GB2104382A - Pharmaceutical formulations comprising human insulin and human C-peptide - Google Patents

Abstract

A pharmaceutical composition is disclosed which comprises, in association with a pharmaceutically acceptable carrier, human insulin and human C-peptide in a molar ratio, human insulin to human C- peptide, of from about 1:4 to about 4:1.

Description

SPECIFICATION Pharmaceutical formulations comprising human insulin and human C-peptide.

Diabetes mellitus is a metabolic disorder characterized by the failure of body tissues to oxidize carbohydrates at the normal rate. Its most important factor is a deficiency of insulin. During the last 60 years people suffering from diabetes have been greatly aided by receiving controlled amounts of insulin. To the present time, the insulin used by diabetics has been isolated from animal pancreases, generally bovine and porcine. Both bovine and porcine insulin differ structurally from insulin generated by the human pancreas. Recently, it has become possible, by recombinant DNA methodology, to produce insulin identical to that produced by the human pancreas. The use of such insulin will enable the diabetic to more closely mimic the natural system than heretofore has been possible.

Nevertheless, it long has been recognized that administration of insulin to the diabetic is alone insufficient to restore and/or maintain the normal metabolic state. Although insulin has its manifested effect on carbohydrate metabolism, diabetes mellitus carries additional disorders, most if not all of which are related to the structure and function of blood vessels. The deficiences leading to these disorders rarely are completely corrected by conventional insulin therapy.

Those vascular abnormalities associated with diebetes often are referred to as "complications of diabetes". They consist generally of microangiopathic changes resulting in lesions in the retina and the kidney. Neuropathy represents an additional diabetic complication which may or may not be related directly or indirectly to the noted microangiopathic changes.Examples of specific manifestations of diabetes complications are (1) diseases of the eye, including retinopathy, cataract formation, glaucoma, and extraocular muscle palsies; (2) diseases of the mouth, including gingivitis, increased incidence of dental caries, periodontal disease, and greater resorption of the alveolar bone; (3) motor, sensory, and autonomic neuropathy; (4) largevessel disease; (5) microangiopathy; (6) diseases of the skin, including xanthoma diabeticorum, necrobiosis lipoidca diabeticorum, furunculosis, mycosis, and pruritis; (7) diseases of the kidneys, including diabetic glomeulosclerosis, arteriolar nephrosclerosis, and pylonephritis; and (8) problems during pregnancy, including increased incidence of large babies, stillbirths, miscarriages, neonatal deaths, and congentital defects.

Many, and perhaps all, of the diabetic complications are the result of the failure of insulin alone to restore the body to its natural hormonal balance.

This invention is directed to pharmaceutical compositions that more nearly achieve and maintain natural hormonal homeostatis in a diabetic state than can be achieved by adminstration of insulin alone.

Thus, this invention concerns a pharmaceutical composition which comprises, in association with a pharmaceuticaily acceptable carrier, human insulin and human C-peptide in a ratio on a molar basis, human insulin to human C-peptide, of from about 1:4 to about 4:1.

The two essential constituents of the pharmaceutical compositions of this invention are human insulin and human C-peptide.

Human insulin is available via a variety of routes, including organic synthesis, isolation from human pancreas, conversion of human proinsulin, conversion of isolated animal insulin, and, more recently, recombient DNA methodology.

Using recombinant DNA methodology, human insulin can be prepared by the separate expression and isolation of human insulin A-chain and human insulin B-chain followed by their proper disulfide bond formation. Alternatively, the recombinant DNA expression product can be human proinsulin itself or a human proinsulin precursor which is converted to human proinsulin.

The proinsulin then is enzymatically cleaved, for example, using trypsin and carboxypeptidase B, to produce human insulin.

Human insulin can also be prepared from porcine insulin. Human insulin differs from porcine insulin by a single amino acid, i.e. the B-chain carboxyl terminal amino acid. Alanine, the B-30 amino acid of porcine insulin, is cleaved and replaced by threonine. in this regard, see, for example, U.S. Patent No. 3,276,961.

The other active constituent of the composition of this invention, human C-peptide, is a portion of a peptide present in human proinsulin and to which the insulin A- and B-chains are joined. This peptide, termed a "connecting peptide", is removed during production of human insulin from proinsulin. The connecting peptide present in human proinsulin has the formula Arg-Arg-G I u-Ala-Glu-Asp-Leu-G In-Val-G ly-Gln-Val-G lu-Leu-G Iy-Giy-Gly-Pro-Gly-Ala-Gly-Ser-Leu- Gln.Pro-Leu-Ala-Leu-Glu-Gly-Ser-Leu-Gln-Lys-Arg.

The human C-peptide present in the composition of this invention differs from the connecting peptide by elimination of four amino acids, two at each end. Thus, the human C-peptide has the structure Glu-Ala-Glu-Asp-Leu-G In-Val-G Iy-Gln-Val-Leu-G Iy-Gly-Gly-Pro-Gly-Pro-G Iy-Ala-Gly-Ser-Leu-Gln-Pro- Leu-Ala-Leu-Glu-Gly-Ser-Leu-Gln.

The human C-peptide constituent of the composition of this invention can be produced by chemical synthesis, see, e.g.. N. Yanaihara, C. Yanaihara. M. Sakagami, N. Sakura, T.

Hashimoto, and T. Nishida, Diabetes 27 (suppl. 1), 149-160 (1978), or from human proinsulin as a result of its cleavage to produce human insulin.

As noted, therefore, the active constituents of the composition of this invention are available via a variety of routes including human proinsulin. In broad outline, the production of insulin using recombient DNA methodology involves obtaining. whether by isolation, construction, or a combination of both, a sequence of DNA coding for the amino acid sequence of human proinsulin. The human proinsulin DNA then Is inserted in reading phase into a suitable cloning and expression vehicle. The vehicle is used to transform a suitable microorganism after which the transformed microorganism is subjected to fermentation conditions leading to (a) the production of additional copies of the proinsulin gene-consisting vector and (b) the expression of proinsulin or a proinsulin precursor product.

In the event the expression product Is a proinsulin precursor, it generally will comprise the human proinsulin amino acid sequence joined at its amino terminal end to a fragment of a protein normally expressed in the gene sequence into which the proinsulin gene has been inserted. The proinsulin amino acid sequence is joined to the protein fragment through a specifically cleavable site. typically methionine This product is customarily referred to as a fused gene product.

The proinsulin amino acid sequence is cleaved from the fused gene product using cyanogen bromide after which the cysteine sulfhydrl moietes of the proinsulin amino acid sequence are stabilized by conversion to their corresponding S-sulfonates.

The resulting proinsulin 5-sulfonate is puried. and the purified proinsulin S-sulfonate then is converted to proinsulin by formation of the three properly located disulfide bonds.

Upon purification of the proinsulin. it is enzymatically cleaved, typically using trypsin and carboxypeptidase B, resulting in formation of human insulin and human C-peptide.

The compositions of this invention contain human insulin and human C-peptide in a ratio, on a molar basis, of from about 1:4 to about 4:1 Preferably, the ratio of human insulin to human C-peptide is from about 1 2 to about 2:1. and. most preferably, from about 1:1 to about 2:1.

As noted, the compositions of this invention are useful in promoting the attainment of natural hormonal homeostasis and thereby preventing or substantially diminishing or retarding those recognized diabetic complications. The amount of the compositions of this invention necessary to maintain natural hormonal homeostasis or to achieve a state that more nearly approaches natural hormonal homeostasis in the diabetic, of course, will depend upon the severity of the diabetic condition. Moreover, the amount will vary depending upon route of adminstration.

Uitimately, the amount of composition administered and the frequency of such administration will be at the discretion of the particular physician. In general, however, the dosage will be in the range affording from about 0.02 to about 5 units of human insulin per kilogram body weight per day, and, prefeably, from about 0.1 to about 1 unit of human insulin per kilogram body weight per day.

The composition is administered parentially, including subcutaneous, intramuscular, and intravenous. The compositions of this invention comprise the active ingredients, human insulin and human C-peptide, together with a pharmaceutically acceptable carrier therefor and, optionally, other therapeutic ingredients. The total amount of active ingredients present in the composition ranges from about 99.99 to about 0.01 percent by weight. The carrier must be acceptable in the sense that it is compatible with other components of the composition and is not deleterious to the recipient thereof.

Compositions of this invention suitable for parential adminstration conveniently comprise sterile aqueous solutions and/or suspensions of the pharmaceutically active ingredients, which solutions or suspensions preferably are made isotonic with the blood of the recipient, generally using sodium chloride, glycerin, glucose, mannitol, sorbitol, and similar known agents. In addition, the compositions may contain any of a number of adjuvants, such as buffers, preservatives, dispersing agents, agents that promote rapid onset of action, agents that promote prolonged duration of action, and other known agents. Typical preservatives are, for example, phenol, imcresol, methyl phydroxybenzoate, and others. Typical buffers are, for example, sodium phosphate, sodium acetate, sodium citrate, and others.

Moreover, an acid, such as hydrochloric acid, or a base, such as sodium hydroxide, can be used for pH adjustment. In general, the pH of the aqueous composition ranges from about 2 to about 8, and, preferably, from about 6.8 to about 8.0.

Other suitable additives are, for example, divalent zinc ion which, if present at all, is generally present in an amount from about 0.01 mg. to about 0.5 mg. per 100 units of human insulin, and protamine salt (for example, in the form of its sulfate), which, if present at all, is generally present in an amount from about 0.1 mg. to about 2 mg. per 100 units of human insulin.

Examples of particular pharmaceutical compositions of this invention are provided in the examples appearing herein below.

Example 1 - Neutral Regular Human Insulin:Human C-peptide Formulation [1:4 human insulin:human C-peptide on molar basis at 40 units (U) insulin per cubic centimeter(cc.)] To prepare 10 cc. of the composition, mix Human Zinc Insulin (28 U/mg.) 400 U Human C-Peptide 30 mg.

Phenol, distilled 20 mg.

Glycerin 160 mg.

Water and either 10% hydrochloric acid or 10% sodium hydroxide sufficient to make a composition volume of 10 cc. and a final pH of 7.0-7.8.

Example 2 - Neutral regular Human Insulin:Human C-peptide Formulation [1:1 human insulin:human C-peptide on molar basis at 100 U insulin per cc.] To prepare 10 cc. of the composition, mix Human Zinc Insulin (28 U/mg.) 1000 U Human C-Peptide 1 9 mg.

Phenol, distilled 20 mg.

Glycerin 160 mg.

Water and either 10% hydrochloric acid or 10% sodium hydroxide sufficient to make a composition volume of 10 cc. and a final pH of 7-0-7.8.

Example 3- Protamine, Zinc Human Insulin:Human C-peptide Formulation [1:1 human insulin:human C-peptide on molar basis at 40 U insulin per cc.] To prepare 10 cc. of the composition, mix Human Zinc Insulin (28 U/mg.) 400 U Human C-Peptide 8 mg.

Phenol, distilled 25 mg.

Zinc Oxide 0.78 mg.

Glycerin 160 mg.

Protamine Sulfate 4.0-6.0 mg.

Sodium Phosphate, crystals 38 mg.

Water and either 10% hydrochloric acid or 10% sodium hydroxide sufficient to make a composition volume of 10 cc. and a final pH of 7.1-7.4.

Example 4 - Protamine, Zinc Human Insulin:Human C-Peptide Formulation [2:1 human insulin:human C-peptide on molar basis at 100 U insulin per cc.] To prepare 10 cc. of the composition, mix Human Zinc Insulin (28 U/mg.) 1000 U Human C-Peptide 9 mg.

Phenol, distilled 25 mg.

Zinc oxide 2.0 mg.

Glycerin 160 mg.

Protamine Sulfate 10-15 mg.

Sodium Phosphate, crystals 38 mg.

Water and either 10% hydrochloric acid or 10% sodium hydroxide sufficient to make a composition volume of 10 cc. and a final pH of 7.1-7.4.

Example 5- Isophane Protamine, Zinc Human Insulin:Human C-peptide Formulation [1:1 human insulin:human C-peptide on molar basis at 40 U insulin per cc.] To prepare 10 cc. of the composition, mix Human Zinc Insulin (28 U/mg.) 400 U Human C-Peptide 8 mg.

tmCresol, distilled 1 6 mg.

Phenol, distilled 6.5 mg.

Glycerin 160 mg.

Protamine Sulfate 1.2-2.4 mg.

Sodium Phosphate, crystals 38 mg.

Water and either 10% hydrochloric acid or 1 0% sodium hydroxide sufficient to make a composition volume of 10 cc and a final pH of 7.1-7.4.

Example 6 - Isophane Protamine. Zinc Human Insulin:Human C-Peptide Formulation [4:1 human insulin:human C-peptide on molar basis at 100 U insulin per cc.] To prepare 10 cc. of the composition, mix Human Zinc Insulin (28 U/mg.) 1 000U Human C-Peptide 5 mg.

mCresol, distilled 1 6 mg.

Phenol, distilled 6.5 mg.

Glycerin 160 mg.

Protamine Sulfate 3.0-6.0 mg.

Sodium Phosphate, Crystals 38 mg Water and either 10% hydrochloric acid or 1 0% sodium hydroxide sufficient to make a composition volume of 10 cc. and a final pH of 7.1-7.4.

Example 7 - Zinc Human Insulin Suspension:Human C-Peptide Formulation [1:2 human insulin: human C-peptide on molar basis at 40 U insulin per cc.] To prepare 10 cc. of the composition, mix Human Zinc Insulin (28 U/mg.) 400 U Human C-Peptide 1 5 mg.

Sodium Acetate, Anhydrous 1 6 mg.

Sodium Chloride, Granular 70 mg.

Methyl p-Hyroxybenzoate 1 0 mg.

Zinc Oxide 0.63 mg.

Water and either 10% hydrochloric acid or 1 0% sodium hydroxide sufficient to make a composition volume of 10 cc. and a final pH of 7.2-7.5.

Example 8- Zinc Human Insulin Suspension:Human C-Peptide Formulation [1:1 human insulin:human C-peptide on molar basis at 100 U insulin per cc.] To prepare 10 cc. of the composition, mix Human Zinc Insulin (28 U/mg.) 1000 U Human C-Peptide 1 9 mg.

Sodium Acetate, Anhydrous 1 6 mg.

Sodium Chloride, Granular 70 mg.

Methyl p-Hydroxybenzoate 10 mg.

Zinc Oxide 1.6 mg.

Water and either 1 0% hydrochloric acid or 10% sodium hydroxide sufficient to make a composition volume of 10 cc. and a final pH of 7 2-7.5.

Example 9 - Neutral Regular Human Insulin:Human C-Peptide Formulation [1:4 human insulin:human C-peptide on molar basis at 40 U insulin per cc.] To prepare 10 cc. of the composition, mix Human Sodium Insulin (28 U/mg.) 400 U Human C-Peptide 30 mg.

Phenol, distilled 20 mg.

Glycein 160 mg.

Water and either 10% hydrochloric acid or 10% sodium hydroxide sufficient to make a composition volume of 10 cc. and a final pH of 7.0-7.8.

Example 10- Neutral Regular Human Insulin:Human C-Peptide Formulation [1:1 human insulin:human C-peptide on molar basis at 100 U insulin per cc.] To prepare 10 cc. of the composition, mix Human Sodium Insulin (28 U/mg.) 1000 U Human C-Peptide 19 mg.

Phenol, distilled 20 mg.

Glycerin 160 mg.

Water and either 10% hydrochloric acid or 10% sodium hydroxide sufficient to make a composition volume of 10 cc. and a final pH of 7.0-7.8.

Claims (6)

1. A pharmaceutical composition which comprises, in association with a pharmaceutically acceptable carrier, human insulin and human C-peptide in a ratio on a molar basis, human insulin to human C-peptide, of from about 1:4 to about 4:1.

2. Composition of claim 1, in which the molar ratio of human insulin to human C-peptide is from about 1:2 to about 2:1.

3. Composition of claim 1, in which the molar ratio of human insulin to human C-peptide is from about 2:1.

4. Composition of claim 1, which contains divalent zinc ion.

5. Composition of claim 1, which contains protamine salt.

6. A pharmaceutical composition as claimed in claims 1 to 5, substantially as hereinbefore described with reference to any one of the examples.