RU2724880C1 - Method of producing radionuclide-labeled microspheres - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention relates to a method of producing radionuclide-labeled microspheres. Method involves emulsification of albumen solution in vegetable oil, thermal treatment of the emulsion, filtration of the formed initial microspheres of albumin, introduction of trivalent radionuclide into initial microspheres of albumen and production of radionuclide-labeled microspheres. First, fraction of initial albumin microspheres with size of 32.5±7.5 mcm, diethylenetriaminepentaacetic acid is added therein and modified albumin microspheres are obtained. Obtained albumin microspheres are converted into lyophilic form by their lyophilic drying and treated with radionuclide solution in hydrochloric acid at pH 3÷5 with subsequent heating at temperature of 90÷100 °C for 85÷95 minutes. Then, radionuclide labeled microspheres are extracted from the suspension by centrifuging.

EFFECT: enlarging the range of the obtained radionuclide-labeled microspheres of albumin.

5 cl, 1 dwg

Description

The invention relates to nuclear medicine, namely to the preparation of preparations labeled with radioactive isotopes.

A known method of producing microspheres for radionuclide therapy [RF patent No. 2485059. "A method of producing microspheres for radiotherapy", publ. 06/20/2013.].

The method includes the formation of microspheres, obtaining a suspension, washing the suspension and subsequent irradiation with thermal neutrons in the reactor, including the formation of microspheres in the form of glass particles by fusion of silicon oxides, yttrium and aluminum.

The disadvantage of this method is the need to use for labeling microspheres only short-lived isotopes with a high value of the activation cross section.

Closest to the technical nature of the claimed solution is a method for producing labeled with a radionuclide microspheres [RF patent No. 2359702. "A method of producing radionuclide-labeled microspheres", publ. 06/27/2009].

The method includes emulsifying albumin in vegetable oil, heat treating the emulsion and filtering the formed albumin microspheres, mixing the stable palladium isotope and palladium-103 radionuclide in the form of palladium chloride in a 0.1 M hydrochloric acid solution with albumin microspheres, processing the resulting mixture with ultrasound to obtain a homogeneous suspension, holding the resulting homogeneous suspension at room temperature for 18-24 hours, isolating the microspheres labeled with a radionuclide from the suspension by centrifugation, and then reducing palladium with sodium hydrosulfide.

A disadvantage of the known technical solution is the need to use only isotopes of noble metals for tagging microspheres.

The objective of the invention is to eliminate this drawback, namely, to provide the possibility of using for labeling microspheres of isotopes other than isotopes of noble metals.

EFFECT: expanding the assortment of albumin microspheres labeled with radionuclides.

In order to achieve the indicated technical result, in the method for producing radionuclide-labeled microspheres, including emulsifying a solution of albumin in vegetable oil, heat treating the emulsion, filtering the resulting albumin microspheres and incorporating the radionuclide into the initial microspheres, it is proposed:

- sequentially isolate the fraction of the initial albumin microspheres with a size of 32.5 ± 7.5 microns (this size of the microspheres is most optimal for their use in the treatment of liver tumors by radioembolization);

- introduce diethylenetriaminepentaacetic acid into the isolated initial albumin microspheres to obtain modified albumin microspheres chemically bound to diethylenetriaminepentaacetic acid;

- translate the obtained modified albumin microspheres into a lyophilic form by freeze drying them;

- treated with a solution of a radionuclide in hydrochloric acid at pH 3 ÷ 5, followed by heating to ensure complete binding of the microspheres with the radionuclide;

- isolate microspheres labeled with a radionuclide from the suspension. In particular cases of application of the method it is proposed:

- firstly, as a radionuclide use trivalent radionuclides used in radiotherapy;

- secondly, to conduct the processing of microspheres with a radionuclide solution at a temperature of 90 ÷ 100 ° C;

- thirdly, heat the radionuclide solution with microspheres for 85 ÷ 95 minutes;

- fourthly, to isolate microspheres labeled with a radionuclide from the suspension by centrifugation.

The invention is illustrated in the flowchart of a method for producing labeled with a radionuclide microspheres, shown in the figure.

The method includes emulsification of a solution of albumin in vegetable oil, heat treatment of the emulsion, filtration of the formed initial albumin microspheres, inclusion of a radionuclide in the initial microspheres of albumin, and preparation of microspheres labeled with a radionuclide and isolation of microspheres labeled with a radionuclide from the suspension.

When emulsifying a solution of albumin in vegetable oil, 1.0 ÷ 2.0 g of albumin is dissolved in 10 ÷ 20 ml of distilled water. The resulting solution is introduced dropwise into a reaction vessel containing 500 ÷ 1500 ml of vegetable oil with stirring at a speed of 1000 ÷ 2000 rpm to obtain a homogeneous mixture.

In a particular case, the emulsification of a solution of albumin in vegetable oil is carried out using albumin of human blood and olive oil.

During heat treatment, the emulsion is heated to 130 ÷ 150 ° C for 2.0 ÷ 2.5 hours, without stopping mixing to denature albumin with the formation of microspheres insoluble in vegetable oil.

Filtration of the formed initial albumin microspheres is carried out by filtering them, washing the precipitate of the initial albumin microspheres from vegetable oil with 4 ÷ 6 portions of 25 ml of diethyl ether and drying it at room temperature.

When a radionuclide is included in the initial albumin microspheres, the following operations are performed sequentially:

- isolate the fraction of the initial albumin microspheres with a size of 32.5 ± 7.5 microns;

- diethylene triamine pentaacetic acid is introduced into the isolated initial microspheres of albumin;

- get modified albumin microspheres chemically bound to diethylene triamine pentaacetic acid; the obtained modified albumin microspheres are converted into a lyophilic form by freeze drying them and treated with a solution of a radionuclide in hydrochloric acid at pH 3 ÷ 5, followed by heating.

After separation of the fraction of modified albumin microspheres, it is dried at a temperature of 90 ÷ 100 ° C for 2.0 ÷ 2.5 hours.

When diethylenetriaminepentaacetic acid is introduced into the isolated initial microspheres of albumin, 0.7 ÷ 1.5 g of diethylene triamine pentaacetic acid dianhydride and 15-30 ml of pyridine are introduced into the reaction vessel, and the resulting mixture is heated at a temperature of 60 ÷ 70 ° С for 10-15 minutes. with stirring, after which 0.7 ÷ 1.5 g of dry isolated initial albumin microspheres are added to it and the reaction mixture is stirred for 6 hours at the same temperature. After completion of the reaction, a suspension of modified albumin microspheres chemically bound with diethylene triamine pentaacetic acid is filtered off and the precipitate of modified albumin microspheres is washed successively with acetic anhydride (50–70 ml), water (50–70 ml), 0.1 M hydrochloric acid solution (50–70 ml ), saturated sodium carbonate solution (50–70 ml), water to pH 7 and ethyl alcohol (50–70 ml), then the obtained modified albumin microspheres are dried.

Modified albumin microspheres are converted into a lyophilic form by freeze drying, for which 24–30 ml of water for injection and 10–15 mg of Tween-80 are placed in a glass container, the mixture is thoroughly mixed. 250–300 mg of dry modified albumin microspheres are added to the resulting solution, the resulting mixture is stirred for 15–20 min until a homogeneous suspension is obtained. The resulting suspension of modified albumin microspheres is packaged in 10 ml injection bottles of 2 ml each. Freeze drying of microspheres of albumin modified with diethylene triamine pentaacetic acid is carried out (the whole process is carried out in a stream of argon). Vials with the obtained lyophilizate of modified albumin microspheres are sealed with rubber stoppers and rolled with aluminum caps.

When processing modified albumin microspheres in lyophilic form with a radionuclide solution, 0.8 ÷ 1.2 ml of water for injection is added to the vial containing the modified albumin microspheres and the contents of the vial are voiced in an ultrasonic bath for 3 ÷ 5 min. After that, the pH is adjusted to 2.0 ÷ 2.2 of the resulting suspension of modified albumin microspheres with 3.0 ÷ 3.5 M hydrochloric acid solution and 200 ÷ 250 mCi of a solution of radionuclide chloride in 0.1 ml of 0.01 ÷ 0 is added to it 05 M hydrochloric acid. The resulting suspension of modified albumin microspheres with the added radionuclide solution is stirred for 5 ÷ 10 minutes. and then bring it with 1.0 ÷ 1.5 M sodium bicarbonate solution to pH 3 ÷ 5.

In special cases, firstly, they treat the microspheres with a radionuclide solution at a temperature of 90 ÷ 100 ° C; secondly, the duration of heating a suspension of modified albumin microspheres with an added radionuclide solution is 85 ÷ 95 minutes.

The introduction of diethylene triamine pentaacetic acid into the isolated initial microspheres of albumin and the preparation of modified albumin microspheres chemically associated with diethylene triamine pentaacetic acid are carried out using diethylene triamine pentaacetic acid dianhydride.

In a particular case, modified albumin microspheres in lyophilic form are treated with solutions of trivalent radionuclides used in radiotherapy.

The modified albumin microspheres in lyophilic form are treated with solutions of the following radionuclides: scandium-47, yttrium-90, yttrium-91, indium-114m, lutetium-177, promethium-149, samarium-145, terbium-149, terbium-151, terbium-161 , dysprosium-165, holmium-166, erbium-169, thulium-170, ytterbium-169, bismuth-212, bismuth-213, actinium-225.

In a particular case, those labeled with a radionuclide are isolated from the suspension by centrifugation.

An example of a specific application of the method of producing radionuclide labeled microspheres.

The albumin solution is emulsified, for which 1.5 g of human blood albumin is dissolved in 11.6 ml of distilled water, and the resulting solution is introduced dropwise into a reaction vessel containing 900 ml of olive oil with stirring at a speed of 1500 rpm.

The emulsion is heat treated by heating it to 150 ° C for 2.0 hours without stopping mixing.

The resulting initial albumin microspheres are filtered by precipitation on a glass filter, washing the precipitate of the initial albumin microspheres from olive oil with 4 portions of 25 ml of diethyl ether and drying it at room temperature.

A fraction of the initial albumin microspheres of size 32.5 ± 7.5 μm was isolated on the microsieves using an ultrasonic disintegrator in ethanol, followed by drying of the obtained fraction at a temperature of 100 ° C in a dry heat oven for 2.0 hours.

Diethylenetriamine pentaacetic acid is introduced into the isolated initial microspheres of albumin, for which 1.0 g of diethylene triamine pentaacetic acid dianhydride and 20 ml of pyridine are placed in a 250 cm ³ round bottom flask equipped with a reflux condenser and a calcium chloride tube. The flask was placed in a water bath located on a magnetic stirrer and the resulting mixture was heated at a temperature of 65 ° C for 10 minutes. with stirring, after which 1.0 g of dry isolated initial albumin microspheres are added to it and the reaction mixture is stirred for 6 hours at the same temperature. After completion of the reaction, a suspension of modified albumin microspheres chemically bound with diethylene triamine pentaacetic acid is filtered off on a glass filter and the precipitate of modified albumin microspheres is washed successively with acetic anhydride (60 ml), water (60 ml), and a 0.1 M hydrochloric acid solution (60 ml), saturated a solution of sodium carbonate (60 ml), water to pH 7 and ethanol (60 ml), then the obtained modified albumin microspheres are dried in a Fischer gun.

Modified albumin microspheres are converted into a lyophilic form by freeze drying, for which 26 ml of water for injection and 13 mg of Tween-80 are placed in a 50 ml round bottom flask equipped with a magnetic stirrer, and the mixture is thoroughly mixed. 260 mg of dry modified albumin microspheres are added to the resulting solution, and the resulting mixture is stirred for 15 minutes until a homogeneous suspension is obtained. The resulting suspension of modified albumin microspheres is packaged with a micropipette with a face value of up to 5 ml in injection bottles with a capacity of 10 ml of 2 ml each (13 bottles in total; the whole process is carried out in an argon stream). Vials with modified albumin microspheres c are placed in a sublimator chamber on a shelf cooled to -40 ° C, frozen and the sublimator vacuum pump is turned on under a pressure of 0.2 mmHg. Art. using a vacuum pump. The modified albumin microspheres are freeze-dried for 48 hours, after which the chamber is filled with dry argon to atmospheric pressure. Bottles with the obtained lyophilizate of modified albumin microspheres are removed from the chamber and sealed with rubber stoppers and rolled with aluminum caps (each vial contains 20 mg of lyophilisate of modified albumin microspheres and 1 mg of Tween-80).

The modified albumin microspheres in lyophilic form are treated with a radionuclide solution: 1.0 ml of water for injection is added to the vial with the modified lyuminized microspheres of albumin obtained and the contents of the vial are voiced in an ultrasonic bath for 3 minutes. After that, the pH of the resulting suspension of modified albumin microspheres was adjusted to 2.2 with a 3.0 M hydrochloric acid solution and 200 mCi of a solution of yttrium-90 chloride in 0.1 ml of 0.05 M hydrochloric acid was added to it. The resulting suspension of modified albumin microspheres with added yttrium-90 solution was stirred for 5 minutes. on the apparatus for stirring and then adjust its pH with a 1.0 M sodium bicarbonate solution to 5.

The resulting suspension of modified albumin microspheres with the added yttrium-90 solution is heated at a temperature of 95 ° C for 90 minutes.

Microspheres labeled with a radionuclide are isolated from the suspension by centrifugation.

As a result, microspheres labeled with a radionuclide with an average activity of yttrium-90 included of 170 mCi were obtained.

The closest technical solution relates to a narrow range of albumin microspheres labeled with radionuclides. Their number is approximately 3-4 radionuclides.

The technical solution allows to expand the range of obtained albumin microspheres labeled with radionuclides, namely, to obtain albumin microspheres labeled with trivalent radionuclides used in nuclear medicine. Their number is at least 15.

Claims (5)

1. A method of producing radionuclide-labeled microspheres by emulsifying a solution of albumin in vegetable oil, heat treating the emulsion, filtering the resulting albumin microspheres, incorporating a radionuclide into the albumin microspheres, and producing radionuclide-labeled microspheres, characterized in that they are sequentially isolated to incorporate the radionuclide into the albumin microspheres a fraction of the initial albumin microspheres with a size of 32.5 ± 7.5 μm, is introduced into diethylene triamine pentaacetic acid into the selected initial albumin microspheres, and modified albumin microspheres chemically bound to diethylene triamine pentaacetic acid are obtained; the modified albumin microspheres obtained are converted into a lyophilic form by freeze drying them hydrochloric acid at pH 3 ÷ 5, followed by heating, then the microspheres labeled with a radionuclide are isolated from the suspension. 2. The method according to p. 1, characterized in that as the radionuclide use trivalent radionuclides used in radiotherapy. 3. The method according to p. 1, characterized in that the processing of the microspheres with a solution of a radionuclide is carried out at a temperature of 90 ÷ 100 ° C. 4. The method according to p. 1, characterized in that the duration of the heating of the suspension of modified albumin microspheres with the added radionuclide solution is 85 ÷ 95 minutes. 5. The method according to p. 1, characterized in that the microspheres labeled with a radionuclide are isolated from the suspension by centrifugation.

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