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`EX 1010
`IPR of U.S. Pat. No. 7,829,595
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`4,931,286
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`HIGH GLOSS CELLULOSE TABLET COATING
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`FIELD OF THE INVENTION
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`The invention relates to pharmaceutical tablets. In
`particular a sodium carboxymethylcellulose/plasticizer
`coating provides high gloss for such tablets.
`BACKGROUND OF THE INVENTION
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`Coated tablets are well known in the pharmaceutical
`industry. In addition to pharmaceutical books, manuals
`and technical literature, patent publications in this field
`include: U.S. Pat. Nos. 4,543,370 and 4,683,256 on a
`tablet coating composition of methylcellulose or so-
`dium ethylcellulose sulphate in water or alcohol; Cana-
`dian Patent 1,217,140 on a solvent coating composition
`comprising polyvinyl pyrrolidone, hydroxymethylcel-
`lulose, ethylcellulose, sodium lauryl sulphate and prop-
`ylene glycol; European Patent Application 0 253 541 on
`a coating with a water permeable but water insoluble
`ethyl cellulose and dibutyl sebacate.
`Aqualon Bulletin VC—556, The Use of K1ucel® Hy-
`droxypropylcellulose, NF, To The Utility ofHydroxpropyl-
`methylcellulose in Aqueous Film Coating, describes how
`tablets coated from water solutions do not give high
`gloss such that a polishing coat step is used after the
`polymer coating in order to improve tablet appearance.
`Film coating of pharmaceutical tablets have been
`carried out for years using organic solvents which pro-
`vided high gloss finishes. With the move toward the use
`of water for tablet coatings to avoid the need for solvent
`recovery systems, it was observed that high gloss tab-
`lets could not be produced without the use of organic
`solvent.
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`SUMMARY OF THE INVENTION
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`A high gloss tablet comprises at least one active in-
`gredient in a binder matrix as a core with an outermost
`coating of sodium carboxymethylcellulose having a
`degree of substitution (D.S.) between 0.2 and 1.4 and a
`degree of polymerization (D.P.) between 100 and 4000
`and a plasticizer.
`In a preferred tablet composition the active ingredi-
`ent is pharmaceutically active, the plasticizer is polyeth-
`ylene glycol and D.S. is between 0.5 and 0.9 and D.P. is
`between 200 and 1000 for sodium carboxymethylcellu-
`lose.
`‘
`A method for preparing high gloss tablets comprises i
`the steps:
`-
`(1) preparing an aqueous solution of sodium carboxy-
`methylcellulose and a plasticizer; and
`(2) applying the solution to tablets to provide a
`weight gain of from 0.1 to 5.0% by weight.
`In a preferred process the sodium carboxymethylcel-
`lulose has a D.S. between 0.5 and 0.9 and a D.P. be-
`tween 200 and 1000, the plasticizer is polyethylene gly-
`col and the weight gain of the tablet is 1.0 to 2.0%.
`DETAILED DESCRIPTION OF THE
`INVENTION
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`It has been discovered that tablets coated with so-
`dium carboxymethylcellulose from a water solution
`have a much higher gloss than with other cellulosic
`polymers. This discovery eliminates the need to in-
`crease the gloss by an additional coating. In addition
`only very small amounts of sodium carboxymethylcel-
`lulose are needed for these high gloss coatings, thus
`providing an unexpected economic advantage in terms
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`of raw material costs and processing times. Further-
`more, sodium carboxymethylcellulose films dissolve
`much more rapidly than films such as hydroxypropyl-
`methylcellulose and thus are less likely to interfere with
`the dissolution of drug from a coated tablet.
`Sodium carboxymethylcellulose is a cellulose gum
`available as AQUALON TM from the Aqualon Com-
`pany as a 99.5% purity free flowing powder which
`meets all specifications of the U.S. PHARMACO-
`POEIA. For the purposes of the present invention the
`sodium carboxymethylcellulose must have a degree of
`substitution (D.S.) between 0.2 and 1.4 by carboxy-
`methyl groups based on 3.0 as total substitution of avail-
`able androhexoic sites, and the degree of polymeriza-
`tion (D.P.) must be between 100 and 400 for the cellu-
`lose polymer being substituted.
`Sodium carboxymethylcellulose provides high gloss
`for a tablet when coated along with a plasticizer to give
`a weight gain to the tablet of from 0.1 to 5.0%. Prefera-
`bly the range is 1.0 to 2.0%. It is not necessary that all
`of the polymer coating comprise sodium carboxy-
`methylcellulose as long as there is sufficient quantity to
`provide the desired gloss.
`is used
`A pharmaceutically approved plasticizer
`along with sodium carboxymethylcellulose as the pri-
`mary components of the tablet coating composition in
`water. Polyethylene glycol with a molecular weight of
`about 400 is a preferred plasticizer. This material and
`other suitable plasticizers are available from Union Car-
`bide Corporation.
`Other ingredients which can be incorporated in the
`tablet coating include: colorants, opacifying materials,
`surfactants, stabilizers, silicas, silicones, preservatives.
`surface treatment agents, flavorants and other polymers
`deemed necessary and useful in promoting the utility,
`value and ease of preparation of the tablet or of coating
`the tablet.
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`In the following Example a spray apparatus known as
`Accela-Cota available from Thomas Engineering was
`employed wherein the Accela-Cota was set up as fol-
`lows:
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`Spray Gun: Binx Model 61
`Fluid Nozzle: 63ASS
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`Air Cap: 66SD
`Nozzle Pressure: 50 psi
`Cylinder Pressure: 50 psi
`Masterflex Head: 7020-50
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`Coating Solution Flow Rate: 30 gm/minute
`Pan Speed: 12 rpm
`Tablet Batch Size: 10 Kg
`Inlet Temperature Setting: 60 C.
`Outlet Temperature: 38 C.
`The invention has industrial applicability for the man-
`ufacture of pharmaceutical tablets. The following exam-
`ple illustrates the practice of the invention.
`EXAMPLE 1
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`With stirring 50 g of sodium carboxymethylcellulose
`available from Aqualon Company as grade 7L2P was
`slowly added to 940 g deionized water. Mixing was
`continued until the solution cleared. Then 10 g polyeth-
`ylene glycol available from Union Carbide as PEG 400,
`USP was added and mixed until a uniform solution was
`obtained. Solution viscosity was measured to see if a
`value between 125 and 150 cps was obtained in order to
`provide good coating using the Accela-Cota.
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`4,931,286
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`Tablets were charged into the pan and allowed to
`warm up for 15 minutes. Then spraying was begun and
`ended when acceptable gloss level had been achieved.
`Numerous runs were made with various sized oval
`and round tablet batches. It was observed that accept-
`able gloss levels were obtained with about 2% or less
`tablet weight gain, but that improvement in gloss could
`require coatings ranging from 0.1 to 5.0% weight gain
`depending on the core composition of the tablet being
`coated. Thus a large tablet core with a rough surface
`would require a heavy polymer coating to give high
`gloss, whereas a small tablet with a very smooth surface
`would require very little coating to give high gloss.
`What is claimed is:
`
`1. A high gloss pharmaceutical tablet comprising of at
`least one active ingredient in a binder matrix as a core
`with an outermost coating of sodium carboxymethylcel-
`lulose having a degree of substitution (D.S.) between
`0.2 and 1.4 and a degree of polymerization (D.P.) be-
`tween 100 and 400 and a polyethylene glycol plasticizer
`wherein the outermost coating is applied from a water
`solution by spray coating.
`2. The tablet of claim 1 where the active ingredient is
`a medicant.
`3. The tablet of claim 2 where the outermost coating
`comprises 0.5 to 5.0% by weight of the total weight of
`the tablet.
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`4. The tablet of claim 3 where the polyethylene gly-
`col plasticizer has a molecular weight of about 4-00.
`5. The tablet of claim 4 where the sodium carboxy-
`methylcellulose has a D.S. between 0.5 and 0.9 and a
`D.P between 200 and 1000.
`6. The tablet of claim 5 where the coating contains a
`colorant.
`7. A method for preparing high gloss pharmaceutical
`tablets comprises the steps:
`(1) preparing an aqueous solution of sodium carboxy-
`methylcellulose having a degree of substitution
`(D.S.) between 0.2 and 1.4 and a degree of poly-
`merization (D.P.) between 100 and 4-00 and a poly-
`ethylene glycol plasticizer; and
`(2) applying the solution to pharmaceutical tablets by
`spray coating to provide a weight gain of from 0.5
`to 5.0% based on the total weight of the pharma-
`ceutical tablet.
`8. The method of claim 7 where the plasticizer is
`polyethylene glycol with a molecular weight of about
`400.
`9. The method of claim 8 where the sodium carboxy-
`methylcellulose has a D.S. between 0.5 and 0.9 and a
`D.P. between 200 and 1000.
`10. The method of claim 9 where the weight gain is
`1.0 to 2.0%.
`III
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