WO2015081006A1 - Water dispersible films and particles for the triggered release of enzymes - Google Patents

Abstract

A composition comprising an ethylene (meth)acrylic acid copolymer and an enzyme is provided. The ethylene (meth)acrylic acid copolymer encapsulates the enzyme. The copolymer does not disperse or dissolve when in contact with high ionic strength media, thus providing protection and stability to the enzyme.

Description

WATER DISPERSIBLE FILMS AND PARTICLES

FOR THE TRIGGERED RELEASE OF ENZYMES

Cross-Reference To Related Application

This application claims priority to U.S. Provisional Application No. 61/909,903, filed November 27, 2013, the disclosure of which is hereby incorporated by reference in its entirety.

FIELD

This disclosure relates to processes and compositions that improve the stability of enzymes toward ionic surfactants by encapsulating the enzyme in films and matrix capsules.

BACKGROUND

Household detergents, such as laundry detergents, are generally delivered as low or high viscosity liquids or in tablet form. In these formulations, the presence of enzymes offers many potential benefits for household laundry processes, including improved soil and stain removal. During the laundry process, the enzymes enable the enzymatic degradation of specific stains into small, more soluble, fragments. Enzymes such as proteases, lipases, amylases, and cellulases, comprise a vital component in consumer and industrial applications due to their efficiency in providing improved removal of a wide variety of stains during both cold and hot temperature washing conditions. However, such enzymes are typically unstable in liquid detergent formulations due to the large excess of surfactants. In these formulations, the activity of enzymes rapidly decreases due to the presence of anionic surfactants, which constitute a major component of detergents.

Although recent advances in enzymatic engineering technologies have produced enzymes with improved stability in the presence of ionic surfactants, these enzymes are often very expensive. The coating of enzymes with a protective polymeric membrane is common in solid detergent formulations where a wide selection of synthetic polymers including polyvinyl alcohol and its copolymers, polyethylene glycol and its copolymers, and others have been used. This approach, however, has not shown to be useful in liquid formations due to disintegration and dissolution of these polymers in the formulations, leading to premature release of the enzyme into the high surfactant liquid detergent formulations. There is therefore a need for polymeric coatings and encapsulants that are stable in liquid formulations and hence provide a stable protective coating for enzymes against the destabilizing effects of ionic surfactants and other ingredients such as bleaches in liquid laundry detergents.

BRIEF SUMMARY

In one aspect, a composition is provided comprising an ethylene (meth)acrylic acid copolymer, wherein at least a portion of the carboxylic acid groups on the copolymer are neutralized; and an enzyme, wherein the enzyme is encapsulated within the ethylene (meth)acrylic acid copolymer.

In another aspect, provided is a process of producing a composition comprising an ethylene (meth)acrylic acid copolymer, wherein at least a portion of the carboxylic acid groups on the copolymer are neutralized; and an enzyme, the process comprising adding the enzyme to the ethylene (meth)acrylic acid copolymer to produce an enzyme composition; and removing water from the enzyme composition.

The invention also provides methods for releasing enzymes in various cleaning systems using various media.

DETAILED DESCRIPTION

Ethylene (meth)acrylic acid (EAA) copolymers can be used in a wide variety of applications including high-performance adhesives, flexible packaging films, and pouches and in extrusion coating and extrusion lamination applications. "(Meth)acrylic", as used herein, means acrylic, methacrylic, or mixtures thereof. The free acid form of ethylene (meth)acrylic acid copolymers can be neutralized to the desired degree with a suitable base. Ethylene (meth)acrylic acid copolymers can be obtained with varying water dispersibility depending on the degree of neutralization. For example, complete water dispersibility, or under certain conditions, complete water solubility, is obtained when the (meth)acrylic acid moiety is completely neutralized with a stoichiometric amount of base whereas partially neutralized EAA copolymers can be water dispersible, water sensitive, or water insensitive depending on the application for which it is aimed.

The present disclosure provides water dispersible compositions of an ethylene (meth)acrylic acid copolymer and an enzyme, wherein the enzyme is encapsulated (i.e., immobilized, embedded or entrapped) within the ethylene (meth)acrylic acid copolymer to form a protective coating, barrier, or membrane around the enzyme, preventing disintegration or dispersion in high ionic strength media, such as in the presence of high ionic strength detergents. The terms encapsulated, immobilized, embedded and entrapped are used interchangeably herein. As used herein, the term "composition" may mean, for example, a mixture, solution, or dispersion. The preferred compositions suitable for use in the present disclosure are prepared from highly neutralized composition of lower molecular weight ethylene (meth)acrylic acid copolymers with high (meth)acrylic acid content of 10 to 20 percent, more commonly known as ionomers. Such compositions may be formed any number of methods known to those of skill in the art.

Due to the ionic strength responsive character of the polymers of the present invention, the protective coating does not disintegrate or disperse in high ionic strength media, but does disintegrate or disperse in low ionic strength media in order to release the encapsulated enzyme. Thus, these polymers are particularly useful for the encapsulation and stabilization of enzymes in high ionic strength liquid laundry detergent formulations because they provide an impermeable membrane or barrier when the encapsulated enzyme matrix is exposed to a high ionic strength formulation for an extended period of time. However, when exposed to low ionic strength media, such as during the washing step in a laundry cycle, the encapsulant or protective coating may readily disintegrate and disperse to release the enzyme.

The weight ratio of the copolymer to the enzyme may be between about 5 : 1 and about 2: 1. For example, the weight ratio of the copolymer to the enzyme may be about 5: 1, about 4: 1, about 3: 1, or preferably about 2: 1. The enzyme may be any enzyme, including, but not limited to, protease, a-amylase, lipase, or multicopper oxidase.

The composition may be formed into a film. In alternative embodiments, the composition may be a powder. The powder may be formed by lyophilization, spray-drying techniques, and/or by reducing the size of a film by physical means. Further processing, e.g., by crushing or grinding of a lyophilized or spray dried product, may be employed to produce the powder or to produce a powder with particles of a desired size or uniformity. The powder may be compressed into tablets in some embodiments. In some embodiments, the encapsulated enzyme may be dispersed in a liquid laundry detergent formulation. Preferably, the enzyme and the copolymer are mixed together, dried, and then added to a liquid formulation. In other examples, the enzyme and copolymer mixture may be added directly to a liquid formulation, without being dried first.

The preferred polymers suitable for use in the composition of the present disclosure are ionomers of copolymers having a hydrophilic comonomer and a hydrophobic comonomer. Most preferred are ionomers of ethylene acrylic acid (EAA) or ethylene (meth)acrylic acid (EMAA). Particularly useful are highly neutralized compositions of lower molecular weight ethylene (meth)acrylic acid copolymers with high (meth)acrylic acid content of 10 to 20 percent, more preferably, around 20 percent (meth)acrylic acid to allow easy water dissolution or composition.

Aqueous compositions of highly neutralized ethylene (meth)acrylic acid can be used to generate freestanding water dispersible ionomer films via solution casting methods. The films are transparent, non-tacky, and heat sealable. Preferred copolymers are ionomer compositions based on functionalized polyolefms with (meth)acrylic acid content ranging from 10 to 20 percent where the (meth)acrylic acid component is neutralized to at least 85 percent or higher with a hard base such as sodium hydroxide or potassium hydroxide. Such compositions may be formed any number of methods known to those of skill in the art.

The temperature at which the films are dried or annealed after casting on glass plate significantly affects whether the films disintegrate in hot or cold water or both. Cast films dried in forced air oven at 40 degrees Celsius break and disintegrate quickly in cold water (i.e., water at a temperature of less than about 10 degrees Celsius), whereas films dried at 60 degrees Celsius are only dispersible in hot water (i.e., water at a temperature of greater than about 45 degrees Celsius). In cases in which the enzyme is heat sensitive, it is more preferable to dry the film at the lowest possible temperature, regardless of the solubility needed. The water dispersible films are stable during storage over a wide range of temperatures and humidity. Thus, a method is provided for fabricating the films in order to retain cold-water dispersibility and provide improved stability.

In particular embodiments, the composition comprises an ethylene (meth)acrylic acid copolymer, wherein at least a portion of the carboxylic acid groups on the copolymer are neutralized. For example, the carboxylic acid groups may be neutralized with a sodium cation to form a sodium salt. In another embodiment, the carboxylic acid groups may be neutralized with a potassium cation to form a potassium salt. The degree of neutralization may be between about 70 percent and about 100 percent, preferably between about 90 percent and about 100 percent, and more preferably between about 98 percent and about 100 percent.

Those skilled in the art will recognize appropriate methods for determining degrees of neutralization. See, e.g., United States Patent No. 3,472,825. Increasing the degree of neutralization increases the dispersibility of the composition in low ionic strength media. The weight ratio of the ethylene to (meth)acrylic acid in the copolymer may be between about

50:50 and about 90: 10, preferably between about 70:30 and about 90: 10, and more preferably between about 75:25 and about 80:20.

The composition does not disintegrate (e.g., it may be insoluble or may not dissolve or disperse) in high ionic strength media, such as media having a salt content of greater than 3 percent, more preferably greater than about 7 percent. Examples of high ionic strength media include caustic, household bleach, seawater, synthetic seawater, and commercial laundry detergent. The composition disintegrates in low ionic strength media, for example, media with a salt content of about 0 to about 2 percent (e.g., tap water, deionized water). Examples of low ionic strength media include deionized water, standard tap water, and the wash liquid of a laundry machine. The media may be in the form of, for example, a solution, a slurry, a dispersion, or a paste.

In further embodiments, the composition may also include at least one additive, such as a plasticizing agent, a crosslinking agent, a disintegrating agent, and/or a surfactant. The crosslinking agent may include, for example, Ca²⁺, Mg²⁺, Al³⁺, or Zn²⁺. The plasticizing agent may be a hydrophobic plasticizer, a hydrophilic plasticizer, or a combination thereof. For example, the plasticizing agent may be benzyl alcohol, a polyalkylene glycol (PAG)- based synthetic water insoluble lubricant, or T-BEP (tris(butoxyethyl) phosphate, an alkyl phosphate film forming aid and plasticizer), among others. The disintegrating agent may be, for example, acrylic acid, polyvinyl alcohol (PVOH), a starch, cellulose, or a second copolymer. The surfactant used in the composition may be, for example, a non-ionic surfactant, an amphoteric surfactant, or mixtures thereof. Where the composition is a film, the surfactant may be non-inonic or amphoteric, in order to provide dispersibility in water at high and low temperatures. Examples of non-ionic surfactants include those known in the art, such as polyoxyethylene glycol alkyl ethers, polyoxypropylene glycol alkyl ethers, glucoside alkyl ethers, polyoxyethylene glycol octylphenol ethers, polyoxyethylene glycol alkylphenol ethers, glycerol alkyl esters, polyoxyethylene glycol sorbitan alkyl esters, and sorbitan alkyl esters. Examples of amphoteric surfactants include those known in the art, such as lauramine oxide.

Also disclosed is a process for producing the composition of the present invention. The process may comprise adding the enzyme to the ethylene (meth)acrylic acid copolymer to produce an enzyme composition and removing water from the enzyme composition. The water may be removed from the enzyme composition by spray-drying or lyophilization. In processes in which the composition is formed into a film, the process may further comprise reducing the size of the film by physical means, such as grinding or pulverization.

EXAMPLES

Table 1 : Appendix

Table 2: List of Enzymes and Properties

Analysis of Polyolefin/Enzyme Films by Headspace Gas-Chromatography/Mass Spectrometry (HS-GC-MS)

Samples are prepared by adding approximately 10-15 milligrams of each sample into a 22 mL headspace vial followed by capping with a Teflon®-lined septum. The samples are analyzed using bulk headspace sampling combined with gas chromatography with mass selective detection (HS-GC-MS). The instrumentation is an Agilent® GC-MS model 6890/5973 equipped with a G1888 headspace autosampler. The samples are heated to 150 degrees Celsius for 10 minutes prior to sampling. The samples are run in split mode using a large split (100: 1) to accommodate the high levels of ethanol and ethyl acrylate that are expected. Calibration standards of ethanol and ethyl acrylate are first prepared with known weight concentration, 1-100,000 ppm wt/wt in THF.

Standards are prepared by weighing 10-15 milligrams of each calibration mix into 22 mL headspace vials and capping with Teflon®-lined septa. The headspace analysis of the standards is done in a full-evaporation mode to eliminate matrix effects that can occur in static headspace sampling. In this mode, a small sample size is used, and the headspace vial temperature is set sufficiently high to allow for full evaporation of the volatile of interest. For this analysis, the standard samples are heated to 150 degrees Celsius for 10 minutes prior to sampling. The standards are also run in split mode using a large split (100:1) to accommodate the high levels of ethanol and ethyl acrylate. A calibration plot is prepared for each volatile of interest using at least three standard concentrations for that compound. The milligram amount of ethanol and ethyl acrylate in each sample is then determined using the linear-least-squares equation from the calibration plot for that compound (peak area vs. mg amount). The ppm (wt/wt) concentration of ethanol and ethyl acrylate in each sample is then determined by dividing the mg amount of each compound by the initial weight of the sample and then multiplying by 1,000,000. Effect of High Salt Concentration

The enzymatic degradation of ethyl acrylate (EA) by free and immobilized Lipozyme® Calb L in different solutions can be investigated using Headspace Gas- Chromatography/Mass Spectrometry (HS-GC-MS). The enzymatic degradation of EA results in the formation of ethanol and acrylic acid. In this experiment, effects of salt and anionic surfactant concentrations on the activity of the enzyme is investigated by monitoring changes in the concentration of EA as well as the formation of ethanol over 26 days.

Preparation of Precursor Composition A

The functionalized polyolefm composition A used for these examples is an ethylene (meth)acrylic acid composition (80 weight percent ethylene and 20 weight percent (meth)acrylic acid) neutralized with sodium hydroxide. The degree of neutralization is 85 percent. The composition can be prepared by procedures known in the art. See, e.g., U.S. Patent Application No. 2011/0319521; PCT Published Application No. WO2011034883; and PCT Published Application No. WO2012082624. Composition A is a 24 weight percent aqueous composition neutralized with sodium hydroxide and having a pH of 10 and a Brookfield viscosity of 500 (Brookfield RVT, #2 spindle, 20 RPM, 25 °C ).

Example 1

0.12 gram of aqueous unprotected Lipozyme® CAL BL concentrate (a lipase) is mixed with 0.5 gram of ethyl acrylate and 8.70 gram of deionized water. The mixture is stirred for 10 minutes and the hydrolysis of the ethyl acrylate by the Lipozyme® Cal BL in low and high ionic strength media is analyzed using Headspace Gas-Chromatography/Mass Spectrometry (HS-GC-MS). The enzymatic activity in the low and high ionic strength media is determined by monitoring the formation of ethanol as well as the amount of residual ethyl acrylate in the mixture. Table 3 summarizes the samples tested while the GC-MS results are summarized in Table 4. The amounts of residual ethyl acrylate and ethanol shown are for each day (i.e., they are not additive from day to day). As shown in Table 4, the free enzyme activity is rapid and the amount of ethanol formed and residual ethyl acrylate detected after 26 days are 17261 ppm and 3968 ppm respectively.

Example 2

0.12 gram of aqueous unprotected Lipozyme® CAL BL concentrate (a lipase) is mixed with 0.5 gram of ethyl acrylate and 8.70 grams of a saturated salt solution (30 wt% NaCl) under the same conditions as Example 1. The unprotected lipase activity decreases significantly in the high ionic strength media and the amount of ethanol formed and residual ethyl acrylate detected after 26 days are 6085 ppm and 25276 ppm respectively.

Example 3

1.8 grams of aqueous unprotected Lipozyme® CAL BL concentrate is mixed with 17.8 grams of polymer composition A. The mixture is stirred for 10 minutes and is placed in glass tubes and then lyophilized. The sample containing tubes are plunged directly into liquid nitrogen. After incubation in liquid nitrogen, the frozen samples are placed under vacuum overnight, resulting in a powder. They are stored in a refrigerator until use. The freeze-dried enzyme-polymer sample contains a polymer:enzyme weight/weight ratio of 2.6: 1.

0.3 gram of lyophilized enzyme/polymer powder is mixed with 0.5 gram of EA and 8.50 grams of deionized water. The mixture is stirred for 10 minutes and the immobilized enzyme/polymer particles fully disperse in the low ionic strength mixture. Enzymatic activity is determined in the same manner as Example 1. Enzymatic activity is slightly higher than that of the unprotected lipase sample, Example 1, and the amount of ethanol formed and residual EA detected after 26 days are 26796 ppm and 1470 ppm respectively. Example 4

1.8 grams of aqueous unprotected Lipozyme® CAL BL concentrate is mixed with 17.8 grams of polymer composition A. The mixture is stirred for 10 minutes and is placed in glass tubes and then lyophilized, resulting in a powder. The sample containing tubes are plunged directly into liquid nitrogen. After incubation in liquid nitrogen, the frozen samples are placed under vacuum overnight. They are stored in a refrigerator until use. The freeze- dried enzyme-polymer sample contains a polymer:enzyme weight/weight ratio of 2.6: 1.

0.3 g of lyophilized enzyme/polymer powder is mixed with 0.5 g of EA and 8.50 g of 30 percent NaCl solution. The mixture is stirred for 10 minutes and the immobilized enzyme/polymer particles remain intact and do not dispersed in the high ionic strength mixture. Surprisingly, enzymatic activity is still detected even though the particles remain intact. The residual EA detected decreases sharply from day 0 to day 26. However, the amount of ethanol formed increases from day 0 to day 26. This suggests that EA is migrating into the particles and preventing premature release of the immobilized lipase. It also suggests enzymatic activity even in high ionic strength media. The amount of ethanol formed and residual EA detected after 26 days are 1826 ppm and 20346 ppm respectively.

As shown in the tables below, the polymer composition of the present invention provides stability and improves enzyme performance even in high salt containing media compared to unprotected enzymes in solutions under the same conditions.

Table 3: Sample information

Table 4: GC/VOC Results: Effect of High Salt Concentration on Enzymatic Activity

Examples 5-10: Effect of High Anionic Surfactant Concentration

The effect of an anionic surfactant on the activity of free and immobilized Lipozyme® Calb L (immobilized by the same process as described in Example 3) in the enzymatic degradation of EA is investigated by adding alkyldiphenyloxide disulfonate. The samples of Examples 5-10 are prepared in the same manner as Example 1, except that 0.5 gram of an anionic surfactant (alkyldiphenyloxide disulfonate) is added to some samples. The samples contained the composition as listed in Table 5 and the results are summarized in Table 6.

Example 5

The sample composition of Example 5 contains EA and unprotected lipase in deionized water. It is prepared in the same manner as Example 1 and contains the weight percentage of the components as listed in Table 5. As shown in Table 6, the free enzyme activity is rapid and the amount of ethanol formed after 26 days is 14208 ppm.

Example 6

The sample composition of Example 6 contains EA, unprotected lipase, 5.1 percent of the anionic surfactant (alkyldiphenyloxide disulfonate), and deionized water and is prepared in the same manner as Example 5. As shown in Table 6, the lipase catalytic activity decreases significantly in the presence of the anionic surfactant leading to the detection of only 180 ppm ethanol after 16 days.

Example 7

The sample composition of Example 7 contains EA, unprotected lipase, 3.1 percent of composition A (24 weight percent solids), 5.1 percent of the anionic surfactant (alkyldiphenyloxide disulfonate), and deionized water. It is prepared in the same manner as Example 1. As shown in Table 6, even though the addition of the aqueous polymer composition A provided some stability for the unprotected enzyme at low ionic strength media, the lipase catalytic activity is still significantly reduced due to the exposure of the unprotected enzyme to the destabilizing effects of the anionic surfactant. The amount of ethanol detected after 16 days is 990 ppm.

Example 8

The sample composition of Example 8 contains EA, unprotected lipase, 3.1 percent of composition A (24 weight percent solids), 5.1 percent of the anionic surfactant (alkyldiphenyloxide disulfonate), and 30 weight percent NaCl solution. It is prepared in the same manner as Example 1. As shown in Table 6, at high ionic strength, the aqueous polymer composition A provides slightly better stability for the unprotected enzyme. However, the lipase catalytic activity due to the anionic surfactant is still low compared to Example 5, which does not contain the surfactant. The amount of ethanol detected after 16 days is 2773 ppm.

Example 9

The sample composition of Example 9 contains immobilized enzyme/polymer powder, EA, 5.1 percent (alkyldiphenyloxide disulfonate), and deionized water. At low ionic strength and in the presence of anionic surfactant, the immobilized lipase/polymer particle is soluble in the media. The enzymatic activity is improved compared to the unprotected enzyme samples of Examples 6-8. The amount of ethanol detected after 16 days is 4275 ppm.

Example 10

The sample composition of Example 10 contains immobilized enzyme/polymer powder, EA, 5.1 percent alkyldiphenyloxide disulfonate, and 30 weight percent NaCl solution. At the high ionic strength and in the presence of anionic surfactant, the immobilized lipase/polymer particle remains intact and does not disperse. Although the amount of ethanol detected, 8511 ppm, is lower than in Example 5, it is clear that immobilization of Lipozyme® Calb L in polymer particles of the present invention provides improved stability and enhanced activity, especially at high ionic strength and high surfactant concentrations, compared to free enzyme under the same conditions. Table 5 : Surfactant Study Sample Information

Table 6: GC/VOC Results: Effect of Anionic Surfactant on Enzymatic Activity of Lipozyme® Calb L.

Examples 11-15: Proteinacious Stain Removal Using Immobilized Protease

Savinase® 16L, a common protease enzyme used for removing protein stains, is encapsulated (i.e., immobilized) in polymers of the present invention via lyophilization in the same manner as Example 3 using 1.9 grams of aqueous unprotected Savinase® 16L concentrate mixed with 17.6 grams of polymer composition A (in Examples 14 and 15). The freeze-dried sample contains a polymer:enzyme weight/weight ratio of 2.5: 1.

Free (Examples 12 and 13) and immobilized (Examples 14 and 15) enzyme polymer particles are added to a commercial monodose laundry detergent and then aged at room temperature and 40 degrees Celsius for 3 days (Table 7). Monodose laundry detergents supply a single dose of detergent for one load of laundry. Monodose formulations typically include a mixture of anionic and non-ionic surfactants, solvents, and other formulation additives. The effectiveness of the aged enzyme and detergent mixtures in removing protein stains is investigated. The stain removal is performing by adding the aged samples to 100 grams of warm tap water and agitating on a shaker for one hour. After the wash, the test panels are removed and rinse gently with cold water. They are then dried and evaluated to determine the extent of proteinacious stain removal. As shown in Table 7, protein stain removal using encapsulated Savinase® enzymes is similar to the stain removal of the free and unprotected Savinase® enzyme sample and better than the commercial detergent without the enzyme. This shows that the enzyme is released from the enzyme/polymer particles and remains active upon release. Furthermore, it is expected that for stability testing of greater than four days, the encapsulated enzyme will have better stain removal because it will be more stable over time than the free enzyme. Table 7: Protein Stain Removal Using Free and Immobilized Protease.

While the invention has been described above according to its preferred embodiments, it can be modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using the general principles disclosed herein. Further, the application is intended to cover such departures from the present disclosure as come within the known or customary practice in the art to which this invention pertains and which fall within the limits of the following claims.

Claims

WHAT IS CLAIMED IS:

1. A composition comprising:

an ethylene (meth)acrylic acid copolymer, wherein at least a portion of the carboxylic acid groups on the copolymer are neutralized; and

an enzyme,

wherein the enzyme is encapsulated within the ethylene (meth)acrylic acid copolymer.

2. The composition of claim 1, wherein the enzyme is protease, a-amylase, lipase, or multicopper oxidase.

3. The composition of claim 1 or claim 2, further comprising a crosslinking agent.

4. The composition of claim 3, wherein the crosslinking agent is a divalent cation.

5. The composition of claim 3 or claim 4, wherein the crosslinking agent comprises Ca²⁺, Mg²⁺, Al³⁺, or Zn²⁺.

6. The composition of any one of claims 1-5, wherein the composition does not disintegrate in high ionic strength media and disintegrates in low ionic strength media.

7. The composition of any one of claims 1-6, wherein the composition is a film.

8. The composition of any one of claims 1-6, wherein the composition is a powder.

9. The composition of any one of claims 1-8, wherein the weight ratio of the ethylene component to the (meth)acrylic acid component is about between about 50:50 to 90: 10.

10. The composition of any one of claims 1-9, wherein the weight ratio of the copolymer to the enzyme is between about 5 : 1 and about 2: 1.

11. The composition of any one of claims 1-10, wherein the degree of neutralization is between about 70 percent and about 100 percent.

12. The composition of any one of claims 1-11, wherein the encapsulated enzyme is dispersed in a liquid laundry detergent formulation.

13. A process of producing a composition comprising an ethylene (meth)acrylic acid copolymer, wherein at least a portion of the carboxylic acid groups on the copolymer are neutralized; and an enzyme, the process comprising:

adding the enzyme to the ethylene (meth)acrylic acid copolymer to produce an enzyme composition; and

removing water from the enzyme composition.

14. The process of claim 13, wherein water is removed from the enzyme composition by spray-drying or lyophillization.

15. The process of claim 13 or claim 14, wherein the composition is a film and further comprising reducing the size of the film by physical means.