CA1088419A - Buffered phenol-dialdehyde sterilizing compositions - Google Patents

Abstract

INVENTOR:
ROBERT I. SCHATTNER

TITLE:
BUFFERED PHENOL-DIALDEHYDE STERILIZING COMPOSITIONS

ABSTRACT:

A room temperature aqueous sterilizing composition comprising from 0.75 - 4.0% by wt. of glutaraldehyde and from 4-15% by wt of phenol and a metal phenate, preferably sodium phenate.
Optionally present are 1-5% by wt of sodium tetraborate, 2-10% by wt of a humectant such as glycerol, di-ethylene glycol or propylene glycol, and a surfactant. A preferred pH range is pH 7.0 - 7.4.

Description

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. . ~ .. - -"Buffered Phenol-Dialdehyde Sterilizing Compositions" ~
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This invention relates to aqueous chemical compositions for room temperature sterilization with improved effect:iveness and longer active life.
Eficient sterilization methods are needed ~or medical, hospital, and industrial applications. For repeaked use, medical and dental instruments and e~uipment re~uire sterilizin~ proce- ;;
dures which are safe, e~fective, and rapid. Yet, the existing procedures and methods are either cumbersome, time consuming, costly, or lack merit.
Chem-ical sterilization at room temperature has ad- ~
~ . ~, vantages over other means of sterilization and, conse~uently, has received considerable attention over the years~ Many "cold ster-ilizing" compositions have been suggested to the art. For more detailed discussion o chemosterilizers and their modes of use, reference is made to "Chemical Sterilizers" by P.M. Borick in Advances in Applied Microbiology, ~ol. 10, pages 291-312, (Academic Press, NY 1968~. -In order to satisfy the criteria for sterilization, a chemical preparation must be capable of killing all forms of . ,~,' ' ,

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microbiological life, including spores which are highly resistant to sterilization. Such a chemical preparation must be bactericidal, fungicidal, and virucidal as well as sporicidal. While disinfectants, germicides, and antiseptic~ are capable of destroying most disease causing organisms, usually they are not cidal to (pa~hogenic) spores and, therefore, are not chemosterilizers. Relatively few antimicrobial agents are truly sporicidal and usable as chemosterilizers. ~-In recent years, the most widely used aqueous chemical sterilizing agent has been a buffered 2 glutaraldehyde sclution. Glutaraldeyhde solution~ prepared with an acied pH are not ordinarily ~poricidal at roorn temperature. However, when made alkaline, aporicidal activity in these solutions i9 very evident.
One of the problems encountered with alkaline glutaraldehyde solutions, however, is their lack of stability. Such solutions lose both their sporicidal activity and identifiable glutaraldehyde in about 2 weeks ater they are made alkaline. Another problem with the alkaline 2% glutaraldehyde solution is the relatively long contact time (10 hours at room temperature) required for sterilization. Thus, the commercially available alkaline glutaraldehyde compositions exhibit limited active life and require lengthy immersion time for sterilizatidn i.e., ~he suppliers adviae agianst using the activated solution more -than two weeks, and call for an immersion time of at least 10 hours at room temperature. Acid glutaraldehyde compositions are claimed to be reIatively more stable than alkaline glutaraldehyde and have extended use life, lbut the acid glutaraldehyde compositions are not sporicidal at room : -.

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temperature. For more detailed discussion of the glutaraldehyde sterilizer compositions heretofore suggested to the art, reference is made to US Patents 3,016,3283,282,775 and 3,697,222.
'- :' The composition of the present invention exhibits impro~ements in stability and active life, with the activated solu~ion having a sterilizing use life of more than 30 days and sterilizing properties within 6 3/4 hours, at room temperature. -SUMMARY OF THE INVENTION
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The present invention i8 an aqueous composition containing glutaraldehyde, 0.75 - 4.0~ by weight, together with phenol and a metallic salt of phenol in total rom 4 -15%. I~e composition may also include, optionally, additional buffering agents, preferably 1 - 5% sodium tetraborate, anionic and/or nonionic surfactants in total from 2-10% and a humectant such as glycerol, propylene glycol or diethylene glycol from 2 - 10%. ;
RATIONALE OF THE I~VENTION
G~lutaraldehyde is acidic and, by itself, does not sterilize (i.e. ls not sporicidal) at room temperatures. US
Patent 3,016,328 teaches that by adding an appropriate alkaline buffer to glutarladehyde, the resultant solution becomes an active sporicide in the pH range of 7.4 to 10Ø
However, in alkaline solution, glutaraldehyde tends to - ;
polymerize and lose its sporicidal activity. Also, alkaline glutaraldehyde is not pH stable. Consequently, the alkaline glutaraldehyde sporicidal formulations tend to lo~e effectiveness over a period of time. As mentioned above, the glutaraldehyde compositions marketed off to use the ~activated) solution after 14 days. A substantial increase '',: ' '::' ' - . . :

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in the active life of a buffered glutaraldehyde would constitute an advance in the art.
An additional area wherein improvement is desired is in kill time, this being the immersion period required for complete sterilization. Alkaline glutaraldehyde formulations with 2% glutaraldehyde as the only active i ingredient are generally accepted to have a 10 hour sterilizing time. Increasing the glutaraldehyde concentration may help,~ bu~ 4% glutaraldehyde is not ,10!' signifl ~tlyj~uperior to 2%~glutaraldehyde as a sporic:ide.
Some imprfvement in ~ill time has been achiev'ed byl~including formaldehyde as another active ingredient with glltaraldehyde. ;Hqw~ver, formaldehyde imparts lunfavorable propertie!s to the~formulation because the composii~ion then emits toxic vapors and~a~pungent odor ~ a~,k~linq!andl,acid~lglut~rlaldehydé, ex~ibit ;~ I corrosive properties!lwith respectfito metal~si,ulse~d~ medical and dental instrumcnts and apparatus. ~ Prèsently marketed glutaraldehyde composi~ions contain rust inhibitors to i 20 prevent corrosion damage. ` .~ ;
i The compositions of this invention are a combination of buffered phenol and glutaraldehyde.
Seperately, phenol, phcnolic derivatives or glu~arladehyde ~
are not capable of room temperature sterilization. ~ -~ ~Alkaline glutaraldchyde i9, of course).
- Buffercd phcnol compos1tlons exhibit unusual properties (as witnes6 the plant growth stimulation described in US Patent 3,674,458) which may not themselves cause lethality, but which might render microorganisms more 30~ susceptable to attack by the glutaraldehyde. Apparently, !
thls is the rationale for improved sporicidal activity.

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_ 5 Test studies indicate that the combination of buffered phenol and glutaraldehyde is substantially more efective than alkaline glutaraldehyde alone for room temperature sterilization.
Also, it has been found that the combination of glutaraldehyde and buffered phenol substantially increases the active life of, and imparts an inherent anti-corrosive ; property to, alkaline glutaraldehyde composition~. The buffered phenol/glutaraldehyde combination is effective at pH levels below 7.4 as well as in the more alkaline range ;; above 7.4. However, a pH of below pH 7.4 is preferred because improvements ln solution stability are apparent in this lower p~l range.
DISCUSSION OF THE INVENTION
The bu~ered phenol/gl~taraldehyde combination, particularly the preferred formulations, has an active steri1izing life~of more than 30 days, requires 6 3/4 hours (and possibly less) immersion time to achieve complete sterilization at room temperature and does not require the addition of a special rust inhibitor. The buffered phenol composition, without glutaraldehyde therein, has a shelf-life of 5 years, or more.
The improvement in useful life and in kill time exhibited by the composition of the present invention is reflected by the improved stability. A more effective gluraraldehyde sterilizer composition will take longer to decline to the minimally acceptable effectiveness levels.
An~improvement in stability provides the user with a composition which retains a higher percentage of its original (kill) activity over the rated use period for the -composition. Tests made on various proportions of buffered ~: ' . ' -:

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tJi~ 9 phenol and glutaraldehyde and on various phenol ocncentrations indicate that where stability improves effectiveness also improves.
Dilution studies, wherein the glutaraldehyde content is varied considerably, indicate that the sporicidal effectiveness of glutaraldehyde remains high in a glutaraldehyde concentration of 0.75-4.0~ by weight. The ~ ' dilution studies also indicate that the combination of buffered phenol and glutaraldehyde is far more bactericidal than either ingredient~alone. ~
' The f~ct that~effectiveness ha~be 'i~ roved by presence of buffe'red phenol alBo iB ' evidencedlby~ Hl!scan ~tudies showing thatl;the ! 8porlcidal aCtivity 0~ Icompo8ition is less~'llmi~ed by p~ 8pec~1ca~1y,lt~e oomposition is ,~
~'~ effectlve over the range of pH~7-~OIland~ rlntly is effective at loo~i temperature at pH less ~aTIl!pH-7-'~. In practiol,~the pH range~,ofl7~0j-7;~.4l~isJ;preferr?~ becl~use ~
improved stab'ility i8i j belie~e;d~to'~,be açh1elve~'in this range. ;' The composition may belad~usted to the desired ph by addition of hydrochloriclacid or reduction of a buffer, or ~ ' both.
The presence of ~odium tetraborate (sodium borate) has been found to be useful as a buffering agent in quantities of from 1-5% by weight.
Also, a phenate, preferably sodium phenate 0.5-5 by weight, is a useful buffering agent. The concentration of phenol/phenate is a 4-15% with the phenol range being 3-10% by weight.
Surfactants are desirable ingredients, serving to '~
facilitate penetration of active ingredients into pores, crevassés and irregular surfaces of objects being ~terilized '.':
,' ''.' ' ' 9 ;', by immersion into the aqueous formulation.
In practice, presence of anionic and/or non-ionic ;
surfactants individually or in various combination, have been found effective. A combination of ~;urfactants with a ratio of 60:40 to 40:60 anionic and non-ionic is preferred.
Exemplary surfactants are sodium n-dodecylbenzene sulfonate and sodium co-coyl sarcosinate. The surfactants improve activity of the formulation. Tests with varying levels of surfactant concentration;indicate that a high surfactant content, i.e., 2-10%,~improve sporicidal activity for the composition as a whole.
; Another lngredient that has been found desirable ; ~l is a h~mectant selectedlfrom,lthe group~consiBtinglolf~
glyceroi, propylene glycol and di`ethylene glycol,lin quantitle8 of frlm 2-10% by wloight.

$l~lprovidl~ n a two-contaiiner form, ona cont~iner holding the glutaraldehyde, è.g. ajs 25l~ ori50% solution, and~the other container;ho?ding the buffi$rllsystem.
20 ~ The specifica~ly;preferred embodiment ~f;¦
phenollphenate buffer, Which i8 detailed in Examplé A below at full strength, may be either diluted or made more concentrated within the range of about 0.4-1.5 times the full strength concentration given in Example A.
Glutaraldehyde may be~ added to a final concentration of - 0.75-4.0~ by weight in~the formulation. However, 2~ -glutaraldehyde~ie preferred.
For further understanding of this invention, the following specific examples of practice thereof are provided.

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EXAMPLE A
The test formulation contained the following ngredients:
I BUFFERED PHENOL % by wt.
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.:, a) Phenol 7.05 `C1' b) Sodium phenate ~ 1.20 c) Sodium borate 2.35 -d) Diethylene glycol',' 6.30 ~10 e) Na-n-dodecyl ben;z~e~e ~ ~
; ~l ' salfonate ~ 1 ' , ,7.00 ~80% active materiaI) ' l ~ "`ll f) Na cocoyl sarcosinate I ~ ~ 10.~5 ; (30%lactive mater'lal) 1 l , g) Di~tilledjH20 ~, ; j ll $~ ~1 l q.8 h) 6M h~ydrochlor1clDcld~ ' oo . . , I I . ~ ' i, , i j , . , I .

25~ Glutaraldehyde ~ l 8.00 ~ ~ I 100.00 Procedure:
.
Add ingredientsla-f to a tared container, then add a I
large portion of~the distilled water and stir. (The solution may be heated to 45C to facilitate solution). With . .
stirring, add (6M) hydrochloric acid or sodium hydroxide - -until pH reaches whatever value is desired in the pH 7-10 range. The non-adjusted ~pH is about 9.5. Add sufficient .
additional distilled water to being to proper total mass.
(I heating i~ not used to facilitate solution, addition of the gydrochloric acid will dissolve the solids as thle pH
nears 7.5).
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The buffered phenol system and glutaraldehyde can be maintained in separate containers until needed. For use, the respective solutions are admixed.
EXAMPLE I
Procedures:
From culture of EPA designated strains of Clostrid-lum sporogenes and Bacillus subtilis spores were grown, col-lected, coated on porcelain penicylinders and suture loops, and dried in partial vacuum exactly as dexcribed in the Official Final Action Sporicidal Test of the A.O.A.C.

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Official Methods of Analy61s, 11th Ed.). l~ , ~ To demonstrate adeguate resistancelof the spores, both types of carriers~ contaminated with both'organisms (a total of our diferent combinations) were e~posed!to 2.5N
HCL atll20C exactly as described ln t~e A O.A.C. S~oricidal Test.l The spores used ijn the testing procedures sùrvived exposure to 2.5N HCL for 2-20 minutes. ~ ~
~ A solution ~(pH 7.25) prepared according to Example A was tested for sporicidal activity with the carriers pre-pared as described above.~;The tests were run at 25~C with 63/4 hours exposure using the procedures described in the sporicidal Test of~the A.O.A.C. To help neutralize any of the chemosterilizer which might be transferred With the carriers into the culture medium, a double tube transfe~ was made in fluid thioglycolate medium contained 0.5% "Tween80".
The carriers in the culture medium were incubated, heat shocked, and reincubated as specified in the sporicidal testing procedure.
The sporicidal activity was tested on a total of 600 replicates as follows:
(a) Three samples representing three different pre-'~
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parations using both types of carriers (porcelain penicylinders and surgical silk suture loops) and -both test organisms tBacillus subtilis and Clos-tridium sporogenes). ~
Thirty replicatesi were tested with each organism ;~-on each type of carrier, a total of 120 replicates .
or carriers for~each sample. ;i , , ~
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(b) Duplicatelsamples of the formulation ater a 60 I; , 10 , , day aging period using 30 replicates with both test organ`isms on both types of carriers. This ~ i l was a~total~of l20 replicates or carrier~ for each ,~, ,";; ~ ,8amp~e.~ " i !
~ESULTS ' '~
There were !~0 Ipositiveelin ~ny of th~l600 A~ The formulation prepared as described i~!iExample A
was tested per1odically over a five week period~against B
20~ subtilis spores to measure!~variation in "D" value at 25C.
over the five weeks ~the D-value method employed hérein ; : . .
; belng described ln detail below). In addition the pH levels were measured. `For control purpo~es a commercial alkaline glutaraldehyde sterilizer composition was similarly tested.

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TABLE II

Commerc:ial Alkaline Glutar- -Buffered Phenlo/Glutaraldehyde aldehyde~
Age of D-value D-va]Lue Solution (25C) E~ ` (25C) ;I pH
Fresh 14 min. 7.30 32 m:in. 8.15 l week 19 " 7.28 44 " 7.55 2 weeks 14 "i 7.28 58 " 7.45 3 weeks -- 7,27 -- 7.30

4 weeks ! ~ 7.22 -- ;7.30

5 weekis 30 " l 7.12 140 "' 7.30 Total change in~pH 0.18 0.85 over 5 week period e C-value mèthod~ To obtainithe D-vaiule of a givenlpreparation, O.L mL~ of aj acillus subtilis spore .: , ~ I i ;l isUsipension~ standardized to contain ljX'10~ spores per ml, was pipo ~ ed into~lq ~ e t~ prep~ nl Wh.{~h had been brought jtolthermoe~ui~1br1um ~in a 25C wiater~blth.
Thils~resulted inl!a Iconcleltratlon of 1 X 106 spoFes~iper ml of itest preparationior a~erit.~ Ir~medlately one ml ~f the ~eist agent aontaining sipore8!wa8 withd~awn and tr~ansiférrled into a~
20 99 ml sterile waeer blank containing 0.5~ Tween`-80. The blank was then shaken,~ diluted, and plated in Dextrose Agar (Di~co) which also contained 0.5% Tween-80. After incubating the plates~48 hours at 37C, the spores which survived grew into colonies which could be counted.
Plate6;were prepared in a similar manner from amples,taken from the test agent at selected intervals from 5 to 45 minutes after the spores were added. The colonies, representing surviving spores, were counted for each time interval for a given;test solution. These counts were 30 converted into common logarithms and plotted again~t time.
A line drawn through these points resulted in the .

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characteristic death curve for the test solution used. From this plot, the time required to reduce the population of viable spores one log was calculated--thus the D-value was obtained for that test solution. ~xcept where aging studies were conducted, the test agents were activated just prior to testing.
B. A 600-tube study as described in Example l was performed on a solution prepared according to Example A
which had been activatled (i.e. the buffer and glutaraldehyde was admixed) 30 days p~rior to testing. This study resulted in nojpositives in any of the 600 replicate tests at 6 3/4 hours contact.
EXAMPLE III
The composition of Example A was tested1for cor~rosion and chFmicaj~ r~ct~ity~lagatnst ;de~ta~ a11d hoopitll`équipment~commonly st~ril'ize~
The formulatlon was ine,rt to~solid ata~nl!ess steel and plated article despite~contact for up to 83 days at temperatureo of ~ro~ ambient to 45C. Plated artioles exhibited reac*ivity (by electrochemical corrosionj only ~t where the plating had~worn through to`the carbon steel.
A mild reactivity to aluminium was found.
The flexibility and elasticity of tubin~ and rubber articles were not impaired after 21 days exposure to the formulation at ambient temperatures. No softening or -size variation could be detected in the moving or mating parts of a similarly exposed plastic syringe.
EXAMPLE IV
The buffered phenol composition of Example A was tested alone diluted 25% with distilled water (20 ml + 5 ml of H20) and in the diluted concentration with varying .

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proportions of glutaraldehyde. (The quantity of H2O added was adjusted to compensate for the water content added with the 25% glutaraldehyde solution). I'he test org~nisms were B. subtllis spores. All test solutions were adjusted to pH
- 8.25. A commercially purchased alkaline glutaraldehyde ~, sterilizer composition was used for control purposes.

The results are tabulated below:
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TABLE IV l ~-~
"D" value Buffered Phenol Glutaraldehyde Conc. (25C) Full Strength i ! 0 15 hours Diluted ~ 0 15 0.25%225 minutes . 50% ~ 90 " 0,'75% ' 39 "
~ 0~90~ 25 "~ .oo% ; 113 j ,1'50% i,l 10 ~ ~ l 2~00% ; ~ 8 Commiercial alkaline !' , ' " ~, , '', !" l ~"
Glutaraldehyde; il ~ 2.00% 1 ~ ;i 3i ~"
EXAMP~E V
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; ~ The formulation of Example A waei p~epared omitting the propylene glycol (humectant~.' A comparative tegt was conducted against the fuil formulation of Example A and a control (commercial alkaline glutaraldehyde sterilizer). B. a subtilis spores were used at 25C and at pH ~.25.
The tests s~owed that with or without propylene glycol the "D" values were less than 5 minutes. The commercial preparation "D" value waq 45 minutes.
EXAMPLE VI
The consequence of relatlve dilution of the phenolic bugger and of~glutaraldehyde are herein exemplified.

The phenolic buffer of Example A was dilutecl with distilled water as indicated in Table VI below.
Glutaraldehyde was added in the wt. percent quantities ,~ I ' ,:, .
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10~ 19 indicated in Table VI below. All compositions were at pH ~ ~;
8.25 and were tested as freshly prepared solutions.
Tabulated bslow are D-25C values for combinations , of the phenolic buffer and glutaraldehyde. ' -TABLE VI '~
.
, (D-values at 25C) , % Glutaraldehyde ~ ' . :.
Buffer ~ ,- ,;
Concentration ~ 0.25 0.5_ _0.S3 1.0 1.5 2.0 ---~

20% Buffer ' ~1,92 120 65~'55~51 26 ~' ' ' 40~ Buffer , " 220 110 45 33,;26 16 ,'' -' 60% Buffer ~l, I80 12035 25 , 21 13 80% Buffer ,~ ,220 150 30 34 19 12 '~
Full Stren'gth Buffer, j '1!, 255 87 -- '17 -- 10 * D-va;lue - Time~,in milAute~ to!lreduce.the sporq population i ~ I ' Also, 2% glqtaraldehydei~in ~ull stren~thlilphenolic , buffer, in 80% phenol~clbu~fe~;and inil60%lphenollc,buffer, ` ' '' all freshly prepareld,lwere,testedlla~ll'yarious ¦IPH leviéls from ,pH 7.0 -~8.3 aga'inst B. subtilis spores. ~"Di' values 3-12 minutes were obtained wlth,ithe,lower "D" value~,;atj,the upper end,of'the pH range.~
EXAMPLE VII ~ !"
The effectiveness o~ the composition ~f Example A ~ ~, against gram positive and gram negative organisms i8 herein exemplified. The!component~ (Table VII-B,C) and the full composition (Table VII-A)~were tested at various concentrations. ;All dilutions were made with distilled , '' water.~ The;test used was the ~se-Dilution test describ,ed in C~

the:AOAC 11th edition~and~test organisms were those strains approved by the AOAC for this method.
' The survival;levels frbm each test are tabulated below~
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- -TABLE VIIA
Survival of Exposed Organisms Dilution of Staphylococcus Salmonella Pseudomonas Phenolic Buffer + aureus choleraesuis aeruoinosa 2% Glutaraldehyde ATCC 6538 .ATCC 10708 ATCC 15442 .

1:2 0/10 1:4 0/10 ~
1:8 j 0/10 , -- --1:10 ~ 0/10 -- 0/20 1:16 0/10 0/10 0/40 1:20 0/10 0/10 0/50 1:30 0/10 0/10 0/10 1:40 , 0/10 0/10 3/20 1:50 , 0/30 0120 ~ --: 1:60 0/10 2/20 --1:64 0/10 -- --~ TABLE VIIB
Survival of ExposedlOrganis~
` ~ Dilution of Staphylococa4s l ,Salmonella P6eudomonas Phenolic ~uf~er aureus cholerae~uis aeruginosa ~no glutaraldehyde) .. ...._ _ : 1:4 `~il/10: -- 0/10 1:8 0/10 0/10 11/10 ;1:10 5/~0 . 0/10 2/10 5/10 301:20 10/10 , 9/10 --1:60 : 10/10 ~ ,__ I l; __ TABLE VIIC
,S,urvival,of Exposed Organism~ . .
- ~ , 1 : Dilution 2~ Staphylococcus Sailmonella Pseudomonas glutaraldehyde aureus Icholeraesuis aerugi~nosa (No phenolic buffer) ... . :
1:2 -- 0/10 -- .~ -- 1:4 ~ 0/10 ~~ : i0/10 0/10 0/10 1:8 ~;0/10 ~ 0/10 :0~10 0/10 -:
~ ~: 1/10 ~ 2/10 0/10 10/10 . ~.
~ , ~1:20 1 10/10,, I ,~llo o/lo lollo : ~
1:30 ~ 10/10 -- -~
1:40 ~ - 10/10 :l:S0 :~ 1:60 , ` ~~~ J I 10jlO 10/10 .:

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l . TABLE VIID
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. Bactericidal effectiveness of the full formulation. .
. compared with each of the phenolic.buffer and 2% glutaraldehyde. ..
as controls: . :
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Test Highest Dilution at Which Bactexicida: .
Organism . . . Full Buffer 2~ Glut.
Formulation Alone Alone .. ~

Staphylococcus aureus 1:64 1:8* 1:8 Salmonella cholerasuis 1:50 1:8 1:8 Pseudomonas aeruyinosa 1:30 ` 1:~ 1:8 , *one test at 1:4 also had a positive 1. Conclusions . 1. The results as su~marized in Table VIID show a much greater bactericidal activity for the composition of Example A than for either component alone.
. 2. Of the three organisms tested, Pseudomonas .
. aeruyinosa is the mast resistant to the disin~ectant action of . the complete formula. However, its resistance to the components separately did not.differ materially from the resistance of the .. :
. ather two organisms.
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Claims (10)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An aqueous sporicidal composition comprising by wt.
from 0.75-4.0% glutaraldehyde and from 4-15% of a mixture of phenol and a metal phenate, the phenol context being from 3-10% and the metal phenate being from 0.5-5% said composition further characterized in having a pH of about 7-10 and an active sterilizing life of at least 30 days.

2. The composition of claim 1 wherein from 1-5% by weight of sodium tetraborate is present.

3. The composition of claim 1 wherein at least one anionic or non-ionic surfactant is present.

4. The composition of claim 3 wherein from 2-10% by wt. of surfactant is present.

5. The composition of claim 4 wherein the surfactant is selected from the group consisting of sodium dodecyl benzene sulfonate and sodium cocoyl sarcosinate.

6. The composition of claim 1 wherein from 2-10% by wt.
of a humectant selected from the group consisting of glycerol, di-ethylene glycol and propylene glycol is present.

7. The composition of claim 1 wherein the phenol to sodium phenate ratio is 5-7 to 1.

8. An aqueous sporicidal composition comprising by weight the following ingredients:
said composition further characterized by having a pH
of about 7-10 and an active sterilizing life of at least 30 days.

9. The composition of claim 8 wherein the composition further comprises by weight.

10. The composition of claim 9 wherein the pH is in the range of pH 7.0-7.4.