MXPA99007660A - Chewable tablets sua - Google Patents

Abstract

The present invention relates to a compressed chewable tablet containing at least one active ingredient, a carbohydrate that can be compressed and disintegrable in water and a binder, these components are dry mixed and compressed to form a convex shaped tablet having a hardness of about 2 to about 11 kp / cm2 and a friability of less than

Description

SMOOTH SMOOTH TABLETS FIELD OF THE INVENTION The present invention relates to soft, compressed and convex shaped chewable tablets, and to a process for preparing said tablets.

BACKGROUND OF THE INVENTION Chewable tablets are widely used in the pharmaceutical industry for patients, such as children, who have difficulty swallowing conventional tablets or capsules. Tylenol® chewable tablets for children are an example of a pediatric chewable acetaminophen tablet sold in the United States. These tablets are packaged in bottles and have a flat surface shape and beveled edge. Samples of these tablets obtained from places of sale had hardness (average of ten tablets) that varied from 5.3 - 13.1 kp or normalized hardnesses of 12.3 - 30.5 kp / cm2. Many commercially available pediatric chewable tablets contain active ingredients that are coated with polymers to mask their unpleasant taste. However, the forces used to compress these tablets can fracture the polymer coatings, which reduces the effectiveness of the taste masking system. Rapidly disintegrating dosage forms, such as those described in the U.S. patent. No. 5,464,632, issued November 7, 1995, are also available to patients, particularly elderly and pediatric patients, who have difficulty swallowing tablets or caplets. However, the fast-disintegrating dosage forms currently available are highly friable, and require the use of special handling and expensive packaging, eg, specially designed bubble packings, to avoid rupture or fragmentation of the tablets. These limitations increase the cost of the product significantly. The shape of the tablet also affects the friability of it. T. Chakrabarti et al. In The Indian Journal of Pharmacy, Vol. 38, No. 3, pp. 62-65 (1975) describe that lower friability was observed in beveled flat tablets followed by standard flat and convex tablets. Similarly, K. Sugimori et al. In Powder Technology, Vol. 58, pp. 259-264 (1989) report that crown formation occurs more commonly in convex shaped tablets than in flat surface tablets. Therefore, there is a need for compressed chewable tablets that have improved flavor, but exhibit low friability so that they can be processed with standard bulk handling equipment and packaged in bottles.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides a compressed chewable tablet containing at least one active ingredient, a water-soluble and compressible carbohydrate and a binder. These components are dry blended and compressed to form a convex shaped tablet having a hardness of about 2 to about 11 kp / cm2. The tablet has a friability of less than 1%. In a preferred embodiment of the present invention, the compressed chewable tablet is prepared by dry blending the active ingredient, the water-disintegrable, compressible carbohydrate and the binder, and then compressing them to form a convex-shaped tablet having a hardness of about 2. at approximately 11 kp / cm2. If the active ingredient has an objectionable taste, it is coated with a taste masking composition. Compression with reduced forces decreases the fracture of the coating used to mask the unpleasant taste of the active ingredient. These convex-shaped chewable tablets are milder than conventional chewable tablets, which results in improvements in product taste, mouthfeel and ease of chewing. The convex geometry of the tablet significantly reduces the friability of the tablet at a certain compression force. This reduction in the friability of the tablet allows the use of lower compression strengths and lower tablet hardnesses, while maintaining the ability to process tablets with conventional bulk handling equipment and pack them in conventional bottles.

BRIEF DESCRIPTION OF THE DRAWINGS Figures 1a and 1b are front and side views, respectively, of a biconvex tablet of the present invention. Figure 2 is a graph of friability (loss of% by weight) against hardness (kp / cm2) for a bevelled edge tablet and flat surface (control) and a concave tablet of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES The chewable and compressed tablets of the present invention comprise at least one active ingredient, a carbohydrate that can be compressed and disintegrable in water and a binder. These ingredients are mixed dry and then compressed to form a convex shaped tablet having a hardness of about 2 to about 11, preferably about 5 to about 8.5 kp / cm2. The friability of the tablet is also preferably less than 1%. Ratchet machines, preferably those capable of applying separate precompression and main compression forces, are used to compress the ingredients into tablets. Since the ingredients are dry blended, soluble as well as water insoluble ingredients can be used to make the tablet. If the active ingredients have an objectionable taste, they can be coated with a taste masking composition. The water-dispersible, compressible carbohydrate used in the present invention includes carbohydrate materials conventionally used in tablets. Carbohydrates facilitate the breakdown of the dosage form after oral administration, and are described in Lieberman et al., Pharmaceutical Dosage Forms, Marcel Dekker, Inc., New York, 2 Ed. Vol. 205-209 (1990), which is incorporated herein by reference. Preferred compressible and water-disintegrable carbohydrates include mannitol, sorbitol, maltitol, dextrose, sucrose, xylitol, lactose and mixtures thereof. The binder of the present invention is used to add cohesiveness to the formulation, then providing the necessary bond to form a cohesive or compact mass after compression. These binders are conventionally used in direct compression tablets and are described in Lieberman et al., Pharmaceutical Dosage Forms, Marcel Dekker, Inc., New York, 2 Ed. Vol. 209-214 (1990), which is incorporated herein by reference. Preferred binders include cellulose, cellulose derivatives, polyvinyl pyrrolidone, starch, modified starch and mixtures thereof, and, in particular, microcrystalline cellulose available from FMC Corp. under the trademark AVICEL® PH 101. The tablets of the present invention are used to orally administer a wide variety of active ingredients. Suitable active ingredients include pharmaceuticals, minerals, vitamins and other nutraceuticals. Suitable pharmacists include analgesics, decongestants, expectorants, antitussives, antihistamines, gastrointestinal agents, diuretics, bronchodilators, sleep-inducing agents and mixtures thereof. Preferred pharmaceutics include acetaminophen, ibuprofen, flurbiprofen, naproxen, aspirin, pseudoephedrine, phenylpropanolamine, chlorpheniramine maleate, dextromethorphan, diphenylhydramine, famotidine, loperamide, ranitidine, cimetidine, astemizole, terfenadine, terfenadine carboxylate, cetirizine, mixtures thereof. and pharmaceutically acceptable salts thereof. The active ingredient (s) are present in the tablet in an effective therapeutic amount, which is an amount that produces the desired therapeutic response after oral administration and can be readily determined by one skilled in the art. To determine such amounts, the particular compound being administered, the bioavailability characteristics of the ingredient, the dosage regimen, the age and weight of the patient, as well as other factors must be considered.

If the active ingredient has an objectionable taste, a coated particle containing the active ingredient coated with a taste masking coating is employed. The active ingredient can be coated with taste masking coatings known in the art, such as those described in the US patent. No. 4,851, 226, issued July 25 to T.W. Julian and others; US patent No. 5,075.1 14, issued on December 24, 1991 to E.J. Roche and patent of E.U. No. 5,489,436, issued February 6, 1996, all of which are hereby incorporated by reference. The commercially available masked taste active ingredients can also be employed. For example, acetaminophen particles that are encapsulated with ethylcellulose or other polymers by a coacervation process can be used in the present invention. Acetaminophen encapsulated by coacervation can be purchased from Eurand America, Inc., Vandalia, Ohio, or Circa Inc., Dayton, Ohio. As used in the present invention, the term "coated particle" refers to a solid active ingredient in the form of a crystal or particle, an agglomerate of individual particles or a granulated particle, which has been encapsulated with a masking composition of flavor, either by film coating or by other process such as coacervation. The tablet can provide an immediate or prolonged release of the active ingredient.

Flavor masking compositions suitable for use as coatings are provided in the following table: Polymer system Coating level1 Relation of polymers2 Cellulose acetate / PVP 5-60% 90/10 to 60/40 Cellulose acetate butyrate / PVP 5-60% 90/10 to 60/40 Cellulose acetate / HPC 5- 60% 90/10 to 50/50 Cellulose acetate butyrate / HPC 5-60% 90/10 to 50/50 Cellulose acetate / EUDRAGIT E100 8-60% All ratios Cellulose acetate butyrate / EUDRAGIT E 100 8 -60% All ratios Ethylcellulose / PVP 8-60% 90/10 to 60/40 Ethylcellulose / HPC 8-60% 90/10 to 50/50 Ethylcellulose / EUDRAGIT E 100 8-60% All ratios HPC 10-60% ND HEC 10-60% ND EUDRAGIT E 100 10-60% ND HPMC 10-60% ND HEC / HPMC 10-60% All relations HPC / HPMC 10-60% All ratios Polymer system Coating level1 Relation of polymers2 HEC / HPC 10-60% All relationships 2-vinylpyridine / styrene copolymer 10-60% ND CgA / 2-vps 8-60% All relations CAB / 2-vps 8-60% All relations Ethylcellulose / 2-vps 8-60% All relations Cellulose triacetate / PVP 8-60% 90/10 to 60/40 Cellulose triacetate / HPC 8-60% 90/10 to 50/50 Cellulose triacetate / EUDRAGIT E 100 8-60% All ratios 1 Percentage by weight of the coated particle in a dry state. 2 Weight PVP - polyvinylpyrrolidone HPC - Hydroxypropylcellulose HEC - Hydroxyethylcellulose HPMC - Hydroxypropylmethylcellulose CA - Cellulose acetate CAB - Cellulose acetate butyrate 2-VPS - 2-vinyl pyridine styrene EUDRAGIT ™ E-100 - methylaminoethyl methacrylate and methacrylic acid esters Neutral available from Rohm Pharma GmbH, Germany.

Substantially all of the active ingredient or the granulated active ingredient should be coated with a layer of a taste masking composition having a thickness of about 3 to about 10 microns. The coating should be substantially free of cries, holes or other imperfections when examined under a scanning electron microscope at 100-500x. If taste masking is required, the active ingredient is preferably coated with a mixture of a first polymer selected from the group consisting of cellulose acetate and cellulose acetate butyrate, and a second polymer selected from the group consisting of polyvinylpyrrolidone and hydroxypropylcellulose . The weight ratio of the first polymer to the second polymer is this mixture is on the scale of about 90:10 to about 50:50, and preferably around 90:10 to about 70:30. The mixture of the first and second polymers can be applied directly on the pure active ingredient or can be applied on a granulated particle containing the active. In the case of a granulated particle, such as a rotogranulated particle, the active will constitute from about 5 to about 90 percent by weight of the particle, with the remainder being the binder or filler. Suitable binders for the granulated particles include polyvinylpyrrolidone, hydroxypropylmethylcellulose, hydroxypropylcellulose and other pharmaceutically acceptable polymers. Fillers suitable for use in such granulated particles include lactose, confectionery sugar, mannitol, dextrose, fructose, other pharmaceutically acceptable saccharides, and microcrystalline cellulose. The coated particles can be prepared by spraying an organic solvent solution of the polymer mixture onto the active ingredient, or a granulated particle containing the active ingredient, in a fluidized bed, such as a Wurster coating apparatus or a rotogranulator. A wide variety of organic solvents can be used to prepare the solution of the polymer mixture. For example, a solvent that is preferred is a mixture of acetone and methanol, but other solvent systems may be employed, including methylene chloride, methylene chloride-methanol, acetone-ethyl acetate, toluene-ethanol and acetone-ethanol. In general, the proportion of the polymer mixture in the solvent solution will be in the range of about 5 to about 20, preferably about 8 to about 15, percent by weight, depending on the solvent and other similar considerations. When a fluidized bed coating operation is used, air, which can be heated, passes through a bed of the solids of the active ingredient to fluidize them, and the solution of the polymer mixture is sprayed onto the fluidized bed and from this way it covers the active ingredient. The air that passes through the bed dries the coating on the active ingredient, so that a coated and dry granule is obtained.

Conventional fluidized bed coating equipment can be used in the present invention to coat the active ingredient or rotogranulated particle containing the pharmaceutical ingredient. This equipment includes the Wurster fluidized bed coating apparatus, in which the solution of the polymer mixture is sprayed from the bottom of the chamber, and a rotogranulator, in which the solution of the polymer mixture is sprayed tangentially . These coating operations are described in more detail in Lieberman et al., Pharmaceutical Dosage Forms, Marcel Dekker, Inc., New York, Vol. 3, pp. 138-150 (1990), which is incorporated herein by reference. The coated particle, in a dry state, generally contains about 5 to about 60, preferably about 10 to 40, percent by weight of the mixture of the first and second polymers. However, the exact proportions of the coating to the active ingredient may vary, depending on the level of taste masking that is required and on whether a prolonged or immediate release of the active ingredient is desired. Larger proportions of the coating tend to provide a prolonged release effect and increase taste masking. The tablet may also contain ingredients other than the coated particles, the carbohydrate and the binder. Additional ingredients include sweeteners, such as aspartame, acesulfame potassium, sucralose and saccharin; and lubricants, such as magnesium stearate, stearic acid, talc and waxes. The dosage form can also incorporate pharmaceutically acceptable adjuvants. Such adjuvants include, for example, preservatives, flavors, antioxidants, surfactants and / or dyes. The tablets, on a dry basis, generally comprise about 0.1 to about 60, preferably about 12 to about 25 weight percent of the active ingredient; from about 30 to about 90, preferably from about 40 to about 65 weight percent of the carbohydrate material compressible and disintegrable in water; from about 1 to about 30, preferably from about 5 to about 20 weight percent of the binder; from about 0.1 to about 5, preferably about 0.5 to about 1.5 weight percent of the lubricant; from 0 to about 5, preferably from about 0.1 to about 3.0 weight percent of the sweetener; from 0 to about 5, preferably from about 0.2 to about 2.0 percent by weight of the flavor and from 0 to about 5, preferably from about 0.01 to about 0.4 percent by weight of the colorant. The weight unit of the tablet will vary depending on the dose of the active ingredient. The unit of weight will generally vary from about 250 to about 1000 mg. A typical dosage form may contain: Ingredient Unit weight (mg) Active ingredient 0.5 - 600 Compressible carbohydrate 80 - 900 Binder 10 - 200 Lubricant 1 - 15 Sweetener 0 - 30 Flavoring 0 - 20 Dye 0 - 10 If taste masking is required, the coated particles of the active ingredient are prepared using the techniques mentioned previously. The particle size of the coated particles, as well as the remaining components, is generally less than 600 microns. The components of the tablet are then mixed dry to form a uniform powder mixture. The mixture is then compressed to form a tablet of the desired hardness using conventional compression tacking techniques. In a preferred embodiment of the invention, the compressed chewable tablet has a convex or biconvex shape and is relatively smooth to provide adequate mouthfeel and taste and ease of chewing. In general, the tablet will have a diameter of about 7 to about 19, preferably about 9 to about 13 mm, and a thickness of about 2 to about 12, preferably about 3 to about 8 mm.

Figures 1a and 1b are top and side views, respectively, of a biconvex tablet 10 of the present invention. The tablet 10 has a pair of opposing surfaces 12 and a lateral surface 14. The intersection of the surfaces 12 with the lateral surface 14 defines the edges 16. The surfaces 12 of the biconvex tablet 10 have two radii of curvature, R- \ and R2. The radius of curvature Ri in the portion of the surface 12 near the edge 16 (smaller axis cup radius) measures about 0.7 to about 7.6, preferably about 2.36 mm. The radius of curvature R2 at the center of the surface 12 of the tablet (cup radius of the major axis) measures about 7 to about 76, preferably about 25.2 mm. Alternatively, the cup radius of the minor axis R-i is about 10% to about 40% of the diameter of the tablet, while the cup radius of the major axis R2 represents about 100% to about 400% of the diameter of the tablet. The radius of curvature of the surface of a simple convex tablet of the present invention (not shown) measures approximately 5 to approximately 60 mm, which represents approximately 75% to approximately 300% of the diameter of the tablet. Triconvex tablets can also be used. The external pressure applied by the tablet press during the compression step is controlled so that the hardness of the tablet is in the range of about 2 to about 1 1, preferably about 5 to about 8.5, kiloponds (kp) per square centimeter (cm2). The resistance to rupture of the tablet, or hardness, depends on the cross-sectional area at the point of rupture of the tablet. To compare values through tablets of different sizes, the breaking strength must be normalized to the area of the rupture. This normalized value, expressed in kp / cm 2, is commonly known in the art as resistance to tablet strain. The hardness is measured by conventional pharmaceutical hardness testing equipment, such as a Schleuniger hardness tester. During the tapping it is preferable to apply the compression forces in two steps. A precompression pressure of about 2 to about 17, preferably about 5.5 to about 1.5, kN / cm 2 is applied. The main compression pressure is then applied from about 3 to about 18, preferably about 7 to about 13 kN / cm2 to complete the compression operation. Alternatively, the tablet can be formed in a compression step using a compression pressure of about 3 to about 18, preferably about 7 to about 13 kN / cm2. The compressed chewable tablet has a friability of less than 1%, preferably less than 0.5%. In the present invention, the friability of the tablet is determined according to the USP Method < 1216 > Tablet Friability, USP 23 (1995) and is expressed as a percentage loss in weight. As shown in Figure 2, as the hardness of a flat surface and beveled edge tablet is reduced, friability increases. However, when the hardness of a concave tablet of the present decreases, the friability remains substantially constant. These discoveries are unexpected in view of the friability reported by T. Chakrabarti and others and K. Sugimori and others, above, for convex tablets. These findings are significant because the tablets of the present invention can be compressed at lower compression forces, but still maintain acceptable friability. This results in a softer tablet having an improved product taste, mouthfeel and chewing facility. Compression at reduced forces also reduces the likelihood of fracturing the coating used to mask the unpleasant taste of the active ingredient. The specific embodiments of the present invention are illustrated by means of the following examples. This invention is not confined to the limitations set forth in these examples, but rather to the scope of the appended claims. Unless otherwise indicated, the percentages and relationships given below are by weight.

EXAMPLE I This example provides a formulation for making a biconvex and compressed chewable tablet containing acetaminophen, coated with a mixture of cellulose acetate and polyvinylpyrrolidone. The weights provided below are based on a unit tablet weight of 385 mg. A coating solution containing a mixture of cellulose acetate and polyvinylpyrrolidone was prepared according to the US patent. No. 4,851, 226 and applied to acetaminophen to obtain coated acetaminophen particles containing approximately 1 1% by weight coating. The ratio of cellulose acetate to polyvinylpyrrolidone was 85:15. The coated acetaminophen particles were combined with the following ingredients to produce the tablets: Ingredients Unit weight, mg.

Acetaminophen particles coated with CA / PVP 89.9 Mannitol (granulated), USP 246.03 Microcrystalline cellulose, NF 30.0 Aspartame, NF 9.0 Coloring 1.27 Citric acid, USP 2.1 Flavoring 2.3 Magnesium stearate 4.4 Weight of the tablet 385.0 Procedure 1. Citric acid, aspartame and dye were combined with a portion of microcrystalline cellulose, and mixed until a uniform color distribution was obtained. This mixture was then passed through a suitable grinder. 2. Magnesium stearate and a portion of the mannitol were combined and passed through a suitable grinder. 3. The remaining mannitol was passed through a suitable disposer and then discharged into a mixer. 4. Mixtures of 1 and 2 above, flavoring, coated acetaminophen and the rest of the microcrystalline cellulose were added to the mixer and mixed until a uniform distribution of the active ingredient was obtained. 5. The mixture was compressed to form biconcave tablets according to the following specifications on a rotary press for tablets Fette model 3090: Punches: 10.3 mm in diameter, biconcave with a radius of curvature of shaft less than 2.36 mm and a radius of curvature of cup of axis greater than 25.2 mm. Pre-compression force: 7.4 - 8.1 kN (8.5 - 9.4 kN / cm2). Main compression force: 8.4 - 9.1 kN (9.7 - 10.6 kN / cm2). Thickness: Objective 4.5 mm Weight: Objective 385 mg Friability *: Objective 0.14 The following measurements were made in the tablets: Physical property Average of 5 Individuals Weight (mg) 382 - 389 379 - 391 Hardness (kp / cm2) 6.0 - 7.4 5.2 - 8.3 Thickness (mm) 4.44. 4.49 4.43 - 4.52 Friability * 0.1 1 - 0.18 * (weight loss, 20 tablets) bulk tablets were transported successfully between Puerto Rico and New Jersey in 53 liter fiber drums containing approximately 30 kg of tablets per drum.

EXAMPLE II This example describes the friability test reported in Figure 2 for the flat surface and beveled edge (FFBE) (control) tablet and the concave tablet of the present invention. The acetaminophen was coated with the taste masking coating described in the example The coated acetaminophen particles were combined with the following ingredients to produce FFBE and concave tablets: Unit weight (mg) Ingredients Concave FFBE Acetaminophen coated with CA / PVP 90.7 90.7 Mannitol (granulated), USP 241.55 226.55 Microcrystalline cellulose, NF 30.0 30.0 Aspartame, NF 5.0 11.0 Potassium of acesulfame 6.0 Coloring 0.35 0.35 Flavoring 22.5 22.5 Magnesium stearate, NF 3.9 3 Weight of the tablet 400.0 385.0 The ingredients were combined and compressed to form tablets in a Manesty Betapress press at different hardness levels by changing the compression forces. The following specifications were used: Concave Punches: Round, concave standard 10.3 mm x 0.965 mm cup depth. Hardness scale: 1.5 - 6.0 kp Weight (10 tablets): 4.0 g (Scale 3.85 - 4.15 g) FFBE Punches: 10 mm, round, with flat surface and beveled edge. Hardness scale: 1.5 - 6.0 kp Weight (10 tablets): 3.85 g (Scale 3.75 - 3.95 g) The friability of the tablets was measured in accordance with Tablet Friability < 1216 > , USP 23 (1995). The friability in% by weight was then plotted against standardized hardness or tensile strength of the tablet in Figure 2.

EXAMPLE III Masked flavor acetaminophen tablets, prepared in the manner described in Example I, were combined with the following ingredients to produce compressed chewable tablets, using the procedure described below: Ingredients Unit weight (mg) Acetaminophen particles coated with CA / PVP 90.7 Mannitol (granulated), USP 243.96 Microcrystalline cellulose, NF 30.0 Aspartame, NF 11.0 Dye 0.04 Ingredients Unit weight (mg) Citric acid, USP 2.1 Flavoring 3.3 Magnesium stearate, NF 3.9 Tablet weight 385.0 Procedure 1. All ingredients except magnesium stearate were combined in a PK blender and mixed for 10 minutes. Magnesium stearate was added to the mixer and mixing was continued for an additional 5 minutes. 2. The tablets were compressed according to the following specifications on a Manesty Betapress press using a round biconcave tool of 330/812 mm diameter with a shaft radius of less than 2.36 mm and a shaft radius greater than 25.2 mm: Objective Precompression force: 0 - 0.1 kN (0 - 0.12 kN / cm2). Main compression force: 6.5 - 6.9 kN (7.5 - 8.0 kN / cm2). Weight: (average of 10): 385 mg Thickness (average of 5): 4.63 mm Hardness (average of 5): 3.0 kp (6.5 kp / cm2) The following measurements were made in the tablets: Physical property Scale Weight (average of 10) 383.5 - 386.7 mg Hardness (average of 5) 2.90 - 3.06 kp (6.27 - 6.61 kp / cm2) Thickness (average of 5) 4.62 - 4.66 mm A sensation preference test was carried out among 130 adults who tested these tablets compared to acetaminophen chewable tablets for children of 80 mg Tylenol® (which had an average hardness of 5.5 kp or 13.4 kp / cm2) obtained from places of sale. The tablets of this example were preferred over the commercial product by 77% of the participants, while 22% preferred the commercial product. The tablets of this example were perceived as less bitter, sweeter and with a more pleasant taste and mouthfeel than the commercial product. Various modifications may be made from the embodiments described above without departing from the spirit and scope of the present invention.

Claims (33)

NOVELTY OF THE INVENTION CLAIMS

1. - A compressed chewable tablet having opposite surfaces, comprising: at least one active ingredient; a carbohydrate compressible and disintegrable in water and a binder, said surfaces have a convex shape and said tablet has a hardness of about 2 to about 11 kp / cm.sup.2.

2. The tablet according to claim 1, further characterized in that said surfaces have a biconvex or triconvex shape.

3. The tablet according to claim 2, having biconvex shaped surfaces and a shaft cup radius of less than about 10 to about 40 percent of the diameter of the tablet, and a shaft cup radius greater than about 100 to about 400 percent of the diameter of the tablet.

4. The tablet according to claim 1, having a hardness of about 5 to about 8.5 kp / cm2.

5. The tablet according to claim 1, which has a friability of less than about 1%.

6. The tablet according to claim 5, having a friability of less than about 0.5%.

7. - The tablet according to claim 1, having a diameter of about 7 to about 19 mm and a thickness of about 2 to about 12 mm.

8. The tablet according to claim 7, having a diameter of about 9 to about 13 mm and a thickness of about 3 to about 8 mm.

9. The tablet according to claim 1, comprising at least one coated particle comprising said at least one active ingredient coated with a taste masking coating.

10. The tablet according to claim 1, further characterized in that the compressible carbohydrate is selected from the group consisting of mannitol, sorbitol, maltitol, dextrose, sucrose, xylitol, lactose and mixtures thereof.

11. The tablet according to claim 1, further characterized in that the binder is selected from the group consisting of cellulose, cellulose derivatives, polyvinylpyrrolidone, starch, modified starch and mixtures thereof.

12. The tablet according to claim 1, further characterized in that the active ingredient is selected from the group consisting of acetaminophen, ibuprofen, flurbiprofen, naproxen, aspirin, pseudoephedrine, phenylpropanolamine, chlorpheniramine maleate, dextromethorphan, diphenylhydramine, famotidine, loperamide. , ranitidine, cimetidine, astemizole, terfenadine, terfenadine carboxylate, cetirizine, mixtures thereof and pharmaceutically acceptable salts thereof.

13. A compressed chewable tablet having opposite major surfaces, comprising: at least one active ingredient coated with a taste masking coating; a carbohydrate compressible and disintegrable in water selected from the group consisting of mannitol, sorbitol, maltitol, dextrose, sucrose, xylitol, lactose and mixtures thereof and a binder selected from the group consisting of cellulose, cellulose derivatives, polyvinylpyrrolidone, starch, starch modified and mixtures thereof, said main surfaces have a convex shape and said tablet has a hardness of about 2 to about 1 1 kp / cm2 and a friability of less than about 1%.

14. The tablet according to claim 13, further comprising: about 0.1 to about 60% of said coated active ingredient; about 30 to about 90% of said carbohydrate; about 1 to about 30% of said binder; about 0.1 to about 5% of a lubricant; 0 to about 5% sweetener; 0 to about 5% flavorant and 0 to about 5% dye, by weight of said tablet.

15. The tablet according to claim 14, having a hardness of about 5 to about 8.5 kp / cm2.

16. - The tablet according to claim 14, which has a friability of less than about 0.5%.

17. The tablet according to claim 14, further characterized in that said surfaces have a biconvex or triconvex shape.

18. The tablet according to claim 17, having biconvex shaped surfaces and a shaft cup radius of less than about 10 to about 40 percent of the diameter of the tablet, and a shaft cup radius greater than about 100 to about 400 percent of the diameter of the tablet.

19. The tablet according to claim 14, further characterized in that said coated active ingredient comprises at least one active ingredient coated with a mixture of a first polymer selected from the group consisting of a cellulose acetate and an acetate butyrate. cellulose, and a second polymer selected from the group consisting of polyvinylpyrrolidone and hydroxypropylcellulose, wherein the weight ratio of the first polymer to the second polymer ranges from about 90:10 to about 50:50.

20. The tablet according to claim 19, further characterized in that the coated active ingredient comprises about 5 to about 60 weight percent of the mixture of the first and second polymers.

21. The tablet according to claim 14, further characterized in that the active ingredient is selected from the group consisting of acetaminophen, ibuprofen, flurbiprofen, naproxen, aspirin, pseudoephedrine, phenylpropanolamine, chlorpheniramine maleate, dextromethorphan, diphenylhydramine, famotidine, loperamide, ranitidine , cimetidine, astemizole, terfenadine, terfenadine carboxylate, cetirizine, mixtures thereof and pharmaceutically acceptable salts thereof.

22. A process for preparing a compressed chewable tablet, comprising the steps of: dry blending at least one active ingredient, a water-disintegratable compressible carbohydrate and a binder and compressing the mixture to form a tablet having opposite surfaces of convex form and a hardness of approximately 2 to approximately 11 kp / cm2.

23. The process according to claim 22, further characterized in that said mixture is compressed to a tablet hardness of about 5 to about 8.5 kp / cm2.

24. The method according to claim 22, further comprising the step of coating said active ingredient with a taste masking coating.

25. The process according to claim 22, further characterized in that said taste masking coating comprises a mixture of a first polymer selected from the group consisting of a cellulose acetate and a cellulose acetate butyrate, and a second selected polymer of the group consisting of polyvinylpyrrolidone and hydroxypropylcellulose, wherein the weight ratio of the first polymer to the second polymer is in the range of about 90:10 to about 50:50.

26. The method according to claim 22, further characterized in that the active ingredient is selected from the group consisting of acetaminophen, ibuprofen, flurbiprofen, naproxen, aspirin, pseudoephedrine, phenylpropanolamine, chlorpheniramine maleate, dextromethorphan, diphenylhydramine, famotidine, loperamide. , ranitidine, cimetidine, astemizole, terfenadine, terfenadine carboxylate, cetirizine, mixtures thereof and pharmaceutically acceptable salts thereof.

27. The process according to claim 22, further characterized in that the compressible carbohydrate is selected from the group consisting of mannitol, sorbitol, maltitol, dextrose, sucrose, xylitol, lactose and mixtures thereof.

28. The process according to claim 22, further characterized in that the binder is selected from the group consisting of cellulose, cellulose derivatives, polyvinylpyrrolidone, starch, modified starch and mixtures thereof.

29. The method according to claim 22, further characterized in that said surfaces have a biconvex or triconvex shape.

30. - The method according to claim 29, further characterized in that said tablet has biconvex shaped surfaces and a shaft cup radius of less than about 10 to about 40 percent of the diameter of the tablet, and a cup radius of greater axis from about 100 to about 400 percent of the diameter of the tablet.

31. The method according to claim 22, further characterized in that said tablet has a friability of less than about 1%.

32. The method according to claim 31, further characterized in that said friability is less than about 0.5%. 33.- The method according to claim 22, further characterized in that a precompression force is applied to said mixture before the application of a main compression force.