GLYCOL AND PRODUCTION METHOD THEREOF

Technical Field of the Invention

The present invention relates to biopolymeric medical solutions, particularly a medical solution comprising hyaluronic acid or sodium salt (sodium hyaluronate) and polyethylene glycol (PEG) for use in the treatment of cystitis disease and production method thereof.

State of the Art

Cyst means urinary bladder, in other words, vesica urinaria; and cystitis means inflammation of the urinary bladder. While cystitis may develop as a result of microbial infection, it may also manifest itself as a result of a chemical irritant or a traumatic injury. Almost half of the adult women go through at least one painful cystitis attack throughout their lifetime. Individuals who suffer from cystitis disease have the symptoms of strong and persistent urge to urinate, burning sensation when urinating, frequent and small amounts of urination, blood in the urine, turbid and strong-smelling urine, low-grade fever, general complaints of fatigue, irritability, loss of appetite and vomiting in children under 5 years old, weakness, confusion, and fever in older women. Cystitis disease is a disorder that is mostly seen among women.

In the treatment of cystitis disease, oral therapies comprising antibiotics, anti-inflammatory medications, antihistamines may be used. In further progressed cases of the disease, patients are treated by resorting surgical operations, and treatment is provided by a variety of solutions. These solutions are used by delivering them from vials to the injector during surgery or by applying them directly from injector to the patient. Solutions based on hyaluronic acid and sodium hyaluronate, which is the sodium salt of said polymer, form a protective layer by injection into the irritated zones because of the glycosaminoglycan which is naturally contained in the structure of said polymers, thus the treatment is provided.

International Patent Application W09625168, describes the use of hyaluronic acid for the treatment of interstitial cystitis. In this document, a novel treatment method of cystitis is disclosed, which comprises the step of contacting the internal bladder and its associated structures in a mammal having interstitial cystitis with a solution comprising hyaluronic acid having an average molecular weight of not less than 2xl0 ⁵ Daltons in a concentration effective to treat cystitis. Furthermore, a method is provided in the examples of said disclosure for the fraction, purification, and isolation of hyaluronic acid.

USA Patent document numbered US20160175342A1, "Continuous release compositions made from hyaluronic acid and therapeutic applications of same", which is another document encountered in the state of art relates a combination of PLGA polymer - PEG (polyethylene glycol) - PLGA copolymer, or the mixture of thereof, combined with hyaluronic acid or hyaluronic acid powders for use in the treatment of cystitis. Furthermore, as evident from the patent document, the molecular weight of polyethylene glycol used in PLGA-PEG-PLGA copolymer is ranging from 4000 to 10000 Da, and the molecular weight of PLGA is ranging from 54000 to 69000. Also, a production method is developed for producing the formulation according to the invention. Said production method provides for a slower release. When the production method is analyzed, it is evident that the method comprises the procedure steps of emulsifying and stirring an aqueous solution of hyaluronic acid or hyaluronic acid salts in an organic solvent containing at least one of poly(lactic- co-glycolic acid) PLGA polymer, poly(lactic-co-glycolic acid) polyethylene glycol- poly (lactic-co-glycolic acid)(PLGA-PEG- PLGA) copolymer or mixtures thereof; mixing said obtained emulsion with an aqueous polyvinyl alcohol solution; adding an aqueous solution (preferably a purified water) to the final emulsion and stirring thereof; filtering the obtained emulsion; freeze-drying the obtained polymer particles; and sterilizing freeze-dried polymer particles.

European Patent EP2099462B1 "Pharmaceutical preparation for the treatment of inflammatory diseases of the urogenital tract" concerns a combination comprising hyaluronic acid or salts thereof with a molecular weight of less than 200 kDa, and at least one chondroitin sulfate for the treatment of cystitis.

The inventor has aimed to develop a new formulation and a novel production method as distinct from the state of the art. The inventor has subjected the product according to the invention to various tests and experiments; and surprisingly found out the stability and biocompatibility of the product is increased and also discovered that the dissolution of the hyaluronate is optimum and no aggregation problems are observed.

Description of The Invention

The object of the present invention, as a distinction from the art, is developing a new formulation comprising the combination of hyaluronic acid or sodium salt (sodium hyaluronate) and polyethylene glycol and a novel production method for the solution. In these solutions developed for the treatment of cystitis, an optimum amount of polyethylene glycol is used as a stabilizer and disintegrant . Polyethylene glycol herein increases the stabilization of the solution, therefore prolongs its shelf-life. Furthermore, it is evident that the product obtained by the production method according to the invention increases the biocompatibility value.

Also, higher values of recovery have been observed in the patients who are treated with the combination comprising hyaluronic acid or sodium salt (sodium hyaluronate) and polyethylene glycol, compared to formulations containing only hyaluronic acid.

Description of The Figures

FIGURE 1 illustrates the result of the MTT viability assay of the cystitis solution.

Detailed Description of the Invention

The present invention relates to a solution for the treatment of cystitis disease, wherein, it comprises the combination of hyaluronic acid or sodium hyaluronate and polyethylene glycol. Furthermore, said combination comprises phosphate buffer and sodium chloride as excipients.

An advantage of the solution according to the invention is that the molecular weight of polyethylene glycol used herein is in a value ranging from 200 to 400 Dalton

Another advantage of the solution according to the invention is that the molecular weight of hyaluronic acid used herein is in a value ranging from 100 to 800 kDalton.

In the present invention; sodium chloride in the concentration range of 0,025-1 mol/L, polyethylene glycol (PEG) in the concentration range of 30-70 g/L, hyaluronic acid sodium salt in the concentration range of 40-120 mg/ml is used. In the present invention, an amount of hyaluronic acid which is equivalent to sodium hyaluronate in the concentration range of 40-120 mg/ml may also be added to the solution.

The invention relates to a production method of the solution comprising the combination of hyaluronic acid or sodium salt (sodium hyaluronate) and polyethylene glycol, wherein, it comprises following procedure steps;

Preparing the phosphate buffer suited for gel from the salt mixture which contains potassium chloride (KC1), potassium dihydrogen phosphate (KH2PO4), sodium chloride (NaCl) and disodium hydrogen phosphate (Na2HPC>4) in the concentration range of 0,1-1 mol/L by stirring at room temperature; Adding sodium chloride to the solution such that, it is in the concentration range of 0,025-1 mol/L,

Adding polyethylene glycol (PEG) to the solution, which is in the concentration range of 30-70 g/L, (In addition to being proven effective for the treatment of cystitis, PEG also provides for hyaluronic acid to be stable without precipitating.)

Adding hyaluronic acid sodium salt (sodium hyaluronate) to the solution, which is in the concentration range of 40-120 mg/ml;

Subjecting the solution to stirring at 24-40°C for 1-5 hours; (until obtaining a clear solution)

Resting the obtained solution at 20-24°C for 20-24 hours.

The phosphate buffer prepared in the first procedure step provides for the pH of the cystitis solution to be acceptable within the body. The pH value of the final product ranges between 6,8 and 7,6. The addition of the sodium chloride in the second procedure step provides for the ionic equilibrium of the solution and helps for the increasing the solubility of sodium hyaluronate.

Furthermore, the method may be realized by adding hyaluronic acid instead of using sodium hyaluronate in the production method. An amount of hyaluronic acid which is equivalent to sodium hyaluronate in the concentration range of 40-120 mg/ml may be added to the solution as well.

Glycosaminoglycan which is used as an active substance for the treatment of cystitis disease can be found in the structure of sodium hyaluronate/hyaluronic acid. For achieving this effect in the solution according to the invention, an optimum amount of hyaluronic acid sodium salt (sodium hyaluronate), which is in the concentration range of 40-120 mg/ml is used.

The production of the cystitis solution is performed by adding the components in order as described above. The stirring rate during production is optimized at 700 rpm. While at the lower stirring rates the hyaluronic acid or sodium salt (sodium hyaluronate) added may aggregate in the solution, overflow may occur in the solution at the higher rates. The ionic equilibrium of the solution is adjusted by stirring phosphate buffer and sodium chloride in the procedure steps. Phosphate buffer provides for the pH of the solution to range between 6,8 and 7,6. Thus, the solution does not cause any harm within the human body. PEG (Mw: 200-400 Da) is added at the next step. It is provided for sodium hyaluronate to uniformly dissipate in the solution by adding PEG, before the hyaluronic acid or sodium salt (sodium hyaluronate). Finally, hyaluronic acid or sodium salt (sodium hyaluronate) is added to the mixture and the solution is stirred for 1-5 hours until it is uniform. While the mixture is generally at room temperature, the stirring procedure may be smoothly performed up until 40°C. Production costs are decreased by performing the procedure at room temperature. An important advantage of the production method of cystitis solution according to the invention is that, adding polyethylene glycol with the molecular weight ranging between 200 and 400 Da to the solution. In addition to being proven effective for the treatment of cystitis, polyethylene glycol also provides for hyaluronic acid or sodium salt (sodium hyaluronate) to be stable without precipitating.

The inventor has conducted the MTT viability assay for the cystitis solution obtained by the production method of the invention .

The results of the MTT viability assay of the solution produced by the production method of the invention, which is performed in accordance with ISO 10993-5 is depicted in Figure 1. While the first column of the graphic represents negative control (medium), the second column represents a cystitis solution, and the third column represents positive control (phenol solution). The results of the MTT show that the solution produces are biocompatible .

The comparison of viscosities of cystitis solution obtained by the production method according to the invention and its commercial equivalent is shown in Table 1. The solution according to the invention shows similar fluidity values to its commercial equivalent. As the commercial equivalent, HYACYST 40 mg/50ml concentration and HYACYST 120 mg/50ml concentration of the product known as Hyacyst are selected. The product with the formulation according to the invention in the concentration ranges of 40 mg/50ml and 120 mg/50ml is prepared to counter with the former and its viscosity values are compared with the commercial product. In addition to that, the pH values of the solution produced according to the invention and its commercial equivalent are ranging between 6.8 and 7.4. As can be seen from Table 1, the cystitis solution produced in different concentrations according to the invention shows similar viscosity values to its commercial equivalent. During the injection of cystitis solution to the patient, the viscosity value is of very high importance. While it is possible to maintain similar viscosity values, the main difference of the product according to the invention is that its recovery characteristics due to the PEG effect are higher than its commercial equivalent. The solutions according to the invention which are produced differently from their commercial equivalent comprise the optimum amount of PEG. This is the main reason that the solutions produced according to the invention enable more effective therapy than their commercial equivalents. The presence of PEG used in the study which is conducted with the solutions according to the invention is observed in a value of 1000 cnr ¹ in the FITR analyses .

Table 1: The comparative viscosity values of cystitis solution and its commercial equivalent. Furthermore, the inventor has performed a sterilization test. The sterilization test is conducted in a sterilizer at 121°C for 15 minutes. As a result of the sterilization test, no shift in product stability has been observed.