WO1991007184A1

WO1991007184A1 - SUBSTANTIALLY ANHYDROUS COMPLEXES OF PVP and H2O¿2?

Info

Publication number: WO1991007184A1
Application number: PCT/US1990/005846
Authority: WO
Inventors: John J. Merianos; Herbert A. Lieberman; Robert B. Login; Paul Garelick
Original assignee: Gaf Chemicals Corporation
Priority date: 1989-11-08
Filing date: 1990-10-15
Publication date: 1991-05-30
Also published as: CA2028354A1

Abstract

What is provided herein are substantially anhydrous complexes of PVP and H2O2 in molar ratios of between about 2:1 and 1:1, respectively, which corresponds to between about 13 % and about 23 % by weight H2O2. The complexes of the invention are substantially uniform, free-flowing, fine white powders. The complexes herein are prepared by reacting PVP and H2O2 in substantially the molar ratio predetermined for the complex. In one suitable process for preparing such complexes the reaction is carried out between the reactants in an anhydrous organic solvent such as ethyl acetate. A method is provided herein for reducing the microbial content of surfaces which comprises contacting said surface with a microbiocidal amount of said free-flowing, substantially anhydrous complex of PVP and H2O2.

Description

- 1 -

SUBSTANTIALLY ANHYDROUS COMPLEXES OF PVP AND H_?Q

This invention relates to substantially anhydrous complexes of polyvinylpyrrolidone (PVP) and hydrogen peroxide (H 0₂) which are, free-flowing, uniform, fine white powders containing a predetermined amount of H₂0 therein.

Stabilized H₂0₂ compositions have found wide utility in commercial and industrial applications, e.g. as disinfectants, sterilization agents, as bleaching materials, washing concentrates, etchants, in cosmetic preparations, as clarification agents for alcoholic and fermented beverages, and as a catalyst in polymerizations requiring a free radical source. In biological applications which require a disinfectant or sterilization agent, such H₂0 compositions require release of an effective amount of oxygen at a controlled rate without storage decomposition caused by interaction with organic matter, light and/or heat.

Shiraeff, in U.S. Patents 3,376,110 and 3,480,557, discloses a solid, stabilized hydrogen peroxide composition of hydrogen peroxide and a polymeric N-vinyl heterocyclic compound prepared in an aqueous solution of the components. These compositions generally were prepared by mixing various weights of PVP and aqueous H₂0₂, and evaporating the solution to dryness. The Shiraeff composition, which was believed to be a solid, dry complex, was described as not necessarily anhydrous due to the hydrophilic nature of the PVP and the water present in the reaction solution. Shiraeff further stated that such amounts of water could be tolerated, however, if it did not affect the solid dry characteristics of the complexes. The H₂0₂ content of the composition was given as being at least 2%, and preferably 4.5 to 70% by weight. Prolonged drying to remove water from such compositions, however, resulted in loss of H₂0₂ forming a brittle, transparent, gummy, amorphous product. In U.S. 3,480,557, the aqueous PVP-H₂0₂ complexes, upon heating to dryness, produced hard, brittle chips which had a variable

H₂0₂ content ranging from about 3.20 to 18.07% by weight, depending upon the drying times.

In accordance with the invention, substantially anhydrous PVP-H₂0₂ complexes are provided having a predetermined molar ratio of PVP to H 0₂ ranging from between about 2:1 to about 1:1, corresponding to a H₂0₂ content of about 13% to about 23%. The substantially anhydrous PVP-H₂0₂ complexes are prepared by reaction of PVP and H₂0₂ in a substantially anhydrous organic solvent and are obtained by filtration of the suspension as a uniform, free-flowing, fine white powder.

The PVP polymeric starting material used in the present invention is available commercially as a solid of varying molecular weight, water solubility and water content. A typical PVP polymer is water soluble PVP-K30 (GAF Corp.) which contains less than 5% water. Other PVP polymers of different molecular weight, water solubility and water content also may be used, as for example, K-90 and K-120; Polyclar AT; Crospovidone; and the like. Both water soluble and water insoluble PVP polymers may be used.

In this process, the PVP powder is suspended in a suitable anhydrous organic solvent, such as a carboxylie acid ester, an alkyl ether, e.g. t-butyl methyl ether, or a hydrocarbon, e.g. cyclohexane. Preferably, however, an alkyl or cycloalkyl ester of a saturated aliphatic carboxylic acid is used, as for example, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate and ethyl propionate. The PVP suspension in ethyl acetate, for example, then is cooled, preferably to about 0°C. , at which temperature precipitation of the desired complex as a fine powder may suitably occur. An anhydrous H₂0₂ solution in an anhydrous organic solvent, preferably the same carboxylic acid ester used to form the PVP suspension, then is prepared according to the process of U.S. 4,564,514. In this step, an aqueous H₂0₂ solution (e.g. a 50% solution) is treated with the ester and then subjected to azeotropic distillation at a predetermined low pressure, e.g. at 200 mm Hg and 55^βC. The resultant product is an anhydrous H₂0₂ solution in the ester having a H₂0₂ concentration in the range of about 20 to 50% H₂0₂.

Thereafter the thus-prepared anhydrous H₂0 solution is slowly added to the cooled PVP suspension in an anhydrous solvent in an amount corresponding to the desired molar ratio of PVP and H₂0₂. Preferably, however, a small excess of the H₂0₂ solution over the desired stoichiometric ratio is used. For example, to prepare a PVP-H 0₂ complex with a 1:1 molar ratio, about 111 g. PVP and 100 g. of a 42% H₂0₂ and 300 ml of anhydrous solvent is used, providing a small excess, e.g. about 5%, over the required stoichiometric amount of 34 g. H₂0 . This excess H₂0₂ is recoverable from the mother liquor.

Upon mixing the PVP and H₂0 , a fine white powder is obtained which is filtered and dried at about 40-50°C. in vacuo to remove residual solvent. The product is a stable, anhydrous complex in the form of a uniform, free-flowing, fine white powder having a H₂0₂ content between about 13% (2:1 molar ratio) and 23% H₂0 (1:1 molar ratio) . iβ water content of the product generally is equal to or less than the amount present in the PVP starting material, and usually is less than 1%, preferably about 0.5%.

An alternative process for preparing the substantially anhydrous complexes of the invention uses a water-insoluble PVP polymeric starting material which is available commercially as a solid of varying molecular weight and water content. A suitable water-insoluble PVP polymer is Crospovidone, sold by GAF Chemicals Corp., which contains about 4% water. These PVP powders preferably are dried at about 105°C. in vacuo for about 2 hours to reduce the water content to less than about 1%.

The dried PVP powders then are suspended at about 5-10°C. under agitation in a substantial quantity of an anhydrous organic solvent, such as a carboxylic acid ester, a dialkyl ether, e.g. t-butyl methyl ether, or a hydrocarbon e.g. hexane or cyclohexane. Preferably an alkyl or cycloalkyl ester of a saturated aliphatic carboxylic acid is used, as for example, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate and ethyl propionate. Ethyl acetate is preferred.

A 70-85% aqueous H₂0₂ solution then is added to the cooled PVP suspension under continued agitation during a period of about 30 minutes to about 1 hour. The amounts of PVP starting material and H₂0₂ solution used correspond to the desired molar ratio of PVP and H 0₂ in the complex. Preferably, however, a small excess of the H₂0₂ solution over the desired stoichiometric ratio is used. This excess H₂0₂ is recoverable from the mother liquor.

Upon mixing the PVP and H₂0 , a uniform, free-flowing, fine, white powder precipitate is obtained which is filtered and dried at about 40-50°C. in vacuo to remove residual solvent and water. The product is a stable, anhydrous complex in the form of a uniform, free-flowing, fine, white powder having a H₂0₂ content between about 18 and 22% H₂0₂. The water content of the product generally is about 2% or less, and usually can be dried to less than about 1%.

Continued drying under these low temperature and vacuum conditions reduces the final water content in the complex to a substantially anhydrous powder with no loss of H₂0₂. EXAMPLE .1

Preparation of Substantially Anhydrous 1:1 PVP-H2O2 Complex

PVP K-30 (GAF Corp.) (4.5% water). 111 g., was suspended in 200 ml. of anhydrous ethyl acetate (0.01% H₂0) , and the suspension was cooled to 0°C. An anhydrous hydrogen peroxide solution in ethyl acetate was prepared by treating 200 g. of 50% aqueous hydrogen peroxide with 6 1. of ethyl acetate and azeotroping in a rotary evaporator to remove 100 g. of water. A 42.7% H₂0₂ solution in anhydrous ethyl acetate was obtained. Then 100 g. of this solution was added slowly over a period of about 1-1/2 hours to the PVP suspension. A fine white precipitate formed which was filtered and dried in vacuo. The resultant water soluble complex contained 23.4% by weight H₂0₂ and 0.5% by weight water, upon drying at 50^βC. in vacuo for 2 hours.

EXAMPLE 2

Preparation of Anhydrous 2:1 PVP-H2O Complex

The process of Example 1 was followed using 50 g. of the H₂0₂ solution in anhydrous ethyl acetate. The resultant complex contained 13.2% H₂0₂ and 0.5% water.

EXAMPLE 3

200 g. of PVP-CI (K-30) was suspended in 300 g. of anhydrous ethyl acetate. Then H₂0₂, 424 g., 19.6% H 0₂ and 0.84% H 0 was added slowly to the cooled (5^βC.) suspension of PVP/ethyl acetate. The addition required 45 minutes. The suspension then was stirred for another 45 minutes, filtered, and washed with anhydrous ethyl acetate. The fine powder was dried at 40-50°C. for 2 hours under vacuum to recover ethyl acetate. The yield was

258.8 g. of water soluble PVP-H 0₂ containing 23.1%

H₂0₂ and 0.4% H₂0 as a free flowing white powder.

The mother liquor of ethyl acetate, 485 g. contained 4.51%

H₂0₂-

EXAMPLE 4

35 g. of crospovidone was suspended in 100 ml. of anhydrous ethyl acetate. Then H₂0₂, 27.5 g. as a 42.7% H₂0₂ solution was added with cooling at 5-10^βC. The mixture was stirred for l hour. The precipitated complex was filtered to provide 46.1 g. of a water insoluble PVP-H 0₂ complex containing 24.9% H₂0₂, after drying at 40-50°C. for 2 hours.

COMPARATIVE EXAMPLE

Preparation of Aqueous PVP-H2O Complex According to U.S. 3,480,557

6 g. of PVP-CI (K-30) (GAF Corp.) (4.5% water) was dissolved in 50 ml. of methanol. Then 7 g. of a solution of H₂0₂ in water (50%) was added, followed by heating at 45^βC. for 2 hours, and evaporation of methanol for 12 hours. A gummy, amorphous residue was obtained which contained 12.92% H₂0₂ and 5% H 0. EXAMPLE 5

Stability of Anhydrous Complex of Example 1

After 43 days at 60°C. the complex lost only 15% of its H₂0₂ activity, which shows excellent stability toward decomposition. At room temperature, decomposition was only 1.5% after 60 days.

EXAMPLE 6

Preparation of Free-Flowing, Fine, White Powders of PVP-H2O2 Complex

PVP-CI (K-30) (GAF Corporation) (4.5% water) was dried at 105°C. in vacuo for 2 hours until it contained only 1.1% water. 160 g. of the dried, water-insoluble PVP was suspended in 450 g. of anhydrous ethyl acetate (0.01% water) , and the suspension was cooled to 5°-10°C. while agitating the suspension. Then 55 ml. of 70% hydrogen peroxide solution in water (71 g. H₂0 ) was added slowly over a period of 35 minutes to the agitated suspension keeping the temperature at 5°-10°C. A fine, white precipitate was formed which was filtered to yield 312 g. of a wet product which was dried at 40°-50°C. in vacuo for 4 hours. 200 g. of a free-flowing fine, white powder was obtained which contained 19.5% H 0₂ and 2.9% water. Further drying under the same conditions for an additional 6 hours reduced the water content to 0.5% while maintaining the H₂0₂ content at 18.5% and without affecting the physical properties of the powder.

In the drying step above, 77.9 g. of mostly ethyl acetate was collected in the vacuum trap which also contained 0.2% H₂0₂ and 3.78% water in the upper layer and 8.0 g. of mostly water (92%) with 0.63% H₂0₂. The filtrate (363 g.) obtained above contained 2.75% H₂0₂ and 1.54% H₂0, the rest being ethyl acetate, which was recycled as described in Example 2 below.

EXAMPLE 7

The procedure of Example 6 is followed using PVP-CI 160 g.; ethylacetate 450 g.; and 85% H₂0₂ 56 g. 197 g. of a PVP-H₂0₂ complex with 19.2% H₂0₂ containing 1.56% H₂0 is obtained. Further drying at 40-50°C. in vacuo will reduce the water content to 0.5% H₂0.

EXAMPLE 8

Preparation of Free-Flowing, Fine, White Powders of PVP-H O Complex by Recycling the Filtrate of Example 1

To the filtrate from Example 6, 363 g., was added 90 g. of fresh, anhydrous ethyl acetate followed by cooling to 5°-10°C. Then 170 g. of dried PVP-CI was added at once whereupon the exothermic reaction increased the temperature to 12^βC. The suspension was cooled to 5°C. with an ice-water bath. Then 58 g. of a 70% H₂0 solution was added over a period of 2 hours with good agitation, a fine, white precipitate was formed and filtered to provide 320 g. of a wet cake which was dried at 40°-50°C. under vacuo for 4 hours to yield 202 g. of a free-flowing, fine, white powder containing 18.9% H₂0₂ and 3.1% H₂0. Further drying under the same conditions for an additional 6 hours lowered the water content to 0.6%, and the H₂0₂ content to 18.3%, without affecting the physical characteristics of the powder. The filtrate weighed 358 g. , and was mostly ethyl acetate with 2.58% H₂0₂ and 1.49% water.

COMPARATIVE EXAMPLE 2

Preparation of Aqueous PVP-H 0₂ Complex according to U.S. 3,480,557

To 6 g. of PVP-CI (K-30) (GAF Corporation) (4.5% water) was dissolved in 50 ml. of methanol was added 7 g. of a solution of H₂0₂ in water (50%) , followed by heating at 45^βC. for 2 hours, and evaporation of methanol for 12 hours. The gummy, amorphous residue contained 12.92% H₂0₂ and 5% H₂0.

EXAMPLE 9

Stability of Anhydrous Complex of Example 6

EXAMPLE 10

Stability of Aqueous Solutions of Anhydrous Complex of Example 6

An aqueous solution of the complex of Example 6 containing 3.75% H₂0 was heated at 58°C. for 96 hours. At the end of this period, the solution analyzed for 2.75% H₂0, which indicated excellent stability for aqueous solutions of the complex of the invention. COMPARATIVE EXAMPLE 3

Stability of Aqueous Solutions of (a) Urea/H₂ ^Q ₂ and (b) HQOQ

(a) Under the same conditions as in Example 10, a urea/H 0₂ solution, after only 36 hours, was reduced in H₂0₂ content from 3.5% to 0.6% H₂0₂. (b) An H₂0₂ solution itself lost all of its 3.0% H₂0₂ content after 36 hours.

Antimicrobial formulations of the complexes of the invention are prepared using a microbiocidal amount of the substantially anhydrous PVP-H₂0₂ complex, and an acceptable diluent and/or other active and inactive ingredients in the form of a suspension, solution, dispersion gel, powder, paste, suppository, aerosol, ointment, tablet, etc. The formulation may also be impregnated into or applied onto a suitable support, such as a gauze, cotton swab, sponge, etc. Generally, the complex will be activated by water present on the surface containing the microbes, the water functioning to release the active H₂0₂ from the complex.

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FORMULATION 1

The suppository dissolves completely in about 1 ml of water in about 10 minutes at a temperature of about 37^βC. Upon contact with water, a slight development of foam starts with simultaneous dissolution of the suppository. The foam development increases constantly until the dissolution is complete. The foam which forms has fine pores, is even and remains as such over an extended period of time. The nonoxynol-9 is a spermaticide, and the amphoteric-19 and PVP-peroxide are microbiocides.

FORMULATION 2

EFFERVESCENT MOUTHWASH TABLET

Ingredient Percent Wt. (grams)

Anhydrous PVP-H₂0₂

(23.1%) (Ex.l) Sodium bicarbonate (granular) Sodium carbonate, anhydrous Citric acid, anhydrous (granular) Aminoacetic acid Flavorants (spray dried) Color

Sodium benzoate (fine powder)

100% 447 mg.

The tablets are compressed with 3/4-in. diameter, flat-faced, bevel-edge tooling. The tablet ingredients, other than the anhydrous PVP-peroxide complex, are mixed, lightly dampened, and granulated. To the slightly dampened granules the anhydrous PVP-peroxide complex is added, and the well-mixed, slightly-moist ingredients are compressed, then immediately thereafter placed in a 70°C. forced draft oven for 1 hour to drive off any residual water. The cooled tablets are immediately packaged in air tight aluminum foil pouches.

The tablets are added to 60 cc (2 oz.) of water for use as an effervescent mouthwash and gargle. FORMULATION 3

NON-AQUEOUS OINTMENT

Ingredient Percent wt.(g.) Anhydrous PVP-H₂0₂ 15 150

(23%) (Ex.l) Sorbitan Monopalmitate 10

(Span* 40-Atlas) Polyethylene Glycol 400 14 140

Monostearate Polyethylene Glycol 400 35 350 Polyethylene Glycol 4,000 35 350

100% 1,000 g.

The polyethylene glycols and the sorbitan monopalmitate are warmed on a water bath to 70^βC. and the complex is added to the well-stirred molten mass. Stirring is continued until the ointment is well-solidified.

FORMULATION 4

ANTIBACTERIAL LIPSTICK

100% 2.00 g.

The formulation is prepared as in 3 above. - 14 -

FORMULATION 5

POLYETHYLENE GLYCOL-CONTAINING OINTMENT

Ingredient Anhydrous PVP-H₂0₂

(23%) (Ex. 1) Sodium Carbonate Polyethylene Glycol 4000 Polyethylene Glycol 400

Heat the polyethylene glycol 4000 and 400 with constant stirring on a water bath at 65°C. Slowly add the micronized anhydrous sodium carbonate and PVP-H₂0₂ complex with constant stirring. Cool until the mass is well mixed and congealed.

FORMULATION 6

100.0%

All D items in formula above should be micropulverized and blended. Sprinkle the xanthum gum into glycerin with constant agitation until uniform (Phase A) . Add the polyethylene glycol 400 (Phase B) to Phase A with continued agitation. Sprinkle in Povidone K-90 until uniform and with constant stirring add the well mixed micronized ingredients of Phase D. Seal unit with cover and apply 28 or more inches of vacuum for 30-45 minutes with continuous agitation. Add all ingredients of phase E, starting with the hydrogen peroxide complex (item 1) , under continued agitation and mix until uniform. Mix under vacuum (28 inches or more) for 5 additional minutes. - 16 -

FORMULATION 7

Blend micronized powders of the above two ingredients until homogeneous. Add ethyl alcohol to the well blended powder until a thick homogeneous paste is achieved. Lay a homogeneous layer of 700 mg plus the ethyl alcohol used for dispersion on 1 sq. inch of bandage. Place the coated bandage material under vacuum and heat until the ethyl alcohol is completely evaporated. The resultant mixture of the H₂0₂ complex and povidone K-90, evenly spread on 1 square inch of bandage will yield about 3% of available H 0₂ from the solid povidone mixture. If substantive icrobicide activity is desired, 0.1% of cetyl pyridinium chloride can be mixed into the above blend before evaporation of the ethyl alcohol.

FORMULATION 9

EAR DROPS SOLUTION

Ingredient Percent Wt. (q.) Anhydrous PVP-H₂0₂ 6.5 6.5 (23%) (Ex. 1) Anhydrous glycerol 93.5 93.5 100% 100g.

FORMULATION 10

SOFT LENS DISINFECTION TABLET

Ingredient Anhydrous PVP-H₂0₂

(23%) (Ex. 1) Sodium bicarbonate (granular) Sodium carbonate, anhydrous Citric acid, anhydrous granular Sodium benzoate (fine powder)

100% 1.84 g.

The tablet ingredients, other than the anhydrous PVP-H₂0₂ and sodium benzoate are mixed, lightly dampened to form a damp granule. To the slightly dampened granules the povidone peroxide and sodium benzoate are added so that granules with a damp feel are compressed using 1-1/4" flat-faced, bevel-edge punches. Immediately after compression the damp tablets are placed in a 70°C. forced draft oven for 1 hour to drive off any residual water. The cooled tablets are immediately packaged in air-tight aluminum foil pouches.

FORMULATION 11

H₂0₂ Activity 3% 3.5% 5.0%

The above powders were mixed together to provide the desired composition.

FORMULATION 12

WOUND DRESSING

Ingredient Anhydrous PVP-H₂0₂

(22.8% H₂0₂) Absolute Ethanol

A 1% H₂0₂ solution of the above composition is applied to a wound. A film is formed which is effective to disinfect the wound.

FORMULATION 13

COLD WATER LAUNDRY TABLET

Ingredient Percent Wt. (g.)

PVP-H₂0₂ (23%) (EX. 1) 81.5 1.50

Sodium benzoate (fine powder) 1.64 0.03

100% 1.84 g.

These anhydrous PVP-H₂0₂ tablets are an effective cold water bleach-disinfectant for cleaning clothes, etc. In use, the PVP portion of the complex can chelate with inorganic ions (e.g. Ca⁺⁺, Mg⁺⁺) in the water to reduce water hardness. It can also provide laundry detergents with the properties of antiredeposition or suspension of dirt, anti-dye transfer, along with its bleaching and disinfectant action.

FORMULATION 14

WATER DISINFECTANT TABLET

Ingredient Sodium bicarbonate Sodium carbonate, anhydrous Citric Acid, anhydrous granules Povidone-H₂0₂ (20%) Sodium benzoate (fine powder)

100.0% 1.59 g. This tablet should be dissolved in one quart of water and allowed to remain for 5 minutes after the tablet is dissolved before the water is ready to drink. To prepare the tablet, follow the same directions as given in Formulation 10 except use a 1 inch flat-faced, bevel-edge punch.

The above formulations and applications illustrate methods of reducing the bacterial content of surfaces using the anhydrous PVP-H₂0₂ complex of the invention.

Claims

WHAT IS CLAIMED IS:

1. A stable complex of PVP and H₂0₂ in a molar ratio of between about 2:1 and about 1:1, respectively, which is obtained as a uniform free-flowing, fine, white powder by direct reaction between suspended PVP and H₂0₂ in substantially the molar ratio predetermined for the complex.

2. A complex according to claim 1 wherein the complex contains essentially little or no water or free hydrogen peroxide therein.

3. A process of preparing a stable, uniform free-flowing powder complex of PVP and H₂0₂ which comprising suspending PVP powders in an anhydrous medium and reacting H 0₂ therewith.

4. A process according to claim 2 wherein the H₂0₂ is reacted in substantially the same molar ratio as desired in the complex.

5. A process according to claim 3 in which PVP is suspended in anhydrous ethyl acetate.

6. A suspension process for preparing uniform, free-flowing fine, white powders of a substantially anhydrous complex of PVP and H 0₂ having an H₂0 content between about 18 and about 22% H 0 which comprises:

(a) forming a suspension of water-insoluble PVP containing less than about 1% water in an anhydrous organic solvent,

(b) slowly adding a predetermined amount relative to the PVP of an aqueous H₂0₂ solution containing about

70 to about 85% by weight H₂0₂, at a temperature of about 0^β-10°C. under agitation to precipitate a PVP-H₂0₂ complex in the form of a uniform, free-flowing, fine, white powder,

(c) filtering, and

(d) drying the wet precipitate to form the desired powders.

7. A suspension process according to claim 6 wherein said organic solvent is anhydrous ethyl acetate.

8. A process according to claim 6 wherein the filtrate is recycled for use in step (a) .

9. A process according to claim 6 wherein drying is carried out at about 50°-60^βC. in vacuo.

10. A method for reducing the microbial content of surfaces which comprises contacting said surface with a microbiocidal amount of a substantially anhydrous complex of PVP and H₂0₂ in the form of a free-flowing powder having an H₂0₂ content of about 3 to 24% by weight, wherein said complex is present in a formulation in an amount of about 0.1 to 15% by weight.

11. A method according to claim 10 wherein said complex is present on a support.

12. A method according to claim 11 wherein said support is a gauze, cotton swab or sponge.

13. A method according to claim 10 wherein said complex is present in a non-aqueous formulation.

14. A method according to claim 10 wherein said surface comes into contact with living tissue.

15. A formulation for reducing the microbial content of surfaces which include a microbiocidal amount of an anhydrous PVP and H₂0 complex, having an H₂0₂ content of about 3 to 24% by weight.

16. A method according to claim 1 further characterized in that said surface is contacted in the presence of water.

17. A formulation according to claim 16 wherein the complex has a molar ratio of PVP and H₂0₂ between about 2:1 and about 1:1.

18. A formulation according to claim 16 which also includes one or more of an acceptable diluent, and an active or inactive ingredient.

19. A formulation according to claim 16 which is in the form of a suspension, solution, suppository, gel, powder, paste, ointment, or tablet, optionally, on a support.

20. A formulation according to claim 16 which is a non-aqueous composition.

21. A formulation according to claim 16 which is a vaginal suppository, an effervescent mouthwash, a non-aqueous ointment, a polyethylene glycol-containing ointment, an anhydrous toothpaste, a tooth powder, a medicated bandage, an ear drop solution, a soft lens disinfectant tablet, a medicated powder, a wound dressing, a cold water laundry tablet, or a water disinfectant tablet.