Hypericin-PVP complex with a high hypericin content.

Abstract

The invention relates to a complex that consists of hypericin or a hypericin salt and polyvinyl pyrrolidone (PVP), the average mass fraction of hypericin or hypericin salt in the entire complex being higher than 6% by weight. The invention further relates to a process for preparing said hypericin-PVP complex, according to which process a mixture of hypericin and PVP is heated to a temperature above the glass transition temperature of the PVP used.

Description

[0001] Hypericin-PVP complex with a high hypericin content

[0002] The present invention relates to a complex of hypericin or a hypericin salt and polyvinylpyrrolidone (PVP), which complex has a particularly high proportion of hypericin.

[0003] Hypericin is found as an ingredient in various plants, especially in Hypericum sp., and as a pigment in protozoa, in some Australian insects, and with side chains as fagopyrin in buckwheat.

[0004] Because of its photodynamic and photochemical properties, hypericin is repeatedly the focus of various research projects investigating the application of the photosensitizer in tumor diagnostics and tumor therapy.

[0005] Photodynamic therapy (PDT) of tumors has developed into a rather peripheral area of ​​oncology over the last 50 years. However, the mechanisms of PDT are largely understood and the methods are well-defined. Following systemic or local application of a photosensitizer, the photosensitizer accumulates in the malignant tissue. When the photosensitizer is excited by light of a suitable wavelength, it can transfer energy to a reaction partner, such as molecular oxygen. The reactive oxygen molecules generated in this process can, in turn, damage the cellular structures of the tumor tissue.

[0006] So far, however, there is a lack of truly suitable photosensitizers that accumulate in tumor cells, are well-tolerated, and meet the physical and chemical requirements of PDT. The method using delta-aminolevulinic acid (5-ALA) as a prodrug for protoporphyrin IX in hollow organs (stomach, intestines, bladder, lungs, etc.) has been the most actively pursued. The disadvantage of 5-ALA and protoporphyrin IX is its instability: the porphyrins are photosensitive and bleach during therapy, losing concentration in the tissue and making precise dosing difficult.

[0007] The stability of hypericin as a photosensitizer is well-established, as is its accumulation in tumor cells. These properties, along with its chemical and physical characteristics, provide optimal conditions for its use as a sensitizer in photodynamic therapy (PDT). In vitro studies have already demonstrated the efficacy of hypericin in PDT across a range of cell lines, and in vivo animal studies further confirm its potential in PDT.

[0008] Hypericin is a hydrophobic substance that is completely insoluble in water and requires various formulations to be used for medical purposes. Such formulations contain various solvents, which are often poorly tolerated and can cause side effects (e.g., alcohol, DMSO, etc.), or solubilizers, liposomes, micelles, or nanoparticles.

[0009] WO 01 / 89576 A2 describes for the first time a practical approach to making hypericin water-soluble and thus applicable by complexing it with polyvinylpyrrolidone (PVP). It discloses complexes with a molar ratio of hypericin to PVP of approximately 1:1. On page 3, it is disclosed that hypericin and PVP can both be present at a concentration of 1 pmol / L. According to the molar mass range of PVP preferred in the application (10,000–90,000 g / mol) and the molar mass of hypericin (504.44 g / mol), this would correspond to a mass fraction of hypericin in the hypericin-PVP complex of between 0.6 and 5 wt%.

[0010] Kubin et al. (Pharmazie 63 (2008) 263-269) describe a manufacturing process based on WO 01 / 89576 A2, in which hypericin, pre-dissolved in ethanol, is heated to 70°C with PVP and water, and the resulting solution is then evaporated. The residue obtained contains the water-soluble hypericin-PVP complex. Figure 8 discloses a solution with a concentration of 50 pmol / L hypericin and 100 pmol / L PVP (PVP 10, PVP 25, or PVP 40). From the molar masses of hypericin (504.44 g / mol) and PVP (10,000 g / mol for PVP 10, 25,000 g / mol for PVP 25, 40,000 g / mol for PVP 40), the molar ratios can be converted into mass fractions. This yields a value of approximately 2.5 wt% for the complex with PVP 10, approximately 1 wt% for PVP 25, and approximately 0.6 wt% for PVP 40.

[0011] Kubin et al. (Photochemistry Photobiology 84 (2008) 1560-1563) describe a clinical study in which hypericin-PVP was used. Hypericin also constituted a mass fraction of 1 wt% in the hypericin-PVP complex.

[0012] WO 2014 / 079972 Al describes devices for PDT in hollow organs such as the bladder and mentions, among other things, the use of hypericin-PVP. The total amount is specified as 0.25 mg hypericin bound to 25 mg PVP. The mass fraction of hypericin in the hypericin-PVP complex is therefore also at most 1% by weight.

[0013] WO 2017 / 054017 Al describes formulations of hypericin in salt form for photodynamic therapy. In the hypericin-PVP preparation method described in Example 1, 250.0 g of a phosphate buffer solution are prepared, containing a total of 1875 mg PVP k25 and 0.0225 mg hypericin per gram of solution. The mass fraction of hypericin in the hypericin-PVP complex is therefore 0.3 wt%.

[0014] WO 2017 / 054018 Al describes formulations of hypericin in salt form for photodynamic diagnosis. In the hypericin-PVP preparation method described in Example 1, 250.0 g of a phosphate buffer solution are prepared, containing a total of 562.5 mg of PVP k25 and 0.0225 mg of hypericin per gram of solution. The mass fraction of hypericin in the hypericin-PVP complex is therefore 1 wt%.

[0015] Feinweber et al. (Photochemical & Photobiological Sciences 13.11 (2014): 1607-1620) describe conjugates consisting of hypericin and hydrolytically degradable polyphosphazenes. To prepare non-covalent conjugates of hypericin and polydi[2-(2-oxo-l-pyrrolidinyl)ethoxy]-phosphazene (PYRP), hypericin (2.4 mg) is dissolved in 2 mL of ethanol and added to PYRP (200 mg), after which the solvent is removed under vacuum. For comparison, hypericin-PVP is used, with this hypericin-PVP complex being prepared using PVP40 "in an analogous manner." The mass fraction of hypericin in the hypericin-PVP complex is therefore at most 1.2 wt%.

[0016] Photodynamic diagnosis using hypericin-PVP in conjunction with fluorescence endoscopy, as is known from the state of the art, is a highly sensitive method and can be performed with very minimal material. As has been published several times, for example, only 0.25 mg of hypericin (a total of 25 mg of the hypericin-PVP complex containing 1 wt% hypericin) is introduced into the bladder in dissolved form. This amount is sufficient to stain the tumors and lesions sufficiently for them to be identified and removed by the urologist. The low mass fraction of hypericin in the hypericin-PVP complex and the associated high proportion of PVP therefore pose no problem for photodynamic diagnosis due to the minimal material required.

[0017] However, this does not apply to applications requiring higher amounts of hypericin, such as photodynamic therapy. In this case, the higher dosage of hypericin necessitates a high amount of PVP. Therefore, there is a need for hypericin-PVP complexes containing a higher proportion of hypericin. One object of the present invention is thus to provide such complexes.

[0018] This problem is solved by a complex of hypericin or a hypericin salt and polyvinylpyrrolidone (PVP), wherein the average mass fraction of hypericin or the hypericin salt in the total complex is greater than 6 wt.%. When "hypericin" is subsequently mentioned, this term shall be understood to include both the free acid and the salts of hypericin, preferably the alkali salts, and particularly preferably the sodium or potassium salt.

[0019] The hypericin-PVP complex according to the invention enables the provision of highly soluble compositions containing large amounts of hypericin without the need for an uncomfortably large amount of PVP. Formulations can thus be formulated more efficiently than before. By avoiding large amounts of adjuvants (PVP) and the associated side effects, the present invention facilitates applications requiring larger amounts of hypericin. This applies particularly to therapeutic procedures such as photodynamic therapy (PDT) for the treatment of tumors.

[0020] The present invention therefore also provides pharmaceutical compositions comprising the hypericin-PVP complex according to the invention.

[0021] In the experimental studies carried out in connection with the present invention, it was unexpectedly shown that a particularly high mass fraction of hypericin in the hypericin-PVP complex can be achieved by heating a mixture of hypericin and PVP to a temperature above the glass transition temperature of the PVP used.

[0022] The present invention therefore also provides a method for producing the complex according to the invention, characterized in that a mixture of hypericin and PVP is heated to a temperature above the glass transition temperature of the PVP used.

[0023] By applying this process, the inventors were able to produce hypericin-PVP complexes containing more than 6 wt%, in particular more than 10 wt%, preferably more than 15 wt%, especially more than 20 wt%, and most preferably more than 35 wt% hypericin. The hypericin content of the complexes according to the invention thus significantly exceeds the hypericin content of hypericin-PVP complexes known in the prior art, thereby enabling new and more advantageous applications of hypericin-PVP.

[0024] The application of the hypericin-PVP complexes according to the invention is particularly advantageous in photodynamic therapy (PDT) for the treatment of tumor diseases.

[0025] The present invention also significantly facilitates other applications requiring larger quantities of hypericin. For example, hypericin, in combination with light, has antiviral and antibacterial effects. The hypericin-PVP complex according to the invention can therefore be used for the sterilization and / or disinfection of surfaces or liquids. The PVP content remains manageable in such applications.

[0026] Hypericin can also be described as 1,3,4,6,8,13-hexahydroxy-10,11-dimethylphenanthro[1,10,9,8-opgra]perylene-7,14-dione. Hypericin can be represented by the following structural formula (here in the form of the free acid):

[0027]

[0028] Hypericin can exist not only as the free acid but also in other forms, such as salts, e.g., alkali metal salts like sodium or potassium salts. Within the scope of the present invention, the term "hypericin" refers to all such possible forms.

[0029] Forms. Polyvinylpyrrolidone (PVP), also known as polyvidone or povidone, is a polymer of the compound vinylpyrrolidone. Commercially, PVP is available in various degrees of polymerization. The degree of polymerization determines the average molar mass of the polymer.

[0030] The present invention relates to a complex of hypericin or a hypericin salt and polyvinylpyrrolidone (PVP), characterized in that the mean mass fraction of hypericin or of the hypericin salt in the total complex is greater than 6 wt.%, preferably greater than 8 wt.%, 10 wt.%, 15 wt.%, 20 wt.%, 25 wt.%, or 30 wt.%.

[0031] Unless otherwise stated, percentages (%) in this invention refer to weight percent (wt%). The mass fraction here represents the relative proportion of the mass of hypericin to the mass of the total complex (hypericin + PVP).

[0032] The proportion of hypericin in the hypericin-PVP complex can also be expressed as a stoichiometric ratio. For example, a hypericin-PVP complex consisting of hypericin in the form of the free acid (molar mass: 504.44 g / mol) and PVP with a mean molar mass of 25 kDa, and which has a mean mass fraction of hypericin in the total complex of 10 wt%, has a mean stoichiometric ratio of hypericin to PVP in the complex of 5.5. The mean stoichiometric ratio here represents the ratio of the amount of hypericin to the amount of PVP.

[0033] The present invention therefore also relates to a complex of hypericin and PVP, characterized in that the mean molar ratio of hypericin to PVP in the complex is greater than 2.5, preferably greater than 3, 4, 5, 7, 10, or 15.

[0034] The proportion (mass fraction as well as molar ratio) of hypericin in the total complex is always to be understood here as the average proportion. A suitable method for determining the average proportion of hypericin in the total complex is high-performance liquid chromatography (HPLC). Those skilled in the art are familiar with carrying out such a determination, as described in Freytag WE (Deutsche Apothekerzeitung 124 No. 46 (1984) 2383-2386). They know how to weigh out an exact quantity of the hypericin-PVP complex, how to determine the concentration of hypericin using a calibration curve and an HPLC measurement, and how to calculate the mass fraction of hypericin in the total complex from this. An example of how such a determination can be carried out is described in Example 5.

[0035] Commercially available PVP is available in a variety of different polymerization degrees and thus medium molar masses. Within the scope of the present invention, molar masses in the range of 10 kDa to 40 kDa are particularly preferred because molecules of this size can still be readily excreted by the kidneys in an unmetabolized state (clearance).

[0036] In a preferred embodiment of the present invention, the hypericin-PVP complex is therefore characterized in that the PVP has a mean molar mass of 10 to 40 kD, preferably of 12 to 25 kD.

[0037] The hypericin-PVP complexes described in the prior art are not well suited as ingredients in pharmaceutical formulations due to their low hypericin content. To achieve sufficiently large quantities of hypericin for pharmaceutical applications, large amounts of the hypericin-PVP complex would have to be used. This would result in an unacceptably high material consumption and / or accumulation of PVP in the patient. The present invention solves this problem. Due to the significantly reduced proportion of adjuvants (PVP), higher dosages of water-soluble hypericin, required for tumor therapy, are possible. This prevents the increased side effects associated with PVP. The new invention thus enables, among other things, the use of hypericin in photodynamic tumor therapy.

[0038] The present invention therefore also relates to a pharmaceutical composition comprising the hypericin-PVP complex according to the invention.

[0039] In a preferred embodiment of the invention, the pharmaceutical composition is characterized in that the composition contains the hypericin-PVP complex according to the invention with hypericin in a concentration of at least 25 mg / L, preferably at least 50 mg / L, 75 mg / L, 100 mg / L, 150 mg / L, or at least 250 mg / L.

[0040] The pharmaceutical compositions according to the present invention can, for example, be administered locally for the treatment of tumors. Because the present invention makes it possible for the first time to produce pharmaceutical compositions containing high concentrations of hypericin without the need for large amounts of povidone-Viteoprotein (PVP), it also enables the production of pharmaceutical compositions that can be administered intravenously. This allows large amounts of hypericin, which subsequently accumulates in tumor cells, to be administered systemically.

[0041] In a further preferred embodiment, the present invention therefore relates to a pharmaceutical composition containing the hypericin-PVP complex according to the invention, characterized in that the composition is intended for intravenous administration.

[0042] In a particularly preferred embodiment, the present invention relates to a pharmaceutical composition containing the hypericin-PVP complex according to the invention, characterized in that the composition is intended for intravenous administration and that the composition contains hypericin in a concentration of at least 25 mg / L, preferably at least 50 mg / L, 60 mg / L, 80 mg / L, 100 mg / L, 150 mg / L or at least 250 mg / L.

[0043] As an amorphous substance, PVP does not have a melting point, but rather exhibits a so-called glass transition temperature. The glass transition temperature depends, among other things, on the degree of polymerization, i.e., the average molar mass, of PVP (see Table 1).

[0044]

[0045] Table 1: Examples of the glass transition temperature of PVP as a function of molar mass.

[0046] In the experimental studies carried out in connection with the present invention, it was unexpectedly shown that a particularly high mass fraction of hypericin in the hypericin-PVP complex can be achieved by heating a mixture of hypericin and PVP to a temperature above the glass transition temperature of the PVP used. Hypericin is stable up to approximately 300 °C and can therefore be complexed with PVP as an intact molecule. This method thus enables the production of the hypericin-PVP complex according to the invention.

[0047] The present invention therefore also relates to a method for producing the hypericin-PVP complex according to the invention, characterized in that a mixture of hypericin and PVP is heated to a temperature which is above the glass transition temperature of the PVP used.

[0048] In this context, the "glass transition temperature of the PVP used" refers to the temperature at which the glass transition of PVP occurs in the present mixture with hypericin. The glass transition temperature of the PVP used can be influenced by the composition of the mixture, for example, by the addition of solvents or water. Methods for determining the glass transition temperature are known to those skilled in the art. Preferably, the glass transition temperature can be determined according to the procedure specified in the DIN standard.

[0049] A preferred embodiment of the inventive method for producing the hypericin-PVP complex is characterized in that the molar mass of the PVP used is at least 12 kDa and the mixture is heated to a temperature of at least 93°C.

[0050] A particularly preferred embodiment is characterized in that the molar mass of the PVP used is at least 17 kD and the mixture is heated to a temperature of at least 130°C.

[0051] Another particularly preferred embodiment is characterized in that the molar mass of the PVP used is at least 25 kD and the mixture is heated to a temperature of at least 155°C.

[0052] Another particularly preferred embodiment is characterized in that the molar mass of the PVP used is at least 35 kD and the mixture is heated to a temperature of at least 175°C.

[0053] It has proven advantageous to add a solvent or a mixture of solvents to the hypericin and PVP mixture. Preferably, the hypericin and PVP mixture is stirred into a paste-like consistency with a small amount of solvent. Additional solvents can help the components to disperse homogeneously and allow larger amounts of hypericin to bind to the PVP. Suitable solvents include, for example, water, ethanol, methanol, pyridine, acetone, ethyl methyl ketone, and pyridine, or mixtures thereof. Water, ethanol, methanol, and pyridine are particularly preferred, especially water and ethanol.Accordingly, a preferred embodiment of the manufacturing process of the hypericin-PVP complex according to the invention is characterized in that a solvent or a mixture of solvents, preferably water, ethanol, methanol, pyridine, acetone, ethyl methyl ketone, and / or ethyl acetate, more preferably water, ethanol, methanol, and / or pyridine, more preferably water and / or ethanol, is added to the mixture of hypericin and PVP.

[0054] In the manufacturing process, it has proven advantageous to maintain the hypericin and PVP mixture at a temperature above the glass transition temperature of the PVP used for a specific period of time. Good results were achieved when the mixture was kept above the glass transition temperature for at least 5 minutes.

[0055] Accordingly, a further preferred embodiment of the inventive manufacturing process of the hypericin-PVP complex is characterized in that the mixture is held for at least 5 minutes at a temperature above the glass transition temperature of the PVP used.

[0056] Photodynamic therapy (PDT) for tumor diseases has developed into a rather peripheral area of ​​oncology over the last 50 years. However, the mechanisms of PDT are largely understood, and the methods are known in the prior art. To date, though, there has been a lack of suitable photosensitizers that accumulate in tumor cells, are well tolerated, and meet the physical and chemical requirements of PDT. The present invention provides hypericin-PVP complexes that meet these requirements and, due to their high hypericin content, are ideally suited for therapeutic applications. The hypericin-PVP complexes according to the invention can be administered either locally or systemically.

[0057] The present invention therefore also relates to pharmaceutical compositions containing a hypericin-PVP complex according to the invention for use in a therapeutic procedure, preferably for use in photodynamic therapy (PDT) for the treatment of tumor diseases.

[0058] The present invention also relates to a method for treating cancer, characterized in that a hypericin-PVP complex according to the invention is administered, preferably in the course of photodynamic therapy (PDT).

[0059] In a preferred embodiment, the present invention provides a method for treating cancer, comprising the steps of:

[0060] - Providing a pharmaceutically acceptable formulation containing a hypericin-PVP complex according to the invention; and

[0061] - Administering an effective amount of this composition to a person who has cancer.

[0062] Preferably, the method for treating cancer includes, as an additional step, the irradiation of the person with light. The light preferably has a wavelength between 400 nm and 800 nm, particularly between 500 nm and 700 nm, and most preferably between 550 nm and 650 nm. The light preferably has an intensity of between 1 mW / cm². 2 and 250 mW / cm² 2 , especially preferably between 2 mW / cm² 2 and 100 mW / cm² 2 , even more so between 3 mW / cm 2 and 50 mW / cm 2 , most preferred between 5 mW / cm² 2 and 25 mW / cm 2 .

[0063] Hypericin, in combination with light, has antiviral and antibacterial effects. Therefore, the complex according to the invention can also be used for the sterilization and / or disinfection of surfaces or liquids. The high proportion of hypericin in the hypericin-PVP complex is a significant advantage because it minimizes PVP consumption.

[0064] The present invention therefore also relates to the use of a hypericin-PVP complex according to the invention for the sterilization and / or disinfection of surfaces or liquids. "Hypericin-PVP" or "hypericin-PVP complex" herein refers to a product containing hypericin and PVP, wherein a compound exists between hypericin and PVP molecules. The word "complex" does not restrict the nature of the compound in any way, but merely means that a compound exists between one or more hypericin molecules and one or more PVP molecules. The compound may, for example, be a non-covalent attachment of hypericin to PVP. "Hypericin-PVP" or "hypericin-PVP complex" refers to the product as a whole and not to a single hypericin-PVP complex at the molecular level.

[0065] The terms "proportion of the complex", "mass fraction", and "amount-of-substance ratio" used herein are always to be understood as average values. They do not refer to each individual complex at the molecular level but rather to an average value of the entire product.

[0066] The present invention is illustrated by the following examples and figures, to which it is of course not limited.

[0067] The figures show:

[0068] Figure 1: Mass fraction of hypericin in the total complex in two hypericin-PVP complexes according to the invention compared to a conventional hypericin-PVP complex. The PVP used for the complexes according to the invention is PVP with a mean molar mass of either 12 kDa (“HypPVP12 melt”) or 25 kDa (“HypPVP25 melt”). The PVP used for the preparation of the conventional complex is PVP with a mean molar mass of 25 kDa (“HypPVP25 dissolved”). The complexes according to the invention were prepared as described in Example 1. The conventional complex was prepared as described in Example 3.

[0069] Figure 2: Comparison of the absorption spectra of sodium hypericinate PVP, hypericin PVP, and hypericin. The photophysical properties of hypericin are retained in the PVP complex, regardless of whether the free acid or the sodium salt of hypericin is used, or whether hypericin is present in complexed form. This means that hypericin does not lose its photophysical properties when complexed with PVP.

[0070] Figure 3: Calibration line for determining the mass fraction of hypericin in the hypericin-PVP complex using HPLC. HPLC runs were performed as described in Example 5 with different amounts of hypericin. The concentration of the weighed-out hypericin (x-axis) was plotted against the area of ​​the absorption peaks at 588 nm, and a linear regression was performed.

[0071] Example 1 - Production of a hypericin-PVP complex according to the invention

[0072] 30 mg of polyvinylpyrrolidone (PVP 25 kDa) was dry-mixed with 15 mg of hypericin (99% HPLC). 200 pL (200 microliters equals 0.2 mL) of ethanol and 100 pL (100 microliters equals 0.1 mL) of water were added to the mixture. The mixture was then stirred and allowed to stand for 20 minutes. Afterward, the mixture was slowly heated to 180°C in a drying oven. The temperature was increased from room temperature to 180°C over a period of approximately 20 minutes. The mixture was held at 180°C for about 8 minutes. Then, the mixture was cooled to room temperature. Subsequently, approximately 3-6 mL of water were added, and the mixture was stirred for 1 hour. During this time, the soluble components, the hypericin-PVP complex, dissolved. The insoluble components and the uncomplexed hypericin were filtered off (pore diameter 0.2–0.4 pm). The filtrate was dried and stored dry until further use.

[0073] Example 2 - Production of a hypericin-PVP complex according to the invention, containing hypericin in the form of the sodium salt

[0074] As in Example 1, however, the sodium salt was used instead of hypericin: Na-hypericinate. Na-hypericinate was prepared according to the procedure of Kapinus et al. (Monatshefte für Chemie 130 (1999) 436-441).

[0075] Example 3 - Production of a hypericin-PVP complex according to the state of the art

[0076] A conventional hypericin-PVP complex was prepared as described in Kubin et al., “How to make hypericin water-soluble,” Die Pharmazie 63 (2008) 263–269. For this purpose, 10 mg of hypericin were dissolved in 2.5 mL of ethanol under ultrasound, followed by the addition of 1000 mg of PVP 25 kDa and 8 mL of distilled water. The mixture was heated to 70 °C for approximately 5 minutes. Then, 5 mL of water were added, and the mixture was stirred for a further 10 minutes. The solution was then dried in a rotary evaporator, and the resulting hypericin-PVP complex was stored dry until further use.

[0077] When attempting to add more hypericin to the complexation, a precipitate occurred, as complexation of significantly larger amounts of hypericin by PVP is not possible under these conditions.

[0078] Example 4 - Characterization of the hypericin-PVP complexes

[0079] Hypericin-PVP complexes were prepared according to the procedures described in Examples 1 to 3.

[0080] The mass fraction of hypericin in the hypericin-PVP complexes was determined by HPLC and appropriate hypericin calibration. Standardized hypericin (> 99%, Planta Naturstoffe VertriebsGmbH) was used as a reference material. The determination of the mass fraction of hypericin in the total complex was carried out as described in Example 5.

[0081] In the complexes according to the invention, mass fractions of up to 40 wt% (hypericin-free acid; preparation according to Example 1) and 41 wt% (sodium hypericinate; preparation according to Example 2) were measured, whereas the mass fraction of the conventional complex was 1 wt% (preparation according to Kubin et al., Die Pharmazie 63 (2008) 263-269 as described in Example 3). Thus, by using the process according to the invention, PVP could be loaded with almost 40 times the amount of hypericin.

[0082] Example 5 - Determination of the mass fraction of hypericin in the total complex

[0083] The mass fraction of hypericin in the hypericin-PVP complexes was determined by HPLC and corresponding calibration with hypericin. The HPLC method was essentially carried out as described in Freytag WE (Deutsche Apothekerzeitung 124 No. 46 (1984) 2383-2386).

[0084] In detail, the HPLC method was performed using:

[0085] - Mobile phase: 568.0 g methanol, 157.8 g ethyl acetate, 185.5 g buffer (13.8 g NaH2P04H20 in 1000 ml distilled water with 85% orthophosphoric acid to pH = 2.1)

[0086] - Column: Nucleosil 120 3C18 (120 mm length, 4 mm inner diameter)

[0087] - Flow rate: 0.6 mL / min

[0088] - Detection: UV-Vis at 588 nm

[0089] Standardized hypericin (> 99%, Planta Naturstoffe Vertriebs GmbH) was used as a reference material for calibration. HPLC runs were performed with varying amounts of the reference material dissolved in the HPLC mobile phase, and the area of ​​the hypericin absorption peaks at 588 nm was determined. A calibration curve was then generated from the measured values ​​using linear regression (see Figure 3).

[0090] To determine the hypericin content of a hypericin-PVP complex prepared according to Example 1 according to the invention, exactly 5 mg of the dried hypericin-PVP complex (powder) were weighed out and dissolved in HPLC mobile phase. An HPLC run was performed as described above, and the proportion of hypericin in the total complex was determined from the absorption signal obtained at 588 nm using the previously established calibration curve. The result was 40 wt% (i.e., 100 mg of hypericin-PVP complex contained, for example, 40 mg of hypericin and 60 mg of PVP).

Claims

1. A complex formed from hypericin or its salts and polyvinylpyrrolidone (PVP) is characterized by the average weight ratio of hypericin or its salts to the total complex being greater than 6% by weight.

2. A complex as claimed in claim 1 is characterized by the average molar ratio of hypericin to PVP in the complex being greater than 2.

5.

3. A complex as claimed in claim 1 or claim 2 is characterized by the average molar mass of PVP being between 10 and 40 kD, with the recommended use being between 12 and 25 kD.

4. A pharmaceutical compound containing a complex as claimed in claims 1 through 3.

5. A pharmaceutical compound as claimed in claim 4 is characterized by the compound being supplied for intravenous administration and containing hypericin at a concentration of at least 25 mg / L.

6. The method for the production of any of the complexes claimed in claims 1 through 3 is characterized by the heating of the mixture of hypericin and PVP to a temperature exceeding the glass transition temperature of the PVP used. 7.The method as proposed in claim 6 is characterized by the addition of a solvent or mixture of solvents, preferably water, ethanol, methanol, pyridine, acetone, ethyl methyl ketone and / or ethyl acetate, preferably water, ethanol, methanol and / or pyridine, preferably water and / or ethanol, to the mixture of hypericin and PVP.

8. The method as proposed in claim 6 or claim 7 is characterized by the mixture being held at a temperature above the glass transition temperature of the applied PVP for at least 5 minutes.

9. The pharmaceutical component as proposed in claim 4 or claim 5, for therapeutic use, should be used for photodynamic therapy (PDT) for the treatment of neoplastic diseases.

10. The use of the complex as claimed in any of Claims 1 through 3, for the sterilization and / or disinfection of surfaces or liquids;