FI96918B - Composition for stabilizing blood plasma during pasteurization - Google Patents

Abstract

Composition for stabilizing blood plasma, whole or lacking cryoproteins, during pasteurization. The composition according to the invention is used for pasteurizing substantial volumes of plasma (up to several hundreds of litres). The invention also concerns a process for the pasteurization of plasma using said stabilizing composition. The pasteurized plasma obtained is for therapeutic use.

Description

96918

Composition for stabilizing blood plasma during pasteurization

The invention relates to a composition for stabilizing blood plasma during pasteurization and to a method using said composition.

Whole human plasma or cryoprocomponent-free human plasma is still used as replacement therapy for severely burned and severely injured or major surgery patients, i.e., in all 10 cases where patients have significant dehydration.

This type of treatment usually uses plasma obtained from individual donors, healthy individuals who have been pre-tested to rule out a possible risk of infection with viral diseases. However, this procedure does not make it possible to avoid all the risks of contamination caused by viruses at the pre-serological stage, in particular the various hepatitis viruses and the AIDS virus.

Therefore, it would be advantageous to develop a method for inactivating viruses that does not affect the various biological functions of the plasma.

It has been clearly shown that the hepatitis B virus is completely inactivated when heated for 10 hours at 60 ° C in the presence of sodium citrate. At 0.5 mol / L [Tabor et al., Thrombosis Res. 22 (1981) 233-238]. However, this treatment results in the loss of biological activity for certain plasma proteins [Tabor et al. and Barrowcliffe et al., Fr.

J. Haemotology 55 (1983) 37-46].

It has been possible to pasteurize various therapeutically valuable, plasma-purified proteins, conventionally at 60 ° C, for 10 hours in the presence of various 2,96918 stabilizers. It should be noted, however, that molecules that stabilize one biological activity may be completely ineffective with another.

For example, albumin can be stabilized with acetyltryptophan and caprylate [Gellis et al., J. Clin. Invest. 27 (1948) 239-244], while plasminogen is not affected at all by these stabilizers. Thrombin can be stabilized at high sugar levels of 10-la [Seegers, Arch. Biochem. 3 (1944) 363-367], while they do not protect prothrombin. The addition of amino acid and sugar has given good results for factor VIII and antithrombin III (DE patent 2,916,711).

EP 0 035 204 discloses the stabilization of α-anti-15 trypsin, antithrombin III, prekallikrein, fibroectin and factor VIII in the presence of a polyol and discloses sucrose as the only example of the latter; however, the publication mentions that factor IX and prekallikrein completely lose their therapeutic activity under the same conditions.

These different experimental results confirm the generally accepted idea that inactivation of whole plasma (fresh plasma, frozen fresh plasma, or cold precipitation supernatant) viruses cannot be achieved by pasteurization.

Since whole plasma is still needed in medicine, the applicant has sought to develop a composition which simultaneously guarantees the protection of the biological activity of all therapeutic agents of interest from denaturation during pasteurization.

However, as the applicant has found that sorbitol provides a certain degree of protection against thermal denaturation when the results vary from one plasma sample to another and the yields are poor, various additional

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96918 3 substances whose mixture with sorbitol would improve its stabilizing effect.

The composition of the invention thus contains a mixture of sorbitol, calcium chloride, heparin and lysine. The concentrations of the various components are adjusted so as to obtain the following final concentrations in the plasma to be pasteurized: - 50 to 80, preferably 60% sorbitol - 0.1 to 1, preferably 0.5 units / ml heparin - 1 to 10, preferably 4 g / l lysine 10 to 3 to 5, preferably 4 mmol / l CaCl 2.

The composition of the invention is added to fresh plasma, frozen and thawed fresh plasma or plasma free of cold precipitating proteins before pasteurization by heating at 60 ± 1 ° C for 10 hours.

After pasteurization, the temperature is gradually lowered to 20 ° C and the solution is dialyzed to remove sorbitol and heparin. The dialysis buffer has a pH of 7 and contains 4-10 mmol / l sodium citrate, 4 mmol / l calcium chloride, 0.13 mol / l sodium chloride and 4 g / l lysine. Dialysis buffers of different compositions can also be used as needed. The solution is then concentrated to restore physiological plasma protein levels. The resulting solution is sterilized by filtration, packaged and frozen or lyophilized.

The invention also relates to a process for the pasteurization of plasma, in which the composition according to the invention is added to the plasma before it is heated and the pasteurized plasma is dialyzed against a buffer as defined above.

This method is particularly advantageous because it can be applied to large batches of plasma collected from multiple sources. More specifically, by pasteurizing batches of 100 to 200 liters or larger, it is possible, after performing appropriate tests, to guarantee that the batches 35 are of uniform quality.

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In addition, batches of plasma pasteurized using the method of the invention can serve as substitutes for patients deficient in coagulation factors for which there are no purified concentrates, such as factor V, XI or XIII.

Pasteurized plasma solutions according to the invention can be used for the treatment of deficiencies of factors V, XI and XIII and, on the other hand, for substitution treatments which require whole plasma or cold precipitation supernatant. The following example illustrates one embodiment of the invention without limiting the scope of the invention.

Example

To the molten plasma (2 L) is added 1000 units of heparin, 8 g of lysine and 220 mg of calcium chloride. The two products are added as salts in powder form with gentle mixing of the plasma. 1200 g of insoluble sorbitol are then gradually poured into the mixture.

Pasteurization is carried out in a 5 liter vessel by heating at 60 eC for 20 to 10 hours using a water bath or a thermostatically controlled tank. After pasteurization, sorbitol and heparin are removed by dialysis using an artificial kidney or an ultrafiltration system such as cartridges using a Pellicon® system. 25 citrate buffer containing 4 g / l lysine, 4 mmol / l

CaCl 2 and 0.13 mol / L NaCl. After dialysis, concentration using the same equipment can be performed to restore coagulation factor concentrations to approximately 1 unit / ml as they are in good quality therapeutic plasma. The product is dialyzed using • an osmolarity of 370 mosmol / l at pH 7. The product is then sterilized by filtration using, for example, a Millipack ™ filter 40 (Millipore) with a pore size of

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96918 s 0.22 μπι. The product is packed in plastic bags for freezing or in bottles for freeze-drying.

Plasma stabilization during pasteurization and ultrafiltration by the addition of calcium, heparin and lysine 5 allows the following yields to be obtained in relation to (compared to "versus") a comparison with a product containing only lysine and sorbitol: FVIIIc 87% versus 66% FVc 77% versus 35% 10 FVIIc 55% versus 52% FIXc 60% versus 49%

Coagulating fibrinogen 81% versus 57% FXI1I 77% versus 71%.

15 No signs of activation of coagulation factors are observed in the presence of this amount of calcium. Thus, the ratio of bovine FVII / coagulant to FVII is 0.95 and that of the reference product is 1.09. The stability tested by monitoring the FVIII activity after storage of the product for 24 hours in a liquid state at ambient temperature is not impaired compared to the control sample (activity yield 100%). This is consistent with a PKA grade of <2% for pasteurized and reference products.

In addition, rat experiments in which the thus pasteurized plasma was injected intravenously show the absence of an antihypertensive effect and do not show any pulse changes.

Claims (9)

Composition for stabilizing blood plasma during pasteurization, characterized in that it is formed from a mixture of sorbitol, heparin, calcium chloride and lysine. Composition according to claim 1, characterized in that the sorbitol concentration is 500 - 800 g / l. Composition according to claim 2, characterized in that the sorbitol concentration is 600 g / l. 4. A composition according to any one of claims 1-3, characterized in that the concentration of heparin is 100-1000 units / l, preferably 500 units / l. Composition according to any one of claims 1-4, characterized in that the calcium chloride concentration is 3-5 mmol / l, preferably 4 mmol / l. 6. A composition according to any one of claims 1-5, characterized in that the concentration of lysine is 1 - 10 g / l, preferably 4 g / l. Process for pasteurizing blood plasma, characterized in that in the plasma a composition according to any one of claims 1-6 is added prior to the heating step and later the said composition is removed by dialysis. Process according to claim 7, characterized in that the dialysis is carried out at a pH of 7 against a buffer solution containing 4-10 30 mmol / 1 sodium citrate, 4 mmol / 1 calcium chloride, 0.13 mol / 1 sodium chloride. and 4 g / l lysine. 9. A process according to claim 7 or 8, characterized in that it can be applied to plasma volumes between 1 liter and several hundred liters.