4 < BG < 6.1 mmol L-1); 271 patients were included. Patient characteristics data, APACHE II score, morbidity and mortality were recorded.

RESULTS

At admission the two groups were comparable. The overall relative mortality was reduced 20% in the intensive insulin treated group (n.s.). In the intensive insulin treated group mortality was 13.1% in the medical patients and 11.2% in the surgical patients compared to 15.8% and 14.4%, respectively, in the conventional treated group (n.s.). The frequency of secondary infections was 21.5% in the intensive insulin treated group and 16.0% in the conventional treated group (n.s.). The proportion of hypoglycaemia increased from 4% to 14% (P < 0.05).

CONCLUSIONS

Following intensive insulin therapy there was a trend towards reduced mortality in medical and non-cardiac surgical patients but less pronounced as in cardiac surgical patients. Intensive insulin therapy increased the frequency of hypoglycaemia. Around 4400 patients would have to be included in any future randomized study to reach significance.

Standardization of calibration and quality control using surface enhanced laser desorption ionization-time of flight-mass spectrometry

BACKGROUND

Protein profiling by surface enhanced laser desorption ionization-time of flight-mass spectrometry (SELDI-TOF-MS) is gaining importance as a diagnostic tool for a whole range of diseases. This report describes a QC procedure, which acts prospectively by checking the calibration before starting profiling experiments.

METHODS

A well-defined protocol for calibration of the Protein Biosystem IIc instrument was established, using a commercial QC sample containing independent certified standards and by determination of acceptance criteria. Instrument calibration was performed externally every week with the standards provided by the manufacturer. QC was performed for the period of 5 months.

RESULTS

According to the acceptance criteria defined in this study, data points should be in the established range of the process mean+/-2 standard deviations for the mass-to-charge ratios (m/z values), peak intensities, signal-to-noise ratios (S/N), and peak resolutions for insulin and apomyoglobin in the QC sample. Moreover, it was demonstrated that the pipetting variability in the handling of the QC sample significantly contributed to systematic errors and that spotting of a larger volume of QC sample resulted in a better reproducibility.

CONCLUSIONS

Stringent quality control of the calibration part of SELDI-TOF-MS experiments prevents unreliable data acquisition from the very start.

The role of formulation in insulin comparability assessments

The concept of comparability can be applied when changes are made to manufacturing processes for biotechnology products subsequent to pivotal clinical trial studies. For many process changes, comparability can be demonstrated based entirely on relevant in vitro data provided that a detailed knowledge of the process/product exists, suitable analytical methodology is employed, and historical data are available for the assessment. Insulin provides an excellent model system to illustrate many important considerations when dealing with comparability exercises for biotechnology products. The physicochemical properties of insulin demonstrate the numerous chemical reactions and physical transformations that are exclusive to proteins. These properties are heavily influenced by formulation conditions and must be carefully evaluated when process changes are made. In addition, physical and chemical testing performed on representative formulations can provide valuable insight when assessing the comparability between pre- and post-change materials. This paper reviews our experience with manufacturing changes involving insulin emphasizing the important role of formulation in the comparability exercise for protein biopharmaceuticals.

Acute insulin response of donors is correlated with pancreatic islet isolation outcome in the pig

AIMS/HYPOTHESIS

Unpredictability of islet isolation outcome remains a frustrating and costly issue in the clinical implementation of islet transplantation. The aim of this experimental study was to test the hypothesis that the donor's insulin secretory reserve, an in vivo surrogate of functional pancreatic mass, is correlated with the outcome of islet isolation.

METHODS

Insulin secretory reserve was evaluated in 28 healthy adult minipigs prior to pancreatectomy and islet isolation. Blood glucose and insulinaemia were measured before and 1, 3, 5, 10, 15, 30, 60 and 90 min after glucose infusion. Following total pancreatectomy, islet isolation was performed according to Ricordi's semi-automated method, and the total number of islets obtained was determined. Fasting blood glucose, insulinaemia, acute insulin response (AIR), maximal insulinaemia and the glucose decay constant (K(G)) were calculated, and possible associations with the outcome of islet isolation were assessed.

RESULTS

AIR and maximal insulinaemia after glucose injection were correlated with the outcome of islet isolation (p<0.01). Mean values for AIR and maximal insulinaemia were significantly different between animals in which islet isolation was successful (n=11) vs those in which it was unsuccessful (n=17) (77.6+/-13.7 microU/ml vs 42.3+/-7.8 microU/ml, p<0.05; 144.7+/-21.6 microU/ml vs 71.9+/-10.4 microU/ml, p<0.05, respectively).

CONCLUSIONS/INTERPRETATION

This study suggests that the donor's pancreatic endocrine mass, as estimated by AIR, is a major determinant of the outcome of islet isolation in large mammals. Our results may explain the frustrating variability of human islet isolation outcome and could lead to a new approach for optimising the selection of brain-dead and/or living pancreas donors.

Preservation of rat livers by cold storage: a comparison between the University of Wisconsin solution and Hypothermosol

OBJECTIVES

The University of Wisconsin solution (UW) is the gold standard for cold storage (CS) of donor livers. However, UW contains the colloid Hydroxyethyl starch (HES), which may cause perfusion deficits due to its high viscosity. Recently, a new CS preservation solution, Hypothermosol (HTS), was introduced which contains the less viscous colloid Dextran. The aim of this study was to assess HTS as a cold storage solution for preservation of the liver.

METHODS

In an isolated perfused rat liver model, hepatocellular damage was assessed after 24 hours of CS. Liver enzymes were measured during reperfusion with Krebs-Henseleit Buffer. Bile was collected during reperfusion as a parameter of liver function.

RESULTS

CS using HTS showed a significant decrease of ALT and LDH levels (as compared to UW) at all time points during reperfusion. For LDH these results where most pronounced at t=10 min (84 +/- 7.09 vs 113 +/- 7.57: p < 0.05) and t=30 min (149.2 +/- 9.68 vs 194 +/-6.52: p< 0.05). Regarding liver function, more bile was produced after 24 hours CS in HTS, but this did not reach statistical significancy.

CONCLUSIONS

Cold storage preservation of rat livers using Hypothermosol results in equal or even better preservation as compared to cold storage using UW.

Comparison of shelf-life estimates for a human insulin pharmaceutical preparation using the matrix and full-testing approaches

The design of a stability study is intended to establish a shelf-life based on testing a limited number of batches of a drug product, which is applicable to all future batches of the drug product manufactured under similar circumstances. In the FDA guidelines for stability testing of new drug products, the matrix design is suggested as the alternative statistical design to the full testing approach. In the last few years, the matrix design has received increasing attention from pharmaceutical companies in order to reduce the cost of stability studies. For this, the full and matrix stability test plans were used on three batches of human insulin pharmaceutical preparation stored under a kinetic mean temperature of 22.7 degrees C for 3 years. The statistical method was suggested by Ruberg and Stegeman (Biometrics, 1991, 47, 1059-1069) and Llabrés et al. (Int. J. Pharm. 2000, 204, 61-68), and was used for comparing batches, and the maximum allowable difference in slopes between batches was used as criteria for estimating a common shelf-life. The results obtained show the conservative nature of the matrix approach, although the difference between the matrix and full shelf-life was less than 1 month. The effect of the matrix method on shelf-life was also studied. The results showed that the model for estimating the shelf-life varied as a function of the permutation used, after testing for both slope and intercept poolability at alpha = 0.25. The batches should be pooled for both full testing and matrix design since the critical significance level required to obtain a power of 0.80 was achieved when the maximum allowable difference in slopes between batches was 1%/month, according to Ruberg and Stegeman. In contrast, when the proposed method by Llabrés et al. was used, the results varied in function of the maximum allowable difference in slopes.

Comparison of Celsior and UW solution in experimental pancreas preservation

BACKGROUND

The University of Wisconsin solution (UW) is the gold standard for pancreas preservation. Celsior (CEL) was formulated specifically for heart preservation. Recently, experimental and clinical experience has been reported on the application of CEL to abdominal organs. In this animal study, pancreas preservation with CEL was compared with that in UW solution.

PATIENTS AND MATERIALS

Heterotopic, allogeneic pancreaticoduodenal transplantation was performed in female Göttingen Minipigs (n = 12 donors, n = 12 recipients). The grafts were flushed and stored for 6 h at 4 degrees C in UW or CEL. The recipients were randomized into two groups receiving either UW (n = 6)- or CEL (n = 6)-preserved grafts with a follow-up of 5 days. Blood flow (laser Doppler), partial oxygen tension, histological changes, endothelin-1 (plasma, immunohistochemistry), lipase, amylase, trypsinogen activation peptide, and C-reactive protein (CRP) were measured.

RESULTS

Partial oxygen tension was lower in the CEL group (P < 0.05). However, blood flow did not differ between UW- and CEL-preserved organs. The histomorphologic analysis of the pancreatic grafts revealed significantly less edema in the UW-preserved organs. Serum levels of amylase, lipase, CRP, and TAP taken from the central venous blood were comparable in the two groups, except for higher amylase values 36 h after reperfusion in the CEL group compared to the UW group (P < 0.05). Likewise, TAP taken from the portal venous effluent of the graft was found to be higher in the CEL group than in UW (P < 0.05). Endothelin-1 serum levels rose significantly during reperfusion without differences between the two groups. ET-1 immunohistochemistry revealed increased local ET-1 during reperfusion in all grafts. However, the ET-1 immunostaining in the CEL group was more pronounced than that in the UW group (P < 0.05).

CONCLUSIONS

Our results suggest that CEL solution is not as effective in preventing pancreatic ischemia/reperfusion damage as the standard UW solution in experimental pancreas transplantation. Increased ET-1 immunostaining and reduced p(ti)O(2) in the CEL group indicate increased microcirculatory damage in the CEL group.

Making the unit of insulin: standards, clinical work, and industry, 1920-1925

The standardization of insulin is generally considered by historians to have been a process conducted by physiologists under the direction of Henry Dale. This article shows that it actually involved many actors and began with the earliest administration to patients in Canada and the United States. During this first phase, the drug company Eli Lilly also contributed actively to the standardization, under the scientific direction of George Clowes. This is not to undermine the role of Dale, whose political leadership was paramount for the international phase of the standardization. His scientific contribution, however, was a continuation of previous work led by physiologists, clinicians, and pharmacists. The production and packaging of insulin in standardized units thus appears to be the result of the impressive working of a transdisciplinary and transnational network. It also highlights how new modes of drug regulation were elaborated by state bodies in the early 1920s and paved the way for more extensive reforms.