FORM 2
THE PATENT ACT 1970
(39 of 1970)
&
The Patents Rules, 2003
PROVISIONAL SPECIFICATION
(See section 10 and rule!3)
1. TITLE OF THE INVENTION: "Novel Coating Technique
2. APPLICANT
(a) NAME: CIPLA LTD.
(b)NATIONALITY: Indian Company incorporated under the Indian Companies ACT, 1956
(c) ADDRESS: 289, Bellasis Road, Mumbai Central, Mumbai - 400 008,
Maharashtra, India
3.PREAMBLE TO THE DESCRPTION
The following specification particularly describes the invention:

Technical field:
The present invention relates to a novel technology to increase the aesthetic appearance of the tablet composition so that they can be patient compliant to both the children and geriatrics.
Background and prior art:
Medicaments in the form of tablets, containing a core comprising active agent and a coating surrounding the core are well known in the art. Coatings are employed around active-containing cores for a variety of reasons. For example, they may effectively protect the active substance from aggressive physiological media prior to the delivery of the medicament to the preferred site of absorption, or they may be employed as a means of modulating the release of the active agent from the core. Coatings may also be employed for aesthetic purposes such as to include a flavourant as a means of masking a bitter-tasting active agent or excipients, or they may be used to impart colour or combinations of colour in order to act as a visual cue to a patient as to the nature of the medicament that is being taken, or as a means of branding.
In today's world of competition and increased importance to aesthetics it has become necessary to even improvise on the presentation of tablets. These also have the advantages they can be made attractive so as to make them acceptable to children who usually are unwilling to take tablets. Another advantage is the ease of identification of tablets to geriatric patients.
EP-B-0,060,023 discloses a method of emphasizing intagliations in colored (i.e. not white) solid articles, in particular tablets, by coating the tablet surface and filling up the intagliations with a coating film comprising an optically anisotropic substance. The powdery material is taught to adhere better to the intagliations of coated tablets than to those of uncoated tablets. Adherence can further be increased by using a mixture of a wax and a powdery material as the deposition material and heating the filled tablets to 40°-90° C. in order to melt the wax. Finally, an outer coating may be applied to the filled tablets but it has been observed that the adhesion of the powdery material to the intagliations is
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not satisfactory as said material shows a tendency to loosen and fall out. Also, the necessity to heat the tablets filled with a wax and a powdery material in order to melt said wax, poses a hardly acceptable risk since many medicines are thermolabile and might deteriorate significantly in the process.
So there remains a need to provide tablets that can be distinguished from other tablets, so as to enable them to avoid any confusion while taking their tablets. Also there remains a need to make the tablets more attractive for children.
The present invention attempts to provide and novel technology to improvise the aesthetics of tablets so that they can be patient compliant to both the children and geriatric patients.
Objectives of the Invention:
The object of the present invention is to provide tablets with improved aesthetics so that they can be patient compliant to both the children and geriatrics.
Another object of the present invention is to ensure that the physicochemical characteristics of the tablets are not hampered.
Yet another object of the present invention is to provide the tablets which are protected from moisture.
A further objective of the present invention is to have various shapes and characters engraved in the tablet with a color different than the tablet.
Yet another object of the present invention is to provide a novel technology to manufacture tablets according to the present invention.
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Summary of the Invention:
There is provided by the present invention tablets having various shapes and characters engraved in the tablet by highlighting the same by selectively depositing and fixing in said engravements a material having a different color than that of the tablet surface.
In another embodiment of the present invention there is provided by the present invention a novel technology to manufacture tablets according to the present invention.
Description of the Invention
As described above aesthetics-in relation to drugs also plays a major role today. It is also necessary to ensure that while improving the aesthetics the physicochemical properties of drug should not be compromised. In addition to that there are many problems when it comes to give tablets to children and geriatrics. Children generally avoid tablets and there are also sometimes when certain drugs cannot be given as oral liquids. In cases if the attractive tablets are provided to children, they will be willing to take it.
Geriatric drugs regimen includes not one but a numbers of tablets and at times it is confusing if the tablets have a similar color and shape. In such cases if the tablets are with different shapes or characters and these are highlighted, it will help them to avoid any confusion.
While addressing these issues one also has to ensure that the physicochemical characteristics of the tablets are not characterized.
According to the present invention there are provided a method to improve the presentation of tablet formulations to address the above mentioned issues.
One embodiment of the present invention relates to a method of highlighting the engravements in coated tablets by coating the said tablets with Shellac and then depositing onto said tablets a suspension comprising a material having a different color, to obtain tablets according to the said method.
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Processes using wax have a disadvantage in that, the wax needs to be melted and so the process becomes time consuming. Also while using wax coatings one has to raise the temperature of the coating pans to about 30°C - 60°C. This can sometimes be disadvantageous when working with thermolabile drugs. The advantage of using shellac is that there is no need of melting and the entire process can be completed in much lesser time as compared to the processes using wax. Also the entire process of coating can be done at room temperature and so there is no problem while working with thermolabile drugs. In the processes using wax, the wax is adsorbed on the surface of the tablets and so there are chances that the wax coatings may hinder the dissolution of the tablets. Shellac coatings form a transparent coating around the tablets and hence will not affect the dissolution. Another advantage of using shellac coatings it imparts a moisture protective coating around the tablet.
Another embodiment of the present invention relates to a method of highlighting the engravements in coated tablets by coating the said tablets with gelatin and then depositing onto said tablets a suspension comprising a material having a different color, to obtain tablets according to the said method. Unlike wax coatings, gelatin does not hinder the dissolution of the tablets.
The tablets used as a substrate preferably are film-coated. Film-coated tablets allow a more selective bonding of the filling material to the engravements and less adherence to the tablet surface than uncoated tablets because of the reduced porosity of the tablet surface (decreased roughness). The engravements may be of different shapes, size and may include figures, marks, characters, design, patterns or any combinations thereof, in a tablet by a punching procedure.
A wide variety of filling materials can be used for the filling of the engravements. Suitable filling agents are, for example, starches, e.g. corn starch, rice starch, wheat starch, potato starch, preferably corn starch or rice starch; celluloses, e.g. methylcellulose, ethylcellulose, carboxymethylcellulose, hydroxypropylcellulose, hydroxypropyl methylcellulose, hydroxypropyl methylcellulose phthalate, crystalline cellulose, preferably microcrystalline cellulose; lactose and other sugar or sugar alcohols, e.g.
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sucrose or mannitol, spray-dried and micronised lactose or mannitol; organic acids, e.g. stearic acid, fumaric acid, citric acid, preferably fumaric acid; or inorganic substances, e.g. sodium chloride, calcium carbonate, preferably sodium chloride, all giving white engravements. Other finely divided filling materials such as titanium oxide, talc, kaolin, calcium oxide, magnesium oxide, magnesium stearate, stearic acid salts like calcium stearate and aluminum lakes. Colored highlights to engravements are obtained by previously dyeing the filling material. The preferred ones are talc, calcium oxide, magnesium oxide, magnesium stearate, stearic acid salts like calcium stearate. The most preferred ones are fillers with magnesium salts like magnesium stearate and magnesium oxide.
Suitable solvents that are used in the present invention include non aqueous solvents like ethanol, isopropyl alcohol, methylene chloride, acetone.
In a further embodiment of the present invention there is provided the method to manufacture the tablets according to the present invention. According to this embodiment of the present invention the film-coated tablet with engravings may further be coated with shellac. The shellac coated tablets may further be coated with a suspension of the filler in non- aqueous solvent. The tablets so obtained may then be polished.
In a still further embodiment of the present invention, there is provided another method to manufacture the tablets according to the present invention. According to this embodiment of the present invention the film-coated tablet with engravings may further be coated with a suspension of shellac and filler in non- aqueous solvent. The tablets so obtained may then be polished.
The above two methods may be carried out using gelatin. Also in case colored highlights are required, colors may suitably be added to the coating suspensions.
The suspensions may be sprayed on the coated tablets in suitable coating equipments like a flow-through type coating pan or in a perforated side-vented pan by means of a spray worked by air pressure. Preferably said suspension is kept at room temperature and is stirred or agitated to prevent sedimentation.
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The tablets obtainable by the aforementioned methods have superior highlighted engravements and said tablets are meant to constitute an aspect of the present invention.
The different steps involved in the filling and coating processes are described in more detail below by means of example and are not intended in any way to limit the scope of the present invention.
Example:
The film coated tablets were coated with a first suspension of shellac in isopropyl alcohol. The shellac coated tablets were then coated with a second suspension of magnesium stearate in ethanol. The above coated tablets were then dried and polished with muslin cloth.


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