A tablet composition

Abstract

The present invention relates to a tablet for providing a liquid cleaning composition on dissolution in water. There is a need for an improved tablet containing significantly high amount of detersive active, which is hard yet dissolves quickly in contact with water. It is found that a disintegrant mix comprising an organic solvent and select water-insoluble compound, and 50 to 90 % by weight surfactant provide a tablet, which is hard enough to resist breakage on transportation / storage yet dissolves fast in water.

Description

Field of the Invention

[0001] The present invention relates to a tablet composition. More particularly, it relates to a unit dose tablet providing a liquid cleaning composition on dissolution in water.Background of the Invention

[0002] Consumers spend considerable amount of time and effort in cleaning their households. They may use different products such as laundry detergent, dishwashing detergent, floor cleaner etc. for cleaning purposes. Such products are available in different formats, for example, powder, liquid, tablet, pod etc. Often consumer prefer to have a product in tablet format since a tablet is compact in size and provides a controlled dosage.

[0003] Typically, a detergent tablet contains concentrated detersive actives, consumers are expected to dissolve the tablet in water to form a cleaning composition. For such tablets, it is desirable that the tablets should be hard enough to resist breakage in transportation / storage and at same time it should dissolve fast in contact with water. Conventionally, a tablet is formed by compacting a homogenised powder comprising the required ingredients. In one hand, a high compression force leads to hard tablets which fails to dissolve fast. On the other hand, lower compression force leads to loosely packed ingredients which helps in faster dissolution, however, does not have the required strength. It is desirable to have a fast-dissolving tablet with sufficient strength.

[0004] It is desired to increase the amount of detersive actives in a tablet for improving the cleaning performance of the tablet. Since detersive actives mostly hygroscopic, it may lead to densely packed hard tablets with relatively slower dissolution rate. Further, increasing detersive actives is compensated with reducing the amount of disintegrants, thereby affecting dissolution further.

[0005] In this regards, WO 08 / 8040151 describes a solid synthetic detergent comprising anionic surfactants, disintegrants and builders, in which at least one surfactant surrounding the particles comprising detergent ingredients acts as disintegrative component, and the disintegrants also include polyvinyl pyrrolidone, succinic acid or citric acid, and sodium bicarbonate.

[0006] WO 04 / 000261 describes a solid cosmetic preparation is obtained by press-moulding at a pressure of 0.5 to 10 kgf / cm 2< of a water-soluble raw cosmetic-preparation material comprising a press-mouldable wet powder which comprises a blowing ingredient comprising an organic acid, e.g., citric acid, and a carbonate, anhydrous sodium sulphate, and a PEG having an average molecular weight of 500 to 3,700 fluidized with a solvent comprising, e.g., DPG and optionally contains a perfume ingredient or detergent ingredient.

[0007] US 2002 082187 describes an effervescent compound which includes a solvent and an effervescent system. The solvent may include a glycol ether, for example, but not limited to, 2-butoxyethanol. The effervescent system used in the effervescent compound may be, for example, but is not limited to, expanded sodium perborate or a mixture of sodium bicarbonate, sodium carbonate, and an acid. WO 01 / 85892 describes highly concentrated fabric softening compositions or articles containing such compositions. It primarily discloses highly concentrated liquid fabric softening compositions, but also an effervescent tablet comprising medium amount of softening actives (15 wt%), hexylene glycol and corn starch among other ingredients.

[0008] Although various tablet compositions are disclosed, there remains a need for an improved tablet containing significantly high amount of detersive active, which is hard, yet dissolves fast in contact with water.

[0009] The present inventors while working on this have surprisingly found that a disintegrant mix comprising an organic solvent and select water-insoluble compound, and 50 to 90 % by weight surfactant provide a tablet, which is hard enough to resist breakage on transportation / storage yet dissolves fast in water.Summary of the Invention

[0010] In a first aspect, the present invention provides a unit dose tablet comprising: a) 50 to 90 %wt. surfactant; and b) a disintegrant mix comprising: an organic solvent; and a water-insoluble compound selected from microcrystalline cellulose, sodium starch glycolate, polyvinyl pyrrolidone, starch, calcium silicate, magnesium stearate and combinations thereof.

[0011] In a second aspect, the present invention provides a process for providing a liquid cleaning composition comprising the steps of providing water in a container, adding a tablet according to the first aspect into the water, wherein the ratio of tablet to water is in the range from 1:10 to 1:1000 by weight.

[0012] These and other aspects, features and advantages will become apparent to those of ordinary skill in the art from reading of the following detailed description. 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. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and / or use are to be understood as modified by the word "about". 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.Detailed Description of the Invention

[0013] By "unit dose" as used herein, implies an amount of a composition suitable for single time use.

[0014] By "effervescent system" as used herein refers to a compound or combination of two or more compounds which produces effervescence in contact with water.

[0015] By "Disintegrant" as used herein refers to ingredients present in a tablet to accelerate dissolution of the tablet in water. In contact with water such ingredients break or disintegrate the tablet into smaller fragments thereby accelerating the dissolution.

[0016] According to the present invention there is provided a unit dose tablet comprising a 50 to 90% by weight surfactant and a disintegrant mix comprising an organic solvent and select water-insoluble compound.

[0017] The tablet according to the present invention comprises a surfactant for providing detersive benefit. The amount of the surfactant is in the range 50 to 90% wt. of the tablet. Preferably higher the amount of surfactant is better the cleaning performance of the tablet. More preferably the amount of surfactant is in the range 55 to 90% wt., even more preferably 60 to 85% wt., most preferably 65 to 80% wt. of the tablet.Surfactant

[0018] Preferably the surfactant is selected from anionic surfactant, non-ionic surfactant and combinations thereof.

[0019] Preferably the tablet comprises anionic surfactant. Preferably the anionic surfactant is selected from alkyl sulphate, alkyl ether sulphate, linear alkyl benzene sulphonate and combinations thereof.

[0020] Anionic surfactant suitable for the present invention includes salts of organic sulphates and sulphonates having alkyl radicals containing from about 8 to about 22 carbon atoms, the term "alkyl" being used to include the alkyl portion of higher acyl radicals. Examples of such materials include alkyl sulphates, alkyl ether sulphates, alkaryl sulfonates, alpha-olefin sulfonates and mixtures thereof. The alkyl radicals preferably contain from 10 to 18 carbon atoms and may be unsaturated. The alkyl ether sulphates may contain from one to ten ethylene oxide or propylene oxide units per molecule, and preferably contain one to three ethylene oxide units per molecule.

[0021] The suitable anionic surfactant includes alkylbenzene sulfonates. Preferably in an embodiment suitable for dishwash comprises linear alkylbenzene sulfonates (LAS) with an alkyl chain length of from 10 to 18 carbon atoms. Commercial LAS is a mixture of closely related isomers and homologues alkyl chain homologues, each containing an aromatic ring sulfonated at the "para" position and attached to a linear alkyl chain at any position except the terminal carbons. The linear alkyl chain typically has a chain length of from 11 to 15 carbon atoms, with the predominant materials having a chain length of about C12. Each alkyl chain homologue consists of a mixture of all the possible sulpho-phenyl isomers except for the 1-phenyl isomer. LAS is normally formulated into compositions in acid (i.e., HLAS) form and then at least partially neutralized in-situ. The counterion for anionic surfactants is generally an alkali metal such as sodium or potassium; or an ammoniacal counterion such as monoethanolamine, (MEA) diethanolamine (DEA) or triethanolamine (TEA), monoisopropanolamine (MIPA). Mixtures of such counterions may also be employed. Sodium and potassium are preferred.

[0022] Preferably the suitable anionic surfactant includes alkyl sulphate surfactant (PAS), such as non-ethoxylated primary and secondary alkyl sulphates with an alkyl chain length of from 10 to 18. Preferably the tablet suitable for laundry application may contain alkyl ether sulphates having a straight or branched chain alkyl group having 10 to 18, more preferably 12 to 14 carbon atoms and containing an average of 1 to 3 ethylene oxide (EO) units per molecule. A preferred example is sodium lauryl ether sulphate (SLES) in which the predominantly C12 lauryl alkyl group has been ethoxylated with an average of 3EO units per molecule. The alkyl ether sulphates may be used alone or in combination with any other anionic surfactant.

[0023] Preferably the anionic surfactant is selected from primary alkyl sulphate, alkyl benzene sulphonates, alkyl ether sulphates and mixture thereof.

[0024] Preferably the amount of the anionic surfactant is in the range up to 100% by weight of the total amount of the surfactant. More preferably, the amount of anionic surfactant is in the range 10 to 90%, even more preferably 20 to 80%, most preferably 30 to 70% by weight of the total amount of surfactant.

[0025] The tablet according to the present invention may comprise a non-ionic surfactant.

[0026] Suitable non-ionic surfactants include water soluble aliphatic ethoxylated non-ionic surfactants including the primary aliphatic alcohol ethoxylates and secondary aliphatic alcohol ethoxylates. This includes the condensation products of a higher alcohol (e.g., an alkanol containing about 8 to 16 carbon atoms in a straight or branched chain configuration) condensed with about 4 to 20 moles of ethylene oxide, for example, lauryl or myristyl alcohol condensed with about 10 moles of ethylene oxide (EO), tridecanol condensed with about 6 to 15 moles of EO, myristyl alcohol condensed with about 10 moles of EO per mole of myristyl alcohol, the condensation product of EO with a cut of coconut fatty alcohol containing a mixture of fatty alcohols with alkyl chains varying from 10 to about 14 carbon atoms in length and wherein the condensate contains either about 6 moles of EO per mole of total alcohol or about 9 moles of EO per mole of alcohol and tallow alcohol ethoxylates containing 6 EO to 11 EO per mole of alcohol.

[0027] Examples of the foregoing non-ionic surfactants include, but are not limited to, the Neodol (trade mark, ex Shell), which are higher aliphatic, primary alcohol containing about 9 to 15 carbon atoms, such as C9 to C11 alkanol condensed with 4 to 10 moles of ethylene oxide (Neodol 91-8 or Neodol 91-5), C12 to C13 alkanol condensed with 6.5 moles ethylene oxide (Neodol 23-6.5), C12 to C15 alkanol condensed with 12 moles ethylene oxide (Neodol 25-12), C14 to C15 alkanol condensed with 13 moles ethylene oxide (Neodol 45-13), and the like. Such ethoxamers have an HLB (hydrophobic lipophilic balance) value of about 8 to 15 and give good O / W emulsification, whereas ethoxamers with HLB values below 7 contain less than 4 ethylene oxide groups and tend to be poor emulsifiers and poor detergents.

[0028] Another group of suitable non-ionic surfactants are alkyl polyglycosides(APG) which are sugar derivatives of fatty alcohol. Example of such surfactants are decyl glucoside, lauryl glucoside, myristyl glucoside.

[0029] The tablet may further comprise a cationic or an amphoteric surfactant in addition to the anionic and the non-ionic surfactant.

[0030] Suitable cationic surfactants are quaternary ammonium salts. According to the present invention quaternary ammonium salts are characterised in that the ammonium salt has the general formula: R1R2R3R4N+X- wherein R1 is a C12 to C18 alkyl group, each of R2, R3 and R4 independently is a C1 to C3 alkyl group and X is an inorganic anion. R1 is preferably a C14 to C16 straight chain alkyl group, more preferably C16. R2, R3 and R4 are preferably methyl groups. The inorganic anion (X-) is preferably chosen from halide, sulphate, bisulphate or hydroxide.

[0031] For the purposes of this invention, a quaternary ammonium hydroxide is considered to be a quaternary ammonium salt. More preferably the anion is a halide ion or sulphate, most preferably a chloride or sulphate. Cetyl-trimethylammonium chloride is a specific example of a suitable compound and commercially abundantly available.

[0032] Another type of quaternary ammonium cationic surfactant is the class of benzalkonium halides, also known as alkyldimethylbenzylammonium halides. The most common type being benzalkonium chloride, also known as alkyldimethylbenzylammonium chloride (or ADBAC). Suitable amphoteric surfactants include derivatives of aliphatic quaternary ammonium, sulphonium and phosphonium compounds having an aliphatic radical of from 8 to 18 carbon atoms and an aliphatic radical substituted by an anionic water-solubilising group, for instance 3-(N-N-dimethyl-N-hexadecylammonium) propane-1 -sulphonate betaine, 3-(dodecylmethyl sulphonium) propane-1 -sulphonate betaine and 3- (cetylmethylphosphonium) ethane sulphonate betaine.

[0033] Examples of amphoteric surfactants suitable for the present invention include cocoamidopropyl betaine (CAPB), cocoamidopropyl amine oxide (CAPAO), cocodiethanol amide (CDEA) and cocomonoethanol amide (CMEA).Disintegrant mix

[0034] The tablet comprises a disintegrant mix. The disintegrant mix comprises an organic solvent and a water-insoluble compound selected from microcrystalline cellulose, sodium starch glycolate, polyvinyl pyrrolidone, starch, calcium silicate, magnesium stearate and combinations thereof. It is observed that said combination in the disintegrant mix aids in quicker dissolution of the tablet.

[0035] Preferably the tablet comprises less than 30 % by weight of the disintegrant mix. More preferably the tablet comprises 1 to 30 % by weight, even more preferably 3 to 25 % by weight, even more preferably 4 to 20% by weight and most preferably 5 to 15% by weight of the disintegrant mix.Organic Solvent

[0036] The disintegrant mix comprises an organic solvent. It is observed that the presence of organic solvent along with select water-insoluble compound accelerates dissolution of the tablet in contact with water.

[0037] Preferably the organic solvent has a Hansen Solubility Parameter P in the range 4 to 12; H in the range 6 to 25; and D in the range 12 to 18. It is preferred that the ratio of P to D is at least 0.3, P to H at least 0.3 and D to H at most 1.4.

[0038] Details on Hansen solubility parameters can be found in the textbooks, such as, "Hansen Solubility Parameters- A User's Handbook", by Dr. Charles Hansen, CRC press, Boca Raton, 1999,2007. There are software and tools commercially available for calculating HSP parameters. One of such employed here is "HSPiP" 5th edition version 5.3.04.

[0039] Preferably the organic solvent is selected from glycol ether, diol, and combinations thereof. Suitable organic solvents include mono propylene glycol (P=9.4; D=16.8; H=23.3), PnP glycol ether (P=4.9; D=15.3; H=11.2). Most preferred organic solvent is mono propylene glycol.

[0040] Preferably the amount of organic solvent is in the range from 1 to 30 % by weight of the total disintegrant mix present in the tablet. More preferably the amount of the organic solvent is in the range 1 to 25 % by weight, even more preferably 1 to 20 % by weight and even more preferably 1 to 15% by weight and most preferably 1 to 10% by weight of the total disintegrant mix present in the tablet.

[0041] The organic solvent may present at an amount 0.1 to 9% by weight, more preferably 0.2 to 8% by weight, even more preferably 0.5 to 7% by weight and most preferably 0.8 to 5% by weight of the tablet.

[0042] Preferably the solvent has vapour pressure more than 0.1 mm Hg at 20 °C, which implies that the organic solvent refers herein does not include perfumes or fragrances.Water-insoluble compound

[0043] The disintegrant mix comprises a water-insoluble compound selected from microcrystalline cellulose, sodium starch glycolate, polyvinyl pyrrolidone, starch, calcium silicate, magnesium stearate and combinations thereof. Polyvinyl pyrrolidone includes crosslinked polyvinyl pyrrolidone.

[0044] Preferably, the water-insoluble compound is present in an amount 70 to 99% by weight of the total amount of the disintegrant mix. Preferably the water-insoluble compound is present in an amount 75 to 95% by weight, more preferably 80 to 95 % and most preferably 80 to 95% by weight of the total amount of the disintegrant mix.

[0045] The water-insoluble compound may present at an amount 0.7 to 29.7% by weight, more preferably 1 to 27% by weight, even more preferably 2 to 25% by weight and most preferably 3 to 20% by weight of the tablet.

[0046] Most preferably the water-insoluble compound in the disintegrant mix is microcrystalline cellulose and / or polyvinyl pyrrolidone.Water soluble salt

[0047] Preferably, the composition comprises a water-soluble salt. Without bound by the theory, it is believed that the water-soluble salt acts as dissolving aid in the tablet. By the term 'dissolving aid' herein refers to ingredients which dissolve quickly in contact with water thereby accelerate dissolution of a tablet.

[0048] Preferably, the salt has a solubility of in the range 0.5 g / 100 mL to 75 g / 100 mL at 25 °C, more preferably in the range 1 g / 100 mL to 70 gm / 100 mL, even more preferably in the range 5 g / 100 mL to 65 g / 100 mL and most preferably in the range 10 g / 100 mL to 60 g / 100 mL at 25 °C.

[0049] The composition preferably comprises a water-soluble salt that is selected from anhydrous forms or hydrates of salts of mono or divalent alkali metals, preferably anhydrous forms or hydrates of salts of mono alkali metals, more preferably wherein the mono alkali metals is sodium or potassium.

[0050] Preferably, the anhydrous forms or hydrates of salts of mono alkali metals is selected from the group consisting of sodium chloride, sodium sulphate, sodium hydrogen carbonate, potassium chloride, potassium sulphate, potassium hydrogen carbonate and mixtures thereof.

[0051] The tablet preferably comprises 0.1 to 20% by weight, more preferably 1 to 15% by weight and most preferably 2 to 10% by weight water-soluble salt.Effervescent system

[0052] Preferably the tablet according to the present invention further comprises an effervescent system. The effervescent system expediate the dissolution of the tablet.

[0053] Preferably the effervescent system comprises an organic acid and a carbonate or bicarbonate salt. Preferably the carbonate or bicarbonate salt is selected from sodium carbonate, potassium carbonate, calcium carbonate, sodium bicarbonate, potassium bicarbonate, calcium carbonate, calcium bicarbonate and magnesium carbonate as well as mixtures thereof. Preferably the organic acid is selected from citric acid, tartaric acid, fumaric acid, malic acid, adipic acid, succinic acid, and mixture thereof.

[0054] The effervescent system may also comprise a salt of an organic acid, such as sodium or potassium salt of an organic acid.

[0055] It is also possible that the effervescent system may comprises a salt of inorganic acid. Preferably, the salt of inorganic acid is an acid salt, which formed by incomplete neutralisation of a bivalent or trivalent acid. Examples of such salts include sodium bisulphate, potassium bisulphate, mono-sodium phosphate etc.

[0056] Preferably the amount of the effervescent system is in the range from 1 to 30% by weight of the tablet. More preferably the amount of the effervescent system is in the range from 1.5 to 25% by weight and even more preferably 2 to 20 % by weight, most preferably 2.5 to 15 % by weight of the tablet.Filler

[0057] Typically, tablets comprise high amounts of filler, however, we have found that this level may be significantly reduced in the present invention by considering the disintegration mix. This is also advantageous in that less filler allows to increase the amount of detersive actives.

[0058] Preferably, the tablet comprises less than 10% by weight, more preferably less than 7% by weight, even more preferably less than 5% by weight and most preferably less than 2 % by weight filler.

[0059] Fillers suitable for use in the tablet include calcium carbonate, zeolite, clays such as bentonite, dolomite and combinations thereof.Fracture Stress

[0060] It is desired the tablet has certain hardness to resist breakage during handling / transportation. One of the ways to assess the hardness of the tablet is diametrical fracture stress (DFS). The tablet preferably has a diametral fracture stress (DFS) ratio of DFS air / DFS water of at least 6, preferably at least 7, preferably at least 8 more preferably at least 9.

[0061] More preferably, the tablet has a diametral fracture stress (DFS) ratio of DFS air / DFS water in the range of 6 to 50, preferably 7 to 45.

[0062] The DFS air / DFS water ratio can be measured using techniques known to the skilled person. The DFS can be measured using a texture analyser, for example a CT3 Brookfield Texture Analyser. For examples, the DFS air / DFS water can be measured using a TA instrument, model TA-XT2i and the Texture Experte software (Texture Technologies Corp., Scarsdale, NY, USA / - Stable Micro Systems, Surrey, England, UK). The instrument is calibrated with a 5 kg load cell and fitted with a stainless steel flat-bottomed cylindrical probe with 1 cm2 surface area (Kobe probe). The methodology consists in positioning the tablet to the flat surface of the probe. The probe moves until a trigger force is detected at which point the TA is set to maintain a predetermined nominal force for a given time (60 sec). As the tablet starts disintegrating, the TA measures the penetration distance as the tablet is compressed while submerged in the medium (water). A constant temperature of the medium of 18°C is maintained during the tests by means of a thermos stated double wall cell and a heating bath / circulator (Haake, Karlsruhe, Germany).Application

[0063] The tablet according to the present invention may be formulated for laundering. The term "laundering" herein refers to treating or washing fabrics. The tablet may be used directly for laundering, wherein a consumer drops the tablet in a bucket of water forming a wash liquor and soak their laundry load in the wash liquor and subsequently wash it. The tablet may be used for machine wash also, wherein consumer dose one of such tablets in a washing machine directly and wash their load.

[0064] It may also be possible to formulate the tablet for providing a liquid detergent. The consumer may prepare a liquid detergent by dissolving the tablet in a secondary container and store it for multiple use.

[0065] Preferably, in laundry context, the anionic surfactant in the tablet is selected from alkyl benzene sulphonates, alkyl ether sulphates, and mixture thereof. The tablet may further comprise other ingredients such as, builders, sequestrants, soil release polymers, perfume, enzyme and preservative.

[0066] The tablet according to the present invention may be formulated for hard surface cleaning. Hard surface cleaning compositions are generally used for cleaning surfaces such as, kitchen utensils, dishes, kitchen platform, tabletop etc. One of such examples is a tablet for dishwashing.

[0067] In dishwashing context, preferably the anionic surfactant in the tablet is selected from primary alkyl sulphate, alkyl benzene sulphonates and mixture thereof.

[0068] The tablet may be used in machine dishwashing, wherein a consumer dose the tablet in dishwashing machine. Moreover, it is preferable not to have excessive foam. Therefore, such tablets contain an antifoaming agent. Preferably the tablets suitable for dishwashing further comprises a solvent for providing degreasing benefit.Process of making tablet

[0069] Preferably, tablets are prepared following conventional tablet making process. In the process a homogenised dry powder is prepared by mixing the ingredients in specified ratio. Subsequently, the powder is filled in a die-block and compressed to form the tablet. A rotary press or a hydraulic press maybe employed to compress the powder to tablet.

[0070] Preferably the pressure applied during the compression is in the range 1 to 100 kg-f / cm 2< , more preferably 2.5 to 75 kg-f / cm 2< , even more preferably 5 to 50 kg-f / cm 2< , and most preferably 7.5 to 30 kg-f / cm 2< .

[0071] There is provided a method for providing a liquid cleaning comprising the steps of providing water in a container, adding a tablet according to the present invention, wherein the ratio of the tablet to water is in the range of 1:10 to 1:1000 by weight. More preferably the ratio of the tablet to water is in the range 1:15 to 1: 700 by weight, even more preferably 1:20 to 1:500 and most preferably 1:25 to 1:300 by weight.Examples

[0072] Dry mix compositions were prepared according to the recipes provided in table 1. In subsequent step, 8 gm of each dry mix composition was taken in die-block and compressed by applying a pressure of 10 kg-f / cm 2< , thereby forming the tablet. Table 1Material (% w / w)Ex-1Ex-2Ex-AEx-BPrimary Alkyl Sulphate76.876.876.876.8Mono propylene glycol1.7--1.7Di-propylene glycol butyl ether-1.7--Microcrystalline cellulose4.34.35.1-Crosslinked polyvinyl pyrrolidone4.34.35.1-Sodium Bicarbonate4.34.34.38.5Citric Acid4.34.34.38.5Perfume4.34.34.34.3

[0073] Ex-1 and 2 are according to the invention containing an organic solvent and select water-insoluble compounds. Whereas Ex-A and B are comparatives, contain either the organic solvent or the select water-insoluble compounds.Evaluation of the tablets

[0074] For evaluating the performance of the tablets, each tablet was added in 250 mL water and allowed to dissolve. The time of dissolution of each tablet was noted using a stopwatch. Table 2Ex-1Ex-2Ex-AEx-BDissolution time< 1 minute< 1 minute>5 minutes>5 minutes

[0075] From the above table, it is evident that Ex-1 and 2 dissolve in less than a minute, that is significantly quicker than Ex- A, B which take more than five minutes to dissolve.

Claims

1. A unit dose tablet comprising: a) 50 to 90% by weight surfactant; and b) a disintegrant mix comprising: - an organic solvent; and - a water-insoluble compound selected from microcrystalline cellulose, sodium starch glycolate, polyvinyl pyrrolidone, starch, calcium silicate, magnesium stearate and combinations thereof.

2. A tablet as claimed in claim 1 wherein the surfactant is selected from anionic surfactant, non-ionic surfactant, and combinations thereof.

3. A tablet as claimed in claim 2 wherein the anionic surfactant is selected from alkyl sulphate, alkyl ether sulphate, linear alkyl benzene sulphonate and combinations thereof.

4. A tablet as claimed in any one of claims 1 to 3 wherein the tablet comprises less than 30% by weight of the disintegrant mix.

5. A tablet as claimed in any one of claims 1 to 4 wherein the amount of organic solvent is in the range 1 to 30% by weight of the total disintegrant mix present in the tablet.

6. A tablet as claimed in any one of claims 1 to 5 wherein the organic solvent has a Hansen Solubility Parameter P in the range 4 to 12; H in the range 6 to 25; and D in the range 12 to 18.

7. A tablet as claimed in any one of claims 1 to 6 wherein the organic solvent is selected from glycol ether, diol and combinations thereof.

8. A tablet as claimed in claim 7 wherein the organic solvent is mono-propylene glycol.

9. A tablet as claimed in any one of claims 1 to 8 wherein the water-insoluble compound is a combination of microcrystalline cellulose and polyvinyl pyrrolidone.

10. A tablet as claimed in any one of claims 1 to 10 further comprising a water-soluble inorganic salt.

11. A tablet as claimed in claim 10 wherein the inorganic salt is selected from sodium chloride, sodium sulphate, potassium chloride, potassium sulphate and combinations thereof.

12. A tablet as claimed in any one of claims 1 to 11 further comprising 1 to 30 % by weight effervescent system.

13. A tablet as claimed in claim 12 wherein the effervescent system comprises an organic acid and a carbonate or bicarbonate salt.

14. A process for providing a liquid cleaning composition comprising the steps of: i) providing water in a container; and ii) adding a tablet as claimed in any one of claims 1 to 13 into the water, wherein the ratio of the tablet to water is in the range from 1:10 to 1:1000 by weight.