CLIAMS:1. A gelatin free shell-forming composition for making hard shell seamless capsule for smoking article, said composition comprising:
a) polymeric base material, wherein said base material is non-animal based bio polymer;
b) a gelling agent;
c) a moisture retaining agent;
d) water;
e) optionally a coloring agent and fillers.
wherein the gelatin free shell composition are resistant to variation in humidity and moisture during storage, during and post process of smoking.
2. The gelatin free shell forming composition as claimed in claim 1, wherein the ratio of said gelling agent to biopolymer carrageenan in the shell forming composition is from about 1:5 to about 1:25.
3. The gelatin free shell forming composition as claimed in claim 1, wherein the ratio of said moisture retaining agent to the dry carrageenan in the shell forming composition is in the range of 1:5 to 1:30 and most preferably, 1: 2 to 1: 12.
4. The gelatin free shell forming composition as claimed in claim 1, wherein said biopolymeric base material is carrageenan alone or carrageenan in combination with at least one non-animal based biopolymers selected from pectins, alginates, locust bean gum, pullulan, modified starches, cellulose, cellulose derivatives, gellan gum, guar gum or guar gum derivatives or their mixtures thereof.
5. The gelatin free shell forming composition as claimed in claim 1, wherein amount of said biopolymeric base material ranges from 2-12 % by weight.
6. The gelatin free shell forming composition as claimed in claim 1, wherein said gelling agent is selected from at least one mono-valent or di-valent metal salts including potassium chloride or calcium chloride or cesium chloride, preferably comprising of potassium chloride.
7. The gelatin free shell forming composition as claimed in claim 1, wherein amount of said gelling agent ranges from 0.2 to 2 % wt.
8. The gelatin free shell forming composition as claimed in claim 1, wherein said moisture retaining agent is at least one member selected from glycerol, sorbitol, mannitol or propylene glycol.
9. The gelatin free shell forming composition as claimed in claim 1, wherein amount of said moisture retaining agent ranges from 0.5 to 2.5 % wt.
10. The gelatin free shell forming composition as claimed in claim 1, wherein said coloring agent is a natural food colorant
11. The gelatin free shell forming composition as claimed in claim 1, wherein amount of said coloring agent ranges from 10 – 50 mg per litre of shell forming solution.
12. The gelatin free shell forming composition as claimed in claim 1, wherein said fillers are organic or inorganic in nature. The organic fillers are selected from a group comprising low viscosity unmodified and modified starches, soluble fibers thereof. The inorganic fillers are selected from group comprising calcium carbonate, magnesium carbonate, bentonite clay, MMT clay thereof.
13. The gelatin free shell forming composition as claimed in claim 1, wherein amount of said fillers ranges from 0.5 to 20 % wt.
14. The gelatin free shell forming composition as claimed in claim 1, wherein the capsule incorporates a desirable flavoring agent in its core.
15. The gelatin free shell forming composition as claimed in claim 1, wherein said biopolymeric base material, carrageenan has gel strength in between 450-1250 g/cm2, preferably in between 600-1250 g/cm2 and more preferably in between 750-1250 g/cm2.
16. The gelatin free shell forming composition as claimed in claim 1, wherein capsules with said composition has a breaking strength of 10-15 N.
17. The gelatin free shell forming composition as claimed in claim 1, wherein said capsule diameter ranges from 2 mm to 4.5 mm.
18. A process for manufacturing gelatin free hard shell seamless capsule as claimed in claim 1, comprising steps of,
a. co-extruding core and shell forming solutions through concentrically aligned nozzle into a hardening bath and straining the capsule there after;
b. gelation of capsules by refrigerating the capsules at a temperature for hours;
c. drying the capsules at low humidity and at low temperature in suitable drying equipment to obtain gelatin free seamless capsules.
19. The process as claimed in claim 18, wherein said temperature of gelation of capsules ranges from 5 to 15°C.
20. The process as claimed in claim 18, wherein said time of gelation of capsules ranges from 15 to 20 hours. ,TagSPECI:Field of the invention:
The present invention relates to gelatin free capsules, more particularly the present invention relates to gelatin free shell forming composition for production of hard shell seamless capsules for flavour delivery in cigarettes and other smoking articles.

Background of the invention:
Conventional cigarettes generally comprise two segments; one segment having a tobacco rod of processed tobacco wrapped in paper and another segment having a filter plug wrapped in paper. The two segments are attached to each other with a tipping paper. Cigarette also exists without the filter plug segments. All other smoking articles such as, cigars, cigarillos, roll your own (RYO), make your own (MYO), bidis, etc. may have one or two segments. The smoker lights the exposed end of the tobacco rod (burning end) and draws smoke from the other end of the smoking article (mouth end/ filter end). Manufacturers of cigarettes and other smoking articles add flavours to enhance or ameliorate organoleptic properties of smoke (smoke sensory attributes).
Addition of flavouring agents by various means such as, through adsorbent materials (US 2002/0166563), through fibrous material (US 2002/0020420), through flavor bearing thread(s) EP 0490559, US 2008/0230079), by inserting flavored fillers (US 4941486 and US 4862905, WO/ 2007/ 036814), by applying flavour to the inner foil liner of the cigarette pack prior to form and seal the cigarette pack WO/2012/085499, EP 0868857), by adding flavor release precursor EP 0746986), by applying flavored sleeves EP 0797931,by applying flavor releasing lip balm type formulation at the mouth end of cigarettes and other smoking articles EP 02162023, etc. are reported in literature.
To modify the sensory attributes further and to give the smoker more control over the derived smoking pleasure, the inclusion of hard shell seamlesss capsule filled with flavour or selective ingredient is proposed in many patents (US 3339558, US 3366121, US 3428049, US 3602231, US 4889144, WO/2003/009711). The basic idea behind these inventions is to give the smoker the choice to release flavour present in the capsules at will to enrich the smoke for a more pleasant smoking experience.
The method of preparation of seamless capsules is well known in the art (US 4251195, US 4695466, US 2911672, US 2531986, EP0513603). The shell forming material extrudes through the outer nozzle and the core solution extrudes through the inner nozzle. While descending from the concentric nozzles, the shell material encapsulates the core material due to surface tension. The droplets formed are cooled or allowed to solidify in hardening liquid (oil or salt solution). The hardened capsules are separated from the hardening liquid bath. A process to remove excess oil from the capsule surface is employed and the capsules are subject to the process of drying.
Gelatin has been the most successful material for manufacturing such hard shell seamless capsules for many end applications. US 7984719, US 8235056, US 20060272636, US 6719933, EP 05/009227 and many others claim the use of gelatin for the manufacture of seamless capsule for use in smoking products and for other end applications. Commercially gelatin based seamless capsules for smoking articles are available from Mane Aromatic Flavour, Nice, France. US 2011/0023896 A1 discloses the use of such gelatin based seamless capsules for smoking articles. The patent also discloses the commercial availability of these capsules from Mane Aromatic Flavour, Nice, France. It is claimed that there is no deformation or destruction of these gelatin capsule during storage at ambient condition.
WO/2007/010407 held by Mane, discloses that gelatin based capsules for use in smoking articles are sensitive to moisture and soften during the process of smoking. It is disclosed that the gelatin capsules lose their physical properties (shape, hardness, crushable sound) when exposed to smoking conditions (heat and moisture during smoking of cigarettes). It further states that the gelatin based capsules lose their physical properties (shape, hardness, crushable sound) when exposed to smoking conditions (heat and moisture during smoking of cigarettes). Moreover, commercially available gelatin based capsules for use in smoking articles are sensitive to moisture and soften during the process of smoking. The percentage decrease of the breaking strength of the gelatin based capsules varies between 30-50% based upon the smoking pattern (by blocking the ventilation holes, etc.) and environmental conditions (humidity and temperature). This causes a considerable amount of difficulty (e.g. does not produce the 'crackling' sound) to the user while smoking. It is claimed that the use of selected hydrocolloids in the outer shell of the gelatin capsule and a coating of the outer capsule by a moisture barrier layer gives the capsules the ability to retain the physical properties mentioned above during the process of smoking. The patent discloses the use of ethanol, iso-propyl alcohol, ethyl acetate or similar organic solvent for the hydrocolloid coating material dissolution, for removing excess surface oil from the capsules. The patent also discloses the usage of organic solvent as a component for the internal liquid phase. The patent also disclosed the method of making seamless capsules as per the process referred in EP 0513603, wherein the nozzle is partially immersed into the hardening liquid.
Both, US 2011/0023896 and WO/2007/010407 have used gelatin, an animal protein, as shell material. Gelatin is commercially extracted from livestock, such as cow, pig, poultry, fish and the like (US 5877287; US 5210182) hence is less attractive to many communities across the world. Moreover, being an animal protein, there is growing concern of allergic effect on consumer especially so after the outbreak of Bovine Spongiform Encephalopathy (BSE), commonly known as “mad cow disease”.Gelatin is prone to changes of physical properties based on atmospheric conditions (heat, moisture and humidity) as is disclosed in the patents. Mane Aromatic Flavor, in WO/2007/010407 discloses the usage of organic solvent for surface oil removal and coating material dissolution. The patent also discloses the usage of organic solvent as part of inner liquid phase (core solution). These organic solvents are highly flammable and pose safety threat. Moreover, traces of these organic solvents in the smoking article may cause skewing of sensory profile. The patent also discloses immersion of the nozzle into the hardening liquid which may not be effective when using formulations which tend to gel quickly. The disadvantages of usage of gelatin as shell forming material have been disclosed in many patents. US 6582727 disclose the tendency of gelatin based capsule to self-cross link and change the hardness of the capsule upon storing for long periods of time.
US 8470215 discloses the possible undesirable interaction of gelatin with triacetin, a commonly used plasticizer in cigarette filter plug. US 6280767 discloses the tendency of gelatin based capsule to stick to each other. The stickiness increases with the increase of the content of plasticizer used to process gelatin for making seamless capsule.
According to US 5431917, the normal moisture level in gelatin based capsule is 10-15 % by the weight of the water in the capsule. If the moisture level of the capsules decreases below 10 %, a prerequisite to get enough strength in hard shell seamless capsule, the capsule shrinks and it may lead to wrinkles, size unevenness, leakage, etc.
US 6719933 disclose the chances of thermal degradation of gelatin due to prolonged heating at higher temperature during the manufacturing of seamless capsules. This has been referred as “hydrolysis”. This disclosure recommends keeping the gelatin solution at lower temperature in the gelatin melting tank to avoid degradation and heating the gelatin solution (secondary heating) to the desirable temperature (80 °C) while transferring the solution to the nozzle for capsule formation. However, as per WO/2007/010407, if the nozzle is dipped in the chilled hardening bath, this could cause solidification of the polymer at the nozzle.
A need to develop a gelatin free biopolymer based hard shell seamless capsule for cigarettes and other smoking article is felt with the view of the above mentioned inherent disadvantages associated with gelatin. There is no commercially available gelatin free hard shell seamless capsule for cigarettes and other smoking articles. However, gelatin free hard shell seamless capsules for other end applications (oral disintegration, etc.) are available. JP 193216/1989 discloses the use of agar-agar gum (KANTEN, Japanese gelatin) for manufacturing seamless capsules for medicinal applications. It discloses the use of high percentage of glycerine in the formulation to reduce the hardness of the capsule for ease of crushing in oral cavity. This formulation is not suitable for making hard shell seamless capsule for smoking articles as high content of plasticizer makes the capsules soft. Moreover, agar emanates a characteristic smell which may be unacceptable in cigarettes and other smoking articles.
US 2009/0208568 discloses the hard shell seamless capsule shell solution composition comprising gellan gum alone or in combination with other gelling agent, filler and a divalent metal sequestering agent. The patent discloses the possible application of such capsule in oral care, food, personal care and the like. In this process the core and shell solution are extruded from the concentric nozzle into calcium chloride solution bath for hardening. In this process the capsules floats at the top and may stick to each other. The patent also uses ethanol for the core preparation posing safety issues due to the high flammability of the solvent if used in cigarettes and other smoking articles.
Gelatin free seamless capsule composition for easy disintegrability is disclosed in US 2005/0069579 A1. It discloses a composition having soluble starch or dextrin as base material with an average dextrose equivalent not more than 10 and average molecular weight not more than 30,000 dalton for oral delivery. It is claimed that the other gelling agents such as, furcellan, carrageenan, LM pectin, curdlen, psyllium seed gum, xanthan gum, locust bean gum, guar gum, gelled starch alone or in combination with others can be used for this purpose. This prior art also discloses the use of shell reinforcing material such as, pullulan, trehalose, gum arabic, etc. The drawing discloses the dipping of the nozzle in the hardening oil maintained at not more than 20 °C. It claims that the formulation is suitable for making disintegrable capsule as the base material and the reinforcing material are highly soluble in water.
Capsules to be used in cigarettes and other smoking articles are subject to high moisture during smoking, hence these capsules are not suitable. As the nozzle is dipped in the chilled hardening oil, this method is not suitable for formulations having the tendency to gel quickly. As disclosed above, with conventional techniques it has not been possible to manufacture hard shell gelatin free seamless capsules for cigarettes and other smoking articles.

The present invention therefore identifies the need to develop hard shell gelatin free seamless capsules and hence provides gelatin free shell forming composition for production of hard shell seamless capsules for flavour delivery in cigarettes and other smoking articles wherein the gelatin free hard shell seamless capsule is incorporated into the filter plug of the smoking article.

Object of invention
An object of the present invention is to overcome the drawbacks of the prior art.

Another object of the present invention is to provide gelatin free hard shell seamless capsules for flavour delivery in cigarettes and other smoking articles.

Yet another object of the present invention is to provide a capsule composition that comprises of carrageenan having gel strength in the range of 750-1250 gm/cm2 alone or in combination with other biopolymers as base material.

Another object of the present invention is to provide hard shell spherical seamless capsules having 10-15N of breaking strength and requires pressure to be applied by the smoker to burst with audible sound and release the core of the capsule.

Yet another objective of the present invention is to manufacture the said capsules having compositions that are not susceptible to variation in humidity and moisture during storage and during the process of smoking.

Yet further objective of the present invention is to provide capsules that are not destroyed or deformed in shape during storage and during the course of smoking.

Summary of the present invention
An aspect of the present invention is to provide a gelatin free shell forming composition comprising
(a) biopolymeric base material,
(b) a gelling agent,
(c) a moisture retaining agent,
(d) a coloring agent,
(e) fillers and
(f) water
wherein the gelatin free shell compositions are not susceptible to variation in humidity and moisture during storage and during the process of smoking.
Another aspect of the present invention is to provide a process for manufacturing gelatin free hard shell seamless capsule as claimed in claim 1, comprising steps of,

a. co-extruding core and shell forming solutions through concentrically aligned nozzle into a hardening bath and straining the capsules;
b. complete the gelation of capsules by refrigerating the capsules at temperature, not exceeding 15 °C for 15-20 hrs.;
c. drying the capsules at low humidity and at low temperature in suitable drying equipment to obtain gelatin free seamless capsules.

Brief Description of the Accompanying Drawings

Figure-1 illustrates the cross sectional view of the hard shell seamless capsules.

Figure-2 (a) illustrates the schematic representation of cigarette and Figure-2 (b) illustrates the components of cigarette with entrapped seamless capsule.
Figure 3 illustrates the analysis of breaking strength and susceptibility to variation in humidity and moisture during storage and during the process of smoking.

Figure 4 illustrates comparison of the capsule hardness after exposure.

Detailed description of the invention
The present invention provides shell forming composition for gelatin free hard shell seamless capsule as flavour delivery system in cigarettes and other smoking articles, wherein the gelatin free hard shell seamless capsule is incorporated into the filter plug.
According to the present invention the smoking articles refers to all other smoking devices such as cigars, cigarillos, RYO’s, MYO’s, etc. consisting of a tobacco rod and a filter plug. The tobacco rod is commonly made by processed tobacco wrapped in wrapping material. Filter plug described in the present invention consists of materials such as wrapping material, plasticizers, etc.
The term “gelatin free” in the present invention refers to all non-animal based biopolymers and that are from bio-origin.
According to the present invention, gelatin free biopolymers refers to and are not restricted to biopolymers such as kappa-carrageenan, iota-carrageenan, pectin, alginates, locust bean gum, pullulan, modified starches, cellulose and cellulose derivatives, gellan gum, guar gum and guar gum derivatives and the like either alone or in combination thereof.
The “Seamless capsule” according to the present invention refers to spherical shaped flavour delivery system or capsule without a visible seam comprising two parts, the inner part which is a liquid herein referred to as core and the outer part, which encloses the core, made of biopolymers herein referred to as shell. The gelatin free seamless capsules comprises of a hard shell and a core. Hard shell seamless capsule in the present invention refers to the seamless capsule with hard or firm shell that requires pressure to break.
Unlike commercially available gelatin based capsules for flavour delivery, the gelatin free capsules of the present invention are not deformed or destroyed during storage or during the process of smoking. Gelatin starts melting at a relatively low temperature of around 35 °C and at temperature of 35-40°C the capsules soften, deform in shape and are destroyed. Also, high amount of plasticizer is required for processing gelatin based capsules. Plasticizers being hydrophilic in nature, tend to pick up moisture and soften the capsules. On the other hand, capsule of the present invention are formed using carrageenan as base material. The melting point of the composition is around 80°C. In addition, the concentrations of gelling agent and the moisture retaining agent in the formulation have been optimized to ensure that the capsules do not pick up moisture and soften during storage or during the process of smoking. Melting point in the present invention refers to the temperature at which the polymer melts.

The core in the present invention is a mixture of flavouring agent in oil. The core may also contain specific aromatic agent such as and are not limited to freshening agent, hot effect agent, cooling effect agent, etc. The oil for core preparation in the present invention refers to food grade oil which is not easily prone to rancidity. Examples of such oils are and are not limited to medium to low chain fatty acid tri-glycerides, mineral oils, etc.
The term “flavour delivery system” in the present invention refers to the capsule which on application of pressure releases the core liquid from the seamless capsules thus delivering the flavour. The flavouring agent in the present invention refers to all flavours used as flavouring agents in cigarettes and other smoking articles. Examples of flavouring agent in smoking articles are and are not limited to menthol, spearmint, apple, cardamom, clove, coffee, etc. The seamless capsule in the present invention is a flavour delivery mechanism which is meant to deliver flavour on demand to the smoker. The seamless capsule when ruptured by the application of pressure releases the flavoured liquid into the filter. The flavour being volatile is carried into the smokers’ pallet along with smoke and gives differentiated smoking experience.

According to one embodiment of the present invention, the shell forming composition contains at least carrageenan as base material. The gel strength of the carrageenan is in between 450-1250 g/cm2, more preferably in between 600-1250 g/cm2 and most preferably in between 750-1250 g/cm2. Gel strength is the measure of the ability of the polymer dispersion to develop and retain its gel form based on resistance to shear. The percentage of carrageenan in the shell forming composition is in the range of 2 -12% by weight.
An embodiment of the present invention provides a composition for gelatin free hard shell seamless capsule comprising gelling agent, moisture retaining agent, an optional food grade coloring agent.
A gelling agent is a material that crosslinks with a substance in liquid form to give it a semi solid structure that does not exhibit any flow properties in steady state despite being formed mostly with liquid. The percentage of the gelling agent helps in varying the strength of the gel. The shell forming composition contains a gelling agent which is a water soluble mono-valent or di-valent metal salt. The amount of gelling agent required in the composition ranges from 0.2 to 2 % wt. Examples of the gelling agent for the present invention are and are not limited to potassium chloride, calcium chloride, cesium chloride and the like. At least one gelling agent in the present invention is potassium chloride. The ratio of potassium chloride to carrageenan ranges from 1:5 to 1:25.
As evident from figure 4 it is noted that shell forming composition with gelling agent to carrageenan ratio in the range of 1:5 to 1:25 has hardness in the desired range 10-15 N even after exposing the capsules to the simulated condition for a period of 10 minutes whereas shell forming composition with gelling agent to carrageenan in the ratio below the specified range has low hardness and high deformity. Shell forming composition with very high gelling agent to carrageenan ratio does not flow and capsules cannot be made with this composition.
The moisture retaining agents used are mainly low molecular weight molecules with functional groups which absorb moisture from environment and retain it in the system in which they are present. The shell forming composition also consists of moisture retaining agent. The amount of moisture retaining agents required in the composition ranges from 0.5 to 2.5 % wt. Example of the moisture retaining agent for the shell forming composition in the present invention are and are not limited to glycerol, sorbitol, mannitol, propylene glycol and the like. The ratio of moisture retaining agent to carrageenan is 1:5 to 1:30 and most preferably, 1:2 to 1:12.

The food grade colouring agent used is a colourant or dye normally used in the food and beverage industry to impart color when it is added to any composition. Natural food colorants or dyes are used as colouring agent in the shell forming composition. It is preferable to use natural colouring agents. 10 – 50 mg of the colouring agent maybe used in one litre of the shell forming composition. An optional food grade colouring agent is used in the shell forming composition for differentiation.
Additionally, fillers can also be included in the shell forming composition. Fillers in the shell forming composition can be organic, inorganic or a mixture of both. Examples of organic fillers in the present invention are and are not limited to low viscosity unmodified and modified starches, soluble fibres, etc. Examples of inorganic filler in the present invention are and are not limited to calcium carbonate, magnesium carbonate, bentonite clay, MMT clay, etc.
The amount of fillers required in the composition ranges from 0.5 to 20 % wt.
Another embodiment of the present invention provides a process for the preparation of the gelatin free seamless capsules. The process for the preparation of the gelatin free seamless capsules comprises the following steps:
The ingredients of the shell forming composition are dispersed in de-mineralized water and heated to make homogenous solution for manufacturing capsules. The core solution is prepared by dissolving the desired flavouring agent in the oil. The hard shell seamless capsule is prepared by extruding both the core and shell forming solution through a concentrically aligned nozzle. The shell solution is extruded through the outer nozzle and the core solution is extruded through the inner nozzle.

In the present invention, the outlet of the nozzle is placed at a height from the hardening liquid. The spherical droplets formed at the nozzle are collected in hardening oil. The hardening oil in the present invention relates to medium to low chain fatty acid or mineral oils. The temperature of the hardening oil is not more than 20 °C, preferably not more than 10 °C and most preferably not more than 5 °C. Vibrator is optionally used to increase the rate of production of capsules.
The capsules are strained and allowed to complete the process of gel formation by refrigerating the capsules at temperature of not more than 15 °C for 15-20 Hrs. The capsules are air dried at low humidity and at low temperature in suitable drying equipment. The preferable relative humidity (RH) is in the range of 15-50 %, more preferably in the range of 15-40 % and most preferably in the range of 15-30 %. The preferable temperature of the drying air is in the range of 15-45 °C, more preferably in the range of 20-40°C and most preferably in the range of 20-30 °C.
The diameter of the seamless capsule is in the range of 2.0 mm to 4.5 mm. The breaking strength or hardness of the seamless capsule according to the embodiment of the present invention is in the range of 10-15N, most preferably in the range of 12 – 15N. The seamless capsule retains its shape and breaking strength and bursts with an audible sound prior to, during and post the process of smoking on application of pressure. The said seamless capsules are not susceptible to variation of humidity and moisture while storing and during the process of smoking.
Carrageenan used in this case, especially kappa carrageenan, is a negatively charged hydrophilic sulfated polysaccharide with a random coil structure. Carrageenan undergoes a conformational change when the sulfate groups interact with potassium chloride to form a double helix structure leading to the formation of a strong gel. The strong interaction leading to the helical structure restricts the uptake of moisture. The concentration of potassium ion plays a critical role in ensuring that the capsule does not pick up moisture. Optimum concentration of potassium ion is critical to the susceptibility of the capsule to moisture.

The concentration of the moisture retaining agent is equally critical in ensuring that the capsule is not susceptible to moisture. The composition of the gelatin free hard shell seamless capsule of the present invention has optimized the concentration of potassium ion and moisture retaining agent such that it prevents the capsule from absorption of moisture/ humidity during storage and/ or during the process of smoking.

The shell composition of the present invention is composed in such a way that it does not affect or react with the components of cigarettes and other smoking articles and with the constituents of smoke.

The terms “components of cigarettes” and “other smoking articles” according to the present invention refers to cut tobacco, filters, paper, glue, plasticizer, additives, flavour etc. i.e. all components that go into making of cigarettes and other smoking articles.
The term “constituents of smoke” refer to the products generated by the combustion of tobacco, additives and paper.
Advantageously, the constituents of the seamless capsule do not alter the smoke profile while smoking.
The term “smoke profile” refers to the smokers’ smoke sensory perception.
The core of the seamless capsule does not react with the shell material and the components of filter plug material. The term components of filter plug refer to the tow material, wrapping material, plasticizers etc. The core releases only upon breaking the seamless capsule by applying pressure. The core thus released enhances the smokers’ smoking experience. The core material does not react with smoke; interfere with the volume of smoke inhaled by the smoker during puffing. The core does not stain the tipping paper of cigarettes and other smoking articles on bursting of the capsule.
The seamless capsules are inserted into the filter plug material of the cigarettes and other smoking articles. Filter rods are manufactured for use as filter plugs in cigarettes. During the process of filter manufacture using crimped cellulose acetate tow and plasticizer the capsules are inserted at regular intervals into the cellulose acetate tow. The intervals at which the capsules are inserted determine the length of the filter plugs. During cigarette making the filter rods are cut to the desired length to form filter plugs. Each filter plug encases a capsule.
Placement of the capsules does not affect the online/ off line filter tip ventilation and the pressure drop of the filter plug.
The term “filter tip ventilation” refers to vent holes in the tipping paper that allows air to enter the mouth of the smoker during puffing.
The term “online ventilation” refers to the method of perforating the tipping paper directly on to the filter assembly unit of the cigarettes making machine.
The term “offline ventilation” refers to the method of perforating the tipping paper in isolation from the filter assembly unit of the cigarettes making machine.
The term “pressure drop” of the filter plug refers to the difference in static pressure between the two ends of the filter plug when a current of air at the rate of 17.5 ml/sec is passed through it.
The present invention is now illustrated by way of non-limiting examples.
Example 1: Composition of the gelatin free hard shell seamless capsules
Table 1:
Shell forming composition
Material Quantity
K-Carrageenan 5 gm
Potassium chloride 0.5 gm
Propylene Glycol 0.75 gm
Food grade colouring agent 2 mg
De-mineralized water 100 gm
Core forming composition
Material Quantity
MCT(Medium chain triglyceride) 80 gm
Menthol 20 gm

Example 2: Process for the preparation of the gelatin free seamless capsules.
The ingredients of the shell forming composition are disperse in de-mineralized water and heated to around 80-90°C to make a homogenous solution for manufacturing capsules. Gelatin is not used as an ingredient in the composition. The core solution is prepared by dissolving the desired flavoring agent in oil. The core and shell forming solutions are extruded simultaneously through concentrically aligned nozzle into a hardening bath. The capsules are strained and allowed to complete the process of gel formation by refrigerating the capsules at temperature of not more than 15 °C for 15-20 Hrs. The capsules are dried at low relative humidity and at low temperature in suitable drying equipment to obtain gelatin free seamless capsules.
Example 3: Process of incorporation of the gelatin free seamless capsule in the smoking article:

Filter rods are manufactured for use as filter plugs in cigarettes. During the process of filter manufacture using crimped cellulose acetate tow and plasticizer the capsules are inserted at regular intervals into the cellulose acetate tow. The intervals at which the capsules are inserted determine the length of the filter plugs. The tow along with the capsules is enclosed in a plug-wrap. During cigarette making the filter rods are cut to the desired length to form filter plugs. Each filter plug encases a capsule.

Example 4: Analysis of gel strength of gelatin free seamless capsules
Table 2:
Sample Gel Strength (gm/cm2)
Base material of the capsules in the present invention 750-1250 gm/cm2

The gel strength of the carrageenan in the present invention has been measured as per the standard process for measuring the gel strength of carrageenan.

The hardness of the capsule shell depends upon the gel strength of the shell forming polymer. Commercially gelatin is available at gel strength not more than 300 gm/cm2. Generally, to obtain the desired hardness (10-15 N), the solid content needs to be high. Carrageenan of the present invention has gel strength of 750-1250 gm/cm2. Hence the percentage of carrageenan used in the formulation to get the desired hardness is less. The percentage of carrageenan used in the present invention ranges from 2-12 % by weight. The most preferable percentage of carrageenan is 4-7.5 % by weight in the formulation. It should be noted that viscosity of polymer solution increases with increase in solid content and after a critical concentration viscosity increases exponentially which may affect processibility in some polymer grades depending upon their initial viscosity.

Example 5: Effect of percentage of carrageenan

To elaborate the effect of percentage of carrageenan on hardness and processibility a set of capsules is prepared with the below formulation. Set-II is the reference sample for the comparison. The formulation of Set-I and Set-III has been made based upon the ratio of gelling agent and propylene glycol in Set-III to show only the effect of the percentage of carrageenan on hardness and processibility.
Table 3:
Material in gms. Set-I Set-II Set-III
Carrageenan 5 12 25
Gelling agent(Potassium chloride) 0.3 0.7 1.5
Propylene Glycol 0.8 2 4.2
Water 200 200 200

Hardness (N) Set-I Set-II Set-III
5.6 N 11.3 N Not Applicable

Process: The formulation is heated to 85-90°C for 45min-1 Hr. to get flowable solution. Set-III didn’t melt at all in the processing temperature range. Capsules are prepared with melt of Set-I and Set-II and dried in air dryer at low relative humidity (RH: 30) and low temperature (20°C). The hardness of the capsules is compared immediately and presented below.

Observation: The data shows that the hardness of the capsules made with lesser percentage of carrageenan do not produce the desired hardness and may break during handling and during the process of insertion of the capsules in the filter rod.

Example 6: Analysis of breaking strength and susceptibility to variation in humidity and moisture during storage and during the process of smoking for gelatin free seamless capsules of the present invention.

Table 4:
Reference sample Breaking Strength (N)
Capsules of the present invention 11.3 N

Observations:
The data obtained from the evaluation shows that percentage decrease of breaking strength of the gelatin free capsules of the present invention is less than 10%. The capsule inside the filter is exposed to moisture and temperature during smoking. Commercially available gelatin based capsules tend to deform or are destroyed i.e. tend to soften resulting in a drop in the breaking strength when exposed to these conditions during the process of smoking. The conditions the capsules are subjected to during smoking are simulated at 90% RH with temperatures of 200C and 400C. Capsules are exposed to conditions of 90% RH and 200C and 90% RH and 400C for a period of 10 minutes and the breaking strength is determined immediately post the exposure (Figure 3). Gelatin free capsules of the present invention is subjected to the conditions mentioned above and the breaking strength data is compared with the reference sample exposed to the ambient condition (RH: 57 %, Temp: 270C).

Result and observation: Higher breaking strength of the capsules pre and post the process of smoking is essential. The capsules must have enough strength to withstand the shear force during handling and during the process of insertion of the capsules in the cigarette filter rod. The post smoking strength of the capsules is required as during/post the smoking of the cigarette the smoker can burst the capsule with audible sound to ensure that the capsule is burst and the flavour is released.

In most of the commercially available gelatin based capsules, the initial breaking strength is high but the breaking strength decreases proportionately with each puff. This is because the gelatin based capsules picks up moisture during the course of smoking and softens and do not possess enough strength to break with audible sound.

Example 7: working ratio of gelling agent to carrageenan ranges from 1:5 to 1:25.
Table 5: Shell forming composition with different amount of gelling agent
Material in gm Set-I Set-II Set-III
Carrageenan 12 12 12
Gelling agent e.g. potassium chloride 0.7 0.2 3.5
Propylene Glycol 2 2 2
Water 200 200 200

Result and observation: Three set of capsules were prepared with the below compositions. The shell forming composition was melted at 80-90 °C. It was observed that Set-III is not melting due to higher percentage of gelling agent. It is known that with increase of the percentage of gelling agent the melting point of carrageenan increases. Capsules were prepared with Set-I and Set-II and the hardness of the capsules were compared with the reference sample after exposing the capsules in a simulated condition (similar to the condition of capsule during smoking) with relative humidity (RH) 90 % and temperature 40 °C for a period of 10 minutes.

Example 8: working ratio of moisture retaining agent to carrageenan is 1:5 to 1:30 and most preferably, 1:2 to 1:12.
Table 6: Shell forming composition with different amount of moisture retaining agent
Materials in gm Set-I Set-II Set-III
Carrageenan 12 12 12
Gelling agent e.g. potassium chloride 0.7 0.7 0.7
Propylene Glycol 0.25 1.5 7
Water 200 200 200

Three set of capsules were prepared with kappa carrageenan as base material by varying the amount of moisture retaining agent, propylene glycol, to evaluate the effect of moisture retaining agent on the physical and mechanical properties of the capsules
Observation: Capsules with very low moisture retaining agent (Set-I) with moisture retaining agent to carrageenan ratio 0.02 are very brittle and breaks while storing and during handling. Capsules of Set-II have moisture retaining agent to carrageenan ratio 0.125 and are not brittle and do not break during storing or handling. Capsules of Set-III have higher moisture retaining agent to carrageenan ratio 0.58 and are soft. They flatten while applying pressure and puncture without producing audible sound.