Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Food or edible as carrier for pharmaceutical
Reexamination Certificate
2000-01-14
2001-08-14
Page, Thurman K. (Department: 1615)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Food or edible as carrier for pharmaceutical
C424S486000, C424S488000, C424S479000, C424S478000
Reexamination Certificate
active
06274162
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the field of aqueous film coating of pharmaceutical, food, confectionery, and agricultural products, and is specifically concerned with providing film coatings having an elegant, extremely glossy, and smooth appearance.
2. Description of the Prior Art
Coating of pharmaceutical dosage forms is well known in the industry. Film coating systems that impart a finished tablet gloss also are known. Cellulosic polymers, maltodextrin, and other polymers have all been used in coatings for substrates such as pharmaceutical tablets, and to some degree impart a desired “coated tablet” appearance or gloss to the pharmaceutical tablets. For example, such coatings made from coating compositions manufactured by Colorcon, of West Point, Pa., and disclosed in Colorcon U.S. Pat. Nos. 4,543,370, 4,683,256, 4,643,894, 4,725,441, 4,828,841, and 5,470,581, Colorcon U.S. patent application Ser. No. 08/778,944, and Colorcon U.S. patent application Ser. No. 08/466,939, all of said patents and said patent applications being incorporated herein by reference, have proven especially effective when used on pharmaceutical tablets.
However, such coatings, especially clear coatings void of pigments, sometimes suffer from “frost” (a white frost-like haze imparted on the tablet surface) when coated at high weight gains for a gloss coat, such as greater than 1.0% weight gain, onto pharmaceutical tablets and the like.
In Berta U.S. Pat. No. 4,820,524, a method of coating a caplet by dipping individual ends of a caplet into a gelatinous solution is disclosed, in which gelatin of bloom strength in the range of 150-270 is used, to produce a shiny film having a thickness from 5-40 mils. Berta U.S. Pat. No. 4,820,524 also discloses a failed attempt to replicate the shine obtained by dipping by spray-coating the caplets in a coating pan with a gelatin system.
Sadek et al. U.S. Pat. No. 5,146,730 discloses a method of coating a tablet by enrobing the tablet in a gelatin coating by application of respective layers of elastic gelatin film to opposite sides of the tablet. Sadek et al. U.S. Pat. No. 5,146,730 discloses that it is essential to use gelatin with bloom values in the range of 120 to 250 to produce the desired film elasticity and adhesion characteristics.
Shen U.S. Pat. No. 5,683,717 discloses a method of spray-coating substrates with a gelatin solution consisting essentially of blooming gelatin (275 bloom), a plasticizer (which is triacetin), a surface-active agent, water, and optionally a coloring agent. The solution is heated and maintained at elevated temperatures during coating, and non-typical conditions are employed in spray-coating (an inlet temperature of 40° C. or less and an outlet temperature of 20° C. or less) to produce the desired effect.
Becker U.S. Pat. No. 5,114,720 discloses a method for coating previously coated tablets with a solution consisting essentially of only a low bloom gelatin (from pork, calfskin or bone) and water for the purpose of imparting a low coefficient of friction, and thus an increased slipperiness and swallowability to the tablet. There is no mention of improved gloss or smoothness.
Johnson et al. U.S. Pat. No. 4,931,286 discloses a high gloss pharmaceutical tablet with an outermost coating of sodium carboxymethylcellulose and a polyethylene glycol plasticizer wherein the outermost coating is applied from a water solution by spray- coating. However, such a coated tablet has a hazy appearance.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a film coating that possesses an elegant, extremely glossy, and smooth appearance.
Another object of the invention is to provide a film coating that does not have a frost-like haze.
Another object of the invention is to provide a film coating from a film coating suspension that may be spray-coated onto tablets and the like at high weight gains substantially higher than 1.0% to produce film coatings having an exceptional shine and smoothness comparable to coatings produced by gel-dipping or enrobing and/or sugar-coating.
Another object of the invention is to provide a film coating from a film coating suspension that may be spray-coated onto tablets and the like using coating conditions typical to traditional spray-coating equipment.
These and other objects are accomplished by our invention, which is described below.
Our inventive dry film coating composition disclosed herein is mixed into water to create an aqueous coating suspension which is spray-coated onto pharmaceutical tablets, producing a smooth and glossy appearance similar to currently marketed gel-dipped, enrobed or sugar-coated medicinal forms, which heretofore has not been obtained, or believed to be obtainable, by spray-coating.
An added benefit to the present invention is that the inventive coating may be formed by spray-coating at weight gains substantially higher than 1% (by dry weight basis) to produce a similar coating thickness as currently commercial gel-dipped or enrobed products, without creating a frost-like or hazy appearance in the coating.
Because the coating of the present invention may be applied to tablets and the like by using traditional spray-coating equipment and room temperature mixing conditions, it represents a substantial time-savings in processing over traditional gel-dipping or sugar- coating processes, which are well-known to be lengthy processes. Further, because the coating of the invention may be applied to tablets and the like by using room temperature mixing conditions and spray- coating conditions typical to traditional spray-coating equipment, application of the film coating is easier than application of a film coating using elevated temperature mixing conditions and non-traditional spray-coating conditions such as those disclosed in Shen U.S. Pat. No. 5,683,717.
If desired, the inventive dry film coating composition may be mixed into water to create an aqueous coating suspension that may be used for dipping or enrobing substrates, such as pharmaceutical substrates, food, confectionery pieces, agricultural seeds, and the like.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the invention, our dry film coating composition for use in forming a coating suspension for film coating pharmaceuticals, food, confectionery forms, agricultural seeds, and the like, comprises gelatin and/or hydroxyethyl cellulose (HEC), and one or more of the following components: a secondary film former(s), a plasticizer(s), a surfactant(s), a glidant(s), a suspension aid(s), a colorant(s), and/or a flavorant(s).
In accordance with the invention, a method of coating substrates such as pharmaceutical tablets, food, confectionery forms, agricultural seed, and the like, comprises mixing gelatin and/or HEC into water to form our inventive aqueous coating suspension, applying the inventive coating suspension onto said substrates to form a film coating on said substrates, and drying the film coating on said substrates. Optionally, but preferably, one or more of the following components may be mixed into water with the gelatin and/or HEC to form the inventive coating suspension: a secondary film former(s), a plasticizer(s), a surfactant(s), a glidant(s), a suspension aid(s), a colorant(s), and/or a flavorant (s).
Our invention also includes the film coating formed on said substrates, the coated substrates, and the methods of making the dry film coating composition and of making our coating suspension.
The film former of the coating is hydroxyethyl cellulose (HEC), or low bloom strength, non-gelling gelatin (preferably, fish gelatin), or combinations thereof.
The secondary film former may be sodium alginate, sodium carboxymethylcellulose (NaCMC), pectin, gelatin, propylene glycol alginate, methylcellulose, polydextrose, polyvinylpyrrolidone, or combinations thereof.
The plasticizer may be glycerin, maltitol solution, propylene glycol, polyethylene glycol, triethyl citrate, glyceryl triacetate, or any other material of similar plasticizing ability, or combinations thereof.
Fegely Kurt A.
Korchok Brian D.
Porter Stuart C.
Steffenino Rita M.
Vesey Charles F.
BPSI Holdings, Inc.
Earley John F. A.
Earley III John F. A.
Fubara Blessing
Harding Earley Follmer & Frailey
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