MXPA97000617A - Human therapeutic albumin with low capacity for the fixation of alumi - Google Patents

Abstract

The present invention relates to therapeutic human albumin with a low capacity for fixing aluminum. A therapeutic human albumin with very low aluminum absorption capacity is disclosed, during the storage time in a glass container, in which the final composition of the adjusted albumin solution of stabilizers and isotonia at the concentration of 5.20-25 % protein in aqueous medium, preferably, or at any other acceptable intravenous therapeutic concentration, has a citrate content in the final albumin composition equal to or less than 0.5 mM (millimolar) and, preferably, less than 0.037 mM ( millimola

Description

HUMAN THERAPEUTIC ALBUMIN WITH LOW CAPACITY FOR THE FIXATION OF ALUMINUM The present invention relates to a composition of human therapeutic albumin with characteristics of low capacity for the absorption and fixation of multivalent metals, coming from the container or container in which the solution is found. The present invention has its main application in the field of therapeutic plasma proteins for its intravenous administration, and especially indicated for solutions of albumin, although it is applicable to other proteins of similar behavior. An essential characteristic that any pharmaceutical preparation must possess is its stability until the expiration date. In order to achieve a prolonged stability, possible structural or functional alterations of the active principle are determined. Sometimes there is a degradation or alteration of the product that leads to the generation of undesirable toxic compounds, whose maximum levels are set by Pharmacopoeia or other legal regulations. In the case of plasma proteins by intravenous administration, and in the specific case of some contaminating metals such as aluminum, the concentration should be as low as possible taking into account the toxicity of the product, which at trace level is capable of producing such diseases as certain senile dementias of the Alzheimer type, dialysis encephalopathy, etc. (Klein, Gordon L .: Aluminum in Parenteral Products: Medical Perspective on Large and S all Volume Parenterals, Journal of Parenteral Science &Technology, 43 (3), 120-124 (1989)). From the toxicity studies it can be deduced that aluminum administered intravenously can be accumulated in the tissues and organs (brain), having a toxic effect in patients with renal dysfunctions, due to its poor elimination. For this reason, the European health authorities have set a level of aluminum in intravenous albumin of less than 200 ppb (jug / 1) in solutions at a concentration of 5, 20 or 25% protein. Obviously, the maximum limit of concentration of aluminum in albumin must be met not only after the preparation of the product but also must be maintained on the expiration date. One of the factors that currently limit the lifespan of a therapeutic human albumin is the increase in the concentration of aluminum over time. Said increase in the concentration of aluminum is produced by the absorption of said metal from the glass containers used to contain the albumin. Indeed, it is known that the container of glass used as container of the product there are not negligible amounts of aluminum capable of being extracted from its crystalline network (Hoiberg, Cherles P .: Aluminum in Parenteral Products: Overview of Chemistry Concerns and Regulatory Actions. Parenteral Science &Technology, 43 (3), 127-131 (1989)). The use of commercial vials of neutral glass or borosilicate (type I), of low alkaline extractability, contains greater amounts of aluminum than the silicate glass with standard surface treatment (ammonium salts or sulfur oxides: type II glass), in such a way that the alkalinity test is not directly related to the possible transfer of aluminum by the glass. For this reason, the use of standard commercial glass of type II to type I is preferable. The current technique does not correctly solve the increase of aluminum during storage, mainly at the highest temperatures, understood as those considered environmentally friendly. -35 ° C (Quagliaro, DA et al .: Aluminum in Albumin for Injection, Journal of Parenteral Science &Technology, 42 (6), 187-190 (1988)). To achieve aluminum levels in albumin solution below 200 ppb (μg / 1), not only immediately after manufacture but also on the expiration date, the preparation of the albumin is carried out, avoiding at all times the exogenous contamination of aluminum in any of the phases of the process of the fractionation of human plasma with cold ethanol or Cohn method (Cohn, Y. et al (1946) J. Am. Chem. Soc. 68, 459-475) (use of aluminum-free or low-content clarifying filters, filtering aids pre-washed in an acid medium, acid or alkaline reagents of recent preparation, ...). Using fraction V as the starting material (according to Cohn numbering) to obtain albumin, ultrafiltration dialysis techniques have been introduced to reduce the concentration of aluminum to levels below 200 ppb (μg / 1). These procedures were first introduced in 1987 by the Scottish National Blood Transfusion Service (McBay, WE et al: Aluminum and human albumin solutions, British Medical Journal, 295, 1062 (1987)), then by the Millipore company in collaboration with the Swiss Red Cross (internal communication) and subsequently a similar method was described by Kabi (patent application WO 91/00290). These procedures were based on the washing of the polyvalent metal albumin by an ionic displacement by monovalent metals, during the dialysis operations. Thus, a metal ion such as aluminum is reduced by diafiltration with retaining membranes of 10 kD or 30 kD, which retain proteins (of higher molecular weight) allowing the passage of ions or molecules smaller than the pore of the membrane. This washing is not easily done if the concentration of monovalent ions is not increased (eg, sodium chloride), which allows the displacement of polyvalent metals such as aluminum. One way to keep the concentration of monovalent ions constant (for example, sodium chloride) is by the known technique of diafiltration at constant volume. Current diafiltration techniques of albumin have been introduced with the aim of reducing aluminum (and other metals) to values below 200 ppb, as well as reducing ethanol and excess salts (sodium chloride; or other free compounds of low molecular weight) that may be present in fraction V of the Cohn fractionation method, used as starting material. In this way, it is feasible to reduce aluminum ions below 200 ppb, and even to a value below 50 ppb, with the application of about 3 volumes of a dialysis solution formed by a salt of monovalent ions (sodium chloride). However, the solutions thus obtained, with a level lower than 200 ppb (μg / 1), stored in their final container (glass type I or II) and subjected to storage (stability) at room temperature (25-35 ° C) ), increase their aluminum level over time progressively, so that they easily exceed the established limits of 200 ppm (μg / 1) on expiration date (3 years, for example). Therefore, it is still technically necessary to solve this phenomenon of aluminum increase during the storage period or storage of protein solutions, mainly for albumin, in its glass container. For this reason, the objective of the present invention has been to achieve an albumin preparation with a low aluminum binding capacity, which could be stored at temperatures higher than usual (ambient or higher), or the limit could be extended of validity time or expiration date. Prior to the present invention, it has been a common belief that the transfer of aluminum from the container (glass) was due exclusively to the capacity of fixing and transporting metals of the albumin itself, and therefore a solution to this problem was not feasible, Unless it affects the composition or surface of the glass used (preparation of special glasses, non-standard). The researches carried out by the inventors have allowed to know the causal nature of the phenomenon of aluminum increase during the storage of albumin in vial, and have allowed to develop a final formula of a human therapeutic albumin that solves the aforementioned drawbacks. The fresh or recovered human plasma from which the therapeutic albumin is prepared contains an anticoagulant solution, in whose formula the citrate ion is always present. When studying the partition of citrate within the plasma fractionation, we observed the presence of relevant amounts of this anion in the fraction V used as starting material for the preparation of albumin (approximately 10-20% with respect to the initial content of citrate in the plasma, depending on the separation system of fraction V). This contamination with citrate is present in all albumin solutions prepared by the Cohn method, and the usual concentration exceeds the value of 1 millimoles / liter in the final composition of the finished product (for example at 20% of proteins), despite if the solution of the starting fraction V is diafiltered to eliminate aluminum up to 200 ppb and even 50 ppb or less. Indeed, the inventors have discovered that the presence of citrate (always present in the fraction V used as starting material) in the solutions of albumin stored in glass sharply accelerates the transfer of aluminum by the glass container containing them. This effect has been demonstrated experimentally, showing a logarithmic response between the rate of transfer and the concentration of citrate. Therefore, the citrate should be reduced to levels lower than the eigenvalues of the fraction V. The mechanism of transfer, although currently not well known, is supposed to be based on a balance between the albumin-citrate complex, whose dissociation '- -' by ionic charge would favor the presence of free citrate, capable of inducing the migration of aluminum from the glass. In the absence of free citrate anion, albumin can not itself extract aluminum, although it is nevertheless a good carrier and can be firmly associated with it or any polyvalent metal. As a result of their research, the inventors have discovered that significant reductions in aluminum increase are obtained when the final composition of the adjusted albumin solution of stabilizers and isotonia at the concentration of the, 20 or 25% protein in aqueous medium, preferably, or at any other acceptable therapeutic concentration intravenously, and dispensed to standard commercial (type II) glass containers (vials), preferably, when the citrate content in the final composition of albumin is equal to or less than 0.5 mM (millimolar) and, preferably, less than 0.037 mM (millimolar). The finished product complies with European specifications and regulations, being less than 200 ppb (μg / 1) of aluminum and usually <; 50 ppb (μg / 1) of aluminum. Likewise, the finished product is stable for more than 3 years at a temperature of 25 ¿10 ° C, without exceeding the limits established on maximum aluminum content to the conservation conditions. The invention will be explained below based on examples, not limiting, to carry out the same. EXAMPLE 1 Three groups of fresh frozen plasma, containing ACD (citric / dextrose) as an anticoagulant, were fractionated by the Cohn method until obtaining fraction V. After diafiltering and adjusting to 20% protein concentration in the adjusted sterile bulk, aseptically dosed 50 ml vials (mouth 20 mm f) of standard type II glass (BSN signature), and were hermetically sealed. Subsequently, they underwent pasteurization (10 hours at 60 ° C) and accelerated quarantine (14 days at 31 ° C). Next, the citrate concentration of each batch was determined and an accelerated cession test of aluminum was carried out in 20% packed albumin, when subjected to 45 ° C, in each case determining the aluminum content at different exposure times. The results obtained are shown in Table 1, and are represented graphically in Figure 1, which relates the aluminum content in ordinates with the exposure time, to each of the citrate concentrations obtained.

TABLE 1 Relationship between the final citrate concentration and accelerated aluminum transfer with the storage time at 45 ° C CONCENTRATION CONCENTRATION ALUMINUM (ppb) REGRESSION CITRATE (Exposure time 45 ° C: days) (CORRELATION) (g / 1) (mM) T = 0 T = 30 T = 60 T = 120 LINEAR 0,21 0,71 20,05 110,3 227,35 446 3, 5906-t + 12,42 (r = 0,9992) 0,036 0,12 24,35 75,48 104,25 - 1,2806- t + 30.26 (r = 0.9922) < 0.011 < 0.037 12.13 12.40 20.43 30.60 0.1422-t + 10.20 (r = 0.8941) It should be noted that although the initial aluminum content (T = 0) is of the same order, and very low in all three cases (less than 25 ppb), the same does not occur with the citrate concentration that appears to be directly responsible for the increase of aluminum * with the exposure time at high temperature (45 ° C). Linear correlations are significant in all cases (mainly, those that contain 0.71 and 0.12 mM citrate), and therefore, so are the different slopes of transfer speed. The different aluminum transfer speeds of 3.5906 and 0.1422 ppb / day obtained by the presence of 0.71 or < 0.037 mM citrate in albumin, respectively, indicating that the transfer rate is 3.5906 / 0.1422 = 25 times between the two citrate concentrations. Example 2 Several batches of final adjusted albumin of stabilizers (sodium caprylate and tryptophate) and isotonia (sodium chloride) at a neutral pH were sterilized by filtration.

Each solution was dosed aseptically in two equal parts, in 50 ml vials (mouth 20 mm 0), standard commercial type II glass (BSN signature) and others with special surface treatment (metabisulfite). The content of citrate and aluminum in the dosed vials was determined, verifying that in the final formulation of the albumin of the 3 batches processed, the citrate content was lower than the limit of quantification of the technique (<0.011 g / 1 or <0.037 mM). These batches were subjected to accelerated aluminum transfer at 45 ° C. From each of the batches, a sample was taken to determine the yield of aluminum with time. The results are in the following Table 2: TABLE 2 Accelerated transfer (45 ° C) of aluminum in albumin with respect to the glass of the vial ROAD GLASS CONCENTRATION ALUMINUM CONCENTRATION (ppb), CITRAT0 (Exposure time 45 ° C: days) CORRELATION (g / 1) (m / M) T = 0 T = 30 T = 60 T = 90 T = 120 LINEAR Metabisulfite < 0.011 < 0, 037 12.13 10.73 17.43 13.00 26.13 0.1009-t + 9.83 (special) (± 5.09) (± 0.60) (± 2.75) (± 2.04) (r = 0.7655) Type II < 0.011 < 0.037 12.13 12.40 20.43 18.13 30.60 0.1422-t +10.20 (BSN) (± 4.24) (± 7.33) (± 4.79) (± 3.83) (r = 0.8941) Taking into account the linear correlations obtained in the kinetics of aluminum transfer, with the two groups of vials of different surface treatment of the glass, and the little difference between the slopes of the straight or transfer speeds, it is concluded that the type of glass it is not determinant in terms of aluminum transfer rate, as long as the citrate is sufficiently reduced (close to the detection limit of the technique <0.011 g / 1).

Example 3 The same solution of final albumin stabilized with sodium caprylate and sodium tryptophanate at 0.016 M each, and at 20% protein concentration, containing 0.15 M sodium chloride and adjusted to pH 7.0 + 0.2, was sterilized by filtration with 0.22 μm membrane. Doses of 50 ml type II glass vials were dosed to which known amounts of sodium citrate were added and pasteurized for 10 hours at 60 ° C. They were subjected to accelerated aluminum cession by storing them at 45 ° C. At the times indicated in table 3, samples were taken for the determination of aluminum.

Table 3 Accelerated transfer of aluminum (at 45 ° C) in albumin 20% with respect to the concentration of citrate CONCENTRATION CONCEN TREATMENT ALUMINUM (ppb) CITRAT0 (exposure time 45 ° C: days) (a / 1) (mM) T = 0 T = 30 T = 60 T = 90 T = 150 < 0.011 < 0.037 9.0 10.0 28.2 31.0 43.6 6.12 1.8 164.2 204.6 330.2 - 721.6 9.51 2.8 161.4 240.6 349 - 886 , 4 23.1 6.8 165.6 287.2 418.8 - 913.6 40.1 11.8 177.2 276.3 585 - • 1,176.0 Clearly, the effect of citrate added expressly on the accelerated transfer of aluminum for the same batch of albumin and glass container is verified. The remarkable difference of final aluminum at 150 days at 45 ° C between the albumin solution with < 0.037 mM and 1.8 mM citrate, which corresponds to 43.6 and 721.6 ppb of aluminum respectively. Thus, a small contamination or citrate residue markedly accelerates the transfer of aluminum.

Claims (1)

1. CLAIMS 1. Human therapeutic albumin, with low capacity for aluminum fixation, characterized in that the final composition of the adjusted albumin solution of stabilizers and isotonia at the concentration of 5.20 or 25% protein in aqueous medium, preferably, or any other acceptable intravenous therapeutic concentration, dispensed in glass vials of type II preferably, has a citrate content in the final albumin composition equal to or less than 0.5 mM (millimolar) and, preferably, less than 0.037 mM ( millimolar ').