Surgical infections have become the issue of the day. According to the clinical statistics worldwide, surgical infectious complications have occurred in almost 30% of all surgeries, causing purulent-septic diseases.

The approaches to the local treatment of pyo-inflammatory diseases need improving, because it is difficult to maintain stable antibiotic concentrations at the site of infection, and, thus, ensure therapeutic efficacy of antimicrobials, by using enteral, parenteral and other routes of their administration. Formation of a restricted area around the site of infection within 36 - 48 hours, dilution of active substances in the body fluids, the action of tissue proteases and the macrophage system quickly reduce the activity of medicinal products.

By applying chemical medications or enzymes on the wound, the desired results may not be obtained because active substances can rapidly degrade (1.5 - 3 hours) when exposed to biologically active substances at the site of infection.

The increase in single doses may lead to serious complications, whereas the preventive use of antibiotics is not only unreasonable, but can result in emergence of resistant strains.

Ideally the local treatment of purulent foci should include permanent and continuous introduction of medicinal substances, thus increasing positive effects of the treatment. However, in reality this is difficult to fulfil. Therefore, immobilization (fixing) of medicine on a matrix, which will ensure continuous introduction of medical substance after a single topical administration, could be a satisfactory solution to this issue.

Among various polymeric materials, one group of organosilicon polymers - organosiloxanes, which are widely used in medical biology, microbiology, etc. are worth discussing  (M.H.Voronkov et al, 1978). Polyorganosiloxanes were initially used as a matrix for immobilization of medicine after a group of scientists of the L.V. PYSARZHEVSKY Institute of Physical Chemistry of the Academy of Sciences of Ukraine had developed the method of synthesis of porous hydrophobic organosilicon adsorbents.

Based on the provided scientific data, Closed Joint-Stock Company “Pharmaceutical Firm “PharCoS” in collaboration with SIC “Borshchahivskiy Chemical-Pharmaceutical Plant” CJSC developed and launched the originator medicinal product GENTAXAN. This product is patented in Ukraine. Now this product is unique in the world by its scientific novelty and clinical efficacy.

GENTAXAN is the first drug manufactured on the basis of polymethylsiloxane as an application sorbent containing immobilized antibiotic (gentamicin sulphate 0.025 g) and coordination complex (zinc-tryptophan 0.025 g).

Polymethylsiloxane (PMS) is white, fine-grained, free-flowing, tasteless and odourless powder with a particle size of 0.16 - 0.25 mm. It does not chemically react with water, body fluids, or organic solvents. As compared to other sorbents, it has large meso- and macroporous structure (a pore size is 18-100 nm; specific surface area is 300 m/g; pore space is 3-4 cm/g). PMS high hydrophobicity, flexibility to form various types of bonds in combination with macroporocity allows immobilization of large molecules of biologically active compounds due to weak intermolecular forces, e.g., electrostatic force, hydrogen bonds, etc. Due to those forces, the substance is kept immobilized on the surface or in the pores of the matrix, while the conformation of the molecule of the substance does not change, and functional groups and physicochemical properties are retained. This type of immobilization has a number of advantages as compared to chemisorption, as the immobilization is due to the chemical bonds with the matrix, which results in decreased activity and changed properties of the immobilized medicinal substance.

In comparison with many other sorbents, the significant advantage of PMS is that in addition to its ability to adsorb (to take out of wounds) lipid-containing substances, including components of cell membranes, hydrophobic cellular metabolites, it also can desorb (release into wounds) the medicinal substance being immobilized in the pores, i.e. the substance, PMS was pre-impregnated with, fully restoring its initial sorption capacity. Due to these properties, effects of medicine are prolonged, high local concentrations of the active substance in wounds are maintained, and local detoxification is provided due to further adsorption and immobilization of toxic substances and metabolites in tissue fluids.

As polymethylsiloxane has a large porous structure, it has a high affinity for organic compounds, due to which it can be used as an absorber of organic toxic substances (amines, phenols, fatty acids, bilirubin, ketones, etc.).

GENTAXAN is an innovative approach to the treatment of wounds.

It should be mentioned that in case of topical application of antibiotics, their action in the wound continues for 1.5-3 hours. A significant advantage of GENTAXAN over many other wound-healing medications is its ability to maintain therapeutic concentrations of the antibiotic in wounds for a long time (up to 8 days) by desorbing (releasing) the biologically active substances immobilized in its pores (gentamicin sulphate and the zinc -tryptophan coordination compound).

GENTAXAN is distinguished from other wound-healing medications (ointments, pastes, solutions) by its high sorption activity, and when it is applied to a wound surface, it is continuously absorbing microorganisms, toxins produced by microorganisms, and decomposed tissues. It is continuously cleansing the wound, thus, ensuring its rapid healing.

Due to the physical and chemical properties of the matrix, GENTAXAN can break down the lipid components of cell membranes of microorganisms, thus, causing damage to the membrane integrity, and bacterial or virus cells become more vulnerable to the action of the biologically active substances immobilized on the matrix, even if the bacteria or viruses are resistant to the medication. Therefore the efficacy of topical treatment significantly increases.

Clinical study findings.

GENTAXAN has been clinically tested at General Surgery Department No. 1 of the O.O. Bogomolets National Medical University under the leadership of MD, Professor V.S.Zemskov; at Ukrainian Burn Centre under the leadership of MD, Professor M.Yu.Povstyany; and at the Surgical Clinic of the Hospital of MMA of SSoU under the leadership of the Head of MMA of SSoU, Major General of Medical Service, corresponding member of the Academy of Medical Sciences of Ukraine, MD M.P. Zakharash.

The clinical studies have shown that GENTAXAN has a prolonged antimicrobial and sorption and detoxication action.

GENTAXAN is active against many gram-positive and gram-negative microorganisms, including Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Citrobacter, Proteus vulgaris, etc.

When applied, GENTAXAN reduces the number of bacteria in a wound to the lowest level (102 - 103 IU/g) on day 3 or 4 of the treatment, accelerates the transition from the hydration phase to the dehydration phase, thus, preventing the risk of purulent-septic complications.

Based on the bacteriostatic titre of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, the antibacterial activity of GENTAXAN is 3 - 11 times higher than that of the ointment Laevomecol, and 18 - 82 times higher than that of the 10% ointment Methyluracil, i.e. the effect of GENTAXAN exceeds the effect of medications represented by these ointments.

According to the clinical data, the use of GENTAXAN for the treatment of patients with septic diseases (postoperative complications, trophic ulcers, phlegmons, and various abscesses) accelerated the removal of fibrinous-necrotic tissues from wounds, reduced exudation within three to four hours.

GENTAXAN has a high sorption activity towards hydrophobic substances, it absorbs toxic substances produced by microorganisms, low-molecular toxic metabolites (pyruvic and lactic acids, peroxides, oxidation products of amino acids, polypeptides, lipids, etc.)., dehydrated fibrin.

GENTAXAN reduces manifestations of the local and systemic intoxication, local inflammation, has a drying and anti-oedema action, and provides an adequate microcirculation and gas exchange in the wound. It accelerates (on the average: 3 - 5 days faster) the wound cleansing, while reducing the duration of degenerative and inflammatory process. GENTAXAN promotes growth of granulation tissue.

It should be noted that the pH of the wound discharge was from 6.0 to 6.5 mmol/l before the application of GENTAXAN, and after the application of GENTAXAN it changed and was 7.5 to 7.8 mmol/l, and it was maintained at that level during the entire treatment period, which promoted wound healing.

GENTAXAN prevents keloid scarring.

Additionally, patients with purulence caused by gentamicin-resistant microorganisms demonstrated good results after using GENTAXAN.

GENTAXAN when used for the treatment of superficial burns of second and third degree accelerated epithelialization of wounds by 3 - 4 days, reduced proteolytic activity of discharge from a wound and protein loss through the wound surface by 1.5 - 2 times, prevented purulence, reduced the duration of treatment by 30-35%.

When GENTAXAN is used for the treatment of burn wounds, it reduces the local inflammatory response, the area of full-thickness burns, prevents tissue destruction, promotes rapid epithelialization of superficial burns and granulation of full-thickness burns, cleans the surface of wounds from microorganisms, and it is a good means for preparation of burn wounds for autodermoplasty. GENTAXAN is effective in drying-out of the wound bed: it prevents dressing from sticking to the wound and, thus, reduces or eliminates pain at dressing removal.

A “GENTAXAN bandage” absorbs phologogenic substances 4 times more as compared with a gauze bandage, and almost two times more as compared with activated carbon type SCN.

The assessment of the results of the use of this product and conventional treatments demonstrated that when GENTAXAN was used, the cost and hospitalization period were reduced by 35 - 50%.

Thus, GENTAXAN has a number of properties that ensure its high therapeutic effectiveness:

- it maintains therapeutic concentrations of gentamicin sulphate and zinc – tryptophan in wounds for long time (8-10 days);

- it provides rapid (2 hours) decrease in a number of any microorganisms in the wound;

- it breaks down lipid components of cell membranes of microorganisms, thus, making bacterial or virus cells more vulnerable to the action of the antibiotics, even if the bacteria or viruses are resistant to the medication;

- it has pronounced local detoxication effects due to its sorption activity, which results in reduction in the amount of discharge from the wound by 50%, and significant lowering of the number of pathogenic microorganisms (from 1010 to 103 - 102 per gram) in the wound;

- it absorbs low-molecular toxic metabolites and products of fibrin degradation on the wound surface;

- it has a drying and anti-oedema action, and accelerates the cleansing of the wound, which leads to reduction in inflammation, and promotion of the regeneration of affected tissues;

- it maintains an adequate microcirculation and gas exchange in the wound;

- it promotes growth of granulation tissue;

- it has a local anaesthetic effect;

- it prevents keloid scarring;

- it effectively dries a wound surface;

- it prevents dressing from sticking to the wound and, thus, reduces or eliminates pain at dressing removal;

- it prevents the development of purulent – septic complications, and sepsis;

- it reduces the duration of treatment, of hospitalization, and treatment costs by 35 - 50%;

- it is practical and easy to use in all conditions, as GENTAXAN can be stored for long time it allows its wide medical, military-medical, sports and everyday use.

 GENTAXAN is recommended for the use in the treatment of:

- infected surgical wounds (postoperative purulent complications, phlegmons, abscesses);

- various infected traumatic wounds;

- trophic ulcers in patients with chronic venous insufficiency, atherosclerosis, thrombophlebitis of subcutaneous veins of the lower extremities;

- burns of II - IiiA - IIIB degrees;

- various forms of erysipelas;

- bedsores; it is used to help heal surface wounds in patients with different diseases which slow regenerative processes (diabetes, immunodeficiency, radiation injury);

- prevention of sepsis in patients with extensive suppurative foci;

- prevention of keloid scarring.

GENTAXAN may be used over the entire period of wound treatment. At the beginning of treatment, dressing should be changed 1-2 times a day, and after the inflammation subsides, dressing may be changed 1 time per one or two days for cleansing the wound from purulent necrotic masses, promoting granulation and epithelialization of the wound.

Perform careful surgical treatment of the wound with antiseptic solutions, and dry it carefully, then spread 0.25 - 1 g of GENTAXAN on the wound surface covering it with a 0.5 -1 mm even layer of GENTAXAN. Use up to 8 - 12 g of GENTAXAN if the wound surface is large, e.g., burn wounds. After the medicine is spread, provide wound drainage according to general procedures and dress up the wound. In case of large surfaces of wounds, gauze pads may be used for cleansing the wounds. If GENTAXAN was removed together with the discharge from the wound and with dressing, dry the wound by using gauze pads and spread an additional portion of GENTAXAN at a recommended above dose. No other procedures on the wound are required.

In case of the treatment of burns, spread GENTAXAN on the burn surface first 5-6 days, as well as during the period of sequestration of burn eschar (15 days). Fix this medicine on the wound by using an aseptic bandage. When re-dressing the wound, remove GENTAXAN completely from the surface of burn wounds by using antiseptics or special shampoos for cleansing wounds. GENTAXAN can be applied to any affected parts of the body.

In case of injury, when a surgical treatment of wound can not be carried out in full, spread GENTAXAN on the wound at a dose of 0.25 -2 g, depending on the wound surface area for not more than 24 hours.

Side effects. When GENTAXAN is used, gentamicin sulphate-associated side effects may occur (allergic reactions: erythema, urticaria, contact dermatitis, itching).

Contraindications. Hypersensitivity to gentamicin sulphate and other components of GENTAXAN.

Overdose. Allergic reactions may occur. If this is the case, GENTAXAN should be discontinued and desensitization therapy should be instituted.

Storage conditions. Store in a dry, dark place at a temperature between 15°C and 25°C.

Shelf life: 3 years.

Presentation. Powder 2.0 g in vials, or dropper bottles; powder 5.0 g in dropper bottles.


   



 
10.02.2000    Author: Volodymyr Sergiyovych ZEMSKOV, Head of the Department of Surgery of the National Medical University, Professor, MD; Inna Mykhailivna SAMODUMOVA, Ph.D. in Chemical Sciences