JPH0366290B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a new, stable insulin formulation particularly adapted for use in continuous insulin delivery devices.

Over the past years, there has been constant increasing effort to develop portable or implantable systems for continuous infusion of insulin, and the primary objective of such efforts has been to address diurnal fluctuations in physiological insulin requirements. The second objective is to give diabetic patients greater control over insulin administration than is possible with conventional insulin administration.

The mechanical part of the device for continuous insulin delivery essentially consists of elements such as an insulin reservoir,
It consists of a pump system and a catheter suitable for delivering insulin to a selected site, which is usually subcutaneous or intraperitoneal. The pump system may be automatically activated and may have additional optional controls to supply insulin when specifically needed.

When the insulin solution is delivered by a syringe, the syringe typically also acts as an insulin reservoir. Syringe-type devices are commonly delivered outside the body. However, all mechanical units are usually constructed for subcutaneous implantation. Significantly more complex systems have also been developed. Insulin reservoirs will usually be adapted for transdermal replenishment.

The propensity of insulin to precipitate from commercially available solutions, thereby causing failure of mechanical parts and delivery catheters, has been found to be a major impediment to the further development and safe clinical application of continuous infusion devices. Additionally, there are obvious reasons for efforts to reduce the size of any type of continuous delivery system, thereby creating a need to obtain more concentrated insulin solutions than were previously available.

It is generally believed that the explanation for the precipitation phenomenon must lie in the tendency of insulin to form insoluble fibrils, particularly when solutions of insulin are kept at high temperatures for long periods of time. There is also evidence that any type of movement of or in the solution induces fibrillation of insulin, including turbulence caused by passage through narrow lumens or pores, for example. Obviously, the insulin solution is exposed to most or all of this type of action in any type of continuous feeding device. The general shortcomings of conventional insulin preparations in this respect are highlighted in the literature, such as a recent research paper by WDLougheed et al. [Diabetologia, vol. 19 (1980)].
1-9].

To solve this problem, acidic insulin solutions or neutral insulin formulations containing sugars such as glucose [DS Schade et al., Satellite Symposium to Sixteenth European Association for the Study of Diabetes Meeting (Satelite-Symposium to16th
European Association for the Study of
Diabetes-Meeting) Greece, September 22, 1980-
23rd, p. 107] or an acidic insulin solution or neutral insulin formulation containing a synthetic nonionic surfactant [H. Thurow, German Patent Application P2952119.5]. It was proposed to do so.

However, insulin is chemically unstable in acids even below body temperature and can react reversibly or irreversibly with carbohydrates. Furthermore, the non-physiological surfactants mentioned above are considered undesirable in drugs for parenteral administration.

These drawbacks have been overcome according to the present invention, which has created a new insulin solution in which the tendency of insulin to precipitate under the conditions prevailing in a continuous insulin delivery device is significantly less than that of conventional insulin formulations. It is something.

The invention is based on the discovery that certain concentrations of calcium or magnesium ions have a stabilizing effect on insulin solutions. This means that
It is generally known that calcium, like many divalent metal ions, forms a poorly soluble complex with insulin and reduces the solubility of zinc insulin at neutral pH [JEPitts et al.: Insulin, Chemistry. , Structure and Function of Insulin and Related Hormones (Insulin, Chemistry,
Structure and Function of Insulin and
Related Hormones), page 674 (Walther de
Gruyter &Co.1980);
Emdin et al.; Diabetologia, vol. 19 (1980), pp. 174-182],
This is a surprising observation.

The present invention comprises a zinc insulin solution, a preservative and optionally an osmotic pressure regulator and/or a PH buffer that does not form complexes or poorly soluble compounds with calcium or magnesium ions, and the conditions prevailing in the insulin delivery system. provides insulin formulations suitable for use in insulin delivery systems by being physically stable under does not exceed an approximate molar concentration of 10 ^-2 , 3 x 10 ^-3 and 2 x 10 ^-3 for insulin concentrations corresponding to 5, 50 and 1000 international insulin units per ml, respectively; Additionally, the concentration of calcium or magnesium in ionized form is at least about 0.4×
10 ⁻³ mol.

In a second aspect of the invention, there is provided a method for producing an insulin formulation suitable for use in an insulin delivery system by being physically stable under the conditions prevailing in the insulin delivery system, the method comprising: Insulin with an essentially ionized form of calcium or magnesium in a concentration sufficient to provide the necessary physical stability, but insufficient to induce precipitation of insulin under normal conditions. It is characterized by the addition of a preservative and optionally an osmotic pressure regulator and/or a PH buffer that does not form a complex or poorly soluble compound with calcium ions or magnesium ions.

Advantageous Embodiments of the Invention and Detailed Description Thereof In general, the stability of an insulin solution (as measured by the test method described below) is determined by increasing the concentration of Ca ⁺⁺ or Mg ⁺⁺ to the point where almost instantaneous precipitation of insulin occurs. As it increases, it increases. At room temperature, Ca ⁺⁺ or
The upper limit of the non-precipitating concentration of Mg ⁺⁺ decreases from about 10 ^-2 mol to about 3 x 10 ^-3 mol over the insulin concentration interval corresponding to 5 to 50 international units (IU) per ml, and 50 to 50 mol per ml. over a concentration interval corresponding to ~ ¹⁰⁰⁰ I.U.

In an advantageous embodiment of the invention, the molar concentration of calcium or magnesium ions in the formulation does not exceed the respective limits and is advantageously greater than or equal to about 0.4×10 ⁻³ . Inorganic acids, such as hydrochloric acid,
Calcium or magnesium salts of sulfuric and nitric acids are preferred, with calcium salts being most preferred.

Preferably, the total molar concentration of salts of metals other than calcium or magnesium, such as sodium salts, does not exceed 0.01 and anions that precipitate or complex calcium or magnesium, such as phosphate, gluconate, citrate or Preferably, the presence of acetate ions is avoided. Therefore, if isotonicity and buffering capacity of an insulin solution is desired, isotonicity is set by a non-electrolyte, such as glycerol, and buffering capacity is set by a non-complexing buffer, such as Tris. is advantageous.

Another preferred embodiment is the use of porcine, bovine or human insulin whose zinc content does not exceed 1% by weight (calculated on the basis of dry insulin crystals). The concentration of insulin in the solution is preferably in the range of 5 to 1500 I.U. per ml, more preferably 40 to 1000 I.U. per ml.

The process for producing the insulin solution of the invention comprises, for example, dissolving crystalline zinc insulin, for example high purity insulin, for example "one-component" insulin (GB 1285023) in water in the presence of an acid, for example hydrochloric acid. Become. an aqueous solution of a preservative, such as a phenol or alkylphenol, such as cresol or methyl parahydroxybenzoate, optionally containing an osmotic agent such as glycerol, preferably in an amount calculated to make the final solution isotonic; Manufactured separately. This solution is then added to the acidic insulin solution, followed by the addition of a base, such as sodium hydroxide solution, to adjust the PH to neutrality. As used herein, neutral is a PH value in the range of about 7-8. At this stage the calculated amount of a calcium or magnesium salt, such as calcium chloride dihydrate, or magnesium chloride hexahydrate, and a buffer (as required), such as Tris, are added and then the PH is readjusted. Alternatively, the calcium or magnesium salt may be dissolved in the acidic insulin solution prior to its neutralization. The resulting solution is finally filled to the calculated volume with water, sterilized by filtration, and then transferred to a sterile vial.

The invention further provides a method for injecting insulin into a human being, characterized in that the insulin preparation used is an insulin preparation according to the invention.

Stability Test The insulin solution thus prepared is subjected to a stability test under strongly controlled conditions in the following manner: Several vials (12.5 ml content) containing the sample (10 ml) each with a rubber cap are heated at 41°C.
A shaking table (HETO, Birkerrod, Denmark) completely immersed in a water bath maintained at ±0.1°C.
01 type T623TBSH02) supplied by T623TBSH02). The platform is subjected to horizontal rocking motions at a frequency and amplitude of 100 rpm and 50 mm, respectively.

The samples are checked for opalescence at regular time intervals with a Fiacher DRT1000 nephelometer with a vial adapter. fibrillation time, sample is 10
Defined as the passage of time to produce turbidity in nephelometric turbidity units (NTU).

Each test is performed with a sample and a control sample without added calcium or magnesium salts is processed in parallel (4-5 vials each).
The stability factor is calculated as the ratio of the mean fibrillation time of the sample to that of the control sample.

Furthermore, details of the implementation of the present invention will be described with reference to the following examples, but these examples are not intended to limit the scope of the present invention in any way.

In the examples, the aqueous solutions and water were sterilized, the aqueous solutions were sterilized by filtration, and the subsequent operations were performed under unconditioned conditions.

Example 1 Calcium chloride per ml in a 2×10 ^-3 molar solution
500 I.U. of Insulin Crystalline monocomponent porcine insulin (7.44 g) containing 0.4% zinc and having a total activity of 200,000 I.U. is dissolved in water (250 ml) containing hydrochloric acid (6.5 ml of 1N) and then An aqueous solution (100 ml) containing glycerol (6.4 g) and phenol (0.8 g) was added to the solution. Adjust the pH of the solution to 7.5 with sodium hydroxide solution,
The total volume was adjusted to 400ml with water. To a known volume (100 ml) of this solution was added 29.4 mg of calcium chloride dihydrate and the resulting solution was sterilized by filtration and then transferred aseptically into a vial (10 ml).

Stability factor: >25 Example 2 Calcium chloride and Tris each 3 x 10 ^-3
and 500 I.U. of insulin per ml in a 0.02 molar solution.Crystalline monocomponent porcine insulin (3.72 g) containing 0.4% zinc and having a total activity of 100,000 I.U. in water containing hydrochloric acid (3.25 ml of 1N) (125 ml) and then an aqueous solution (50 ml) containing glycerol (3.2 g) and phenol (0.4 g) was added. The pH was adjusted to 7.5 with sodium hydroxide solution. Tris (0.48g) and calcium chloride (88mg dihydrate)
was added. The pH was adjusted to 7.5 with hydrochloric acid and the volume was made up to a total of 200 ml with water. The resulting solution was sterilized by filtration and then aseptically transferred into vials (10 ml).

Stability factor: 5.1 Example 3 500 I.U. of insulin per ml in a 0.5 x 10 ^-3 molar solution of calcium chloride Crystalline monocomponent porcine insulin (5.58 g) containing 0.4% zinc and having a total activity of 150000 I.U. ) was dissolved in water (150 ml) containing hydrochloric acid (4.9 ml of 1N) and calcium chloride (22 mg dihydrate), then an aqueous solution (100 ml) containing glycerol (4.8 g) and phenol (0.6 g) was added. did.

The pH of the solution was adjusted to 7.5 with sodium hydroxide solution and the total volume was adjusted to 300 ml with water. The resulting solution was sterilized by filtration and then aseptically transferred into vials (10 ml).

Stability factor: 2.3 Example 4 Calcium chloride per ml in a 2 x 10 ^-3 molar solution
500I.U. of insulin 0.002M with addition of 88mg of calcium chloride dihydrate
The procedure was similar to that of Example 3, except that a solution was made containing calcium chloride.

Stability factor: >25 Example 5 Calcium chloride per ml in a 2 x 10 ^-3 molar solution
200 I.U. of insulin 300 ml of the insulin solution prepared according to Example 4,
Diluted with 450 ml of a neutral aqueous solution containing glycerol (7.2 g), phenol (0.9 g) and calcium chloride (132 mg dihydrate). The resulting insulin solution containing 200 I.U./ml was sterilized by filtration and transferred aseptically into vials (10 ml).

Stability factor: 12 Example 6 Calcium chloride per ml in a 2 x 10 ^-3 molar solution
40 I.U. of Insulin Crystalline monocomponent porcine insulin containing 0.4% zinc and having a total activity of 40000 I.U. is dissolved in 120 ml of water containing hydrochloric acid (1280 μ of 1N), then phenol (2 g) and glycerol. (16 g) in water (730 ml) was added. An aqueous solution (40 ml) containing sodium hydroxide (2000 μ of 1N) was added, followed by an aqueous solution (15 ml) containing calcium chloride (220 mg dihydrate). Finally, the pH was adjusted to 7.4 with sodium hydroxide solution and the total volume was adjusted to 1000 ml with water. Sterilize the solution by filtration;
After that, it was aseptically transferred to a vial (10 ml). Stability factor: 3 Example 7 1 in (2×10 ^-3 ) molar solution of magnesium chloride
Insulin at 500 I.U. per ml Crystalline monocomponent porcine insulin (3.72 g) containing 0.4% zinc and having a total activity of 100000 I.U. is dissolved in water (125 ml) containing hydrochloric acid (3.25 ml of 1N). Then an aqueous solution (50 ml) containing glycerol (3.2 g) and phenol (0.4 g) was added. The pH was adjusted to 7.5 with sodium hydroxide solution. Add magnesium chloride (81 mg hexahydrate), readjust the pH to 7.5 with sodium hydroxide, and bring the volume up to 200 ml with water.
I changed it to ml. The resulting solution was sterilized by filtration and then aseptically transferred into vials (10 ml). Stability factor: 6 Example 8 1 in (2×10 ^-3 ) molar solution of magnesium chloride
100 I.U. of insulin per ml Crystalline monocomponent porcine insulin (3.72 g) containing 0.4% zinc and having a total activity of 100000 I.U. is dissolved in water (125 ml) containing hydrochloric acid (3.25 ml of 1N). , glycerol (16g) and phenol (2
An aqueous solution (800 ml) containing g) was added. The pH was adjusted to 7.5 with sodium hydroxide solution. Magnesium chloride (407 mg hexahydrate) was added, the pH was readjusted to 7.5, and the volume was made up to a total volume of 1000 ml with water. The resulting solution was sterilized by filtration and then transferred to vials (10
ml) aseptically transferred.

Stability factor: 4 Example 9 Calcium chloride per ml in a 2 x 10 ^-3 molar solution
100 I.U. of human insulin Manufactured in accordance with British Published Patent No. 2069502;
Crystalline semi-synthetic human insulin (2.04 g) containing 0.4% zinc and having a total activity of 55000 I.U. was dissolved in water (275 ml) containing hydrochloric acid (1.8 ml of 1N). Calcium chloride dihydrate (14.7 mg) was added to a known amount (25 ml) of this solution, followed by an aqueous solution (20 ml) containing glycerol (0.8 g) and phenol (0.1 g). The pH of the solution was adjusted to 7.4 with sodium hydroxide solution and the total volume was adjusted to 50 ml with water.

The resulting solution was sterilized by filtration and then aseptically transferred into vials (10 ml).

Stability factor: 7.

Claims (1)

[Scope of Claims] 1. A zinc insulin solution, a preservative, and optionally an osmotic pressure regulator and/or a pH buffering agent that does not form complexes or poorly soluble compounds with calcium or magnesium ions, in an insulin supply system. In insulin formulations suitable for use in insulin delivery systems by being physically stable under conditions governing The concentration of calcium or magnesium is 5 per ml,
10 ^-2 and 3 × 10 ^-3 for insulin concentrations corresponding to 50 and 1000 international insulin units, respectively.
and an insulin formulation not exceeding an approximate molar concentration of 2×10 ⁻³ and further characterized in that the concentration of calcium or magnesium in ionized form is at least about 0.4×10 ⁻³ molar. 2. The insulin preparation according to claim 1, wherein calcium or magnesium is supplied by a salt of hydrochloric acid, sulfuric acid or nitric acid. 3. The insulin preparation according to claim 1, which contains calcium essentially in ionized form. 4. The insulin preparation according to any one of claims 1 to 3, having an insulin concentration in a range corresponding to 5 to 1500 international insulin units, preferably 40 to 1000 international insulin units per ml. 5 Claim 1 in which the PH is in the range of 7 to 8
The insulin preparation according to any one of Items 1 to 4.