SK146197A3 - Composition of tyrosine and polymerised allergen - Google Patents

Abstract

A pharmaceutical composition comprising tyrosine and a polymerised allergen is prepared by (a) polymerising an allergen, and obtaining product with molecular weight at least 100kD, (b) mixing an aqueous solution of the allergen with a solution of tyrosine in a strong aqueous acid, (c) neutralising the mixture of solutions, thereby co-precipitating tyrosine and polymerised allergen, and (d) optionally, mixing the product with a physiologically acceptable carrier. Pharmaceutical composition is used for production of medicament to use in desensibilising therapy for allergy.

Description

(57) Annotation:

The process for preparing a pharmaceutical composition comprising a tyrosine and a polymerized allergen comprises the steps of: (a) polymerizing the allergen, (b) mixing an aqueous allergen solution with a solution of tyrosine in an aqueous solution of a strong acid, (c) neutralizing the mixture of solutions optional ratios of mixing the product with a physiologically acceptable carrier. The pharmaceutical composition is used in the manufacture of a medicament for use in desensitizing therapy suffering from allergy.

A pharmaceutical composition, a process for its manufacture and its use

Technical field

The invention relates to a novel composition of the compositions for use in desensitizing therapy suffering from allergy.

BACKGROUND OF THE INVENTION

GB-A-1 492 973 describes a process for the preparation of tyrosine coprecipitates containing a modified dispersed allergen. The allergen has been modified with an agent such as glutaraldehyde, which causes intramolecular cross-links and reduces the hypersensitivity of the product to the unmodified allergen.

EP-A-0 367 306 and Nakada et al. (Allergy, 54 [1985] 437 et seq.) Discloses a process for preparing polymerized allergens by prolonged cross-linking treatment to achieve intermolecular cross-linking, followed by filtration or dialysis to remove unpolymerized product. The polymerized allergens described have reduced allergenicity.

SUMMARY OF THE INVENTION

The present invention provides a pharmaceutical composition of tyrosine and a polymerized allergen. Mostly the allergen is coated and / or adsorbed on tyrosine, for example by coprecipitation.

The allergen may be derived from any allergy-causing substance such as pollen (for example, weed pollen or birch pollen), food, insect venom, mold, animal fur, or domestic fine dust (D.farinae or D. pteronyssinus). In this regard, the allergen is derived from D.pteronyssinus. The term allergen as used herein includes a mixture of allergens, which may be from one or more sources.

The present invention also provides a process for the preparation of a pharmaceutical composition comprising (a) polymerizing an allergen, (b) mixing an aqueous solution of the allergen

(C) neutralizing the mixture of solutions by co-precipitating tyrosine and the polymerized allergen; and (d) optionally mixing the product with a physiologically acceptable carrier.

Suitable physiologically acceptable carriers include phenol salt water and sterile water.

The allergen is polymerized by treatment with a dialdehyde such as glutaraldehyde in an aqueous solution at a pH of from 3 to 10, usually 7 ± 1, and a temperature between 0 to 100 ° C, preferably between 4 to 37 ° C for a maximum of 10 hours, e.g. temperature. The weight ratio of allergen to glutardehyde is usually in the range of 1:25 to 1: 2, for example around 1: 4, although a higher allergen ratio can be used in conjunction with a longer reaction time (see, for example, EP-A-0 367 306 where it was used). ratio about 3: 1 and reaction time about 7 hours).

The low molecular weight product is subsequently removed by gel filtration or dialysis, for example by tangential flow dialysis, the product is freeze-dried or used directly in the next step. The molecular weight is usually interrupted to at least 100 kDaltons, for example at least 250 kDaltons, more preferably 300 kDaltons.

The polymerized allergen solution at pH 7 ± 1, obtained as a reaction mixture from the polymerization process or solid solvation, is mixed with a solution of tyrosine in a strong acid. The strong acid is usually an inorganic acid, preferably hydrochloric acid. The polymerized allergen solution used in this step typically contains the allergen protein in an amount of 0.1 µg / ml to 100 µg / ml. The weight ratio of allergen to tyrosine in the composition is usually in the range of 1: 4.10 ⁵ to 1: 4.10 ² .

The resulting mixture of allergen and tyrosine solutions is neutralized. By neutralization is meant a pH adjustment in the range of 4.0 to 7.5. It is important that in no case, or at least for an extended period of time, during the neutralization the pH of the solution rises well above 7.5. This condition can be met by vigorously mixing the solution using only the required amount of base, if desired. Various buffering agents may advantageously be added to the allergen solutions to promote pH control during the mixing and neutralization stages.

The use of neutralization is to separate the streams of the tyrosine solution by means of an acid while the neutralizing base will pass into the allergen solution. The flow rates of the added solutions are controlled by the pH value by means of a device that regulates the flow of one or both of the solutions so that the pH of the reaction stirring remains substantially constant at a predetermined level. It has been found that optimum results are usually achieved with pH control ranging from 6.5 to 7.5, although the exact pH may vary according to the nature of the allergen.

The result of neutralization is an immediate precipitation of tyrosine in and / or on which the allergen solution is occluded and / or adsorbed. After precipitation, the mixture is immediately eluted or allowed to stand for several hours within one to two days prior to elution. The desired precipitate is obtained as fine as possible and is achieved by rapidly neutralizing the solution associated with vigorous stirring during the reaction.

The resulting precipitate may be separated from the solution by centrifugation or filtration and elution e.g. saline phenol prior to resuspension in a physiologically friendly carrier, such as saline phenol or sterile water, for the preparation of injectable compositions suitable for use in desensitizing therapy.

The following example illustrates the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Example

A neutral solution with approximately 2.5 mg / ml of the extracted D.pteronyssinus protein was partially purified by dialysis or fractionation and was polymerized by adding an equal volume of 1% (mg / ml) glutardehyde solution. The mixture was stirred at room temperature for about 2 hours. The reaction was quenched by supplying an equal volume of 2% (mg / ml) glycine solution. The mixture was stirred for another hour at room temperature. The low molecular weight material was removed by diafiltration through a membrane excreting a molecular weight above 300 kDaltons.

The mixture was then sterile filtered and freeze-dried.

The polymerized allergen solution was also prepared directly from the sterile filtered solution or by freeze-drying the solid. This solution contained 10 μς / ΓηΙ in phosphate buffer at pH 7 ± 1. The allergen solution was co-precipitated with styrosine while adding one volume of a solution of L-tyrosine in HCL (prepared by dissolving 24 g of L-tyrosine in 100 ml of 3.4 M HCL) and one volume of 3.2 M NaOH to four volumes of the allergen solution with vigorous stirring.

The suspension thus prepared was centrifuged, washed repeatedly with saline buffer solution to remove contaminants, and resuspended to the original volume in saline buffer solution pH 6 + 1.

Claims (7)

What is claimed is: 1. A pharmaceutical composition comprising tyrosine and a polymerized allergen. Pharmaceutical composition according to claim 1, characterized in that the allergen is coated with and / or adsorbed to tyrosine. Pharmaceutical composition according to claim 1 or 2, characterized in that the allergen is derived from D.pteronyssinus. A pharmaceutical composition according to any one of claims 1 to 3 for use in therapy. A pharmaceutical composition according to any one of claims 1 to 3 for use in desensitizing therapy suffering from allergy. I A process for the manufacture of a pharmaceutical composition according to any one of the preceding claims, characterized in that it comprises the following steps: (a) polymerizing the allergen, (b) mixing an aqueous allergen solution with a solution of tyrosine in an aqueous solution of a strong acid, (c) neutralizing a mixture of solutions by co-precipitation of tyrosine and a polymerized allergen; and (d) optionally mixing the product with a physiologically acceptable carrier. Use of a pharmaceutical composition according to any one of the preceding claims 1 to 3 in the manufacture of a medicament for use in desensitizing therapy suffering from allergy.