DESC:
Field of the invention
The present disclosure relates to cleaning composition. More particularly, the present disclosure provides a surfactant-based cleaning composition comprising at least one enzyme.

Background and the prior art
Enzymes when added in surfactant-based cleaning composition are particularly vulnerable to degradation on account of several physical as well as chemical factors linked with presence of other ingredients in the formulations (especially anionic surfactants like non-ethoxylated sulfated/sulfonated surfactants), pH of the formulation as well as temperature.

Effectiveness of these enzyme-based formulations is therefore to a significant extent dictated by the stability of the enzyme within the composition not only during its shelf life but also during the use of these formulations.

Various surfactant-based cleaning compositions comprising one or more enzymes have been disclosed in WO2015144561, US2019376008 and EP3647398. These prior art documents deal with enzymes modified through recombinant technology to ensure their stability in the presence of other components of the formulations that would comprise them.

Another approach for improving stability of already known enzymes and recombinant variants thereof in various types of formulations is by changing the composition to avoid ingredients that would be prejudicial to enzyme stability under working conditions. These kinds of formulations that comprise enzymes in combination with various other ingredients intended for different end applications are disclosed in US2009312226, US2014/0336094 and US2019376008.

Effectiveness of these enzyme-based formulations is therefore to a significant extent dictated by the stability of the enzyme within the composition not only during its shelf life but also during the use of these formulations. There always exists a need for an enzyme-based formulation wherein the stability of the enzyme in the formulation is not compromised at wider pH range and as well as higher temperatures during shelf-life or during the actual use of the formulation.

In specific, it is noted that higher amounts of LABSA (Linear alkyl benzene sulphonic acid) is not compatible with enzymes, in particular amylase enzymes. In presence of high amount of LABSA, enzyme stability drops significantly even at room temperature and it is severely compromised at higher temperatures.

There always exists a need for an enzyme-based formulation wherein the stability of the enzyme in the formulation is not compromised at wider pH range and as well as higher temperatures during shelf-life or during the actual use of the formulation.

Furthermore, besides enzyme stability and cleansing efficacy, foam is another consumer desirable attribute. Hence, it remains a challenge for the product formulators to arrive at a product formulation that not only provides temperature stability and operability at a wider range of pH (5-8.5), but also a formulation that cleans well without compromising on the foam characteristics. Such foam characteristics are usually attained owing to use of non-ethoxylated sulfated/sulfonated surfactants.

Object of the present invention
It is one of the objects of the present invention to provide a cleaning composition comprising at least one enzyme.

It is one of objects of the present invention to provide a cleaning composition that cleans well without compromising on the foam characteristics.

It is one of the objects of the present invention to provide a cleaning composition that is stable across a wide range of pH.

It is one of the objects of the present invention to provide a cleaning composition that is stable at higher temperature.

It is one of the objects of the present invention to provide a cleaning composition that has low active detergent content yet higher consistency.

Summary of the Invention
Accordingly, the present invention provides a cleaning composition comprising: 3 wt% to 10 wt% of at least one non-ethoxylated anionic surfactant; 6 wt% to 20 wt% of at least one ethoxylated anionic surfactant; 0.05% to 1.5% by wt. of at least one enzyme; wherein the composition is stable at a pH in the range of 5 to 8.5.

Detailed Description of the invention
The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the scope of the invention as defined by the appended claims and their equivalents.

It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.

Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments and/or in combination with or instead of the features of the other embodiments.

It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, steps or components but does not preclude the presence or addition of one or more other features, steps, components or groups thereof.

In the context of the present disclosure, the expression “thermostable composition” means a stable composition comprising an active enzyme at a temperature in the range from about 5oC to about 50oC. An active enzyme means an enzyme that exhibits enzymatic activity after exposure to a temperature in the range from 5oC to about 50oC and is stable for a time span of upto 4weeks.

The expression "stable compositions at wide range of pH" with reference to the cleaning composition of the present disclosure means that the enzyme present in the composition is in a condition to exhibit enzymatic activity while being in the composition across pH range from about 5 to 8.5.

The expression, cleaning composition means a composition that may be used to clean various articles, objects, surfaces that include but are not limited to floors, toilets, bathrooms, tables, walls, roofs etc. as well as surfaces of hard objects such as cars (car wash) and dishes, plates, cups, glasses, bowls, cutlery such as spoons, knives, forks, serving utensils, ceramics, plastics, metals, china, glass and acrylics.

The present disclosure provides a cleaning composition that is temperature stable even beyond 50°C at a wider pH range that is closer to skin pH (5 – 8.5). The cleaning composition in accordance with the present disclosure comprises:

a. at least one non-ethoxylated anionic surfactant (such as Linear alkyl benzene sulphonic acid (LABSA), a-olefin sulfonate (AOS));
b. at least one ethoxylated anionic surfactant (such as Sodium laureth sulfate (SLES 1EO to 10EO));
c. at least one amphoteric surfactant; and
d. at least one enzyme,
wherein the formulation is stable at a pH in the range of 5 to 8.5;

Non-ethoxylated anionic surfactant
The non-ethoxylated anionic surfactant can be chosen from the group consisting of anionic sulfonate surfactants that do not contain any ethylene oxide groups. Examples of anionic sulfonate surfactants include the salts of C9-C20 linear alkyl benzene sulfonate, C8-C24 alpha-olefin sulfonate, C8-C22 primary or secondary alkane sulfonates, paraffin sulfonates, and mixtures thereof.

The cleaning composition of the present invention preferably contains at least 3% by wt., more preferably 3% to 10% by wt. and even more preferably 4% to 10% by wt. of non-ethoxylated anionic surfactant.

In one of the preferred embodiments, the cleaning composition of the present disclosure comprises of at least two different non-ethoxylated anionic surfactants, each one being selected from the group that consists of linear alkylbenzene sulfonate and alpha-olefin sulfonate.

Preferably the non-ethoxylated anionic surfactant in the cleaning composition of the present disclosure is selected from the group that includes but is not limited to LAS, LABSA, AOS and the like.

Without bound by theory, it has been observed that higher amounts of LABSA (Linear alkyl benzene sulphonic acid) are prejudicial to the stability of enzymes, in particular amylase enzymes. In presence of high amount of LABSA, enzyme stability drops significantly even at room temperature and it is severely compromised at higher temperatures.

In one of the embodiments, the cleaning composition of the present disclosure comprises a combination of LABSA and Alpha-Olefin-Sulfate as non-ethoxylated anionic surfactants such that the total amount of LBSA in the non-ethoxylated anionic surfactant combination is in the range from about 45% to 60% with respect to the total weight of non-ethoxylated anionic surfactants in the composition.

Ethoxylated anionic surfactant
The ethoxylated anionic surfactant can be chosen from the group that includes but is not limited to C10-C16 alkyl sulfate containing 1 to 10 ethylene oxide groups per molecule.

The cleaning composition of the present invention preferably contains at least 6% by wt., preferably 6% to 20% by wt. of ethoxylated C10-C14 alkyl ether sulfate surfactant containing 1 to 10 moles of ethylene oxide.

According to a particularly preferred embodiment, the cleaning composition contains 7% to 20% by wt.; preferably from about 7 to 15 wt% of ethoxylated C10-C14 alkyl ether sulfate surfactant containing 1 to 5 moles of ethylene oxide.

In one the embodiments, the ethoxylated anionic surfactant is sodium laureth sulfate with EO units ranging from 1 to 5 EO.

Typically, the ratio of ethoxylated anionic surfactant to non-ethoxylated anionic surfactant ranges from about 10: 1 to 10: 7.5 preferably, 8:1 to 10:7.5, and more preferably between 6:1 to 10.5:7.5.

Amphoteric surfactant
The amphoteric surfactant is selected from the group that includes but is not limited to betaine, alkyldimethylbetaine, sulfobetaine, and combinations thereof.

Preferably, the cleaning composition contains at least 1% by wt., preferably 1.5% to 10% by wt. of amphoteric surfactant, even more preferably 2% to 7% by wt. of amphoteric surfactant.

A preferred amphoteric surfactant that is employed in accordance with the present invention is a betaine. A preferred betaine used in the cleaning composition according to the present invention is cocamidopropyl betaine.

Typically, the ratio of amount of non-ethoxylated surfactant to the amount of amphoteric surfactant is from 1:1 to 3:1

In one of the embodiments, the amphoteric surfactant is cocamidopropyl betaine while the non-ethoxylated surfactants present in the cleaning composition of the present invention are LABSA and Alpha Olefin Sulfonate.

Enzyme
One of the very essential components of the present invention is an enzyme. The cleaning composition of the present invention comprises at least 0.05% by wt. of enzyme which is selected from the group that includes amylase. In one of the preferred embodiments, the enzyme is an alpha amylase.

In one of the preferred embodiments, the cleaning composition contains 0.1% to 1.5% by wt., preferably 0.2% to 1.2% by wt. of an amylase, and most preferably, from about 0.3 to 1%.

Suitable amylases may be from bacterial origin, fungal origin, or it may also include chemically modified or modified recombinant versions of amylases available naturally. Some examples of such amylases include Preferenz S1000, Preferenz S100, Termamyl, Stainzyme, etc.

Furthermore, the cleaning composition of the present invention can additionally contain other enzymes besides an amylase, selected from the group that includes but is not limited to proteases, mannanases, lipases, pectinases, cellulases, and oxidases.

Water
The cleaning composition of the present invention can be in a liquid or a gel format. The amount of water in the present composition is atleast 45% by wt. typically varies from the about 60 to 85 wt%; preferably from about 63 wt% to about 80wt%, more preferably 50% by wt. of water.

The pH range at which the cleaning composition is stable is 5 to 8.5.

Typically, the active detergent content of the cleaning composition of the present disclosure varies in the range from about 6 % to about 25%.

Temperature range at which the cleaning composition is stable is upto 500C for 4 weeks. This is equivalent to 18-24 months product stability on shelf at ambient conditions applicable across India.

Cleaning composition in accordance with the present disclosure may be of varying consistency and depending on the viscosity, it may be in the form of a gel or as a clear liquid formulation. It may be coloured, not coloured. Further, it may be hazy or it may comprise a wide variety of suspended solids in the form of soluble or insoluble beads, particles, granules, encapsulates and the like.

In one of the embodiments, the cleaning composition of the present disclosure is preferably in a gel form having viscosity in the range from about 1200 cps to 4000 cps, preferably, 1400 cps to 3500 cps and most preferably, from about 1500 cps to 2500 cps.

In one of the embodiments, the cleaning composition of the present disclosure is transparent. In another embodiment, the cleaning composition of the present disclosure further comprises at one opacifying agent and it is opaque.

The cleaning composition of the present disclosure may further comprise a wide variety of excipients and additives that are selected from the group that includes but is not limited to builders, humectants, pH modifiers, thickeners, preservatives, electrolytes, stabilizers and the like.

Additional optional ingredients ordinarily known to persons skilled in the art such as builders, perfumes, fragrances, colorants, pigments, dyes, abrasive agents, disinfectants, antioxidants, bleaches and bleach activators, chelating agents or sequestrants, solvents, essential oils or natural oils, optical brighteners, opacifiers, hydrotropes, or combinations thereof may be added to the cleaning composition of the present disclosure. The cleaning composition of the present invention preferably contain no more than 5% by wt. of any of these additional optional ingredients as listed above.

Cleaning composition in accordance with the present disclosure is now being illustrated by way of following non-limiting Examples. It should be understood that these Examples, while indicating certain embodiments, are given by way of illustration only. From the above discussion and these Examples, one skilled in the art can ascertain the essential characteristics, and without departing from the spirit and scope thereof, can make various changes and modifications of the embodiments to adapt it to various usages and conditions.

Example I
Materials
• LABSA- 90% AM from A.R Stanchem Pvt. Ltd
• AOS liquid- 38% from Godrej industries
• SLES.1EO- 70% paste from Galaxy surfactants
• CAPB solution- 29% from Galaxy surfactants
• Amylase- Preferenz S210 from Danish co.
• Sodium hydroxide 48% solution
• CaCl2. 2H2O- Used as is from Sisco
• Trisodium citrate dehydrate- SD fine chemicals (LR grade)
• Citric acid- SD fine chemicals (LR grade)
• Sodium formate- SD Fine chemicals (LR grade)
• Sodium chloride- SD Fine chemicals (LR grade)
• Monopropylene glycol- SD fine chemicals (LR grade)
• De-ionized water
• Fragrance- from IFF
Control- Non-enzymatic dish wash liquids such as Vim liquid (Batch no B0202, mfg June 2021) was used as benchmark sample.

Process for preparing cleaning composition
Water was taken in a 1L beaker. Required quantity of sodium hydroxide solution was added, followed by the addition of LABSA. The solution was stirred for 20 mins. This was followed by the addition of MPG, AOS liquid, SLES paste and CAPB solution. This mixture was stirred to ensure complete dissolution of all the ingredients. All the salts like calcium chloride, sodium formate, sodium citrate was added to this mix, followed by stirring to ensure complete dissolution. Enzyme and fragrance were added to this mixture and stirred for 5-10 mins.

Thermal stability: Procedure:
To test the stability, all the samples were stored in PET bottles and subjected to 50oC in a hot-air oven for a period of 4 weeks. Post the completion of the said timeline, the samples were removed from the ovens, cooled over night at ambient temperature and then evaluated.

Estimation of foam volume and rinsability:
Detergent solution of fixed concentration (2.5 g/L) was prepared by dissolving a known weight of the formulation in 1 litre of 30 FH (2:1 Ca/Mg) water. The temperature of the wash solution was maintained at 25-27oC.
1. 50 ml of this solution was taken in 250 ml graduated measuring cylinder with a glass stopper. It was shaken 10 times and the volume of foam thus generated was recorded after 1 min as the initial foam volume.
2. To evaluate the rinsability, after step 1, the wash solution was discarded carefully from the measuring cylinder. 50 ml of 30FH water was added to it and it was shaken 10 times and the volume of foam was noted after 1 min as the foam volume after 1st rinse.
3. Step 2 was repeated till the time no more foam was produced. The total number of rinses was noted.

Enzyme efficacy test: Evaluation of wash performance-
Wash performance on standard test tiles which are extremely sensitive to enzymes are used as a measure of enzyme efficacy. DM 177 tiles (mixed starch, extra severe on melamine), procured from Center for Test materials (Netherland) were used to evaluate the efficacy of amylases in the cleaning composition.

Wash parameters:
• Wash condition- Soak and rinse
• Water hardness- 30 FH (2:1, Ca/Mg)
• Volume of wash liquor- 1.2 L
• Detergent dosage- 10 g/L
• Soaking time- 30 mins
• Rinsing- twice
• Drying- Air drying, in a cool, dry place, away from direct sun exposure.

Evaluation:
Wash performance was measured using L* a* b* values using Konica Minolta chromameter. L* (lightness) values are luminosity indices, expressed as numbers from 0 to 100, with more black colors closer to 0 and more white colors closer to 100. Higher L* value indicates higher % of stain removal and better cleaning which in turn corresponds to higher enzyme efficacy. It is desirable for the compositions within the scope of the invention to have better wash performance (at least 15-20% more) in comparison to the non-enzymatic benchmark.

Method of evaluation of residual wash performance
Residual wash performance of the samples were measured by conducting the wash performance experiment with the samples post storage at 50oC for 4 weeks. It is desirable for the formulations within the scope of the invention to have less than 10% drop in wash performance (as measured by the L* values) post storage.

Effect of individual components
Cleaning compositions were prepared on the basis of the components shown in Table 1. Composition 1 is an example of a cleaning composition according to the present disclosure which is compared with examples A to D which are not within the scope of the present invention.
Table 1
AM (%) Ex-1 Comp-A Comp-B Comp-C Comp-D
LABSA 90 4 0 12 1.5 4
AOS 38 3 0 6 1 3
SLES. 1EO 70 12 19.7 0 12 12
CAPB 29 4 4 4 0 4
Sodium hydroxide sol 48 1.3 0 3.9 0.5 1.3
Amylase As is 1 1 1 1 0
CaCl2. 2H2O 100 0.1 0.12 0.12 0.12 0.12
MPG 100 2 2 2 2 2
Trisodium citrate 100 0.2 0.25 0.25 0.25 0.25
Sodium formate 100 0.3
Sodium chloride 100 0.6 0.6 0.8 0.8 0.8
Fragrance 100 0.15 0.15 0.15 0.15 0.15
Water 100 Rest Rest Rest Rest Rest
pH 6-6.5 6-6.5 6-6.5 6-6.5 6-6.5

These compositions were evaluated for foamability (initial foam volume), ease of rinse, wash performance (as a measure of initial enzyme efficacy) and residual wash performance (post storage at 50oC, for 4 weeks). The results are summarized below in table 2.
Table 2:
Control Ex-1 Comp-A Comp-B Comp-C Comp-D
Initial foam volume (ml) 150 140 150 65 80 145
1st rinse foam volume (ml) 120 90 110 40 40 90
2nd rinse foam volume (ml) 44 36 60 14 20 40
3rd rinse foam volume (ml) 20 5 30 0 5 5
4th rinse foam volume (ml) 10 0 10 0 0 0
Total number of rinses 5 4 5 3 4 4
Fresh Wash performance (L* on DM177) 70.8 86.7 86.8 86.4 85.9 71
% improvement in wash performance over control - >20 >20 >20 >20 <1
Residual wash performance, 50oC/ 4 weeks (L* on DM177 tiles) NA 85.8 86.1 71.9 83.4 NA
% drop in wash performance post storage at 50oC/4 weeks NA 1 <1 16.8 2.9 NA

Composition represented by Ex-1 is comparable to the control in terms of the initial foam volume, but requires lesser number of rinses and also provides better stain removal efficacy (>20%) in comparison to the control and hence is within the scope of the present invention. Comp-A does not provide rinse benefit wrt control and is outside the scope of the invention. Comp-B produces less foam initially and also shows significant drop in wash performance upon storage at 50oC for 4 weeks and denotes enzyme instability and hence is outside the scope of the present invention. Comp C produces significantly less foam initially and hence is not desirable. Comp D is non-enzymatic and does not provide any improvement over the control in terms of the cleaning efficacy.

Example II
Effect of wt.% of non-ethoxylated surfactant
Cleaning compositions were prepared on the basis of the components shown in table 3. Ex-1, 2 and 3 are examples of cleaning composition according to the present disclosure which is compared with comparative examples E and F which are not within the scope of the present invention.
Table 3:
AM (%) Ex-1 Ex-2 Ex-3 Comp-E Comp-F
LABSA 90 4 2 5 1.5 9
AOS 38 3 1 5 1 2
SLES. 1EO 70 12 12 12 12 12
CAPB 29 4 4 4 4 4
Sodium hydroxide 48 1.3 0.65 1.6 0.5 2.9
Amylase As is 1 1 1 1 1
CaCl2. 2H2O 100 0.1 0.1 0.1 0.1 0.1
MPG 100 2 2 2 2 2
Trisodium citrate 100 0.2 0.2 0.2 0.2 0.2
Sodium formate 100 0.3 0.3 0.3 0.3 0.3
Sodium chloride 100 0.6 0.6 0.6 0.6 0.6
Fragrance 100 0.15 0.15 0.15 0.15 0.15
Water 100 Rest Rest Rest Rest Rest
pH 6-6.5 6-6.5 6-6.5 6-6.5 6-6.5

These compositions were evaluated for formability (initial foam volume), ease of rinse, wash performance (as a measure of initial enzyme efficacy) and residual wash performance (post storage at 50oC, for 4 weeks). The results are summarized below in table 4.
Table 4:
Control Ex-1 Ex-2 Ex-3 Comp-E Comp-F
Initial foam volume (ml) 150 140 120 145 100 150
1st rinse foam volume (ml) 120 90 70 100 80 90
2nd rinse foam volume (ml) 44 36 20 40 50 35
3rd rinse foam volume (ml) 20 5 0 5 20 5
4th rinse foam volume (ml) 10 0 0 0 8 0
Total number of rinses 5 4 3 4 5 4
Fresh Wash performance (L* on DM177) 70.85 86.7 86.4 86.2 86.1 87
% improvement in wash performance over control - >20 >20 >20 >20 >20
Residual wash performance, 50oC/ 4 weeks (L* on DM177 tiles) NA 85.8 86.1 84.2 85.8 72.3
% drop in wash performance post storage at 50oC/4 weeks NA 1.03 <1 2.3 <1 16.89

Composition represented by Ex-1-3 are comparable to the control in terms of the initial foam volume, but requires lesser number of rinses and also provides better stain removal efficacy (>20%) in comparison to the control, post storage at 50oC for 4 weeks, minimal drop in wash performance is observed for these samples and hence these are within the scope of the present invention. Comp-E does not provide rinse benefit with respect to control and is outside the scope of the invention. Comp-F shows significant drop in wash performance upon storage at 50oC for 4 weeks and denotes enzyme instability and hence is outside the scope of the present invention.

Example III
Effect of wt.% of ethoxylated surfactant
Cleaning compositions were prepared on the basis of the components shown in table 5. Ex-1, 4 and 5 are examples of cleaning composition according to the present disclosure which is compared with comparative examples G and H which are not within the scope of the present invention.
Table 5:
AM (%) Ex-1 Ex-4 Ex-5 Comp-G Comp-H
LABSA 90 4 3 6 4 2
AOS 38 3 1.5 4 3 2
SLES. 1EO 70 12 6 20 5 21
CAPB 29 4 4 4 4 4
Sodium hydroxide 48 1.3 0.98 1.95 1.3 0.65
Amylase As is 1 1 1 1 1
CaCl2. 2H2O 100 0.1 0.1 0.1 0.1 0.1
MPG 100 2 2 2 2 2
Trisodium citrate 100 0.2 0.2 0.2 0.2 0.2
Sodium formate 100 0.3 0.3 0.3 0.3 0.3
Sodium chloride 100 0.6 0.6 0.6 0.6 0.6
Fragrance 100 0.15 0.15 0.15 0.15 0.15
Water 100 Rest Rest Rest Rest Rest
pH 6-6.5 6-6.5 6-6.5 6-6.5 6-6.5

These compositions were evaluated for formability (initial foam volume), ease of rinse, wash performance (as a measure of initial enzyme efficacy) and residual wash performance (post storage at 50oC, for 4 weeks). The results are summarized below in table 4.
Table 6:
Control Ex-1 Ex-4 Ex-5 Comp-G Comp-H
Initial foam volume (ml) 150 140 100 160 110 150
1st rinse foam volume (ml) 120 90 70 100 70 140
2nd rinse foam volume (ml) 44 36 20 40 15 120
3rd rinse foam volume (ml) 20 5 0 10 0 60
4th rinse foam volume (ml) 10 0 0 0 20
Total Rinse water Volume (ml) and number of rinses 5 4 3 4 3 5
Fresh Wash performance (L* on DM177) 70.85 86.7 86.8 87.1 87.5 86.4
% improvement in wash performance over control NA >20 >20 >20 >20 >20
Residual wash performance, 50oC/ 4 weeks (L* on DM177 tiles) NA 85.8 83.6 86.3 75 86.1
% drop in wash performance post storage at 50oC/4 weeks NA 1.03 3.7 <1 14.2 <1

Composition represented by Ex-1, 4 and 5 are comparable to the control in terms of the initial foam volume, but requires lesser number of rinses and also provides better stain removal efficacy (>20%) in comparison to the control, post storage at 50oC for 4 weeks, minimal drop in wash performance is observed for these samples and hence these are within the scope of the present invention. Comp-G shows significant drop in wash performance upon storage at 50oC for 4 weeks and denotes enzyme instability and hence is outside the scope of the present invention. Comp-H does not provide rinse benefit with respect to control and is outside the scope of the invention.

Example IV
Effect of wt.% of amphoteric surfactant
Cleaning compositions were prepared on the basis of the components shown in table 7. Ex-1 and 6, are examples of cleaning composition according to the present disclosure which is compared with comparative examples I and J which are not within the scope of the present invention.
Table 7:
AM (%) Ex-1 Ex-6 Comp-I Comp-J
LABSA 90 4 2 1 6
AOS 38 3 1 0.5 5
SLES. 1EO 70 12 6 6 21
CAPB 29 4 1 0.5 11
Sodium hydroxide 48 1.3 0.65 0.32 1.95
Amylase As is 1 1 1 1
CaCl2. 2H2O 100 0.1 0.1 0.1 0.1
MPG 100 2 2 2 2
Trisodium citrate 100 0.2 0.2 0.2 0.2
Sodium formate 100 0.3 0.3 0.3 0.3
Sodium chloride 100 0.6 0.6 0.6 0.6
Fragrance 100 0.15 0.15 0.15 0.15
Water 100 Rest Rest Rest Rest
pH 6-6.5 6-6.5 6-6.5 6-6.5

These compositions were evaluated for formability (initial foam volume), ease of rinse, wash performance (as a measure of initial enzyme efficacy) and residual wash performance (post storage at 50oC, for 4 weeks). The results are summarized below in table 8.
Table 8:
Control Ex-1 Ex-6 Comp-I Comp-J
Initial foam volume (ml) 150 140 100 80 140
1st rinse foam volume (ml) 120 90 60 50 130
2nd rinse foam volume (ml) 44 36 15 10 80
3rd rinse foam volume (ml) 20 5 0 0 40
4th rinse foam volume (ml) 10 0 0 0 15
Total Rinse water Volume (ml) and number of rinses 5 4 3 3 5
Fresh Wash performance (L* on DM177) 70.85 86.7 86.5 86.9 86.4
% improvement in wash performance over control NA >20 >20 >20 >20
Residual wash performance, 50oC/ 4 weeks (L* on DM177 tiles) NA 85.8 85.7 86.2 86.1
% drop in wash performance post storage at 50oC/4 weeks NA 1 <1 <1 <1

Composition represented by Ex-1 and 6, are comparable to the control in terms of the initial foam volume, but requires lesser number of rinses and also provides better stain removal efficacy (>20%) in comparison to the control, post storage at 50oC for 4 weeks, minimal drop in wash performance is observed for these samples and hence these are within the scope of the present invention. Comp-I shows significant drop in initial foam with respect to control. Comp-J does not provide rinse benefit with respect to control and is outside the scope of the invention.

Example V
Effect of the ratio of ethoxylated anionic surfactant to non-ethoxylated anionic surfactant
Cleaning compositions were prepared on the basis of the components shown in table 9. Ex-1 and 7, are examples of cleaning composition according to the present disclosure which is compared with comparative examples K and L which are not within the scope of the present invention.

Table 9
AM (%) Ex-1 Ex-7 Comp-K Comp-L
LABSA 90 4 3 1 6
AOS 38 3 1 0.5 5
SLES. 1EO 70 12 20 20 11
CAPB 29 4 4 4 4
Sodium hydroxide 48 1.3 0.97 0.32
Amylase As is 1 1 1 1
CaCl2. 2H2O 100 0.1 0.1 0.1 0.1
MPG 100 2 2 2 2
Trisodium citrate 100 0.2 0.2 0.2 0.2
Sodium formate 100 0.3 0.3 0.3 0.3
Sodium chloride 100 0.6 0.6 0.6 0.6
Fragrance 100 0.15 0.15 0.15 0.15
Water 100 Rest Rest Rest Rest
pH 6-6.5 6-6.5 6-6.5 6-6.5
Ratio of ethoxylated to non-ethoxylated anionic surfactant 1.7:1 5:1 13.3:1 1:1

These compositions were evaluated for formability (initial foam volume), ease of rinse, wash performance (as a measure of initial enzyme efficacy) and residual wash performance (post storage at 50oC, for 4 weeks). The results are summarized below in table 10.
Table 10
Control Ex-1 Ex-7 Comp-K Comp-L
Initial foam volume (ml) 150 140 150 150 140
1st rinse foam volume (ml) 120 90 100 110 90
2nd rinse foam volume (ml) 44 36 40 60 40
3rd rinse foam volume (ml) 20 5 5 30 5
4th rinse foam volume (ml) 10 - - 5 -
Total number of rinses 5 4 4 5 4
Fresh Wash performance (L* on DM177) 70.85 86.7 87.4 86.8 86.1
% improvement in wash performance over control NA >20 >20 >20 >20
Residual wash performance, 50oC/ 4 weeks (L* on DM177 tiles) NA 85.8 86.2 84.2 75.7
% drop in wash performance post storage at 50oC/4 weeks NA 1 1.4 2.9 12.1

Composition represented by Ex-1 and 7, are comparable to the control in terms of the initial foam volume, but requires lesser number of rinses and also provides better stain removal efficacy (>20%) in comparison to the control, post storage at 50oC for 4 weeks, minimal drop in wash performance is observed for these samples and hence these are within the scope of the present invention. Comp-K does not provide rinse benefit with respect to control and is outside the scope of the invention. Comp-L shows significant drop in wash performance upon storage at 50oC for 4 weeks and denotes enzyme instability and hence is outside the scope of the present invention.

Example VI
Effect of the ratio of non-ethoxylated anionic surfactant to amphoteric surfactant

Cleaning compositions were prepared on the basis of the components shown in table 11. Ex-1 and 8, are examples of cleaning composition according to the present disclosure which is compared with comparative example M which is not within the scope of the present invention.
Table 11
AM (%) Ex-1 Ex-8 Comp-M
LABSA 90 4 5 4
AOS 38 3 4 3
SLES. 1EO 70 12 15 12
CAPB 29 4 3 9
Amylase As is 1 1 1
CaCl2. 2H2O 100 0.1 0.1 0.1
MPG 100 2 2 2
Trisodium citrate 100 0.2 0.2 0.2
Sodium formate 100 0.3 0.3 0.3
Sodium chloride 100 0.6 0.6 0.6
Fragrance 100 0.15 0.15 0.15
Water 100 Rest Rest Rest
pH 6-6.5 6-6.5 6-6.5
Ratio of non-ethoxylated anionic surfactant to amphoteric surfactant 1.75:1 3:1 0.77:1

These compositions were evaluated for formability (initial foam volume), ease of rinse, wash performance (as a measure of initial enzyme efficacy) and residual wash performance (post storage at 50oC, for 4 weeks). The results are summarized below in table 12.

Table 12
Control Ex-1 Ex-8 Comp-M
Initial foam volume (ml) 150 140 140 160
1st rinse foam volume (ml) 120 90 85 130
2nd rinse foam volume (ml) 44 36 35 60
3rd rinse foam volume (ml) 20 5 5 40
4th rinse foam volume (ml) 10 - - 15
Total Rinse water Volume (ml) and number of rinses 5 4 4 5
Fresh Wash performance (L* on DM177) 70.85 86.7 85.8 86.2
% improvement in wash performance over control NA >20 >20 >20
Residual wash performance, 50oC/ 4 weeks (L* on DM177 tiles) NA 85.8 82.2 83.2
% drop in wash performance post storage at 50oC/4 weeks NA 1 4.2 3.6

Composition represented by Ex-1 and 8, are comparable to the control in terms of the initial foam volume, but requires lesser number of rinses and also provides better stain removal efficacy (>20%) in comparison to the control, post storage at 50oC for 4 weeks, minimal drop in wash performance is observed for these samples and hence these are within the scope of the present invention. Comp-M does not provide rinse benefit with respect to control and is outside the scope of the invention.

Example VII
Effect of pH of formulation:
Cleaning compositions were prepared on the basis of the components shown in table 13. Ex-1, 9 and 10, are examples of cleaning composition according to the present disclosure which is compared with comparative examples N and O which are not within the scope of the present invention.

Table 13
AM (%) Ex-1 Ex-9 Ex-10 Comp-N Comp-O
LABSA 90 4 4 4 4 4
AOS 38 3 3 3 3 3
SLES. 1EO 70 12 12 12 12 12
CAPB 29 4 4 4 9 2
Sodium hydroxide 48 1.3 1.3 1.3 1.3 1.3
Amylase As is 1 1 1 1 1
CaCl2. 2H2O 100 0.1 0.1 0.1 0.1 0.1
MPG 100 2 2 2 2 2
Trisodium citrate 100 0.2 0.2 0.2 0.2 0.2
Sodium formate 100 0.3 0.3 0.3 0.3 0.3
Sodium chloride 100 0.6 0.6 0.6 0.6 0.6
Fragrance 100 0.15 0.15 0.15 0.15 0.15
Water 100 Rest Rest Rest Rest Rest
Additional quantity of citric acid/sodium citrate added to adjust the pH
pH 6.5 5.3 8.1 4.7 8.8

These compositions were evaluated for wash performance (as a measure of initial enzyme efficacy), residual wash performance (post storage at 50oC for 4 weeks) and physical stability. The results are summarized below in table 14.

Table 14
Control Ex-1 Ex-9 Ex-10 Comp-N Comp-O
Fresh Wash performance (L* on DM177) 70.85 86.7 86.9 86.2 86.9 85.9
% improvement in wash performance over control NA >20 >20 >20 >20 >20
Residual wash performance, 50oC/ 4 weeks (L* on DM177 tiles) NA 85.8 82.1 85.7 70.3 85.1
% drop in wash performance post storage at 50oC/4 weeks NA 1 5.5 <1 19.1 <1
Physical stability Pass (Clear) Pass
(Clear) Pass (Clear) Pass (Clear) Pass (Clear) Fail
(Precipitation)

Composition represented by Ex-1 and 9, provides better stain removal efficacy (>20%) in comparison to the control and also shows consistent wash performance post storage at 50oC, 4 weeks and hence these are within the scope of the present invention. Comp-N shows a drop in residual wash performance which implies enzyme stability and hence is outside the scope of the invention. Comp-O shows is unstable physically.

Example VIII
Effect of the wt.% of amylase
Cleaning compositions were prepared on the basis of the components shown in table 15. Ex-1, 11 and 12, are examples of cleaning composition according to the present disclosure which is compared with comparative example P which is not within the scope of the present invention.

Table 15
AM (%) Ex-1 Ex-11 Ex-12 Comp-P
LABSA 90 4 4 4 4
AOS 38 3 3 3 3
SLES. 1EO 70 12 12 12 12
CAPB 29 4 4 4 4
Amylase As is 1 0.05 2 0.03
CaCl2. 2H2O 100 0.1 0.1 0.1 0.1
MPG 100 2 2 2 2
Trisodium citrate 100 0.2 0.2 0.2 0.2
Sodium formate 100 0.3 0.3 0.3 0.3
Sodium chloride 100 0.6 0.6 0.6 0.6
Fragrance 100 0.15 0.15 0.15 0.15
Water 100 Rest Rest Rest Rest
pH 6-6.5 6-6.5 6-6.5 6-6.5

These compositions were evaluated wash performance (as a measure of initial enzyme efficacy). The results are summarized below in table 16.
Table 16
Control Ex-1 Ex-11 Ex-12 Comp-P
Fresh Wash performance (L* on DM177) 70.85 86.7 84.53 88.9 74.5
% improvement in wash performance over control NA >20 >20 >20 5.2

Composition represented by Ex-1, 11 and 12, provides better stain removal efficacy (>20%) in comparison to the control and also shows consistent wash performance post storage at 50oC, 4 weeks and hence these are within the scope of the present invention. Comp-P does not provide significant improvement in wash performance with respect to non-enzymatic control and hence is outside the scope of the patent.
,CLAIMS:
1. A cleaning composition comprising:
(i) 3 wt% to 10 wt% of at least one non-ethoxylated anionic surfactant;
(ii) 6 wt% to 20 wt% of at least one ethoxylated anionic surfactant;
(iii) 0.05% to 1.5% by wt. of at least one enzyme,
wherein the composition is stable at a pH in the range of 5 to 8.5.

2. The composition as claimed in claim 1, wherein said ethoxylated anionic surfactant and said non-ethoxylated anionic surfactant is present in a ratio 10: 1 to 10:7.5.

3. The composition as claimed in claim 1, wherein said non-ethoxylated anionic surfactant is selected from LAS (Linear Alkylbenzene Sulphonate), LABSA (Linear alkyl benzene sulphonic acid), AOS (alpha olefin sulphonate).

4. The composition as claimed in claim 1, wherein said composition comprises at least two different non-ethoxylated anionic surfactants, each one being selected from LABSA and Alpha-Olefin-Sulfate and LAS.

5. The composition as claimed in claim 4, wherein said LABSA is in the range from about 45wt% to 60wt% with respect to the total weight of non-ethoxylated anionic surfactants in the composition.

6. The composition as claimed in claim 1, wherein said ethoxylated anionic surfactant is selected from alkyl ether sulfates, preferably ethoxylated sodium laureth sulfate with EO units ranging from 1 to 5 EO.

7. The composition as claimed in claim 1, further comprising at least one amphoteric surfactant.

8. The composition as claimed in claim 1, wherein said amphoteric surfactant is present in an amount ranging from 1 wt% to 10 wt%.

9. The composition as claimed in claim 7, wherein said amphoteric surfactant is selected from the group that includes but is not limited to betains, sultains, preferably cocamidopropyl betaine.

10. The composition as claimed in the preceding claims, wherein said non-ethoxylated surfactant and amphoteric surfactant is present in a ratio from 1:1 to 3:1.

11. The composition as claimed in claim 1, wherein said enzyme is at least one selected from the group consisting of amylase.

12. The composition as claimed in claim 1, wherein said enzyme is alpha amylase.

13. The composition as claimed in claim 1, wherein the total enzyme content of the formulation is in the range from 0.05 to 1.5%.

14. The composition as claimed in claim 1, wherein said cleaning composition is in a gel form or as a clear liquid formulation.

15. The composition as claimed in claim 1, characterized in that the enzyme in the formulation remains stable at 50°C for a period of 4 weeks.

16. The composition as claimed in claim 1, wherein said composition further comprise builders, humectants, pH modifiers, thickeners, preservatives, electrolytes, stabilizers, perfumes, fragrances, colorants, pigments, dyes, abrasive agents, disinfectants, antioxidants, bleaches, chelating agents, optical brighteners, opacifiers, hydrotropes.