WO2005061689A1

WO2005061689A1 - Solid cleaning composition for tabletting

Info

Publication number: WO2005061689A1
Application number: PCT/DK2004/000901
Authority: WO
Inventors: Anders Bjerre Kristensen; Jamshid Faramarzi; Thomas Krejberg
Original assignee: Danlind As
Priority date: 2003-12-22
Filing date: 2004-12-22
Publication date: 2005-07-07

Abstract

A solid effervescent based cleaning composition suitable for tabletting comprising a perfume component as well as a solubility intensifier and a clay is provided. A method for preparing the cleaning composition is also disclosed.

Description

SOLID CLEANING COMPOSITION FOR TABLETTING

Field of the invention

This invention relates to a solid cleaning composition suitable for tabletting and to tablets made from said composition and in particular tablets for use in cleaning hard surfaces such as e.g. windows and tiles.

Background of the invention

The cleaning of hard surfaces requires cleaning compositions having specific properties. Thus, such cleaning compositions should be effective in removing dirt and unwanted stains from surfaces and leaving surfaces with a shiny appearance without streaks. Furthermore, it is very important that the composition leaves a pleasant smell after use.

Cleaning compositions in tablet form have several advantages over liquid and powdered cleaning compositions. Thus, because they are compressed and contain no water they are economical for shipping and storage. Furthermore they facilitate an easy and correct dosing and do not cause problems with emission of dust during use.

In order to be user friendly, cleaning tablets should disintegrate fairly rapidly. A rapid disintegration may be achieved by chemical means, i.e. an effervescent system or by physical means, i.e. a disintegrant. Especially the use of an effervescent system in a tablet formulation is often a challenge, since such systems are very sensitive to moist which results in problems during tabletting and storage.

US patent No. 6,596,682 discloses a water soluble tablet comprising a cleaning composition. The cleaning composition contains an effervescent system consisting of an organic acid and sodium bicarbonate. Moreover, the tablet can contain two polymeric disintegrants which help disintegrate the tablet when water is added. The tablet also contains a solubilizing agent in the form of a crosslinked N-2-polyvinyl pyrrolidone having a particle size of 15 to 125 microns.

Said tablet has the following composition:

40-60% by weight of an alpha hydroxy aliphatic acid,

20-40% by weight of an alkali metal carbonate or bicarbonate,

2-8% by weight of a magnesium containing inorganic salt,

1 -9% by weight of a clay,

1-10% by weight of a sulfonated anionic surfactant,

0.1-4% by weight of an alkali metal salt of a polycarboxylic acid,

0.1-4% by weight of a solubilizing agent,

0.5-1 % by weight of an alkali metal salt or an alkaline earth metal of a fatty acid such as magnesium stearate, and

0.1-5% by weight of blue colored speckles of citric acid and/or green colored speckles of citric acid.

In a preferred embodiment the composition also comprises perfume. US patent No. 6,358,911 discloses detergent tablets containing a compressed and a non-compressed portion, where perfume is confined to the non-compressed part of the tablets.

In order to be commercially acceptable a cleaning composition for use in the cleaning of hard surfaces should not only be effective in removing dirt and unwanted stains, but should also, as mentioned above, leave a pleasant smell after use. The latter is of great psychological importance, because a pleasant smell gives an impression of impeccable cleanliness to the user. However, the use of perfumes in high concentrations may be a challenge to any formulator. Perfumes are complex blends of various organic compounds such as alcohols, aldehydes, ethers, aromatic compounds and varying amounts of essential oils (e.g. terpenes) where the essential oils also serve to dissolve the other components of the perfume. The organic compounds of a perfume may react with the other components of a cleaning composition thereby impairing the storage stability drastically. Moreover, due to the oily nature of the perfume, it may also affect the flowability of the powder during the tabletting process resulting in an uneven dosing of the tablet and lot of rejects. In the case of effervescent based cleaning compositions, it may also affect the ability of the effervescent systems to be active upon contact with water. Finally, a high content of perfume may also result in an unacceptable long disintegration time of the tablet as well as reduce the ability of the composition to foam upon contact with water.

An object of the present invention is to provide cleaning compositions for the production of tablets having a high concentration of perfume.

Another object of the invention is to provide cleaning tablets which maintain their strength and structure over long periods of storage and/or shipping and still have short disintegration times. A further object of the invention is to provide strongly perfumed cleaning compositions which can be tabletised at normal production speed around 500-1000 tablets per minute using standard rotary tabletting machines without production problems such as poor powder flowability and stickiness to die or piston surfaces.

Summary of the invention

Surprisingly, it has been found that it is possible to obtain cleaning compositions for the manufacture of cleaning tablets which have a high content of perfume and are able to maintain their strength and structure as well as a short disintegration time during storage.

Thus, the cleaning composition of the invention comprises

a) 0.1-25% by weight of at least one nonionic, anionic, cationic or amphotheric surfactant,

b) 15-60% by weight of an effervescent agent,

c) 20-60% by weight of an acid,

d) 1-25% by weight of a solubility intensifier,

e) 0.1 -20% by weight of a clay,

f) 1-10% by weight of a perfume,

g) up to 10% by weight of conventional additives. The invention is based on the discovery that by carefully adjusting the content of solubility intensifier and clay it is possible to manufacture effervescent based solid cleaning compositions with a high content of perfume and which are stable during storage and have short disintegration times, e.g. below 4 minutes in cold water.

Detailed description of the invention

The term "perfume" refers to fragrant or a mixture of substances including natural (i.e. obtained by extraction of flower, herb, blossom or plant), artificial

(i.e., mixture of natural oils or oil constituents) and synthetically produced odoriferous substances. Typically, perfumes are complex mixtures of various organic compounds such as alcohols, aldehydes, ethers, aromatic compounds and varying amounts of essential oils (e.g. terpenes) such as from 0% to 80%, usually from 10% to 70% by weight, the essential oils themselves being volatile odoriferous compounds and also serving to dissolve the other components of the perfume. In the present invention the precise composition of the perfume is of no particular consequence to cleaning performance so long as it meets the criteria of having a pleasant odour. The perfume should be cosmetically acceptable, i.e. non-toxic, hypoallergenic etc.

The term "solubility intensifier" refers to a solubilizing agent that enhances the disintegration of the tablet in the water when added to water. A solubility intensifier is characterized by having a high solubility in water, thereby facilitating a fast and homogeneous penetration of water into the tablet. This will ensure optimum conditions for the effervescent system and thereby provide for the quickest possible disintegration time.

The term "disintegration time" refers to the time it takes the tablet to disintegrate in a standard test system: The disintegration time is determined by placing tablets in separate baskets made from a stainless steel net having a mesh size of approximately 5 mm and placing said baskets in beakers containing 1 I of tap water of water hardness 180-250 ppm CaCO3 having a temperature of 20 °C.

The time it takes for the tablets to disintegrate without stirring and to leave the basket determines the disintegration time.

The term "tablet strength" refers to strength of the tablet when an external force is applied onto the tablet in a standard test system:

The tablet strength is determined by using a Holland tablet tester CT5. The tablet is placed on a plane surface and under a stainless steel piston having a diameter of 8 mm. The piston is then caused to move downwardly and into the surface of the tablet at a speed of 50 mm/min. The force exerted on the tablet by the piston is determined by a strain gauge and the maximum force detected during the penetration defines the tablet strength.

The surfactants of a cleaning composition are active in removing dirt and grease. Examples of suitable surfactants according to the invention are liquid, powdered, needle shaped or granular detergents having suitable cleaning properties and being capable of generating a foam during or after the disintegration of the tablets in water without unduly impairing the disintegration process.

As mentioned above the surfactants may be nonionic, anionic, cationic or amphoteric. The surfactants may be used alone or in combination. Non limiting examples of suitable surfactants are aliphatic ethoxylated/ propoxylated non-ionic surfactants, non-ionic surfactants of the alkyl- polyglucoside type, anionic surfactants of the linear alkylbenzene sulphonate type (LAS) and of the fatty alcohol sulphate type (FAS). Co-granulates of suitable surfactants and builder/binder components are also applicable to use as surfactants. An example of an amphoteric surfactant is Ampholak® X07- SD80 from Akzo Nobel in Sweden.

Benzalconium chloride BTC824P100 powder from Stepan in France is an example of a cationic surfactant. Particularly preferred are anionic surfactants of granular form such as Sulfopon® 1216 G, a C12-C16 fatty alcohol sulphate, from Cognis in Germany.

As mentioned above the surfactants are used in a concentration of 0.1-25% by weight. Preferably the concentration of surfactant is 1-15% by weight, more preferably 2-10% by weight.

A part of the surfactant used may be added in the form of a foam booster.

Due to the high content of perfume, the foam level of the cleaning composition in use is significantly reduced because of foam suppressing alcohols, ethers and different organic solvents in the perfume. Foam boosters can be many different types of ingredients which stabilize the foam. An example is a coconut fatty acid diethanolamide such as Ufanon KDS from Unger. A preferred foam booster is an alkyl sulfo acetate in the form of a coarse granulate or in small flakes such as Lathanol® LAL from Stepan in France. The foam booster preferably constitutes from 0.1-5% by weight of the cleaning composition, more preferable from 0.5-2% by weight of the cleaning composition.

As used herein the term "effervescent agent" means a compound or composition which in the presence of water reacts with the acid compound of the cleaning composition so as to generate a gas, e.g. carbon dioxide. Examples of suitable effervescent agents are percarbonates, bicarbonates, carbonates, bicarbonates, co-granulates of silicates and sodium carbonate like Nabion® 15 from Rhone Poulenc. Preferred effervescent agents are alkali metal bicarbonates or carbonates such as sodium and potassium carbonate and/or sodium and potassium bicarbonate. The most preferred alkali metal carbonate is sodium carbonate.

The effervescent agent is preferably present in an amount of from 25-45% by weight.

As mentioned above the cleaning composition comprises an acid which reacts with the effervescent agent in the formulation and forms a gas, e.g. carbon dioxide. This is the primary disintegration system of the composition. Suitable examples of acids are organic acids such as carboxylic acids and/or inorganic acids such as sulphamic acid. Preferred acids are organic acids such as citric acid, malic acid and adipic acid. The most preferred organic acid is anhydrous citric acid with an average grain size of 300 micron.

The acid preferably constitutes from 30 to 50% by weight of the composition.

The ratio of effervescent agent to acid in the composition may be varied in order to obtain a higher or lower pH of the composition in use. A low pH of the cleaning composition is preferred for cleaning ceramics and porcelain surfaces such as toilets bowls and cisterns. A pH of 6-8 is preferred for cleaning hard surfaces such as windows.

The sodium carbonate used in the compositions according to the present invention can be either a light density sodium carbonate (density 400-580 g/l), a dense density sodium carbonate (density 10OOg/l - 1100 g/l), or mixtures of light density sodium carbonate and dense density sodium carbonate in a weight ratio of 5:1 to 1 :5. Due to the presence of a solubility intensifier, which primarily dissolves quickly in water, a rapid transport of water throughout the entire tablet is facilitated. However a high solubility in cold water is not the only parameter which can promote a rapid transport of water throughout the entire tablet for shortest possible dissolution time. Secondly also the actual grain size of the solubility intensifier and the physical structure of the individual crystals are affecting the ability of the solubility intensifier to maximize the degree of water transport throughout the tablet interior.

Suitable ingredients are characterized by having a solubility in cold water higher than 10 g pr. 100 ml water at 20°C or more preferable higher than 50 g pr. 100 ml water at 20°C and even more preferable higher than 75 g/100 ml. Non limiting examples are sodium gluconate, sodium citrate, sodium acetate, urea and sorbitol. The preferred solubility intensifier is sodium acetate.

Examples of solubility levels for different ingredients are shown in the table below:

Table 1

The solubility intensifier preferably constitutes 2-20% by weight, and more preferred 5-15% by weight of the composition.

The clay which as mentioned above is present in an amount of from 0.1 to 20% by weight of the cleaning composition exerts a stabilising effect on the cleaning composition and reduces the disintegration time after long term storage at the warehouse, in the supermarket or with the consumer. Suitable clays are both naturally occurring and synthetic colloid-forming clays.

Suitable clays can be smectite clays including montmorillonite (bentonite), hecto te, saponite and the like. Available bentonite clays are the Laundrosil® types from Sud-Chemie AG in Germany or Detercal® / Detersoft® types from Laviosa Chimica Mineraria S.p.A. in Italy. Attapulgite clays include the materials commercially available under the tradename Attagel, e.g. Attagel 40, Attagel 50 and Attagel 150 from Engelhard Minerals and Chemicals Corporartion in USA. Mixtures of smectite and attapulgite types in weight ratios of 4:1 to 1 :5 are also useful herein. Other types of clays are rectorite, hydrobiotite, corrensiten, allettite, tosudite, tarasovite, allevardite, Japanese bentonite, Awazu acid clay, kaolinite-smectite clinchore, chamosite, nimite, thuringite, sudoite and cookeite. Clays of the laponite type are synthetic layered silicates. A preferred clay is Laponite RD. Laponite RD is a synthetic hydrous sodium lithium magnesium silicate consisting of colloid or macromolecular layered silicates in the form of amorphous disc-shaped crystals. Natural clay such as Bentonite and Hectohte have a similar disc- shaped crystal structure.

The clay preferably constitutes 0.5-15% by weight, more preferred 1-10% by weight of the composition.

It is known to the person skilled in the art that if a certain type of clay is replaced by another type of clay, it may be necessary to adjust the content of the solubility intensifier accordingly. It should also be appreciated that the clay as well as the solubility intensifier may be used alone or in combination with other clays and solubility intensifiers, respectively.

As mentioned above the perfume preferably constitutes 1-10% by weight of the composition, more preferred 2-9% by weight of the composition and most preferred 3-8% by weight of the composition.

In a preferred embodiment the perfume preferably constitutes 3.5-10% by weight of the composition, more preferred 4.0-10% by weight of the composition, even more preferred 4.5-10% by weight of the composition and most preferred 5.0-10% by weight of the composition.

The perfume used according to the invention may be incorporated directly into the powder, in a carrier associated form by using a highly absorbing substrate or in an encapsulated form. In a preferred embodiment the perfume is used directly in the cleaning composition.

The cleaning composition of the invention may contain up to 10% by weight of conventional cleaning composition additives to improve the general appearance, detergency and produceability. Non limiting examples are builders, bleaching agents and activators, complexing agents or sequestering agents, polymers, sodium silicates, disinfecting agents, corrosion inhibitors, surface protecting agents like waxes, dyes and/or coloured speckles, bulking agents/diluents (sodium chloride, sodium sulfate), lubricants, tabletting additives such as polyethylene glycol (molecular weight = 200-8000) or general tablet disintegrants such as starch, starch derivatives, alginates, cellulose derivatives, Microcrystalline celluloses (MCC), carboxymethyl cellulose (CMC), CMC-based polymers, pyrrolidone derivatives such as polyvinyl polypyrrolidones (PVPP) etc.

The cleaning composition may contain phosphates to support the cleaning performance. All types of phosphates can be used in powder or granular form. Non limiting examples of phosphate salts are builders such as the alkali metal thpolyphosphates, sodium, potassium and ammonium pyrophosphate, sodium and potassium orthophoshate, sodium polymeta/phosphate. Most preferred are sodium thpolyphosphates in granular form with an average grain size of 200-800 micron, even more preferred are sodium thpolyphosphates in granular form with an average grain size of 400-800 micron.

In a preferred embodiment the cleaning composition according to the invention is phosphate free.

In a preferred embodiment the composition comprises 40 % by weight of citric acid, 35 % by weight of sodium carbonate, 10 % by weight of sodium acetate, 5 % by weight of Laponite RD, 5 % by weight of anionic surfactant, 1 % by weight of non-ionic surfactant, 1 % by weight of tabletting additives and 3 % by weight of perfume.

By measuring for example the disintegration time of a tablet or the tablet strength it is possible to evaluate the general quality of a certain tablet composition. It is especially important that the disintegration time is not too long in use. The disintegration may be determined by placing tablets in separate baskets made from a stainless steel net having a mesh size of approximately 5 mm and placing said baskets in beakers containing 1 I of tap water of water hardness 180-250 ppm CaCO3 having a temperature of 20 °C. The time it takes for the tablets to disintegrate without stirring and to leave the basket determines the disintegration time.

In a preferred embodiment the tablets according to the present invention has a disintegration time of less than four minutes, more preferred the disintegration time of the tablets is less than three minutes.

The invention also relates to a method for preparing a cleaning composition according to the present invention comprising mixing the ingredients.

The mixing of the ingredients according to the present invention is carried out using conventional mixing equipment known to the person skilled in the art, e.g. Nauta mixer. Liquid ingredients may be added by spraying them on the other ingredients through a spraying device, e.g. a nozzle. The ingredients are added one by one and mixed until a homogenous mixture is obtained, preferably the ingredients are mixed for 1-3 minutes between each addition.

When the cleaning composition ingredients are mixed, it is an advantage to add the surfactants and the foam boosters in granular or powder form in the end of the mixing process in order to avoid the powder becoming sticky, which may eventually prolong the final disintegration time of the tablet. Moreover, it has surprisingly been found that it is also an advantage to add the clay in the end of the mixing process, but before adding the surfactants and the foam boosters, because it prevents the clay from adsorbing the dye particles ensuring a homogenous and much more intensive colouring of the tablet. In a preferred embodiment the clay is added before adding the surfactants and foam boosters, which are added in the end of the mixing step.

In a preferred embodiment of the method of the invention the solid cleaning composition is compressed into tablets. The tabletting of the powder according to the present invention is carried out using conventional tabletting equipment known to the person skilled in the art, e.g. a rotary tabletting press Model PH 423 from Korsch AG in Germany equipped with a conventional die and piston known to the person skilled in the art. An appropriate tablet weight is achieved by adjusting the filling depth of the die in a manner known to the person skilled in the art. In order to achieve suitable tablet strength the press force is also adjusted in a manner known to the person skilled in the art. The tabletting speed is around 100-2500 tablets per minute, preferably around 250-1500 tablets per minute, most preferably around 500-1000 tablets per minute.

In yet a preferred embodiment of the method of the invention the tablets are packed using conventional packing equipment known to the person skilled in the art. Preferably the packing is an in line packing process.

The invention also relates to tablets prepared from a cleaning composition as described above.

The tablets of the invention may have any suitable shape and size and may be composed of more than one layer, e.g. 2-3 or even more layers. The cleaning tablets according to the invention can be made either as a single layer tablet or a multi-layer tablet, in a preferred embodiment the tablet is a single layer tablet.

Cleaning tablets for all purpose cleaning are of rectangular form having the dimensions 26 x 36 mm with a tablet weight of from 6 to 20 g and a tablet height of 5 to 18 mm.

Preferably all purpose cleaning tablets are cylindrical and have a diameter of from 12 mm to 50 mm with a tablet weight of from 1 to 40 g and a tablet height of from 12 mm to 18 mm.

Particularly preferred is 0 20 mm for a tablet weight of 4 g and a tablet height of 11 mm or 0 22,5 mm for a tablet weight of 5 g and a tablet height of 9 mm.

Following the tabletting process, the tablets are packed into their final container. They may be packed together in any conceivable number directly into a suitable container, together in a bag using a vertical bag filler, packing a certain amount of tablets into a blister packing, preferably two tablets are packed together, more preferably each tablet is packed separately. Most preferred the tablets are flow packed separately in a suitable foil using hot or cold seal techniques. The packing material can be made from polypropylene (PP) with a metalised layer for improved barrier properties against moisture and oxygen.

The invention will be described in further detail with reference to the following examples. Examples

Example 1 : In line manufacture and packing of cleaning tablets: Mixing Mixing was performed in a 1200 L conical Nauta mixer, in which a rotating screw is moving around the periphery of the mixer driving the powder from the bottom and up toward the top. Liquids were pumped through a mono pump via 1/2 inch steel tubes ending inside the Nauta mixer, spraying directly the liquids unto the powder via a special nozzle.

STEP 1 :

The powdered dye was dissolved and thoroughly dispersed in the liquid polyethylene glycol (PEG).

STEP 2:

The dye solution was sprayed unto the organic acid during mixing and mixed further for 2-3 minutes.

STEP 3: Sodium carbonate, sodium acetate and clay were added and mixed for 2 - 3 minutes whereafter the liquid perfume was sprayed directly unto the ingredients and mixed further 1-2 minutes.

STEP 4: Surfactants in powder or granular form (including the foam booster surfactant) were added and the mixing was continued for another 1 - 2 minutes and the batch was then discarded into a stainless steel transport silo. Tabletting

The tabletting step was carried out on a standard rotary tabletting press Model PH 423 from Korsch AG in Germany. The transport silo was placed on top of the tabletting press allowing the powder to flow by gravity through the powder feeding tubes via the feed frame into the die of the press. The wanted tablet weight is achieved by adjusting the filling depth of the die. In order to achieve a suitable tablet strength the press force was adjusted to around 5-35 kN. The tabletting speed was around 500-1000 tablets pr. minute.

Packing

In line packing was carried out using a flow packer packing each tablet into polypropylene(PP)-foil at a speed of 500-1000 tablets per minute using a Carrera 2000 PC flow packer from llapac in Italy.

After flow packing the tablets were packed into boxes, packed into cartons and put unto a pallet for shipment to the customer.

Example 2: Stability testing of tablets containing 2.5%, 5.0% and 7.5% clay, 10% sodium acetate and 3% perfume (by weight)

A number of solid cleaning agents were prepared and compressed into tablets having the following dimensions: 0 = 18 mm, tablet weight = 4 gram and height = 13 mm.

The composition of these cleaning agents and the properties of the cleaning tablets are set forth in the following table.

All tablets were flow packed individually in PP cold seal foil and stored in climate cell at 35°C / 75% Relative Humidity (R.H.). As will appear from said table cleaning tablets containing both sodium acetate and a clay have essentially the same strength as tablets containing only one of these components, but significantly lower disintegration times of formulas 1 , 2, 3, 4, 5 and 6 compared with I, II and III.

TABLET CHARACTERISTICS AFTER STORAGE IN CLIMATE CELL AT 35°C / 75 % R.H. Table 2

The abbreviation "0 aq" refers to an anhydrous ingredient. Example 3: Stability testing of tablets containing varying amounts of clay, sodium acetate and perfume

All tablets were flow packed individually in PP cold seal foil and stored in climate cell at 35°C / 75% Relative Humidity (R.H.).

As will appear from said table cleaning tablets containing both sodium acetate and a clay have essentially the same strength as tablets containing only one of these components, but significantly lower disintegration times of formulas 7, 8, 9, 10, 11 and 12 compared with I, II and III.

TABLET CHARACTERISTICS AFTER STORAGE IN CLIMATE CELL AT 35°C / 75 % R.H. Table 3

*The abbreviation "0 aq" refers to an anhydrous ingredient n m = not measured Example 4: Stability testing of tablets containing varying amounts of sodium actetate while keeping the content of clay constant

As will appear from said table cleaning tablets containing both sodium acetate and a clay have essentially the same strength as tablets containing only one of these components, but significantly lower disintegration times of formulas 13, 14, 15, 16, 17, 18, 19, 20, 21 and 22 compared with IV, V, VI, VII and VIII (Table 4 and 5). Apparently an increasing amount of clay seems to stabilize the disintegration time.

TABLET CHARACTERISTICS AFTER STORAGE IN CLIMATE CELL AT 35°C / 75 % R.H. Table 4

exp. = expanded ^*The abbreviation "0 aq" refers to an anhydrous ingredient TABLET CHARACTERISTICS AFTER STORAGE IN CLIMATE CELL AT 35°C / 75 % R.H. Table 5

"The abbreviation "0 aq" refers to an anhydrous ingredient.

Claims

C l a i m s :

1. A solid cleaning composition suitable for tabletting comprising

a) 0.1-25% by weight of at least one nonionic, anionic, cationic or amphotheric surfactant

b) 15-60% by weight of an effervescent agent

c) 20-60% by weight of an acid

d) 1-25% by weight of a solubility intensifier

e) 0.1-20% by weight of a clay

f) 1-10% by weight of a perfume

g) up to 10% by weight of conventional additives

provided that the composition does not contain N-2-polyvinyl pyrrolidone.

2. A cleaning composition according to claim 1 comprising 1-15% by weight of at least one surfactant, more preferably 2-10% by weight.

3. A cleaning composition according to any one of claims 1 to 2 comprising 0.1-5% by weight of a foam booster, more preferably 0.5-2% by weight.

4. A cleaning composition according to any one of claims 1 to 3, comprising 25-45% by weight of an effervescent agent.

5. A cleaning composition according to any one of claims 1 to 4, comprising 30-50% by weight of acid.

6. A cleaning composition according to any one of claims 1 to 5, comprising 2-20% by weight of solubility intensifier, preferably 5-15% by weight.

7. A cleaning composition according to any one of claims 1 to 6, comprising 0.5-15% by weight of clay, more preferably 1-10% by weight.

8. A cleaning composition according to any one of claims 1 to 7 comprising 2- 9% by weight of perfume, more preferably 3-8% by weight.

9. A cleaning composition according to any one of claims 1 to 8, wherein the anionic surfactant is a C12-C16 fatty alcohol sulphate.

10. A cleaning composition according to any one of claims 3 to 9, wherein the foam booster is an alkyl sulfo acetate.

11. A cleaning composition according to any one of claims 1 to 10, wherein the effervescent agents are sodium and potassium carbonate and/or sodium and potassium bicarbonate, more preferably sodium carbonate.

12. A cleaning composition according to claim 11 , wherein the sodium carbonate has a density of 400-580 g/l.

13. A cleaning composition according to any one of claims 1 to 12, wherein the acid is citric acid, malic acid and adipic acid, more preferably citric acid.

14. A cleaning composition according to any one of claims 1 to 13, wherein the solubility intensifier is sodium acetate.

15. A cleaning composition according to any one of claims 1 to 14, wherein the clay is a hydrous sodium lithium magnesium silicate.

16. A cleaning composition according to any one of claims 1 to 15, which further comprises conventional detergent components or conventional tabletting additives selected from the group consisting of builders, bleaching agents and activators, complexing agents, polymers, sodium silicates, disinfecting agents, corrosion inhibitors, surface protecting agents like waxes, dyes and/or coloured speckles, bulking agents/diluents, lubricants, or general tablet disintegrants.

17. A method of preparing a cleaning composition comprising the step of mixing the components of the cleaning composition according to claim 1.

18. A method according to claims 17, wherein the clay is added before admixing the surfactants in the end of the mixing step.

19. A method of preparing a cleaning tablet, wherein the cleaning composition according to any one of claims 1-16 is tabletised using conventional tabletting machine.

20. A method of packing a cleaning tablet, wherein the tablet obtained according to claim 19 is packed using conventional packing equipment.

21. A cleaning composition tablet comprising a cleaning composition according to any one of claims 1 to 16.

22. A cleaning composition tablet according to claim 21 , wherein the tablet is a single layer tablet or a multi-layer tablet, more preferably a single layer tablet.

23. A cleaning composition tablet according to claims 21-22, wherein the tablet is of a rectangular form having the dimensions 26 x 36 mm with a tablet weight of from 6 to 20 g with a tablet height of 5 to 18 mm.

24. A cleaning composition tablet according to claims 21-22, wherein the tablet is of a cylindrical form having a diameter of from 12 to 50 mm with a tablet weight of from 1 to 40 gram and a tablet height of from 12 mm to 18 mm.

25. A cleaning composition tablet according to claim 24, wherein the tablet has a diameter of 20 mm for a tablet weight of 4 g and a tablet height of 11 mm.

26. A cleaning composition tablet according to claim 24, wherein the tablet has a diameter of 22.5 mm for a tablet weight of 5 g and a tablet height of 9 mm.

27. A cleaning composition tablet according to any one of claims 21-26, wherein the tablet is packed in a water-impermeable packing material.

28. A cleaning composition tablet according to claim 27, wherein the tablet is packed together with one or more tablets.

29. A cleaning composition tablet according to claim 27, wherein two tablets are packed together, more preferably each tablet is packed separately.

30. A cleaning composition tablet according to claims 27-29, wherein the packing material is polypropylene.

31. A cleaning composition tablet according to any one of claims 27-30, wherein the packing material has a metallic layer.