Circadian profiles of blood glucose and plasma free insulin during treatment with semisynthetic and biosynthetic human insulin, and comparison with conventional monocomponent preparations

Analysis of the Glucose-Dependent Transcriptome in Murine Hypothalamic Cells

Glucose provides vital energy for cells and contributes to gene expression. The hypothalamus is key for metabolic homeostasis, but effects of glucose on hypothalamic gene expression have not yet been investigated in detail. Thus, herein, we monitored the glucose-dependent transcriptome in murine hypothalamic mHypoA-2/10 cells by total RNA-seq analysis. A total of 831 genes were up- and 1390 genes were downregulated by at least 50%. Key genes involved in the cholesterol biosynthesis pathway were upregulated, and total cellular cholesterol levels were significantly increased by glucose. Analysis of single genes involved in fundamental cellular signaling processes also suggested a significant impact of glucose. Thus, we chose ≈100 genes involved in signaling and validated the effects of glucose on mRNA levels by qRT-PCR. We identified Gnai1–3, Adyc6, Irs1, Igfr1, Hras, and Elk3 as new glucose-dependent genes. In line with this, cAMP measurements revealed enhanced noradrenalin-induced cAMP levels, and reporter gene assays elevated activity of the insulin-like growth factor at higher glucose levels. Key data of our studies were confirmed in a second hypothalamic cell line. Thus, our findings link extra cellular glucose levels with hypothalamic lipid synthesis and pivotal intracellular signaling processes, which might be of particular interest in situations of continuously increased glucose levels.

Modulated release metoprolol succinate formulation based on ionic interactions: In vivo proof of concept

A modulated release, multiunit oral drug delivery technology using a system based on ionic interactions of anions of salts with quaternary ammonium ions of the ammoniomethacrylate polymer is described. The system consisted of a drug layered, EUDRAGIT NE-coated salt core which was further coated with EUDRAGIT RS. The relative effects of different anions on the polymer permeability have been investigated by studying their influence on the in vitro drug release. A prototype formulation of metoprolol succinate using this technology was developed and the drug release from the formulation was adjusted to have a release profile which would match the circadian rhythm i.e. a higher amount of drug would be available after an initial lower release (accelerated type of release). The formulation was tested in vivo in 12 healthy human volunteers in an open label, randomized, two-treatment, two-period, single dose crossover bio-study with reference formulation Beloc-zok. The in vivo release demonstrated that compared to the reference, a higher amount of drug was available in the plasma from the 7th hour onwards. A higher AUC of the drug was also observed compared to the reference formulation. An in vitro-in vivo correlation was attempted to identify a bio-relevant in vitro dissolution medium for the formulation.

'Human' insulin versus animal insulin in people with diabetes mellitus

BACKGROUND

Human insulin was introduced for the routine treatment of diabetes mellitus in the early 1980s without adequate comparison of efficacy to animal insulin preparations. First reports of altered hypoglycaemia awareness after transfer to human insulin made physicians and especially patients uncertain about potential adverse effects of human insulin.

OBJECTIVES

To assess the effects of different insulin species by evaluating their efficacy (in particular glycaemic control) and adverse effects profile (mainly hypoglycaemia).

SEARCH STRATEGY

A highly sensitive search for randomised controlled trials combined with key terms for identifying studies on human versus animal insulin was performed using The Cochrane Library, MEDLINE and EMBASE. We also searched reference lists and databases of ongoing trials. Date of latest search: July 2004.

SELECTION CRITERIA

We included randomised controlled clinical trials with diabetic patients of all ages that compared human to animal (for the most part purified porcine) insulin. Trial duration had to be at least one month in order to achieve reliable results on the main outcome parameter glycated haemoglobin.

DATA COLLECTION AND ANALYSIS

Trial selection as well as evaluation of study quality was performed by two independent reviewers. The quality of reporting of each trial was assessed according to a modification of the quality criteria as specified by Schulz and by Jadad.

MAIN RESULTS

Altogether 2156 participants took part in the 45 randomised controlled studies that were discovered through extensive search efforts. Though many studies had a randomised, double-blind design, most studies were of poor methodological quality. Purified porcine and semi-synthetic insulin were most often investigated. No significant differences in metabolic control or hypoglycaemic episodes between various insulin species could be elucidated. Insulin dose and insulin antibodies did not show relevant dissimilarities.

AUTHORS' CONCLUSIONS

A comparison of the effects of human and animal insulin as well as of the adverse reaction profile did not show clinically relevant differences. Many patient-oriented outcomes like health-related quality of life or diabetes complications and mortality were never investigated in high-quality randomised clinical trials. The story of the introduction of human insulin might be repeated by contemporary launching campaigns to introduce pharmaceutical and technological innovations that are not backed up by sufficient proof of their advantages and safety.

Chronopharmaceutics: gimmick or clinically relevant approach to drug delivery?

Due to advances in chronobiology, chronopharmacology, and global market constraints, the traditional goal of pharmaceutics (e.g. design drug delivery systems with a constant drug release rate) is becoming obsolete. However, the major bottleneck in the development of drug delivery systems that match the circadian rhythm (chronopharmaceutical drug delivery systems: ChrDDS) may be the availability of appropriate technology. The last decade has witnessed the emergence of ChrDDS against several diseases. The increasing research interest surrounding ChrDDS may lead to the creation of a new sub-discipline in pharmaceutics known as chronopharmaceutics. This review introduces the concept of chronopharmaceutics, addresses theoretical/formal approaches to this sub-discipline, underscores potential disease-targets, revisits existing technologies and examples of ChrDDS. Future development in chronopharmaceutics may be made at the interface of other emerging disciplines such as system biology and nanomedicine. Such novel and more biological approaches to drug delivery may lead to safer and more efficient disease therapy in the future.

'Human' insulin versus animal insulin in people with diabetes mellitus

BACKGROUND

Human insulin was introduced for the routine treatment of diabetes mellitus in the early 1980s without adequate comparison of efficacy to animal insulin preparations. First reports of altered hypoglycaemia awareness after transfer to human insulin made physicians and especially patients uncertain about potential adverse effects of human insulin.

OBJECTIVES

To assess the effects of different insulin species by evaluating their efficacy (in particular glycaemic control) and adverse effects profile (mainly hypoglycaemia).

SEARCH STRATEGY

A highly sensitive search for randomised controlled trials combined with key terms for identifying studies on human versus animal insulin was performed using the Cochrane Library (issue 2, 2002), Medline (1966 to May, 2002) and Embase (1974 to February, 2002). We also searched reference lists and databases of ongoing trials. Date of latest search: May 2002.

SELECTION CRITERIA

We included randomised controlled clinical trials with diabetic patients of all ages that compared human to animal (for the most part purified porcine) insulin. Trial duration had to be at least one month in order to achieve reliable results on the main outcome parameter glycated haemoglobin.

DATA COLLECTION AND ANALYSIS

Trial selection as well as evaluation of study quality was performed by two independent reviewers. The quality of reporting of each trial was assessed according to a modification of the quality criteria as specified by Schulz and by Jadad.

MAIN RESULTS

Altogether 2156 participants took part in the 45 randomised controlled studies that were discovered through extensive search efforts. Though many studies had a randomised, double-blind design, most studies were of poor methodological quality. Purified porcine and semi-synthetic insulin were most often investigated. No significant differences in metabolic control or hypoglycaemic episodes between various insulin species could be elucidated. Insulin dose and insulin antibodies did not show relevant dissimilarities.

REVIEWER'S CONCLUSIONS

A comparison of the effects of human and animal insulin as well as of the adverse reaction profile did not show clinically relevant differences. Many patient-oriented outcomes like health-related quality of life or diabetes complications and mortality were never investigated in high-quality randomised clinical trials. The story of the introduction of human insulin might be repeated by contemporary launching campaigns to introduce pharmaceutical and technological innovations that are not backed up by sufficient proof of their advantages and safety.

Immunogenicity of semisynthetic human insulin in man. Long-term comparison with porcine monocomponent insulin

The levels of circulating IgG-insulin antibodies were determined in two groups of diabetic patients before and at 3-month intervals after starting insulin treatment either with monocomponent porcine insulin (n = 17) or with human semisynthetic insulin (SH) (n = 16). Patients were followed during 15.1 +/- 1.0 and 19.9 +/- 1.1 months, respectively (m +/- SEM). In addition, the quality of metabolic control and residual B-cell function were evaluated in the group under treatment with SHI. The percentage of patients who remained antibody-free after 12-21 months of treatment was 67.75% in the human insulin-treated group and only 25-43% in the one receiving porcine insulin (p less than 0.01). Moreover, insulin antibody titers, when present, were usually lower in subjects treated with human insulin. In SHI-treated patients: metabolic control was excellent during the first months of treatment as evidenced by values of mean daily blood glucose (7.3 +/- 0.6 mmol/l), M-index according to Schlichtkrull (7.4 +/- 2.4) and Hb1c (6.8 +/- 0.6%); residual B-cell function, evaluated at 3-month intervals by a circadian profile of plasma C-peptide did not decrease throughout the study; and a significant deterioration of blood glucose control occurred after 18 months of treatment, which might have been due to a less intensive supervision of the patients by the physicians and/or less careful attention by the patients themselves. This observation confirms the need for a continuous education of the patients regardless of the type of insulin used.