Soap bars comprising mild surfactants and fillers

Abstract

The present invention relates to composition of soap bars based on synthetic non-soap surfactants. The invention particularly relates to soap bar composition having pH of 6 to 8 and regarded as mild. Disclosed is an extruded soap bar composition comprising: a) 15 to 40 wt% acyl isethionate; b) 1 to 6 wt% water-soluble organic filler; and, c) 15 to 45 wt% water-insoluble filler having particle size 10 to 20 pm comprising: i) an inorganic filler having density of 2.0 to 2.6 g / cc and Moh's hardness 1 to 3; and, ii) an organic filler having density of 1.05 to 1.3 g / cc; and, wherein, ratio of the water-insoluble inorganic filler to the water-insoluble organic filler is from 1 :0.1 to 1 :1.2 parts by weight. The bars of this invention have appropriate density and can be prepared or manufactured by a comparatively less energy intensive process due to careful selection and combination of ingredients. Only small amount of water-soluble organic filler is required to ensure that the bar composition can be processed, milled and plodded in an economical and less energy intensive manner.

Description

[0001] “SOAP BARS COMPRISING MILD SURFACTANTS AND FILLERS”

[0002] Field of the Invention

[0003] The present invention relates to composition of soap bars based on synthetic non-soap surfactants. Such bars are generally known as syndet bars. The invention particularly relates to soap bar composition having pH of 6 to 8 and regarded as mild.

[0004] Background of the invention

[0005] Soap bars may be classified into various categories such as conventional soap bars which contain 40 to 80% fatty acid soap. The pH of such bars is usually above 8. Sometimes bars contain combination of soap and synthetic non-soap surfactants for combined cleaning benefits of soap and such surfactants. Such bars are milder than pure soap bars and referred to as soap-syndet bars. On the other hand, there are compositions that contain only synthetic non-soap surfactants or a significant proportion of synthetic surfactants over soap. Bars made of such compositions are called syndet bars, and their pH is usually in the range of 6 to 8, preferably 6.5 to 7.5. Such compositions are milder than their high-pH counterparts. There is a growing demand for personal wash compositions more suitable to our skin and which provide mild and gentle cleaning.

[0006] Bars of soap are conventionally manufactured by milling, plodding and stamping a semisolid mass of soap, which usually is added in the form of pre-prepared soap noodles or flakes, along with a variety of other components.

[0007] Fatty acyl isethionates (e.g., cocoyl isethionates) are non-soap anionic surfactants widely used in mild soap bars because they lather well and are mild.

[0008] Acyl isethionates are produced by esterification of fatty acids or by reaction of fatty acids having carbon chain length of Cs-2o with isethionic acid. Fatty acyl isethionates, especially, sodium cocoyl isethionate, is commercially available in the form of noodles that can be directly processed, i.e., milled / plodded, further in the presence of other ingredients, to make soap bars. Usually, such commercial noodles contain other ingredients like stearic acid, other surfactants like betaines or sulphosuccinates, starch and glycerine. Therefore, when such noodles are used as raw material for making soap bars, the other ingredients contained in the noodles become part and parcel of the resultant bars. Soap bars may be moulded in any suitable shape and could technically be made of any size or grammage. However, from the consumer’s point of view, such bars need to be of a suitable size, neithertoo large nortoo small, and easily grippable in a hand without involving much dexterity at the time of use. Bars also need to convey an appropriate size impression, i.e., that the consumer need to be reassured that the size and dimensions of the bars are commensurate with the grammage, i.e. actual weight of the bars.

[0009] Fatty acid isethionates are expensive raw materials, therefore formulations scientists have developed various ways to reduce the content of isethionates and proportionately replace it with other ingredients.

[0010] US5756438 A (Jergens Company, 1998) discloses soap bars prepared by a tableting process. The ingredients are mixed together, and heated to melt a waxy binder. Melting of the binder may be achieved by high shear mixing of all components combined, by heating the entire mixture in a jacketed vessel or other heating device or by separate heating of the binder component alone, followed by addition to the other components previously mixed together. The composition is compressed using a tablet press, or briquette-forming apparatus of conventional nature. The bars rely on proper combination of three fundamental components, a surfactant or surfactant system, filler, and a waxy binder.

[0011] US6906018 B1 (Unilever, 2005) discloses use of sugar in bars where the sugar and water to form gel like structures that provide bar hardness and cohesiveness. The bars contain 25 to about 60 wt% sugar and further comprise 0.5 to 10 wt% co-structurant salt or inorganic or organic filler. The co-structurant is water soluble. Examples include PEG, talc, clay, zeolites, calcites, silicas, aluminium silicates, calcium magnesium carbonates such as dolomites), bicarbonates, borates, sulphates, starch, protein and wax.

[0012] US2014378363 A1 (Henkel) discloses soap bars that comprise talc and starch as fillers.

[0013] US5543072 A (Mona Industries, 1996) discloses personal wash bar (syndet bar) composition containing 25 to 65 wt% synthetic surfactants. The syndet bar compositions contain 15 to 35 wt% acyl isethionates and 10 to 30 wt% sulfosuccinate. The bars contain significant amount of free fatty acid, i.e., 25 to 40 wt%, 2 to 10 wt% organic hydrophilic agent like PEG, and 5 to 20 wt% organic binder / filler such as hydrolysed starch. US4151105 A (Hewitt Soap Co, 1979) discloses low pH soap having 20 to 40 wt% sodium isethionate and / or sodium lauryl sulfoacetate, 10 to 30 wt% paraffin, 5 to 15 wt% powdered starch and 10 to 30 wt% dextrin. First the premelted wax and paraffin is added to a crutcher and temperature is adjusted to 90 to 100 °C. range. Then liquid coconut-oil fatty acid is added and crutcher is agitated under heat. This is continued until a smooth slurry is obtained. Then dextrin is introduced followed by starch-water slurry. The resulting mix is dropped on a cold roll and taken off in the form of a chip or flake. The (chips or flakes) are passed through a plodder. The effluent from the plodder is collected in soap buggies. The buggies feed the conventional soap equipment line consisting of an amalgamator, mills, vacuum plodder, and soap press.

[0014] The formulation of Hewitt prior art is prepared by a highly energy intensive process which begins with heating and cooling of a soap-mix which is further milled and plodded.

[0015] There is need for soap bar composition that comprises acyl isethionate and fillers where pH of the bars is 6 to 8, and density is 1 .15 to 1 .3 g / cc. As described earlier, density of soap bars is an important feature due to its impact on size impression of the soap bars. A given mass of soap mix, when compacted or moulded into a bar, will occupy a smaller volume or a bigger volume depending on density of the soap mix composition. Even if consumers are offered the same mass of soap in a smaller size [due to higher density] it is likely that consumers may not prefer to buy and use such bars.

[0016] Summary of the invention

[0017] It has been determined that a careful mix and selection of the right kind of fillers and the right amounts of fillers can solve at least some of the problems of prior art. The bars of this invention have appropriate density and can be prepared or manufactured by a comparatively less energy intensive process due to careful selection and combination of ingredients as described hereinafter.

[0018] Disclosed is an extruded soap bar composition comprising: a) 15 to 40 wt% acyl isethionate; b) 1 to 6 wt% water-soluble organic filler; and, c) 15 to 45 wt% water-insoluble filler having particle size 10 to 20 pm comprising: i) an inorganic filler having density of 2.0 to 2.6 g / cc and Moh’s hardness 1 to 3; and, ii) an organic filler having density of 1 .05 to 1 .3 g / cc; and, wherein, ratio of the water-insoluble inorganic filler to the water-insoluble organic filler is from 1 :0.1 to 1 :1 .2 parts by weight.

[0019] It is essential to ensure the total amount of water-insoluble filler is within the range of 15 to 45 and that ratio of the water-insoluble inorganic filler to the water-insoluble organic filler is from 1 :0.1 to 1 :1 .2 parts by weight. What is also essential is that the amount of water-soluble organic filler is in the narrow range of 1 to 5 wt%. We have determined that a small amount of water soluble organic filler is required to ensure that the bar composition can be processed, milled and plodded in an economical and less energy intensive manner.

[0020] Detailed description of the invention

[0021] These and other aspects, features and advantages will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims. For the avoidance of doubt, any feature of one aspect of the present invention may be utilized in any other aspect of the invention. The word “comprising” is intended to mean “including” but not necessarily “consisting of’ or “composed of.” In other words, the listed steps or options need not be exhaustive. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Similarly, all percentages are weight / weight percentages unless otherwise indicated. Numerical ranges expressed in the format “from x to y” are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format “from x to y”, it is understood that all ranges combining the different endpoints are also contemplated. In other words, in specifying any ranges of values, any upper value can be associated with any lower value.

[0022] The present invention relates to an extruded soap bar composition comprising: a) 15 to 40 wt% acyl isethionate; b) 1 to 6 wt% water-soluble organic filler; and, c) 15 to 45 wt% water-insoluble filler having particle size 10 to 20 pm comprising: i) an inorganic filler having density of 2.0 to 2.6 g / cc and Moh’s hardness 1 to 3; and, ii) an organic filler having density of 1 .05 to 1 .3 g / cc; and, wherein, ratio of the water-insoluble inorganic filler to the water-insoluble organic filler is from 1 :0.8 to 1 :0.15 parts by weight. It is preferred that the acyl isethionate comprises at least one of sodium lauroyl isethionate or sodium cococyl isethionate. Lauroyl isethionate is a kind of fatty acyl isethionate and is an anionic surfactant prepared by reacting isethionate salt such as alkali metal isethionate with an aliphatic C12 fatty acid generally having Iodine Value less than 20 g / g. The alkali metal cation is sodium. Alternatively, it is magnesium, potassium, lithium, ammonium or substituted ammonium cation or other counterion. Alternatively the acyl isethionate comprises sodium cococyl isethionate. Alternatively the composition comprises sodium lauroyl isethionate and sodium cococyl isethionate as a combination. In the combination, preferably there is major proportion of sodium lauroyl isethionate and minor proportion of sodium cococyl isethionate. By major proportion is meant at least 70 %, preferably at least 80% and more preferably at least 90% of the combination.

[0023] The lauroyl isethionate or cococyl isethionate may also comprise some amount of unesterified isethionate salt for example, sodium isethionate, which may eventually get incorporated into the personal wash composition.

[0024] Fatty acyl isethionates are commercially available in two distinct forms; as flakes or neat form with active content of about 60 to 80%, and as noodles with active content of about 40 to 50% but also containing stearic acid and CAPB. Noodles may also contain starch and glycerine. A variety of suppliers and commercial manufacturers offer a range of isethionates in the aforesaid and other forms.

[0025] Therefore, if a composition needs to be prepared comprising a certain predetermined wt% of fatty acyl isethionate, then formulation scientists should bear in mind that commercial supplies of such isethionates often contain other ingredients. When the composition of the invention comprises acyl isethionate at the higher end of the range 15 to 40 wt%, it is preferred that the acyl isethionate is used in the neat form, as opposed to the noodle form. Likewise, when the composition of the invention comprises acyl isethionate at the mid to lower end of the range 15 to 40 wt%, it is preferred that the acyl isethionate is used in the noodle form, as opposed to the neat or flake form. This is because the active content of most commercial supplies of fatty acyl isethionate in the noodle form is around 30 to 40%, the rest being primarily stearic acid.

[0026] Fillers

[0027] The soap bar composition of the invention comprises 1 to 6 wt%, preferably 1 to 5 wt% water-soluble organic filler. More preferably the extruded soap bar composition of the invention comprises 1 to 4.5 wt% water-soluble organic filler. Preferably the water-soluble organic filler is at least one of polyethylene glycol, sorbitol, sucrose, glucose, fructose, lactose, maltose, palatinose, and leucrose, pre-gelatined starch, dextrin or maltodextrin. It is particularly preferred that the water-soluble organic filler is dextrin or maltodextrin. It is preferred that the water-soluble organic filler is not glycerine.

[0028] Dextrin can be procured from variety of suppliers. Dextrins are low molecular weight carbohydrates obtainable by the hydrolysis of starch forming D-glucose units linked by a- (1 — >4) bonding starting with an a-(1 — >6) glycosidic bond. It is preferred that the dextrin has dextrose equivalent between 1 and 30%, preferably between 1 and 13% based on dextrose (glucose) with 100%. Dextrose equivalent (DE) is a measure of the amount of reducing sugars present in a sugar product, expressed as a percentage on a dry basis relative to dextrose. Maltodextrins are composed of a-(1 — >4) bonding glucose only and have an average polymerization degree of between 10 and 20 and a dextrose equivalent of 3 to 20%, preferably 10 to 20%. Cyclodextrin can be any of the known cyclodextrins such as, unsubstituted cyclodextrins containing from six to twelve glucose monomers.

[0029] The soap bar composition of the invention comprises 15 to 45 wt% water-insoluble filler having particle size 10 to 20 pm comprising: i) an inorganic filler having density of 2.0 to 2.6 g / cc and Moh’s hardness 1 to 3; and, ii) an organic filler having density of 1 .05 to 1 .3 g / cc.

[0030] The ratio of the water-insoluble inorganic filler to the water-insoluble organic filler is from 1 :0.1 to 1 :1.2 parts by weight., more preferably 1 :0.1 to 1 :1 parts by weight.

[0031] Preferably the composition comprises 15 to 35 wt% water-insoluble filler. Preferably the composition comprises more of water-insoluble filler when the acyl isethionate is towards the lower end of the range of 15 to 40 wt%. Correspondingly preferably the composition comprises less of water-insoluble filler when the acyl isethionate is towards the upper end of the range of 15 to 40 wt%.

[0032] Preferably the inorganic filler is talc, calcite or a clay. When the inorganic filler is a clay, it is preferred that the clay is at least one of kaolinite, dickite, halloysite, nacrite, smectite, montmorillonite, nontronite, illite, bentonite, attapulgite, palygorskite, sepiolite, hormite, pyrophyllite, chlorite, or aluminosilicate. It is preferred that the water-insoluble organic filler is starch, cellulose, guar gum, sodium hydroxypropyl starch phosphate, aluminium starch octenyl succinate, xanthan gum, sclerotium gum, pectin, karaya, gum arabic, agar, carrageenan, alginate, hydroxypropyl cellulose, hydroxypropyl methylcellulose, ethyl cellulose, carboxymethyl cellulose, or microcrystalline cellulose.

[0033] It is preferred that the water-insoluble organic filler is starch. Preferably the starch is wheat or corn starch, potato starch, rice starch or starch from tapioca. Untreated starch has the advantage that it is present in the bar soaps in the form of small solid grains. Mixtures of different starches may be used. Preferably the starch is natural starch, i.e. an unmodified starch. These starches have different contents of amylose and amylopectin.

[0034] It is further preferred that the extruded soap bar composition of the invention comprises 0.5 to 4 wt% glycerine, more preferably 1 to 3 wt%.

[0035] It is preferred that pH of the bar composition of the invention is 6 to 8, more preferably 6.5 to 7.5. It is preferred that the density of said soap bar composition is 1 .15 to 1 .3 g / cc.

[0036] It is further preferred that the extrudable soap bar composition of the invention comprises 5 to 25 wt% free fatty acids (FFA), preferably 5 to 20 wt%. It is preferred that the fatty acid is stearic acid or alternatively hysteric acid. Inclusion of free fatty acids increases hardness of the soap bars. When the isethionate is utilised in the form of noodles, then the noodles inherently comprise about 30 to 40 % fatty acids, especially stearic acid.

[0037] Preferably the extruded soap bar composition of the invention comprises an amount of soap such that pH of the composition is 6 to 8. In such cases it is preferred that the soap consists of water-soluble soap and water-insoluble soap in which ratio of water-soluble soap to the water-insoluble soap is 1 :0.4 to 1 :1 .4 parts by weight.

[0038] Soap

[0039] The term "soap" means alkali metal or alkaline earth metal salts of fatty acids. It is preferred that the fatty acids are derived from coconut oil, palm oil, palm kernel oil or non-tropical nut oils. Preferably the carbon chain length is C12 or higher. Preferably at least 85% fatty acids have C12 to C18 chain length. Further preferably the fatty acids comprise fatty acids derived from aforesaid oils and tallow or any other source of unsaturated fatty acids. A preferred soap feed stock is a mixture of 15 to 20% coconut fatty acids and 80 to 85% unsaturated fatty acids. The soaps may contain unsaturation in accordance with commercially acceptable standards. It is preferred that there is no excessive unsaturation in the fatty acids.

[0040] The soap preferably consists of water-soluble soap and water-insoluble soap and ratio of water-soluble soap to the water-insoluble soap is 1 :0.4 to 1 :1.4 parts by weight. This ratio is determined based on the total soap content of the composition. Preferably the ratio of water-soluble soap to the water-insoluble soap is 1 :0.6 to 1 :1 .3 parts by weight.

[0041] Preferably the solubility of the water-soluble soap is equal to or greater than that of 82 / 18 tallow / coconut soap, whose solubility is 1.1 g / litre at 40°C. Preferably the water-soluble soap is an alkali metal salt of C8 to C24 fatty acids. In a most preferred aspect the alkali metal is sodium.

[0042] Further preferably the solubility of the water-insoluble soap is less than 1.1 g / litre at 40°C. More preferably the water-soluble soap is an alkaline earth metal salt of C8 to C24 fatty acids. Preferably the alkaline earth metal salt is magnesium. Alternatively, the alkaline earth metal salt is calcium.

[0043] Depending on the format of the composition the total surfactant content is variable. The bars may be of any shape such a rectangular or ovoid bar and this shape is usually achieved by the shape of the die or mould that is used for extrusion of the soap mass.

[0044] Additional ingredients

[0045] In addition to the ingredients disclosed earlier, the composition of the invention may comprise one or more of the following ingredients. The choice of the ingredients and their wt% will largely depend on the nature of the composition, i.e. aqueous or non-aqueous as well as the format of the composition such as whether it is a soap bar.

[0046] Surfactants

[0047] The composition of the invention may comprise one or more additional non-soap surfactant other than the lauroyl isethionate.

[0048] A surfactant is necessary for basic cleansing action and the nature and type of surfactant, or surfactants, would vary largely based on the intended use of the composition. The amount of non-soap anionic surfactant could vary largely depending on the nature and purpose of the end-use composition. Preferably the non-soap anionic surfactant is alkyl sulphate, alkyl ether sulfate, alkaryl sulfonate, ester sulphonate, alkyl succinate, alkyl sulfosuccinate, alkyl ether sulfosuccinate, N-alkyl sarcosinate, alkyl phosphate, alkyl ether phosphate, and alkyl ether carboxylic acid, taurate or a glycinate. More preferably the nonsoap anionic surfactant is alkyl sulphate, alkyl ether sulphate, isethionate or ester sulphonate.

[0049] Alkyl sulphates and alkyl ether sulphates

[0050] When the composition of the invention comprises an alkyl sulphate it is preferred that the composition comprises 2 to 5 wt% alkyl sulphate.

[0051] Ta urates

[0052] When the composition of the invention comprises a taurate, it is preferably comprises sodium methyl lauroyl taurate, potassium methyl lauroyl taurate, sodium methyl myristoyl taurate, potassium methyl myristoyl taurate, ammonium methyl myristoyl taurate, sodium methyl cocoyl taurate, potassium methyl cocoyl taurate, ammonium methyl cocoyl taurate, sodium methyl oleoyl taurate, potassium methyl oleoyl taurate, ammonium methyl oleoyl taurate, sodium lauroyl taurate, potassium lauroyl taurate, ammonium myristoyl taurante, sodium cocoyl taurate or potassium oleoyl taurate.

[0053] Preferably the composition comprises 1 to 10 wt% taurates.

[0054] Glycinates

[0055] When the composition of the invention comprises a glycinate, preferably the glycinate is alkyl glycinate or acyl glycinate. More preferably, the glycinate surfactant comprises C8-24 alkyl glycinate, C8-24 acyl glycinate, or a mixture thereof. It is particularly preferred that the glycinate is cocoyl glycinate and more preferably sodium cocoyl glycinate. The glycinates are generally used in the form of their salts, preferably alkali metal salt, and / or ammonium salt.

[0056] Preferably the composition comprises 1 to 10 wt% glycinates.

[0057] Alkyl succinate, alkyl sulfosuccinate, alkyl ether sulfosuccinate

[0058] When the composition of the invention comprises alkyl succinate, alkyl sulfosuccinate, alkyl ether sulfosuccinate, preferably the sulphosuccinate is cocamidomonoethanolamine sulphosuccinate, with chain length distribution of at least 90% of C8to C18fatty acid. Preferably the composition comprises 1 to 10 wt% alkyl succinate, alkyl sulfosuccinate, or alkyl ether sulfosuccinate or any combination thereof.

[0059] Sarcosinate

[0060] When the composition of the invention comprises a sarcosinate preferably the sarcosinate is one or more of Cocoyl Sarcosine, Lauroyl Sarcosine, Myristoyl Sarcosine, Oleoyl Sarcosine, Stearoyl Sarcosine, Sodium Cocoyl Sarcosinate, Sodium Lauroyl Sarcosinate, Sodium Myristoyl Sarcosinate, Ammonium Cocoyl Sarcosinate or Ammonium Lauroyl Sarcosinate. Preferably the composition comprises 1 to 10 wt% sarcosinate.

[0061] Benefit agents

[0062] The cleansing composition optionally comprises 0.5 to 10 wt% benefit agent which may be selected depending on the nature of the composition. Preferred benefit agents include moisturizers, emollients, sunscreens, and / or anti-ageing compounds, antioxidants, perfumes, polymers, chelating agents, colorants, deodorants, dyes, foam boosters, germicides, anti-microbials, lathering agents, pearlescers, skin conditioners, stabilizers, Sodium metabisulphite, ethylene diamine tetra acetic acid (EDTA), or ethylene hydroxy diphosphonic acid (EHDP), retinoids, resorcinol or vitamin B3.

[0063] The personal cleansing composition of the invention preferably comprises 0.01 to 5 wt% electrolytes such as sodium sulphate, sodium chloride, sodium acetate, sodium citrate, potassium chloride, potassium sulphate, sodium carbonate and other mono or di or tri salts of alkali metals, more preferred electrolytes are sodium chloride, sodium sulphate, sodium citrate, potassium chloride and an especially preferred electrolyte is sodium chloride, sodium citrate or sodium sulphate or a combination thereof. It is preferred that the electrolyte is not of alkaline earth metal because such electrolytes may affect the ratio between soluble and insoluble soap.

[0064] Conventionally, milled and plodded soap bars are made by saponification of fat and oils, forming the dried soap into noodles, mixing the various desired additives such as perfume into the soap noodles, passing the mixture formed through a mill or series of mills to form ribbons of soap, passing the milled soap mixture through a plodder to form billets of soap and cutting the billets into individual unit bars of suitable size followed by stamping the bars into the desired shape. Shape

[0065] When the personal cleansing composition of the invention is a bar of soap, it may be in any of the regular forms in which such products are available.

[0066] The invention will now be explained in detail with the following exemplary embodiments. All chemicals are from commercial sources. To the best of the applicant’s knowledge, the invention is not based on any bioresource or biological material procured from India.

[0067] Examples

[0068] Example 1

[0069] A series of extruded soap bars was prepared using sodium cocoyl isethionate in noodle form as per the details shown in Table 1 . The noodles contained inter alia starch and the starch content included in the noodles is shown in the table below. No additional starch was added to the formulations A and B but the additional starch content of composition C and D is included in the relevant cell of the table, as added starch. Observations were recorded at the stage of sigma mixer and extruder. All compositions of Table 1 are outside the invention (comparative). The syndet noodles contained 40% sodium cococyl isethionate with about 40% stearic acid and about 4% starch.

[0070] Table 1 The data in Table 1 indicates the difficulties experienced while making extruded soap bars without any maltodextrin with high filler content. See examples B to D. As composition A was prepared from commercial noodles directly without any filler, bars could be prepared with ease.

[0071] Example 2: Comparative examples with maltodextrin

[0072] A series of extruded soap bars was prepared using sodium cocoyl isethionate in noodle form as per the details shown in Table 2. The syndet noodles contained (on 100% wt basis) 40% sodium cococyl isethionate with about 40% stearic acid and about 4% starch. For example, composition E contained 60 X 0.4 = 24 g Sodium cocoyl isethionate and 60 X 0.4 = 24 g stearic acid.

[0073] The noodles contained (on 100% wt basis) inter alia starch. The starch content as coming from and included in the noodles is shown in the table below. No additional starch was added to the formulations A and B but the additional starch content of composition C and D is included in the relevant cell of the table. Observations were recorded at the stage of sigma mixer and extruder. All compositions of Table 1 are outside the invention (comparative)

[0074] Table 2 The data in Table 2 indicates the difficulties experienced while making extruded soap bars with high amount of maltodextrin and high filler content.

[0075] Example 3: Inventive compositions with maltodextrin

[0076] A series of extruded soap bars was prepared using sodium lauroyl isethionate in noodle form as perthe details shown in Table 3. The syndet noodles contained 40% sodium lauroyl isethionate with about 40% stearic acid.

[0077] The noodles did not contain starch. Therefore, all starch added to the formulations 1 to 3 was included to precisely control the amount. Observations were recorded at the stage of sigma mixer and extruder. All compositions of Table 3 are inside the invention.

[0078] Table 3

[0079] The data in table 3 when compared to Tables 1 and 2 demonstrates that a careful mix and selection of the right kind of fillers and the right amounts of fillers can solve at least some of the problems of prior art. The bars of this invention have appropriate density and can be prepared or manufactured by a comparatively less energy intensive process due to careful selection and combination of ingredients. It is essential to ensure the total amount of waterinsoluble filler is within the range of 15 to 45 and that ratio of the water-insoluble inorganic filler to the water-insoluble organic filler is from 1 :0.1 to 1 :1.2 parts by weight. It has been demonstrated that it is essential that the amount of water-soluble organic filler is in the narrow range of 1 to 6 wt%. We have demonstrated that only a small amount of water- soluble organic filler is required to ensure that the bar composition can be processed, milled and plodded in an economical and less energy intensive manner.

Claims

WE CLAIM:1) An extruded soap bar composition comprising: a) 15 to 40 wt% acyl isethionate; b) 1 to 6 wt% water-soluble organic filler; and, c) 15 to 45 wt% water-insoluble filler having particle size 10 to 20 pm comprising: i) an inorganic filler having density of 2.0 to 2.6 g / cc and Moh’s hardness 1 to 3; and, ii) an organic filler having density of 1 .05 to 1 .3 g / cc; and, wherein, ratio of the water-insoluble inorganic filler to the water-insoluble organic filler is from 1 :0.1 to 1 :1 .2 parts by weight.2) An extruded soap bar composition as claimed in claim 1 wherein said acyl isethionate comprises at least one of sodium lauroyl isethionate or sodium cococyl isethionate.3) An extruded soap bar composition as claimed in claims 1 or 2 wherein said composition comprises 15 to 35 wt% water-insoluble filler.4) An extruded soap bar composition as claimed in any of claims 1 to 3 wherein said water-soluble organic filler is at least one of polyethylene glycol, sorbitol, sucrose, glucose, fructose, lactose, maltose, palatinose, leucrose, pre-gelatined starch, dextrin or maltodextrin.5) An extruded soap bar composition as claimed in claim 4 wherein said water-soluble organic filler is dextrin or maltodextrin.6) An extruded soap bar composition as claimed in any of claims 1 to 5 wherein said inorganic filler is talc, calcite or clay.7) An extruded soap bar composition as claimed in any of claims 1 to 6 wherein said water-insoluble organic filler is starch, cellulose, guar gum, sodium hydroxypropyl starch phosphate, aluminum starch octenylsuccinate, xanthan gum, sclerotium gum, pectin, karaya, gum arabic, agar, carrageenan, alginate, hydroxypropylcellulose, hydroxypropyl methylcellulose, ethylcellulose, carboxymethyl cellulose or microcrystalline cellulose.8) An extruded soap bar composition as claimed in any of claims 1 to 7 wherein ratio of the water-insoluble inorganic filler to the water-insoluble organic filler is from1 :0.9 to 1 :0.15 parts by weight.9) An extruded soap bar composition as claimed in any of claims 1 to 8 wherein said composition comprises 0.5 to 4 wt% glycerine.10) An extruded soap bar composition as claimed in any of claims 1 to 9 wherein pH of the bar composition is 6 to 8.11) An extruded soap bar composition as claimed in claim 10 said composition comprises an amount of soap such that pH of the composition remains within 6 to 8.12) An extruded soap bar composition as calmed in claim 11 wherein the soap consists of water-soluble soap and water-insoluble soap in which ratio of water-soluble soap to the water-insoluble soap is 1 :0.4 to 1 :1 .4 parts by weight.13) An extruded soap bar composition as claimed in any of claims 1 to 12 wherein density of said bar is 1 .15 to 1 .3 g / cc.14) An extruded soap bar composition as claimed in any of claims 1 to 3 wherein said composition comprises 5 to 25 wt% free fatty acids.

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