Stable insulin for implantable delivery systems: in vitro studies with different containers and solvents.

The stability of a new insulin formulation (lyophilized U100 insulin, Organon) was investigated in vitro in conditions reproducing those of in vivo implanted devices, i.e., constant horizontal agitation at 37 degrees C for 4 wk in various containers and 8 wk in different solvents. Physical stability was assessed by ultraviolet absorption, chemical stability by HPLC, and biological stability by hypoglycemia tests in mice. Insulin precipitated in glass vials but remained clear and active in polyethylene reservoirs and after passage through catheter and pumps in motion, although only 83-90% of insulin was delivered chemically intact. In acidic solvent, insulin showed a major gradual transformation into deamidized derivatives (up to 78% after 8 wk), although still fully active and clear, as expected from previously published excellent in vivo results with acidic insulins. Heparin addition to neutral insulin solution (500 IU/ml) did not alter the properties of the two compounds and might thus be tried to prevent in vivo catheter obstruction due to fibrin deposition.

Six month administration of gelified intranasal insulin in 16 type 1 diabetic patients under multiple injections: efficacy vs subcutaneous injections and local tolerance.

OBJECTIVE: Nasal insulin administration is a potential route for intensive insulin management, less invasive and more rapid than subcutaneous injections. Previous studies have shown poor bioavailability (less than 15%) with nasal insulin administration with various absorption enhancers. The aim of the study was to evaluate in type 1 diabetic patients, the metabolic efficacy and local tolerance of a new gelified sprayed nasal insulin containing glychocolate and methylcellulose as absorption promoters. MATERIAL AND METHODS: The study was conducted in 16 type 1 diabetic patients (HbA1c 8.6+/-0.2%) in a cross-over trial including 2 six month randomized periods: a) NPH twice daily + 3 pre-prandial nasal insulin doses + nasal supplementation in case of unexpected hyperglycaemia; b) NPH twice daily + 3 pre-prandial regular insulin injections. End points were HbA1c levels, hypoglycaemic episodes and tolerance evaluated at month 0, 2, 6 and 8 on clinical symptoms and objective nasal assessments. RESULTS: Four patients were withdrawn because of nasal burning (3 cases) and persistent sinusitis (1 case), and one patient had purulent sinusitis at the month 6 examination. At month 6, HbA1c levels were comparable (8.3 +/- 0.1 vs 8.6 +/- 0.1%, m +/- SEM, NS) for nasal and subcutaneous period respectively. The number of hypoglycaemic events was identical during the 2 periods (88 episodes). Nasal tolerance with the gelified form was better than with the already reported lyophilized form but, when present, symptoms were more marked, suggesting a potentiating additional role of methylcellulose excipient on nasal intolerance. CONCLUSIONS: 1) Gelified nasal insulin is as efficient as subcutaneous regular insulin in type 1 diabetic patients. 2) Other galenic forms should be investigated to improve nasal tolerance and bioavailability.

Extreme insulin resistance: clinical management by external subcutaneous insulin infusion.

Management of very high insulin requirements in rare extreme insulin resistance syndromes is difficult and poorly documented. We report a case of a type B insulin-resistant patient requiring approximately 10,000 units of insulin per day, i.e. beyond the possibilities of current insulin formulations and delivery devices. Only the Panomat C10 portable pump model (Disetronic) and U500 Humulin (Lilly) allowed the required rate of 400 units per hour to be attained only when the reservoir was changed twice daily and the site and catheter were changed once daily. Three months after discharge, the patient was in good general and local condition, but with only fair diabetes control (glycated haemoglobin 9.5%).

Circulating immune complexes containing bovine insulin in a patient with systemic allergic manifestations.

A woman treated for 15 days with bovine insulin for gestational diabetes presented with severe urticaria of the chest and back, distant from the injection site. She had neither local reaction nor general manifestations. Replacement of bovine NPH insulin by biosynthetic human NPH was followed by regression of urticaria. We isolated the circulating immune complex (CIC), mainly of IgG class, from the patient's serum. It disappeared when bovine insulin administration had been ceased for 48 h. There were no specific IgE-insulin-antibodies. The IgG-CIC were dissociated. Insulin was identified by RIA in the CIC. Insulin characterization was carried out by high-performance liquid chromatography (HPLC), which showed that the insulin in the complexes was injected bovine insulin.

High and very high dosages of the oral contraceptive lynestrenol: a three-month feeding study in female rats.

PIP: Lynestrenol, a progestagen used as an oral contraceptive, was tested in 105 Wistar female rats. Group A rats received .08 mg/kg/day for 3 months; Group B rats received .8 mg/kg/day for 3 months; Group C rats received 8 mg/kg/day for the 1st month, 16 mg/day for the 2nd month, and 32 mg/day for the 3rd month; and Group D rats served as controls without medication. Groups A and B were given the drug with their diet. Group C was dosed by esophageal tube. Some rats in each group died during the investigation. Group C rats consumed 10% less food than control rats and had a slower weight gain (p .001). Ratios of weights of liver, spleen, and kidneys to body weight were high in Group C rats. In Groups B and C rats, ovaries were small and corporalutea were rare and small. Vesicular ovarian follicles were mostly normal. Endometrial glands were less numerous and many were atrophic. It is concluded that lynestrenol was well tolerated by the rats for 3 months. An ovarian-blockade effect had been produced in the rats.^ieng

Toxic dose-range findings and post-treatment reversibility assessment in female rats on a three-month oral treatment with the progestational agent allylestrenol.

PIP: The dosage of allylestrenol which could cause toxic evidence in rats after continuous administration for 90 days was determined. Reversibility of toxic and sexual effects was investigated at 3 weeks posttreatment. Group A rats received 1 mg/kg/day; Group B rats received 10 mg/kg/day; Group C rats received 100 mg/kg/day for 1 month, 200 mg/day for the 2nd month, and 300 mg/day for the 3rd month; and Group D were controls without any dosage. Hematological studies were done before treatment, at termination of treatment, and at the end of the posttreatment period. Some rats died during the therapy period. Postmortem studies were done on all animals. Growth rates were similar during the 1st month but Group C animals did not gain afterward. Food intake was 40% lower in Group C. The A, B, and D groups had similar food consumption. Blood determinations were unchanged in all but Group C rats where cholesterol was 51% higher. Vaginal smears showed no estrus or proestrus in Group C animals whose mean ovary weight was 72% less than controls. A 35% weight drop of adrenals and hypophysis was found in Group C. Liver weights were increased in Group C but no histologic evidence of liver injury was detected. For 3 weeks after completion of treatment no deaths occurred in Group C animals and food intake and body weight gains increased. Hematological and blood biochemical values and organ weights returned to normal in Group C rats.^ieng

Effect of insulin concentration on bioavailability during nasal spray administration.

The bioavailability of rapid-acting insulin administered as a nasal spray was studied in 6 type 1 (insulin-dependent) diabetic patients. They received long-acting bovine insulin (Ultratardum 40 U/ml, Organon) as basal treatment at 8 a.m. Rapid-acting insulin was also administered at 8 a.m., then at noon and 6 p.m, subcutaneously on day 1 as a 100 U/ml solution and intranasally by aerosol spray as a 100 U/ml and 500 U/ml with 1% (w/v) 9 lauryl ether solution on day 2 and day 3 respectively. On days 2 and 3, the dose of insulin was at least nine times higher than the subcutaneous dose on day 1. Free and total plasma insulin concentrations were assayed after the noon insulin administration. The peaks of the free and total plasma insulin levels were reached earlier and the return to basal levels was obtained earlier after nasal insulin administration than after insulin injected subcutaneously. The bioavailability of nasal spray insulin versus subcutaneous insulin with a 100 U/ml insulin solution was similar to that with a 500 U/ml insulin solution: 5.14 +/- 0.38% (m +/- SEM) and 4.64 +/- 0.46% according to the total plasma insulin level. This study suggests that the bioavailability of nasal spray insulin is not increased by increasing insulin concentration in our experimental conditions.

A new non-invasive method for treating insulin-reaction: intranasal lyophylized glucagon.

The main therapeutic indication for glucagon is the treatment of hypoglycaemia in insulin overdosed Type 1 (insulin-dependent) diabetic patients. We have previously shown that an intranasal spray of 7.5 mg glucagon with deoxycholic acid as surfactant was able to correct an i.v. insulin-induced hypoglycaemia in diabetic patients. However, bioavailability and stability needed to be improved before intranasal glucagon could be introduced into clinical practice. This has now been achieved with a freeze-dried mixture of glucagon (1 mg) and glycocholic acid (1 mg) as a surfactant. Kinetics and efficacy have been controlled by (1) comparing subcutaneous and intranasal glucagon in 12 healthy non-hypoglycaemic subjects; (2) testing intranasal glucagon in six Type 1 diabetic patients in whom hypoglycaemia was induced by an i.v. bolus of insulin and (3) comparing subcutaneous and intranasal glucagon in six Type 1 diabetic patients in whom hypoglycaemia was induced by adding extra subcutaneous regular insulin to their usual morning dosage. Our results show that 1 mg of intranasal glucagon is as effective as 1 mg of subcutaneous glucagon in terms of the rise in blood glucose. Differences in kinetics between the subcutaneous and the intranasal routes may be observed: intranasal glucagon initiates the blood glucose rise earlier than does the subcutaneous form but the effect of the latter is more sustained. Glycocholic acid appears to be a perfectly tolerated agent in acute conditions. The use of intranasal lyophylized glucagon, for the reversal of hypoglycaemia in Type 1 diabetes, seems to be a clinically relevant alternative to its parenteral equivalent and should now be ready to be introduced in the market.

Effect of intranasal glucagon on blood glucose levels in healthy subjects and hypoglycaemic patients with insulin-dependent diabetes.

Glucagon in solution with a surfactant (deoxycholic acid 1% w/v) was administered by intranasal spray to 6 healthy fasting subjects and 6 insulin-dependent diabetics with insulin-induced hypoglycaemia. In the normal subjects, intranasal glucagon increased plasma glucose levels, with a dose-response effect. In the diabetic patients, plasma glucose levels showed a mean increase of 100% above nadir values in approximately 26 min in response to 7.5 mg intranasal glucagon; hypoglycaemic symptoms were relieved within about 7 min. These results suggest that intranasal glucagon is effective and may represent an alternative to parenteral glucagon or glucose or to oral sugar as the first-line treatment of hypoglycaemic episodes in insulin-dependent diabetics.

Efficacy and tolerance of intranasal insulin administered during 4 months in severely hyperglycaemic Type 2 diabetic patients with oral drug failure: a cross-over study.

AIMS: We have evaluated the local tolerance and the metabolic efficacy of a lyophilized nasal insulin preparation in 10 severely hyperglycaemic Type 2 diabetic patients. METHODS: The study included two 4-month randomized periods: (A) three preprandial doses of nasal insulin secondarily combined with one evening subcutaneous NPH if the desired glycaemic control was not achieved; (B) two NPH injections daily. We assessed: (i) diabetes control on monthly HbA1c levels and occurrence of hypoglycaemic events; (ii) local tolerance on clinical symptoms, rhinoscopy, nasal muco-ciliary clearance and nasal biopsies; (iii) insulin absorption at months 0 and 4. RESULTS: One patient was withdrawn because of cough and dizziness after each nasal application. HbA1c was not significantly different at month 4 (9.4 +/- 0.5% vs. 8.8 +/- 0.2%, A vs. B). Blood glucose control remained only fair in the majority of our patients. Nasal insulin was able to replace the daytime fraction of the subcutaneous insulin with a 18% efficacy. Side-effects included transient nasal hyperactivity (pruritus, sneezing and rhinorrhoea) and chronic persistence of nasal crusts. Plasma insulin profiles were not significantly different between months 0 and 4. CONCLUSIONS: The utilization of nasal insulin (with or without NPH) was associated with similar diabetes control compared with NPH twice daily. Nasal insulin alone was able to achieve an adequate glycaemic control in three of the 10 patients.