APPARATUS

FIELD OF THE INVENTION

The present invention relates to a composition for microbial inactivation used in chirurgical apparatus. More specifically, it is a composition for microbial inactivation in medical and chirurgical permanent instruments that can be reusable, preferably on those which cannot be sterilized by heat or corrosive chemical agents. The said composition has virucidal, bactericidal, fungicidal, mycobactericidal and sporocidal activity.

BACKGROUND OF THE INVENTION

Sterilization is the process in which chemicals or physical agents are used to destroy all viable forms of microbial life.

The continuous development on therapeutic and diagnostical methods using endoscopic instruments caused a revolution in patient care submitted to chirurgic procedures. For instance, these high-tech instruments like rigid, flexible, disposable and reusable endoscopes, show many shapes, being slim, long, delicate, creating difficulties in cleaning and incompatibility with high temperatures sterilization. These difficulties have lately led to a proliferation of hospital infections.

In apparatus for medical use, the Health Ministry of Brazil adopts three different classes:

a) Critical - instruments that penetrate in sterile tissue or in the vascular system. These instruments must be sterile, which means that all microorganisms and bacterial spores must be eliminated. Comprised under this category are objects such as biopsy tweezers, sclerosis needles, polypectomy loops and accessories used in ERCP.

b) Semi-critical - Instruments that have direct contact with mucosal tissue or non-intact skin. These instruments must be submitted to a high-level disinfection, which means microorganism elimination having only as exception some bacterial spores. Flexible endoscopes belong to this category.

c) Non-critical - Instruments that have contact with intact skin, but not mucosal tissue, which must be submitted to a low-level disinfection.

Combining physical and chemical processes allows a broader, and better cleaning process, like the combination of chemical effects with the addition of high temperatures for the optic-fiber endoscopes disinfection and other instruments, radiation (gamma, microwave), plasma, hydrogen peroxide, peracetic acid, ethylene dioxide, among others, although the last one listed is used under restrictions, because it can cause some occupational hazards, besides demanding investments in new facilities, since ethylene dioxide in the pure gas form is more expensive and extremely explosive.

The instruments used in video-surgery must be viewed separately, as their cleaning is made just after their use, with 0.2% peracetic acid for about ten minutes, being then rinsed with water. Even though it is an excellent chemical disinfectant agent for endoscopes, its use is not recommended in materials having metallic components that are not stainless steel, since this acid promotes metal oxidation and damages the inner material. It is also risky to submit endoscopes to peracetic acid when those have been previously processed by 2% glutaraldehyde, because damages to the lens sealing system might occur, damaging the equipment.

Therefore, the prior art describes several chemical and physical procedures for microbial inactivation used in chirurgical instruments, each one having advantages and disadvantages, such as the occupational hazards, as in the case of the ethylene dioxide sterilization or low temperature vapor and formaldehyde, where has been proved that those substances may cause carcinogenic and mutagenic effects. The automatic gas sterilization, using ethylene oxide, hydrogen peroxide plasma or vapor at low temperatures with formaldehyde gas are manual methods, where operational errors might occur, besides the toxic risks for the patient, the professionals or the environment. In the case of physical sterilization, the washing machines that use. water jets or ultra-sound do automate the cleansing process but, when used in complex conformation objects, they are not effective in the removal of the dirt fixed in the recesses, mainly on those with narrow lumens (example: sphyncterotomies); instruments with sharp edges or knurls with no opening holes that can be used for internal cleaning (example: video instruments); catheters with balloons (example: cardiac catheters); non-removable materials, among others.

Thus, technical literature does not describe, nor suggests a composition for microbial inactivation used in medical supplies or instruments with permanent use and and viable for reutilization, with virucidal, bactericidal, fungicidal, mycobactericidal and sporocidal activity, such composition for microbial inactivation used in chirurgical apparatus being now described and claimed in the present application.

SUMMARY OF THE INVENTION

Generally, the present invention relates to a composition for microbial inactivation used in chirurgical apparatus comprising about 0.50 to 9.0% weight/volume of the composition of trisodium citrate, about 0.01 to 0.50% w/v of a composition of polymeric biguanides, about 0.10 to 3.0% of a biosurfactant, about 0.50 to 9.0% w/v of edetate disodium and pure water q.s.p..

This invention is characterized by a composition for microbial inactivation used in chirurgical apparatus of triple action by a chelating substance associated with a biocide and a biosurfactant.

This invention is characterized by a composition for microbial inactivation used in chirurgical apparatus useful in reusable chirurgical apparatus, preferably on those that cannot be sterilized by heat due to their thermal instability.

This invention is characterized by a composition for microbial inactivation used in chirurgical apparatus that have atoxic, efficient non-corrosive, that acts in a wide pH range and is not an antibiotic, avoiding bacterial resistance.

This invention is characterized by a composition for microbial inactivation used in chirurgical apparatus that can be used in cleansing equipments with ultra-sound.

This invention is characterized by a composition for microbial inactivation be used in chirurgical apparatus that prevents the formation of biofilms and bacterial and fungi growth that colonize the internal or external surface of the apparatus or instrument by contamination processes due to their use or manipulation.

This invention is characterized by a composition for microbial inactivation used in chirurgical apparatus with wide range of activity and low toxicity for the human beings and the environment, being nevertheless compliant to the regulations of various countries all over the world. DETAILED DESCRIPTION OF THE INVENTION

An object of the present invention is a composition for microbial inactivation used in chirurgic apparatus comprising a synergic action of a chelantic component, a biocide component and a biosurfactant, providing a composition that has virucidal, bactericidal,, fungicidal, mycobactericidal and sporocidal activity with potential effect on biofilms.

A biofilm includes cells, microorganisms and extracellular polysaccharides, which are formed around materials inserted in the human body. The strategies used for biofilm removal include mechanical actions such as the production of ultra-sound by brushes that realize the mechanical treatment; detergents on the active surface, (surfactants) which have the ability to change superficial tension of the biofilm, making easier its removal; enzymes; oxidants and chelants, although the chelantic components make calcium and magnesium sequestration, destabilizing media and favoring the removal; antimicrobial agents; bacteriophages; among others.

The composition for microbial inactivation used in chirurgical instruments comprehends about 0.50 to 9.0% weight/volume of a composition of trisodium citrate, about 0.01 to 0.50% w/v of a polymeric biguanides composition, about 0.10 to 3.0% of a biosurfactant, about 0.50 to 9.0% w/v of edetate disodium and pure water q.s.p.

Preferably, the composition for microbial inactivation used in chirurgical instruments comprises about 1.00 to 6.0% weight/volume of trisodium citrate composition, about 0.01 to 0.04% w/v of polymeric biguanides composition, about 0.10 to 2.0% of a biosurfactant, about 1.0 to 5.0% w/v of edetate disodium and pure water q.s.p.

Preferably the polymeric biguanides are polihexamethylene biguanide (PHMB).

Preferably the biosurfactant is alkyl polyethylene glycol ether .

Optionally, about 5.0 to 70.0% w/v of an 96° alcohol composition is added to the formula, preferably about 10.0 to 40.0 w/v of the composition, to potentiate the microbiocide effect.

Tests show evidences that the antimicrobial and sporocidal properties are effective.

A serie of microbial inoculums have been prepared from Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhimurium, Acinetobacter baumannh, Bacillus subtilis, Geobacillus stearothermophilus strains at concentrations of 10 ⁶ UFC/mL and Candida albicans at concentration of 10 ⁵ UFC/mL

"In vitro" anti-microbiological efficiency tests:

1ml_ of the composition object of the present invention had been added to 2mL of the microbial suspensions separately so the final volume would maintain the initial concentration of each microorganism. 1 mL of this preparation has been inoculated in specific culture media for each microorganism to its quantification, after 48 hours of incubation at 35°C.

Obtained results, illustrated in Table 1 , show the best microbiocidal effect after exposition of 10 to 60 minutes.

TABLE 1 : "in vitro" Anti-microbial efficiency results using the composition object of the present invention, when compared to the exposition time.

Sporocidal action :

After the anti-microbial efficiency test, 1ml_ of the composition object of the present invention has been added to 2 mL of the microbial suspensions separately so that the obtained volumes would keep the initial concentration of each microorganism. Then, there have been inoculated 1 mL of this preparation in specific media for each microorganism for its quantification, after 48 hours incubation at 35°C.

The obtained results, presented on Table 2, show the best sporocidal effect after about 10 to 60 minutes of exposition.

TABLE 2: sporocidal efficiency results using of the composition object of the present invention, in relationship with the exposure time.

Detergent Concentration/Exposition Concentration/Exposition time- 10 minutes time- 60 minutes

Bacillus subtillis zero Zero

Geobacillus zero Zero

stearothermophilus