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Title:
POLYMERIC POWDERED COATING COMPOSITION FOR MAKING LIQUID FILLED POLYMERIC BEADS AND METHODS THEREOF
Document Type and Number:
WIPO Patent Application WO/2013/128253
Kind Code:
A1
Abstract:
A powdered polymeric coating composition for coating liquid filled beads or capsules comprising modified cellulose, alkali salts of alginate, natural gum, starch, metal oxide, wherein said modified cellulose, alkali salts of alginate, natural gum, starch, metal oxide are present in amounts of 5 to 20%, 60 to 85%, 2 to 12%, 2 to 10%, 0.5 to 5% w/w by weight of the powdered polymeric coating composition and are mixed in ratios ranging from 0.5:8:0.5:0.25:0.1 to 2:15:2:2:1, preferably 1:8:2:0.25:0.1 to 1:12:1 :1:0.2. Also provided are methods for coating and preparing coating liquid filled beads or capsules with the powdered polymeric coating composition.

Inventors:
BISWAS SAMARES CHANDRA (IN)
MUKHERJEE SOUMITRA (IN)
MURUGESAN KAVITHA (IN)
JOSHI KRISHNA (IN)
Application Number:
PCT/IB2012/056913
Publication Date:
September 06, 2013
Filing Date:
December 03, 2012
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
ITC LTD (IN)
International Classes:
B01J13/14; B01J13/22; C09D105/00
Domestic Patent References:
WO2003018186A12003-03-06
WO2009003724A12009-01-08
Foreign References:
KR20040053548A2004-06-24
US5093130A1992-03-03
US20110104218A12011-05-05
JPH0421513B21992-04-10
US5093130A1992-03-03
Attorney, Agent or Firm:
MAJUMDAR, Subhatosh et al. (5Harish Mukherjee Road,West Bengal, Kolkata 5, IN)
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Claims:
CLAIMS:

1. A powdered polymeric coating composition for coating liquid filled beads or capsules comprising modified cellulose, alkali salts of alginate, natural gum, starch, metal oxide wherein said modified cellulose, alkali salts of alginate, natural gum, starch, metal oxide are present in amounts 5 to 20%, 60 to 85%, 2 to 12%, 2 to 10%, 0.5 to 5% w/w by weight of the powdered polymeric coating composition and mixed in ratios ranging from 0.5:8:0.5:0.5:0.1 to 2:15:2:2:1 , preferably 1 :8:2:0.25:0.1 to 1 :12:1 :1 :0.2.

2. A powdered polymeric coating composition for coating liquid filled beads or capsules comprising modified cellulose, alkali salt of alginate, natural gum, starch, pectin, multivalent metal salts of long chain (C12-C18) fatty acids, metal oxide; said modified cellulose, alkali salt of alginate, natural gum, starch, pectin, multivalent metal salts of long chain (C12-C18) fatty acids, metal oxide being present in amounts of 4 to 10%, 50 to 80%, 5 to 16%, 2 to 8%, 1 to 15%, 0.25 to 6%, 0.5 to 5% w/w by weight of the powdered polymeric coating composition and mixed in ratios ranging from 0.5:8:0.5:0.25:0.5:0.2:0.1 to 2:15:2:2:2:2:1 most specifically 1 :8:2:0.25:1 :0.5:0.1 to 1 :12:1 :1 :2:1 :0.2.

3. The powdered polymeric coating composition as claimed in claim 1 wherein said composition preferably contains modified cellulose, alkali salt of alginate, natural gum , starch, metal oxide in a ratio of 1 : 10: 1 .5 : 1 : 0.2.

4. The powdered polymeric coating composition as claimed in claim 1 wherein said composition preferably contains modified cellulose, alkali salt of alginate, natural gum , starch, metal oxide in a ratio of 1 : 10: 1 : 0.5: 0.2.

5. The powdered polymeric coating composition as claimed in claim 2 wherein said composition preferably contains modified cellulose, alkali salt of alginate, natural gum , starch, pectin, metal salts of long chain (C12-C18) fatty acids, metal oxide in a ratio of 1 : 10:

1 .5 : 1 : 0.2 : 0.1 : 0.2.

6. The powdered polymeric coating composition as claimed in any of the preceding claims, wherein said alkali salt of alginate is selected from sodium alginate and potassium alginate.

7. The powdered polymeric coating composition as claimed in any of the preceding claims, wherein said modified cellulose is hydrophobically modified cellulose derivatives.

8. The powdered polymeric coating composition as claimed in any of the preceding claims, wherein said starch is selected from native starch, gelatinised starches and pregelatinized starches.

9. The powdered polymeric coating composition as claimed in any of the preceding claims, wherein said natural gums is selected from acacia gum, arabic gum and xantham gum.

10. The powdered polymeric coating composition as claimed in any of the preceding claims, wherein said inorganic metal oxide is selected from zinc oxide, titanium dioxide, ferric oxide, talc and metal salts of silicates.

11. The powdered polymeric coating composition as claimed in any of claims 2 and 5, wherein said pectins is selected from native pectins and modified pectins.

12. The powdered polymeric coating composition as claimed in any of claims 2 and 5, wherein said multivalent metal salts of long chain (C12-C18) fatty acids is selected from magnesium stearate and zinc stearate.

13. A process for coating of liquid filled capsules/beads comprising steps of :

(i) preparing a powdered blend of polymers selected from modified cellulose, alkali salts of alginate, natural gum, starch, metal oxide,

(ii) coating liquid filled capsules/beads with powdered blend obtained in step i) by gently shaking the beads in the powdered polymer blends,

(iii) drying the coated beads at 30 to 502C for 30 mins to obtain coated liquid filled beads or capsules;

wherein said modified cellulose, alkali salts of alginate, natural gum, starch, metal oxide are present in amounts of 5 to 20%, 60 to 85%, 2 to 12%, 2 to 10%, 0.5 to 5% w/w by weight of the powdered blend of polymers and are mixed in ratios ranging from 0.5:8:0.5:0.25:0.1 to 2:15:2:2:1 , preferably 1 :8:2:0.25:0.1 to 1 :12:1 Λ :0.2.

14. The process for coating of liquid filled capsules/beads as claimed in claim 13, wherein said blend of polymers optionally comprises pectin, multivalent metal salts of long chain (C12- C18) fatty acids such that said modified cellulose, alkali salt of alginate, natural gum , starch, pectin, multivalent metal salts of long chain (C12-C18) fatty acids, metal oxide are present in amounts of 4 to 10%, 50 to 80%, 5 to 16%, 2 to 8%, 1 to 15%, 0.25 to 6%, 0.5 to 5% w/w by weight of the powdered blend of polymers and are mixed in ratios ranging from 0.5:8:0.5:0.25:0.5:0.2:0.1 to 2:15:2:2:2:2:1 most specifically 1 :8:2:0.25:1 :0.5:0.1 to 1 :12:1 :1 :2:1 :0.2.

15. A process for preparation of coated liquid filled beads or capsules comprising steps of : i) preparing a system comprising of a solution or dispersion or emulsion of a liquid active ingredient and/or of a solid active ingredient in an aqueous solution of an alkali metal salt of a polysaccharide acid; an emulsifier and optionally, other water soluble or water dispersible substances,

ii) forming discrete droplets of said system of step i); iii) converting said droplets to water-insoluble gel beads by introducing said droplets in an aqueous or alcoholic solution containing multivalent cations to form a particulate suspension,

iv) isolating said gel beads from said suspension,

v) preparing a powdered blend of polymers selected from modified cellulose, alkali salts of alginate, natural gum, starch, metal oxide,

vi) coating the soft beads of step (iv) with powdered polymer blend obtained in step (v) by gently shaking the beads in the powdered polymer blend,

vii) drying the coated beads at 30-502C for 30mins to obtain said coated liquid filled beads or capsules;

wherein said modified cellulose, alkali salts of alginate, natural gum, starch, metal oxide are present in amounts 5 to 20%, 60 to 85%, 2 to 12%, 2 to 10%, 0.5 to 5% w/w by weight of the powdered blend of polymers and are mixed in ratios ranging from 0.5:8:0.5:0.25:0.1 to 2:15:2:2:1 , preferably 1 :8:2:0.25:0.1 to 1 :12:1 :1 :0.2.

16. The process for preparation of coated liquid filled beads or capsules as claimed in claim 15, wherein said blend of polymers optionally comprises pectin, multivalent metal salts of long chain (C12-C18) fatty acids such that said modified cellulose, alkali salt of alginate, natural gum, starch, pectin, multivalent metal salts of long chain (C12-C18) fatty acids, metal oxide are present in amounts of 4 to 10%, 50 to 80%, 5 to 16%, 2 to 8%, 1 to 15%, 0.25 to 6%, 0.5 to 5% w/w by weight of the powdered blend of polymers and are mixed in ratios ranging from 0.5:8:0.5:0.25:0.5:0.2:0.1 to 2:15:2:2:2:2:1 most specifically 1 :8:2:0.25:1 :0.5:0.1 to 1 :12:1 :1 :2:1 :0.2.

17. A process for preparation of coated liquid filled beads or capsules comprising steps of :

(i) preparing a system comprising of a solution or dispersion or emulsion of a liquid active ingredient and/or of a solid active ingredient in an aqueous solution of; an emulsifier or surfactant and multivalent metal ions selected from Ca++, Fe++ and Fe+++ and optionally, other water soluble or water dispersible substances,

(ii) preparing a system comprising of a solution or dispersion of polymer/s in an aqueous solution,

(iii) forming discrete droplets of said system of step 1 ;

(iv) converting said droplets to water-insoluble gel beads by introducing said droplets in the polymer dispersion as obtained in step 2,

(v) isolating said gel beads from said suspension, (vi) preparing a powdered blend of polymers selected from modified cellulose, alkali salts of alginate, natural gum, starch, metal oxide,

(vii) coating the soft beads of step (v) with powdered polymer blend obtained in step (vi) by gently shaking the beads in the powdered polymer blend,

(viii) drying the coated beads at 30-502C for 30mins to obtain said coated liquid filled beads or capsules;

wherein said modified cellulose, alkali salts of alginate, natural gum, starch, metal oxide are present in amounts of 5 to 20%, 60 to 85%, 2 to 12%, 2 to 10%, 0.5 to 5% w/w by weight of the powdered blend of polymers and are mixed in ratios ranging from 0.5:8:0.5:0.25:0.1 to 2:15:2:2:1 , preferably 1 :8:2:0.25:0.1 to 1 :12:1 Λ :0.2.

18. The process for preparation of coated liquid filled beads or capsules as claimed in claim 17, wherein said blend of polymers optionally comprises pectin, multivalent metal salts of long chain (C12-C18) fatty acids such that said modified cellulose, alkali salt of alginate, natural gum, starch, pectin, multivalent metal salts of long chain (C12-C18) fatty acids, metal oxide are present in amounts of 4 to 10%, 50 to 80%, 5 to 16%, 2 to 8%, 1 to 15%, 0.25 to 6%, 0.5 to 5% w/w by weight of the powdered blend of polymers and are mixed in ratios ranging from 0.5:8:0.5:0.25:0.5:0.2:0.1 to 2:15:2:2:2:2:1 most specifically 1 :8:2:0.25:1 :0.5:0.1 to 1 :12:1 :1 :2:1 :0.2.

Description:
POLYMERIC POWDERED COATING COMPOSITION FOR MAKING LIQUID FILLED POLYMERIC BEADS AND METHODS THEREOF

Field of Invention

The present invention relates to materials and methods for coating soft beads or capsules, and more particularly to powdered polymeric coating compositions for coating soft beads or capsules containing oil, active ingredients, fragrances, flavours and colouring materials.

Background and Prior art

Prior art teaches the encapsulation of fragrance, flavour, active ingredients, colouring materials in polymeric matrix with pre emulsification. The main purpose of encapsulation is to provide protection for a flavor or incompatible/unstable ingredient from escape or degradation. Therefore, there remains immense scope in developing an encapsulating technology that will help prevent the escape of volatile components (e.g. fragrance, flavor) from formulation or enhance the stability of active ingredients (e.g. antioxidants) or help keeping the incompatible ingredients separated in formulation. Technically encapsulation involves coating of a material or a mixture of materials with or entrapped within another material or system. The coated material is called active or core material, and the coating material is called shell, wall material, carrier or encapsulant.

The conventional techniques used for encapsulation include spray drying, air suspension, extrusion coating, spray cooling/chilling, centrifugal extrusion, rotational suspension separation, coacervation with various carbohydrates with and without the use of crosslinking agents and inclusion complexes. The general process for encapsulating sensitive compounds comprises of two steps: the first is often emulsification of a core material system followed by coating with a dense solution of a wall material such as a polysaccharide or protein. According to the encapsulation process used, the matrices/wall of encapsulation shows various shapes (films, spheres, irregular particles), various structures (porous or compact) and various physical structures (amorphous or crystalline dehydrated solid, rubbery or glassy matrix) that will influence diffusion of flavours or external substances (oxygen, solvent). Conventionally, encapsulated particles (beads) containing active ingredient/ingredients are prepared by a process that comprises the following steps:

1 . Preparation of a system consisting of a solution or dispersion or emulsion of a liquid active ingredient and/or of a solid active ingredient in an aqueous solution of an acid polysaccharide in the form of an alkali metal salt, an emulsifier and, optionally, one or more other water soluble or water dispersible substances

2. Formation of discrete droplets of said system; converting said droplets to water- insoluble gel beads by introducing said droplets in an aqueous or alcoholic solution containing multivalent cations, thereby building a particulate suspension

3. Based on the application, optionally isolating said gel beads from the suspension or drying the isolated beads

The beads obtained using conventional techniques contain >90% water, so their shell is very soft. In order to get a hard shell capsule the water content in the hard shell needs to be reduced either by drying in air or in a drier at ambient temperature or at higher temperature. Removal of water from the shell below 50% mostly resulted in the changes in shape and size as well as complete loss of volatile materials encapsulated within the shell.

Further prior art teaches methods that use high temperature, which limits the stability of the volatile compounds and temperature sensitive compounds in the macro/micro capsules. Besides, imparting hardness to the shell, material requires multiple coating or extended exposure to multivalent metal salt solution (6 to 12hrs).

Various polymers are known in the art that have been used in providing coatings on beads or capsules. WO2009003724 discloses controlled release bead comprising: i) a microcrystalline cellulose core unit ii) a water soluble coat surrounding said core unit and comprising a vinyl pyrrolidone polymer, iii) a drug layer comprising the drug active and a pharmaceutical acceptable binder; and iv) a controlled release layer comprising a pH independent polymer, preferably a polyacrylate. It discloses providing an outermost film coat for improving the mechanical properties of the bead. Preferably such an outermost film coat is not a functional coat, i.e. it does not substantially modify the controlled release rate of the bead. Such outermost film coat comprises preferably hydroxypropyl methyl cellulose and/or talc. Accordingly the outermost coating does not affect the release of the actives and furthermore the compositions were directed to solid formulations and not liquid filled capsules/beads. JP 4021513 discloses that the dissipation speed of a liquid included in a gel can be controlled by coating a silica gel bead with a polymer composition containing a water- insoluble alginic acid salt. JP'513 discloses a silica sol having a pH of 8.0-8.5 and produced by mixing water glass with a mineral acid ejected from a nozzle into air and the droplets being thrown into water and washed with water to obtain spherical silica beads having particle diameter of 1 -5 mm. The beads are immersed in an aqueous solution of a water-soluble alginic acid salt or its mixture with a water-soluble polymer (e.g. PVA) to form a coating film of the polymer composition on the surface of the bead. The coating film is cured by throwing the beads into an aqueous solution of a water-soluble alkaline-earth metal salt to obtain a bead coated with a polymer composition containing a water- insoluble alginic acid salt. The bead is thrown into an amphiphatic liquid (e.g. methanol) and left standing for 1 to 48 hr to substitute the water in the bead with the amphiphatic liquid. However the coating method in JP 4021513 employs a polymer composition containing water-insoluble alginic acid salt in non-aqueous solvent, and the final beads are obtained after 48 hours.

US5093130 discloses methods and materials for coating hydrogel capsule containing botanic tissue with an inert substance that decrease capsule surface adhesiveness and facilitates singulation and flowability of the hydrogel capsules. US5093130 discloses powder coatings composed of at least one hydrophobic powder capable of forming a discontinuous film about the capsule surface. It discloses various hydrophobic powders such as polyvinylchloride granules, calcium stearate granules, magnesium stearate granules, talc and stearic acid, fumed silica compounds, other suitable compounds such as finely divided silicon dioxide, aluminum silicate, metallic oxides such as titanium dioxide, various polyalcohols including cetyl alcohol and polyvinyl alcohol, cellulose and its derivatives, methylcellulose, ethylcellulose, and acetylcellulose. It also discloses a dry coating process where coating is accomplished by rolling the capsules in the powder for 1 second to 30 minutes. Other suitable application methods include shaking or spraying the hydrophobic compounds onto the hydrogel capsules. However the coating materials are designed in such a way to release the active (adjuvant) from the porous hydrogel to plant tissue grown on it. According to US'130 the particle size of the coating material is a critical parameter to reduce the surface adhesiveness. The coatings of US'130 have been designed to decrease capsule surface adhesiveness and facilitate singulation and flowability of the hydrogel capsules.

The present invention has now found that polymeric coating compositions comprising specific polymers in specific amounts provide a solution for stabilization of liquid/actives filled capsules/beads where the liquid/active is retained in the coated capsules/beads; the shape of the capsules/beads can be maintained and also the release of the actives can be controlled.

Object of the Invention

It is an object of the present invention to overcome the drawbacks of the prior art.

It is another object of the present invention to provide a coating to a liquid filled capsule/bead, which provides mechanical strength to the capsule/bead wall.

It is a further object of the present invention to prevent destabilization of beads/capsules and prevent change in its shape and loss of liquid inside.

It is yet another object of the present invention to provide coated capsule/bead which retains the encapsulated materials (specifically highly volatile) and stabilizes unstable active ingredients.

It is yet another object of the present invention to provide coated capsule/bead which retains the encapsulated materials (specifically highly volatile) and stabilizes unstable active ingredients. It is yet another object of the present invention to provide coated capsule/bead which retains the encapsulated materials (specifically highly volatile) and stabilizes unstable active ingredients that are available on demand. Summary of the Invention

According to one aspect of the present invention there is provided a powdered polymeric coating composition for coating liquid filled beads or capsules comprising modified cellulose, alkali salts of alginate, natural gum, starch, metal oxide wherein said modified cellulose, alkali salts of alginate, natural gum, starch, metal oxide are present in amounts of 5 to 20%, 60 to 85%, 2 to 12%, 2 to 10%, 0.5 to 5% w/w by weight of the powdered polymeric coating composition and are mixed in ratios ranging from 0.5:8:0.5:0.25:0.1 to 2:15:2:2:1 , preferably 1 :8:2:0.25:0.1 to 1 :12:1 :1 :0.2.

According to another aspect of the present invention there is provided a powdered polymeric coating composition for coating liquid filled beads or capsules comprising modified cellulose, alkali salt of alginate, natural gum, starch, pectin, multivalent metal salts of long chain (C 12 -C 18 ) fatty acids, metal oxide; said modified cellulose, alkali salt of alginate, natural gum, starch, pectin, multivalent metal salts of long chain (Ci 2 -Ci 8 ) fatty acids, metal oxide being present in amounts of 4 to 10%, 50 to 80%, 5 to 16%, 2 to 8%, 1 to 15%, 0.25 to 6%, 0.5 to 5% w/w by weight of the powdered polymeric coating composition and mixed in ratios ranging from 0.5:8:0.5:0.25:0.5:0.2:0.1 to 2:15:2:2:2:2:1 most specifically 1 :8:2:0.25:1 :0.5:0.1 to 1 :12:1 :1 :2:1 :0.2.

According to another aspect of the present invention there is provided a process for coating of liquid filled capsules/beads comprising steps of:

i) preparing a powdered blend of polymers comprising modified cellulose, alkali salts of alginate, natural gum, starch, metal oxide,

ii) coating liquid filled capsules/beads with powdered blend obtained in step i) by gently shaking the beads in the powdered polymer blends, iii) drying the coated beads at 30-50 e C for 30 mins to obtain coated liquid filled beads or capsules;

wherein said modified cellulose, alkali salts of alginate, natural gum, starch, metal oxide are present in amounts of 5 to 20%, 60 to 85%, 2 to 12%, 2 to 10%, 0.5 to

5% w/w by weight of the powdered polymeric coating composition and are mixed in ratios ranging from 0.5:8:0.5:0.25:0.1 to 2:15:2:2:1 , preferably 1 :8:2:0.25:0.1 to 1 :12:1 :1 :0.2. According to a further aspect of the present invention there is provided a process for preparation of coated liquid filled beads or capsules comprising steps of :

i) preparing a system comprising of a solution or dispersion or emulsion of a liquid active ingredient and/or of a solid active ingredient in an aqueous solution of an alkali metal salt of a polysaccharide acid; an emulsifier and optionally, other water soluble or water dispersible substances, ii) forming discrete droplets of said system of step (i);

iii) converting said droplets to water-insoluble gel beads by introducing said droplets in an aqueous or alcoholic solution containing multivalent cations to form a particulate suspension,

iv) isolating said gel beads from said suspension,

v) preparing a powdered blend of polymers comprising modified cellulose, alkali salts of alginate, natural gum, starch, metal oxide,

vi) coating the soft beads of step (iv) with powdered polymer blend obtained in step v) by gently shaking the beads in the powdered polymer blend, vii) drying the coated beads at 30-50 e C for 30mins to obtain said coated liquid filled beads or capsules;

wherein said modified cellulose, alkali salts of alginate, natural gum, starch, metal oxide are present in amounts of 5 to 20%, 60 to 85%, 2 to 12%, 2 to 10%, 0.5 to 5% w/w by weight of the powdered polymeric coating composition and are mixed in ratios ranging from 0.5:8:0.5:0.25:0.1 to 2:15:2:2:1 , preferably 1 :8:2:0.25:0.1 to 1 :12:1 :1 :0.2. According to a further aspect of the present invention there is provided a process for preparation of coated liquid filled beads or capsules comprising steps of:

i) preparing a system comprising of a solution or dispersion or emulsion of a liquid active ingredient and/or of a solid active ingredient in an aqueous solution of; an emulsifier or surfactant and multivalent metal ions (such as but not limited to Ca++, Fe++, Fe+++ etc) and optionally, other water soluble or water dispersible substances,

ii) preparing a system comprising of a solution or dispersion of polymer/s in an aqueous solution,

iv) forming discrete droplets of said system of step (i); iv) converting said droplets to water-insoluble gel beads by introducing said droplets in the polymer dispersion as obtained in step (ii),

v) isolating said gel beads from said suspension,

vi) preparing a powdered blend of polymers comprising modified cellulose, alkali salts of alginate, natural gum, starch, metal oxide,

vii) coating the soft beads of step (v) with powdered blend of polymers obtained in step (v) by gently shaking the beads in the powdered polymer blend, viii) drying the coated beads at 30-50 e C for 30mins to obtain said coated liquid filled beads or capsules;

wherein said modified cellulose, alkali salts of alginate, natural gum, starch, metal oxide are present in amounts of 5 to 20%, 60 to 85%, 2 to 12%, 2 to 10%, 0.5 to 5% w/w by weight of the powdered polymeric coating composition and are mixed in ratios ranging from 0.5:8:0.5:0.25:0.1 to 2:15:2:2:1 , preferably 1 :8:2:0.25:0.1 to 1 :12:1 :1 :0.2.

Detailed Description of the Invention

The present invention provides powdered polymeric coating compositions for coating of soft beads obtained using conventional encapsulation method containing oil, active ingredients, fragrances, flavours and colouring materials. According to one embodiment of the present invention there is provided a polymeric coating compositions comprising materials selected from alkali salt of alginate, pectin, modified cellulose, native/modified starch, natural gum, mannose polymers along with inorganic metal oxide and multivalent metal salts of long chain (Ci 2 -Ci 8 ) fatty acids.

The encapsulation of oil, active ingredients, fragrances, flavours and colouring materials involves use of polymeric bead, capsules etc, within which the actives are packed. The polymeric beads or capsules consist of a wall material composed of mixture of polymers selected from biopolymers such as polysaccharides and the liquid inside the polymeric shell composed of flavours, fragrances, vitamins or colouring materials, polyols, surfactants (ionic or non ionic) and multivalent metal salts. The coating polymers compositions, according to the present invention, can be used for coating of such freshly prepared beads. The coated beads can subsequently be dried at ambient (20-30 e C) temperature or at higher (40-95 e C). The present inventors have surprisingly found that a powdered polymeric coating composition comprising modified cellulose, alkali salts of alginate, natural gum, starch, metal oxide wherein said modified cellulose, alkali salts of alginate, natural gum, starch, metal oxide are present in amounts 5 to 20%, 60 to 85%, 2 to 12%, 2 to 10%, 0.5 to 5% w/w by weight of the powdered polymeric coating composition and are mixed in ratios ranging from 0.5:8:0.5:0.25:0.1 to 2:1 5:2:2:1 , preferably 1 :8:2:0.25:0.1 to 1 :12:1 :1 :0.2.

The powdered polymeric coating composition of the present invention can further comprise pectin, multivalent metal salts of long chain (Ci 2 -Ci 8 ) fatty acids such that said modified cellulose, alkali salt of alginate, natural gum, starch, pectin, multivalent metal salts of long chain (Ci 2 -Ci 8 ) fatty acids, metal oxide are present in amounts of 4 to 10%, 50 to 80%, 5 to 16%, 2 to 8%, 1 to 15%, 0.25 to 6%, 0.5 to 5% w/w by weight of the powdered polymeric coating composition and mixed in ratios ranging from 0.5:8:0.5:0.25:0.5:0.2:0.1 to 2:1 5:2:2:2:2: 1 most specifically 1 :8:2:0.25:1 :0.5:0.1 to 1 :12:1 :1 :2:1 :0.2. The alkali salt of alginate that can be employed in the present invention includes but not limited to sodium or potassium alginate.

The modified cellulose that can be employed in the present invention includes hydrophobically modified cellulose derivatives.

Further starch in accordance with the present invention can be modified or in native form. The modified starch includes gelatinised or pregelatinized starches.

The natural gums that can be included in the present invention is selected from acacia gum, arabic gum, xantham gum etc.

Pectins that can be employed in the present invention includes both native and modified pectins. Inorganic metal oxide according to the present invention can be but not limited to zinc oxide, titanium dioxide, ferric oxide, talc, metal salts of silicates. The multivalent metal salts of long chain (Ci 2 -Ci 8 ) fatty acids include but not limited to magnesium stearate, zinc stearate.

According to one embodiment of the present invention, the polymeric coating composition contains modified cellulose, alkali salt of alginate, natural gum, native/modified starch, pectin, multivalent metal salts of long chain (Ci 2 -Ci 8 ) fatty acids, metal oxide mixed in a ratio of 1 :10:1 .5:1 :0.2:0.1 :0.2.

According to another embodiment of the present invention, the polymeric coating composition contains modified cellulose, alkali salt of alginate, natural gum, starch, metal oxide mixed in a ratio of 1 : 10: 1 .5 : 1 : 0.2.

According to further embodiment of the present invention the polymeric coating composition contains modified cellulose, alkali salt of alginate, natural gum, starch, metal oxide mixed in a ratio of 1 : 10: 1 : 0.5: 0.2. The coating on walls of the liquid filled capsules/beads in accordance with the present invention provides a hardness of 5-20 N.

The various liquid that can be filled inside the capsule/beads include but not limited to flavours, such as menthol, mint, coffee and fragrances, oils, liquid nutrients such as vitamins and essential oils.

The present invention also provides a process for coating of liquid filled capsules/beads comprising steps of :

i) preparing a powdered blend of polymers comprising alkali salt of alginate, starch, modified cellulose, natural gums along with inorganic metal oxide in accordance with the present invention,

ii) coating liquid filled capsules/beads with powdered blend obtained in step i) by gently shaking the beads in the powdered polymer blends, iii) drying the coated beads at 30-50 e C for 30mins to obtain the polymeric coated beads of the present invention. The present invention further provides a process for preparation of the polymeric beads comprising steps of :

1 . preparing a system consisting of a solution or dispersion or emulsion of a liquid active ingredient such as but not limited to flavours, such as menthol, mint, coffee and fragrances, oils, liquid nutrients such as vitamins and essential oils, nicotine and/or of a solid active ingredient such as but not limited to nutrients, vitamins, antioxidants, spices in an aqueous solution of an acid polysaccharide in the form of an alkali metal salt such as but not limited to sodium and potassium salt of alginates, an emulsifier such as anionic, non-ionic, cationic surfactants such as sodium/potassium alkyl sulphates tweens, spans, alkyl glucosides, fatty alkyl chlorides and, optionally, one or more other water soluble or water dispersible substances such as but not limited to nutrients, vitamins, antioxidants, spices;

2. forming discrete droplets of said system of step 1 ;

3. converting said droplets to water-insoluble gel beads by introducing said droplets in an aqueous or alcoholic solution containing multivalent cations such as but not limited to Ca +2 , Fe +2 , Fe +3 , thereby building a particulate suspension;

4. isolating said gel beads from the suspension;

5. preparing a powdered blend of polymers comprising alkali salt of alginate, modified cellulose, and native/modified starch, natural gums along with inorganic metal oxide in accordance with the present invention;

6. coating of the soft beads of step 3 with powdered blend obtained in step 4 by gently shaking the beads in the powdered polymer blends;

7. drying the coated beads at 30-50 e C for 30mins to obtain the polymeric coated beads of the present invention.

The liquid filled polymeric beads or capsules according to the present invention can also be prepared by a process comprising steps of : i) preparing a system comprising of a solution or dispersion or emulsion of a liquid active ingredient and/or of a solid active ingredient in an aqueous solution of; an emulsifier or surfactant and multivalent metal ions selected from Ca++, Fe++ and Fe+++ and optionally, other water soluble or water dispersible substances, wherein emulsifiers or surfactants are selected from anionic, amophoteric, cationic and nonionic surfactants and water-soluble or dispersible substances are selected from substances like oil, fragrances, flavors and coloring materials, proteins, peptides, micronutrients, vitamins, antioxidants, probiotics, enzymes, minerals, conditioners, vitamins, nicotine and their mixture thereof;

ii) preparing a system comprising of a solution or dispersion of polymer/s in an aqueous solution, the polymers are chosen from alkali salt of alginate, pectin, starch, modified cellulose, modified starch, mannose polymers, glucan polymers, gums ( \cac/ ' a glutenin) powder and proteins and their mixture thereof;

iii) forming discrete droplets of said system of step i;

iv) converting said droplets to water-insoluble gel beads by introducing said droplets in the polymer dispersion as obtained in step ii;

v) isolating said gel beads from said suspension;

vi) preparing a powdered blend of polymers comprising modified cellulose, alkali salts of alginate, natural gum, starch, metal oxide;

vii) coating the soft beads of step (iv) with powdered polymer blend obtained in step (v) by gently shaking the beads in the powdered polymer blend;

viii) drying the coated beads at 30-50 e C for 30mins to obtain said coated liquid filled beads or capsules;

wherein said modified cellulose, alkali salts of alginate, natural gum, starch, metal oxide are present in amounts of 5 to 20%, 60 to 85%, 2 to 12%, 2 to 10%, 0.5 to 5% by weight of the powdered polymeric coating composition and are mixed in ratios ranging from 0.5:8:0.5:0.25:0.1 to 2:15:2:2:1 , preferably 1 :8:2:0.25:0.1 to 1 :12:1 :1 :0.2.

The powdered blend of polymers in the above processes can further comprise pectin, multivalent metal salts of long chain (Ci 2 -Ci 8 ) fatty acids such that said modified cellulose, alkali salt of alginate, natural gum, starch, pectin, multivalent metal salts of long chain (C12-C18) fatty acids, metal oxide are present in amounts of 4 to 10%, 50 to 80%, 5 to 16%, 2 to 8%, 1 to 15%, 0.25 to 6%, 0.5 to 5% w/w by weight of the powdered polymeric coating composition and mixed in ratios ranging from 0.5:8:0.5:0.25:0.5:0.2:0.1 to 2:15:2:2:2:2:1 most specifically 1 :8:2:0.25:1 :0.5:0.1 to 1 :12:1 :1 :2:1 :0.2.

One of the major advantage of the present coating process is that it does not require prolonged coating (6-12 hrs) time. The coating time according to the present invention is the coating process takes 1 -5 mins and total drying process takes 30-60 mins.

The coated beads or capsules of the present invention provide the following benefits:

1) Prevent destabilization of bead shape and ensure liquid to be retained inside the capsule,

2) Provide hard shell beads that increase the shelf life of the beads,

3) Delivery of unstable active such as but not limited to volatile liquids, antioxidants, vitamins, photo unstable nutrients in stable form,

4) Delivery of fragrance and flavor (both control release and on demand, i.e., on application of mechanical force such as pressure),

5) Deliver the molecule in active form.

The coated bead or capsules of the present invention is thus useful in personal care formulations, food products, Tobacco (smokeless and smokable) products, etc. The present invention is now illustrated by way of non limiting examples.

Example 1

Preparation of polymeric coated beads in accordance with the present invention Step 1 : The active ingredients (flavours, fragrance, vitamins) are dissolved either in water or surfactant or oil

Step 2: 2-1 Og of the step 1 solution was mixed in 1 .0% Sodium alginate containing solution Step 3: The solution or dispersion of step 2 is dropped into 1 % CaCI 2 Solution in water

Step 4: A powder coating material was prepared by blending 1 g of native/modified cellulose, 10 g of Sodium alginate, 1 .5 g of Acacia gum, 1 g of starch, 2g pectin, 1 g magnesium stearate and 0.2 g Zinc oxide

Step 5: 1 -2 g of powder coating material was spread on a tray and the soft gel beads formed in step 3 were removed and put on the tray with powder coating material and rolled on it for coating the surface of the bead properly for about 1 -5 min

Step 6: The beads were taken out of the tray and dried in air at 30 to 50°C for 30 to 60 min to get hard-shell beads Example 2:

Preparation of polymeric coated beads in accordance with the present invention Step 1 : 1 %Sodium alginate dispersion was prepared in water Step 2: 15% menthol solution was prepared in propylene glycol

Step 3: 5g of step 2 solution was mixed with calcium chloride, water and surfactant Step 4: Step 1 solution was diluted 2 to times and poured in flat surface container

Step 5: Step 3 solution was dropped into the step 4 solution

Step 6: A powder coating material was prepared by blending 1 g of modified cellulose, 10 g of Sodium alginate, 1 .5 g of Acacia gum, 1 g of native/modified starch, 2g pectin, 1 g magnesium stearate and 0.2 g Zinc oxide

Step 7: 1 -2 g of powder coating material was spread on a tray and the soft gel beads

formed in step 3 were removed and put on the tray with powder coating material and rolled on it for coating the surface of the bead properly for about 1 -5 min Step 8: The beads were taken out of the tray and dried in air at 30 to 50°C for 30 to 60 min to get a hard shell beads The bead obtained in the present invention has the following essential characteristics:

1 . Shape : Spherical

2. Size: varies from 0.1 to 10mm more specifically 3 - 5 mm.

3. Hardness: 5 - 20 N more specifically 7 - 14 N

4. Core liquid content: 1 - 100 μΐ more specifically 5 - 25μ1

Example 3

Various coated capsules/beads have been prepared according to the process in Example 1 with varying amounts of polymers in the coating as mentioned in Table 1 . Further as mentioned in Table 1 only specific combinations of polymers (1 , 8 and 10) provides the desired hardness, retention of liquid and desired shape. This shows that the present invention provides unexpected results over a specific range of components in specific amounts.

Table 1

s. Components Composition range Observations

No.

1 Modified Cellulose 1 : 10: 1 .5 : 1 : 0.2 : 0.1 : Required hardness, (hydrophobically modified 0.2 (Amounts in weight liquid retained.

cellulose), Alginate, Acacia, percentage - 7.1 , 71 .4, Shape retained

Starch, Pectin, Magnesium 10.7, 7.1 , 1 .4, 0.7, 1 .4 %

Stearate, Metal Oxide (zinc w/w)

oxide)

2 Modified Cellulose 1 Did not work

(hydrophobically modified (Amounts in weight

cellulose) percentage - 100 % w/w)

3 Modified Cellulose 2:1 Beads were sticky and (hydrophobically modified (Amounts in weight extremely hard cellulose) & Acacia percentage - 67, 33 % w/w)

4 Modified Cellulose 1 :1 :1 to 1 :5:1 1 Soft beads & shape

(hydrophobically modified (Amounts in weight changed cellulose), Alginate & Acacia percentage - 33.3, 33.3,

33.3 to 6, 29, 65 % w/w)

Modified Cellulose 1 :7:1 Soft beads

(hydrophobically modified (Amounts in weight

cellulose), Alginate & Acacia percentage - 1 1 , 78, 1 1 %

w/w)

Modified Cellulose 1 :8:1 to 1 :10:1 Required hardness & (hydrophobically modified (Amounts in weight leakage observed over cellulose), Alginate & Acacia percentage-10, 80, 10, to a period of time

8.3, 83.4, 8.3 % w/w)

Modified Cellulose 1 :1 1 :1 to 1 :13:1 High hardness & (hydrophobically modified (Amounts in weight leakage observed over cellulose), Alginate & Acacia percentage-7.7, 84.6, 7.7 a period of time

to 6.6, 86.8, 6.6 % w/w)

Modified Cellulose 1 :10:1 .5:1 :0.2 Required hardness, (hydrophobically modified (Amounts in weight liquid retained.

cellulose), Alginate, Acacia, percentage-7.3, 73, 10.9, Shape retained Starch, Metal Oxide (ZnO or 7.3, 1 .5 % w/w)

ΤΊ02)

Modified Cellulose 1 :10:2.5:1 :0.2 Beads were clumping (hydrophobically modified (Amounts in weight together

cellulose), Alginate, Acacia, percentage-6.8, 68, 17,

Starch, Metal Oxide (ZnO or 6.8, 1 .4 % w/w)

ΤΊ02)

Modified Cellulose 1 :10:1 :0.5:0.2 Required hardness, (hydrophobically modified (Amounts in weight liquid retained.

cellulose) , Alginate, Acacia, percentage-7.9, 78.7, 7.9, Shape retained Starch, Metal Oxide (zinc 3.9, 1 .6 % w/w)

oxide) (ZnO or ΤΊ02)

Modified Cellulose 1 :10:1 .5:0.2:1 Soft beads

(hydrophobically modified (Amounts in weight

cellulose) , Alginate, Accaia, percentage-7.3, 73, 10.9,

Metal Oxide (zinc oxide), Clay 1 .5, 7.3 % w/w)

Modified Cellulose 0.25:5:0.5:0.25:1 :0.5:0.1 (hydrophobically modified (Amounts in weight Shape changed cellulose), Alginate, Acacia, percentage-3.3, 65.8, 6.6,

Starch, Pectin, Magnesium 3.3, 13.1 , 6.6, 1 .3 % w/w)

Stearate, Metal Oxide (zinc

oxide)

Modified Cellulose 0.25:15:2:2:1 :0.5:0.1 Shape Changed (hydrophobically modified (Amounts in weight

cellulose), Alginate, Acacia, percentage-1 .2, 71 .9, 9.6,

Starch, Pectin, Magnesium 9.6, 4.8, 2.4, 0.5 % w/w)

Stearate, Metal Oxide (zinc

oxide)