HU196315B - Diagnostic preparations for detecting pulmonary lesions and process for producing the same - Google Patents

Abstract

The present invention relates in particular to a diagnostic solid specimen containing radiolabelled solid particles for detecting pathological lesions of the lung, characterized in that it has an isotope-labeled solid of 0.1 to 1.0 µm diameter, commonly used in medical diagnosis, with 8-hydroxyquinoline. latex particles or silica gel particles of 5 to 10 µm in diameter and optionally suspending agent. -1-

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates in particular to diagnostic agents containing labeled microparticles and inacroparticles for the detection of pathological lung lesions and to a process for their preparation.

More particularly, the present invention relates to isotope-labeled, biologically indifferent, monodisperse, micro- and macroparticulate diagnostics for the detection of pathological lesions and functional disorders that are localized to various areas of the lungs. These diagnostics are also suitable for scintigraphy and detectable radionuclides.

The diagnostics of the present invention are advantageously used for the joint or separate examination of the lung tracheal bronchial and / or alveolar self-cleaning mechanism, the simultaneous monitoring of the upper respiratory self-cleaning mechanism and lung ventilation, and the diagnosis of lung connective tissue and malignant lesions. Compared to other formulations used in this field, the subject subject is less exposed to radiation.

In addition to medical diagnostics, the diagnostics of the present invention are advantageously useful in animal experiments for the experimental study of the above group of questions.

Currently, the clinic has 99m ^r p _c for pulmonary scintigraphy. _{nia,) va-based} human serum albumin labeled Eng ll3min dIII (USA) particles in (0.1 to 10 pm) and makroaggregátokat (10,100 PTN) is used [Chest 83: 127; 250 (1983); Chem. Abs. 97, 70942m (1979); 32993q (1975)].

These are delivered by inhalation. In addition, the isotopically-labeled cxides of various metals are 2 to 5 µm, e.g. HeadO ₃ , [Chem. Abs. 94, 152646u (1981)], and the use of Teflon particles labeled with 5-7 µm ^99m Tc (Europcan Journal of Respiratory Discase 61, 47 (1980)).

The presently used compositions have several disadvantages. Thus, the monodispersity of HSA microparticles and macroaggregates labeled with 'Tc' and ¹ > Jn for ventilation studies is inadequate. Therefore, they are deposited to different degrees in the respiratory tract of the lungs, depending on the particle size distribution, which makes it difficult or even impossible to evaluate the scintigram. Another disadvantage of HSA-based microparticles is that they are quite stable so that they begin to break down in the body immediately after inhalation. This means that the signaling isotope is released from the particles and can be detected independently, thereby increasing background activity and falsifying the test result.

The disadvantage of labeled metal oxide diagnostics is that they are sometimes toxic and only slowly cleared from the body. The disadvantage of those containing tellon support is the relatively high purchase price and the fact that the signaling isotope is not chemically bonded to the surface of the Teflon.

SUMMARY OF THE INVENTION The object of the present invention is to overcome the above drawbacks by monodisperse, inert biological, inert, isotopically short-lived isotopes of the size most suitable for biological assays, non-degradable, non-lung, and nuclear scintigraphy for the preparation of a composition comprising traceable particles.

The invention is based on the discovery that the binding stability of the labeled isotopes can be substantially increased by binding a complexing agent to the surface of the solid support. Of the known complexing agents, e.g. ethyleneamino-tetraacetic acid, salicylic acid, anthranilic acid, 8-hydroxyquinoline, 8-hydroxyquinoline being most preferred. It has been found that the above objectives are more prominent in the range of 0.15 to 1.0 µm, latex (e.g., polystyrene glycine acrylate) and 5 to 10 µm, silica-based, isotope-labeled "functional groups on particles"; they form a stable complex with nearly 60 metals, and some of these metals have been labeled with particles with short half-life isotopes used in medical diagnostics.

The odorless silica gel modified with the 8-hydroxyquinoline functional group is stable from 0 to 9, optimally at pH 7.5, and can last for years at room temperature. Similarly, latex particles modified with the 8-hydroxyquinoline n-group remain stable for half a year at pH 2-14, optimally 4 to 9, even at 4 ° C in physiological saline solution (e.g. physiological saline). Both functionalized media can be sterilized at 100 ° C for 100 minutes prior to isotopic labeling

Based on the above, the present invention is a diagnostic diagnostic of particulate solid carrier particles, particularly characterized by a tube with 8-hydroxyquinoline residues, for the detection of pathological changes in the lungs. solid-state microparticles of 0.1 to 1.0 p in diameter labeled with isotopes labeled in Italian for use in medical diagnosis and / or

It also contains niacroparticles having a diameter of 5 to 10 μ, optionally under physiological conditions and suspending medium to provide an appropriate β 1 -value.

The solid carrier used is required to be biologically inert, of suitable size, monodisperse and sterilizable.

One carrier for the diagnostic of the present invention, preferably silica gel. Suitably sized silica gel containing the 8-hydroxyquinoline moiety is commercially available (e.g., 5 or 7 pm from Serva; Anal. Chem. 51, 366, 1979). The number of functional groups on silica gel was 600 pmol / g gel Olt. The surface area of the gel, determined by nitrogen adsorption with the BET (Rrunauer-Emmett-Teller) equation, was 320 m ² / g.

The other carrier material of the diagnostic agent of the invention may be any biologically inert latex. Latex is referred to as an aqueous dispersion of fine particulate polymers and copolymers (0.1-1.0 µm diameter). According to the invention, they are prepared so that any inert polymer is suitable, preferably

196,315

0.1 1.0 sheep grains on an inlet surface of a l'enylamoyl group to which 8-hydroxyquinoline is coupled. Thus, the latex is approx. 200-300μηιο1 quinoline / g latex may be added. The BET value is 60 m ² / g.

Particles can be labeled using isotopes commonly used in medical diagnostics, e.g. Cr, Mii, Fc, Ga, In, TI, Te, Λιι, Th, Ag, etc. Of these, preferably a few hours. Or several days lived 'technéeiumot or ^1' - ^ indiumol 'and be used a longer half-life (27 days) ⁵¹ chromium.

Micro- and macroparticles labeled with short half-life isotopes ( ^99m Te, ¹¹³ⁿ 'In) are useful in human diagnostics.

However, the micro- and macroparticles labeled with longer half-life isotopes ( ⁵¹ Cr, ⁵⁹ Fe, ^ski Mn, ⁶⁷ Ga, ⁿ Ag) can be advantageously used in animal studies of healthy and pathological lung self-cleaning processes, lung ventilation, pharmacology, occupational health, etc. territory.

Isotopically-labeled 8-hydroxyquinoline particles, either silica gel or latex carrier, are stable in the pH range of 3 to 9, but especially in the range of 5 to 7. The labeled isotope can be washed off the surface of the particles with only 1 M hydrochloric acid. Λ Complex formation is not affected even by the 2M sodium chloride solution.

The stability of the diagnostics of the invention has also been demonstrated in animal experiments. After inhalation of ⁵¹ Cr-labeled silica gel or latex particles, 95-98% of the radioactivity is localized in the lungs. No radioactivity in the urine, which would indicate the presence of a labeled isotope separated from the solid support, could not be detected.

The diagnostics of the invention also include a suspending medium. The suspending medium used is a buffer solution which provides the appropriate pH and the components which provide the physiological conditions.

Diagnostics of the present invention are prepared by the modified 8-hydroxyquinoline group particles in 99m7 _{'c.; 2 O} t _{(5pp the} | to mark previously reduced with a reducing agent MJC-mal for other signaling isotope (such as ⁵¹ Cr, H3niin) their chloride salt (e.g. ^sl CrCl2, ^113m InCI _2), in physiological conditions, and optimal pH for the signaling.. The labeled isotope is 95% -98% complexed with the functional group on the surface of the particles within 5 minutes, very advantageously.

Labeling of 8-hydroxyquinoline-modified particles with m-tc is preferably carried out using Na-pertechnecate (NamTcO ₄ ) or K-pertechnecate (K ^m TcO ₄ ). The high specific activity technetium isotope used for labeling is from any suitable generator commonly used in practice [e.g. Radiochemical Center Amersham (London), Isocommerz (NDK), CIS (France), or IZINTA (Budapest) J can be obtained with physiological saline in the form of Na-pertechnecate. The reduction of the technetium salt is carried out with an alkabane reducing agent, preferably stannous chloride (SnCl ₂ ). The fresh alkaline pertechnetate eluate obtained from the generator is mixed with succinic chloride and the particles in the presence of an acidic medium, preferably at a pH of 4 to 6. After standing for a few minutes, the particles are pelleted by centrifugation. The labeled particles are suspended in physiological saline.

Labeling of the particles used for human lung scintigraphy in general, as described above, while minimizing the number of particles, can advantageously be accomplished by providing the Jetzell Diagnostic with valuable information on pulmonary venilation and / or lung self-cleaning processes.

8-Hydroxyquinoline! labeling of modified particles with other short or longer half-lives isotopes (e.g., ⁵¹ Cr, ⁶⁷ Ga, 1 < 3 >&gt; 1η, etc.) is preferably performed with carrier-free radionuclides in any cationic form. For labeling with '1mM, 113m1n freshly eluted with 0.05N hydrochloric acid from any suitable generator (Radiochemical Amersham, CIS, etc.) suitable for use in the labeling of 8-hydroxyquinoline moieties is used. The modified particles are mixed with the eluate in a medium containing acidic components, preferably containing 4,6 µl. After standing, the suspension is pelleted by centrifugation. The labeled particles are suspended and used in physiological saline, preferably physiological saline. The high specific activity formulation obtained in this way allows the number of particles to be minimized during the test, thereby reducing the overall radiation exposure of the patient.

The diagnostics of the invention are conveniently administered by inhalation.

Experiments in rats, rabbits and dogs have shown that the diagnostics used are non-toxic and that the minimum dry solids content of the tests alone does not cause morphological and functional damage to the lungs.

Contrary to what is known, the diagnostics of the present invention are also suitable for the joint or separate examination of the tracheal bronchial and alveolar respiratory tract. Depending on the purpose of the test, they can be presented in 3 different shapes. The formulation may include labeled latex particles for testing alveolar self-cleaning, lung ventilation, or labeled silica gel particles for tracheo-bronchial self-cleaning, and both for both functions. Reagent preparations (kits) may contain unlabeled particles, radiopharmaceuticals may contain labeled particles.

As described above, the diagnostic of the present invention can be formulated with a reagent composition comprising, in addition to the particles, the following components:

(a) a sterile, pyrogen-free solution, with or without a reducing agent, to provide the pH and physiological conditions required for optimal labeling;

(b) centrifuging the suspended particles to sterilize the suspension with a neutral pH and physiological solution and suspending the labeled isotope.

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The main advantages of the diagnostics according to the invention are:

1. The label isotope can be bonded to the solid support with high stability, and consequently the loss of material is negligible.

2. Due to the monodispersity of the latex particles used in the ventilation tests, only the exact area to be examined is mapped.

3. Due to the high binding stability, low solids, high specific activity formulations can be prepared.

4. The examination of the tracheo-bronchial and alveolar respiratory tract becomes possible.

5. They can be used in a number of areas where research and studies on lung air exchange (ventilation) and self-cleaning (clearance) are needed.

6. Non-toxic (rat, rabbit, dog).

The invention is illustrated by the following non-limiting examples.

Example 1

Sterilized silica gel particle (5 μιη) modified with the 8-hydroxyquinoline functional group was labeled with ⁵¹ Cr isotope by adding 7400 kBq of carrier-free ⁵¹ CrCl ₂ (1ZINTA, Budapest, specific activity 2000 GBq / g). to 2 mg of suspension in sterile physiological saline, pH 8 was adjusted with 0.1 M NaOH. The slurry was shaken at room temperature for 5 minutes and then centrifuged at 150-200 g / vc for 5 minutes. The pelleted pellets were suspended in 1 ml of sterile physiological saline and the radioactivity was determined.

The incorporation of ⁵¹ Cr was 92%, representing today a specific activity of 3404 kBq / mg. In this form, the preparation is ready for use.

Example 2

Labeling of sterilized silica gel (5 μιη) or latex (0.25 μιη) particles modified with the 8-hydroxyquinoline functional group was performed by suspending 2-2 mg of each particle in 10 ml of sterile saline. To the suspension was added 370 MBq 99inTc (pH 4-6) in 1 mL of 0.1 M HCl, reduced with 1 mg of stannous chloride. After shaking for 5 minutes, the macroparticles were centrifuged at 150-200 g and the microparticles at 300-400 g for 5 minutes, and the supernatant and sediment were radioactively determined. The latter was on average 98 ± 1.6%. The pelleted pellets were resuspended in 1 ml of sterile physiological saline and used.

Example 3

The _N -3 _n -isotope _was labeled with 8-hydroxyquinoline functionalized sdlikagel (5 μιη) or latex (0.25 μιη) particles by suspending the particles (2-2 mg) in 2 ml of sterile physiological saline (pH = 4). -6) followed by shaking with 0.5 mL of H3ni, freshly eluted with 0.05 M HCl, at 370 MBq, pH 4-6. After 5 minutes, the suspension was centrifuged (macroparticle 150-200 g, microcarticle 300-400 g for 5 min) and the amount of bound and free ^113m ln was determined. Bound activity was greater than 95% for both macroparticles and microparticles. The particles were taken up in 1 ml of neutral 0.9% sterile saline.

For use in human medicine, ι is considered to be preferable to isotopic labeling of particles; sterilization (at 100 ° C for 30-60 minutes) and use of sterile containers with pyrogen-free suspension solutions.

After radioactivity labeling, bound radioactivity can be monitored with a Gamma counter type NK 350. For more than 5% free 'Cr, 99my _c> 113mj _n , a second wash-centrifugation is recommended, resulting in less than 0.1% free label ^: zotopic contamination.

Inhalation of stably labeled macro- and microparticles, with appropriate radiation protection, can be fired by any suitable aerosol generator commonly used in human medicine (ultrasonic or compressed air aerosol generator type TUR US1 3.50).

Claims (9)

Claims 1. Diagnosis containing isotope-labeled solid carrier particles, mainly for the detection of pathological lung lesions, characterized in that the isotope-labeled solid carrier with a diameter of 0.1-1.0 μ is used in isotope-labeled solid carriers with 8-hydroxyquinoline residues or containing 5 to 10 μm of silica gel and optionally suspending medium. 2. diagnosis of according to claim 1 ^- Ikumi, wherein said solid comprises horodzóként biologically inert latex polymer microparticles. Diagnostic according to claim 1, characterized in that the solid support contains silica gel macroparticles. 4. The diagnostic agent according to claim 1, characterized in that the marker isotope 99mT _c ^) t ¹ 1 ³ 'In ^11; or ^Cr-S1 was contains. Diagnostic according to claim 1, characterized in that it contains latex microparticles with a diameter of 0.25 μ or a silica gel macroparticle with a diameter of ⁵¹ Cr. Diagnostic according to claim I, characterized in that it contains 0.25 μ diameter latex microparticles or 5 μ diameter silica gel macroparticles labeled with 'Te' isolator. 196,315 Diagnostic according to claim 1, characterized in that it contains biopsy-labeled latex microparticles having a diameter of 0.25 μm or silica gel macroparticles having a diameter of 5 μm. Diagnostic according to Claim 1, characterized in that it contains physiological saline as a suspending medium. 9. A process for the manufacture of a diagnostic device according to claim 1, characterized in that the latex having a diameter of 0.1 to 1.0 μm or a silica gel having a diameter of 5 to 10 μm with 8-hydroxytit choline groups is optionally used in medical diagnostics, optionally in its reduced form, in the presence of components which provide the optimum pH for labeling, pelleted and optionally formulated in the presence of a physiological solution as a suspending medium.