U.S. patent number 3,607,759 [Application Number 04/817,199] was granted by the patent office on 1971-09-21 for denture soak tablet.
This patent grant is currently assigned to Colgate-Palmolive Company. Invention is credited to Jordan B. Barth.
United States Patent |
3,607,759 |
Barth |
September 21, 1971 |
DENTURE SOAK TABLET
Abstract
This disclosure relates to the process of preparing a
water-soluble effervescent denture soak tablet free of capping or
picking tendencies, which comprises the thorough blending of the
water-soluble ingredients including a carbonate, organic acid and
at least one oxidizing agent, the terminal addition and blending of
a water-soluble detergent to the above formulation, subjecting the
homogenous mixture to normal pressures in a tableting device,
yielding tablets with clean surfaces and sharp edges. The terminal
addition of the water-soluble detergent to the formulation
lubricates the dies and permits easy and clean ejection of the
tablet.
Inventors: |
Barth; Jordan B. (East
Brunswick, NJ) |
Assignee: |
Colgate-Palmolive Company (New
York, NY)
|
Family
ID: |
25222559 |
Appl.
No.: |
04/817,199 |
Filed: |
April 17, 1969 |
Current U.S.
Class: |
510/100; 510/108;
510/375; 510/446; 510/477; 510/509; 510/475; 510/377; 510/117;
252/186.22 |
Current CPC
Class: |
C11D
3/0052 (20130101); A61K 8/02 (20130101); C11D
3/3902 (20130101); C11D 7/12 (20130101); A61Q
11/02 (20130101); A61K 2800/222 (20130101) |
Current International
Class: |
C11D
7/12 (20060101); C11D 3/39 (20060101); C11D
7/02 (20060101); C11D 3/00 (20060101); C11d
007/54 () |
Field of
Search: |
;252/95,96,99,186,100 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Weinblatt; Mayer
Claims
I claim:
1. In a process of preparing a water-soluble neutral pH,
effervescent tablet having clean surfaces and sharp edges, and
consisting essentially of about 5%-75% of a water-soluble
alkali-metal carbonate, about 5%-50% of a nontoxic water-soluble
organic acid, and about 5%-50% of at least one inorganic peroxygen
compound, said carbonate, organic acid, and peroxygen compound
constituting a major portion of said tablet, the improvement which
comprises the terminal addition of 0.1%-5% of at least one
water-soluble anionic or nonionic detergent to the above
formulation and forming a homogeneous mixture, and molding said
mixture into a tablet whereby said detergent lubricates the mold
and said tablet is easily released therefrom with clean surfaces
and sharp edges.
2. In a process in accordance with claim 1, wherein the
water-soluble detergent is anionic.
3. In a process in accordance with claim 1, wherein a mixture of
anionic and nonionic detergents are used.
4. In a process in accordance with claim 1, wherein the tablet
contains a maximum of 0.25% flavor oils.
5. In a process in accordance with claim 1, wherein the tablet
contains 0.005%-0.5% of a nontoxic water-soluble dye capable of
being oxidized to its colorless state within 10 to 30 minutes.
6. In a process in accordance with claim 1, wherein the
water-soluble carbonate is a bicarbonate.
7. In a process in accordance with claim 1, wherein the
effervescent tablet contains 1%-60% of a nontoxic solid,
water-soluble acid anhydride.
8. In a process in accordance with claim 1, wherein the tablet
contains 0.14% to 5% polyvinylpyrrolidone, molecular weight 10,000
to 360,000.
Description
The present invention relates to the production of a water-soluble
effervescent denture soak tablet having clean surfaces and sharp
edges and free of capping and picking tendencies, and more
particularly to a tablet which is completely water-soluble even
though it contains a die lubricant.
The prior art is replete with disclosures of cleansing tablets and
processes for their manufacture, useful for myriad purposes
inclusive of denture soak formulations. Problems commonly
encountered in the manufacture of tablets include (1) sticking of
the tablet to the compression die, (2) tablets that chip, cap or
break easily. These are well recognized in the art and have been
solved in many different ways, inclusive of using specific
granulation methods with or without limiting the granules to
specific mesh sizes, hydrating the tablets, subsequent heating
treatments, specific compounding steps whereby a portion of the
ingredients are moistened prior to compression, coating the tablets
with specific products such as amides or a urea complex, etc.
However, aforesaid solutions have been useful for specific
formulations and only partially effective in certain
procedures.
Accordingly, it is an object of this invention to overcome
tableting processing difficulties and provide a completely soluble
effervescent tablet having clean surfaces and sharp edges.
It has now been found that picking and capping difficulties
normally encountered in tableting procedures has been substantially
completely eliminated by the particular procedure of adding at
least one water-soluble detergent as a final step in the
formulations prior to the tableting step. The detergent acts as a
lubricant and permits clean and easy ejection of the tablet from
the compression die. The ingredients may be in the form of powders
or granules of varying sizes. The water-soluble ingredients
consisting essentially of at least one oxidizing agent, a carbonate
and an organic acid are thoroughly mixed and blended prior to the
addition of the water-soluble detergent. All other optional
ingredients inclusive of flavor oils, flavor carriers, binders,
dyes, etc. are added to the basic formulation above prior to the
addition of the water-soluble detergent. The final procedural step
must constitute the addition and mixing of the water-soluble
detergent. The thoroughly blended mixture is then fed to the die
cavity of the tableting machine, where it is subjected to normal
pressures (about 3-5 tons). The tablets having clean surfaces and
sharp edges are ejected from the mold with ease, leaving clean
surfaces in the die cavity for continuous tablet formation.
More specifically, this invention relates to a process of preparing
a completely water-soluble, neutral pH, effervescent tablet having
clean surfaces and sharp edges, and comprising about 5%-75% of a
water-soluble carbonate, about 5%-50 % of a water-soluble organic
acid and about 5%-50% of at least one oxidizing agent, the
improvement which comprises the terminal addition of 0.1%-5% of at
least one water-soluble detergent to the above formulation and
forming a homogeneous mixture, and molding said mixture into a
tablet whereby said detergent lubricates the mold and said tablet
is easily released therefrom with clean surfaces and sharp
edges.
As a source of one effervescent gas, namely carbon dioxide, there
may be used a water-soluble alkali-metal carbonate compound
selected from the group consisting of sodium bicarbonate, sodium
carbonate, sodium sesquicarbonate, potassium carbonate, potassium
bicarbonate, and mixtures thereof, which reacts with a solid
organic acid selected from the class consisting of tartaric acid,
citric acid, malic acid, maleic acid, fumaric acid, succinic acid,
etc. and mixtures thereof, in the presence of water to produce
effervescence (bubbles). The carbonate content and acid content may
each vary from about 5%-75% and preferably 35%-50% by weight of the
total composition. However, maximum effervescence level is attained
when 3 parts carbonate to 2 parts acid concentration is
utilized.
An acid anhydride may be utilized in addition to or as a partial
substitute for the organic acid. Such anhydrides are particularly
effective in producing sustained effervescence when dissolved in
water and also function as an internal desiccant in the prevention
of premature evolution of CO.sub.2. The acid anhydrides utilized
herein are nontoxic, solid water-soluble inorganic or organic
materials and capable of hydrolyzing and subsequently reacting with
the inorganic carbonate to evolve CO.sub.2. Specific examples of
acid anhydrides include boric anhydrides, succinic anhydride,
adipic anhydride, fumaric anhydride, tartaric anhydride, citric
anhydride, malic anhydride, maleic anhydride and the like. The acid
anhydride content may vary from about 1%- 60% and preferably from
5%-10% by weight of the total composition.
The oxidizing agents offer in addition to active oxygen another
source of effervescence (liberation of molecular oxygen) and are
preferably the persalts such as the alkali-metal perborates,
persulfates, percarbonates, perphosphates and the like. The simple
addition of these water-soluble peroxygen compounds to water
produces a highly effective source of active oxygen which is
particularly useful in oxidation reactions, thereby providing
considerably improvements in applications where peroxygen compounds
are employed such as for antiseptic, cleansing and bleaching
activity. The degree of effervescence which relates to both the
volume and speed is dependent on the particular peroxygen compound
employed. For example, sodium perborate monohydrate has three times
as much active oxygen as potassium persulfate, but the latter has a
stronger oxidation potential (stronger oxidizing agent) and is less
effected by moisture. Consequently, it is preferred to use a
mixture of persalts in order to obtain the combined advantages of
both oxidizing agents. The total amount of oxidizing agents
utilized herein may vary from 5%-50 % and preferably 20%-40% by
weight of the total composition, the distribution between the
various agents being dependent on the desired end result. More
specifically, a composition having less active oxygen but yielding
stronger oxidizing action will utilize a greater amount of the
persulfate salt, whereas a formulation requiring a greater and
quick release of active oxygen will employ a greater amount of the
perborate. Other suitable solid peroxygen compounds include
ammonium persulfate, sodium persulfate, sodium pyrophosphate
peroxide, sodium carbonate peroxide, etc.
In the formation of tablets from the aforedescribed effervescent
formulation, the mixture is preferably in the granular form in
order to be easily fed to the die cavity of the tableting machine.
However, this does not preclude the direct feeding of the powdered
mixture to the compression molding machine in the formulation of
tablets. One satisfactory granulation method constitutes in the wet
granulation of the mixture by the addition thereto of a solution of
a binding material such as polyvinylpyrrolidone in an anhydrous
solvent such as isopropanol, breaking it up into granules via an
oscillator or like apparatus, screening and drying. The ingredients
may be separately granulated and the granulations mixed prior to
compression molding, or the powdered mixture of ingredients may be
granulated prior to tableting. Polyvinylpyrrolidone is a polymer of
vinylpyrrolidone having a molecular weight between 10,000 and
360,000, soluble in water and in organic solvents such as aliphatic
alcohols (methyl, ethyl, propyl, isopropyl, butyl alcohols),
ketones (acetone, methyl ethyl ketone), chlorinated hydrocarbons
(methylene chloride, ethylene dichloride, trichloroethylene,
trichloroethane, chloroform, carbon tetrachloride), etc. The amount
of polyvinylpyrrolidone in the tablet may vary from 0.14% to
5%.
Another method of granulation is slugging whereby the powdered
mixture is fed into a tableting device in order to make a poor
grade tablet which is easily broken up into granules and
screened.
Still another granulation method involves the formation of sheets
from the powdered mixture by passing the mixture between two
rollers, breaking the sheets into granules and screening.
A lubricant must be added to the dry effervescent mixture, whether
in the form of powder or granules, as a final addition step prior
to compression molding into tablets. This lubricates the dies in
the tableting device and permits the clean and easy ejection or
removal of the tablets therefrom. No sticking or breakage occurs,
thereby permitting the tableting machine to run continuously and
efficiently. The art is replete with myriad lubricants inclusive of
fatty acids, soaps, fatty acid salts, etc.
It has now been found that the addition of at least one
water-soluble detergent lubricant to the effervescent mixture as a
terminal addition step in the tableting process, is productive of
clean, sharp-edged tablets, readily and completely soluble in
water. In addition to its lubricant properties, the detergent
assists in the cleansing action of the composition. Both the
anionic and nonionic detergents are effective lubricants in amounts
of about 0.1% to 5.0% by weight of the total composition. Although
one surface active agent performs the required lubrication,
excessive foaming sometimes occurs upon dissolution of the
formulation in water, thereby requiring the adjunct of a foam
depressant such as a silicone, etc. However, the use of a
combination of anionic and nonionic detergents eliminates excessive
foaming, thereby obviating the necessity of adding a foam
depressant.
Suitable anionic detergents include water soluble salts of organic
sulfoxy compounds having in their molecular structure an alkyl or
acyl radical of carbon atom content within the range of about 8 to
about 18 and a sulfonic acid or a sulfuric acid ester radical.
Important examples of these anionic detergents are: sodium or
potassium alkyl benzene sulfonate in which the alkyl group contains
from about 9 to about 15 carbon atoms in either a straight chain or
a branched chain which is derived from polymers of propylene;
sodium and potassium alkyl glyceryl ether sulfonates, especially
those ethers of higher fatty alcohols derived from the reduction of
coconut oil; the reaction product of higher fatty acids with sodium
or potassium isethionate, where, for example, the fatty acids are
derived from coconut oil; sodium or potassium alkyl sulfonates and
sulfates, especially those alkyl sulfates derived by the sulfation
of coconut or tallow fatty alcohols and mixtures of such alkyl
sulfates; dialkyl esters of sodium or potassium salts of
sulfosuccinic acid, for example, the dihexyl ester; sodium and
potassium salts of sulfated or sulfonated monoglycerides derived,
for example, from coconut oil; sodium or potassium salts of higher
fatty alcohol esters of sulfacarboxylic acids, for example, the
sodium salt of the lauryl alcohol ester of sulfoacetic acid; sodium
or potassium salts of a higher fatty acid amide of methyl taurine
in which the higher acyl radical for example, are derived from
coconut oil. Examples of other useful anionic detergents are acyl
sarcosinates, e.g. sodium N-lauroyl sarcosinate.
Nonionic detergents include a water solubilizing polyoxethylene
group in chemical combination with an organic hydrophobic compound
such as polyoxypropylene, alkyl phenol, the reaction product of an
excess of propylene oxide and ethylene diamine, and aliphatic
alcohols. The nonionic synthetic detergents have a molecular weight
in the range of from about 800 to about 11,000. Other nonionic
synthetic detergents useful in the present invention are:
condensation products of 10 to 30 moles of ethylene oxide with one
mole of an alkyl phenol containing 6 to 12 carbon atoms, either in
a straight or branched chain, in the alkyl group (e.g. nonyl or
octylphenol); condensation products of 10 to 30 moles of ethylene
oxide with 1 mole of an aliphatic straight or branched chain
alcohol containing 8 to -8 carbon atoms (e.g. lauryl alcohol or
tallow fatty alcohol); condensation products of ethylene oxide and
the reaction product of propylene oxide and ethylene diamine
wherein the reaction product has a molecular weight of 2500-3000,
for example and the condensation product has a polyoxyethylene
content of 40% to 80%.
The effervescent denture soak composition may contain certain
water-soluble dyes which act as timing indicators by turning
colorless at the completion of the cleansing action. The initial
coloration of the dye, upon dissolution of the dry composition in
water, is bleached out in a period of time approximating the time
required for cleaning the denture. The type and amount of dye
selected is dependent on the desired completion time of the
cleansing activity as well as on the composition and pH of the
denture product. It has been found that a period of at least 10-15
minutes and up to 30 minutes is a desirable cleansing time.
Accordingly, at substantially neutral pH, the azo dyes have been
found particularly desirable due to their ability to be readily
oxidized to a colorless state in the required time. A specific
example of an azo dye is acid red -14 (ext D and C red -10) which
is the disodium salt of 2-(4-sulfo-1-napthyl-azo)
1-napthol-4-sulfonic acid. Other dyes with suitable fading times
are FD and C Blue -2, FD and C Green -1, FD and C Green -2, FD and
C Violet -1, D and C Yellow -10, Ext D and C Violet -2 and Ext D
and C Yellow -3. The amount of dye incorporated in the composition
may vary from about 0.005% to 0.5% and preferably from 0.01%-0.04%
by weight of the total.
Various other adjuvant materials may also be incorporated in the
present denture soak preparation. Minor amounts of flavor oils such
as oils of spearmint, peppermint and wintergreen may be included to
impart a mild and pleasant flavor and odor to the cleaned denture.
However, when adding a flavor oil in amounts not exceeding 0.25%,
it has been found desirable to also incorporate minor amounts about
1.00% of a flavor retainer or carrier such as magnesium carbonate
to avoid the separation of the oil droplets from the rest of the
dry composition. Other flavor retainers may be utilized provided
they readily absorb the flavor oils and prevent flavor weeping.
Minor amounts of other suitable water-soluble additives may be
included such as sweeteners, foam depressants, preservatives,
buffers, fillers, diluents, binders, etc., provided they do not
adversely affect the properties and characteristics of the denture
soak tablet.
The denture cleansing tablets of the instant invention may be
packaged in bulk in assorted containers or individually wrapped in
tin foil, polyethylene, cellophane or other foils. It is desirable
that aforesaid product completely dissolve in water to yield a
clear solution having a substantially neutral pH, at which carbon
dioxide and some oxygen become readily available, thereby providing
the effervescence required for the proper cleansing of dentures. An
alkaline solution has the disadvantage of hastening the corrosion
of metal parts of the dentures, whereas acid solutions tend to etch
the dentures.
The term denture includes all kinds of orthodontic appliances such
as false teeth, removable dental plates and bridges, artificial
teeth and the like.
The following specific examples are further illustrative of the
nature of the present invention, but it is to be understood that
the invention is not limited thereto. The compositions are prepared
in the usual manner as indicated, and all amounts of the various
ingredients are by weight unless otherwise specified.
Ingredients %
__________________________________________________________________________
Na H CO.sub.3 30.00 Citric acid 20.00 KH SO.sub.5 28.00 Na BO.sub.2
H.sub.2 O.sub.2 15.00 Polyvinylpyrrolidone (M.W. 40,000) 1.10
Flavor oils 0.25 Mg CO.sub.3 1.00 FD and C Blue -2 0.015 Na H
CO.sub.3 2.385 Sodium Lauryl Sulfate 0.25 Sodium benzoate 2.00
__________________________________________________________________________
The sodium bicarbonate, citric acid, potassium persulfate, sodium
perborate and a 1.1% solution of polyvinylpyrrolidone in
isopropanol are thoroughly blended. The flavor oils are thoroughly
mixed with magnesium carbonate and subsequently blended with the
first mixture. The dye is mixed with 2.385% sodium bicarbonate and
subsequently added to the flavored mixture. The sodium lauryl
sulfate and the sodium benzoate is finally added and thoroughly
mixed (about 1 minute) with the dye and flavored composition to
produce a homogeneous mixture which is fed to a tableting machine
and compressed under normal pressure (3-5 tons). The tablets do not
cap or pick or break easily, but have sharp edges and clean
surfaces.
Example II
The flavor content of Example I is increased to 1.0%, and 0.04% FD
and C Violet -1 in 1.71 sodium bicarbonate is substituted for the
blue dye. This mixture is subjected to normal pressure in a
tableting device, yielding cap-free, pick-free tablets.
Example III
Sodium salt of dodecyl benzene sulfonate is substituted for sodium
lauryl sulfate in Example I. The resultant tablets are sharp-edged
and clean.
---------------------------------------------------------------------------
EXAMPLE IV
Ingredients %
__________________________________________________________________________
Tartaric acid 21.50 Acid red -14 .01 Na H CO.sub.3 34.14 KH
SO.sub.5 28.00 Na BO.sub.2 H.sub.2 O.sub.2 15.00 Sodium salt of
dodecyl benzene sulfonate 0.1 Flavor 0.25 Mg CO.sub.3 1.00
__________________________________________________________________________
three separate granulations are made; the tartaric acid and the
Acid Red dye are wetted with an aqueous isopropanol solution and
dried, the Na H CO.sub.3 is wetted with an aqueous isopropanol
solution and dried, the KH SO.sub.5 and Na BO.sub.2 H.sub.2 O.sub.2
are wetted and dried as above. The flavor is blended with the
magnesium carbonate and mixed with the three granulations. The
sodium salt of dodecyl benzene sulfonate is added to and mixed with
the above granulated mixture for 1 minute and then subjected to
compression molding at normal pressure in a tableting device. The
tablets have clean surfaces and sharp edges and are readily and
completely soluble in water as an efficient denture cleanser.
Example V
Malic acid is substituted for the tartaric acid in Example IV,
yielding similarly improved tablets.
Example VI
Succinic acid is substituted for the tartaric acid of Example IV,
resulting in improved tablets.
---------------------------------------------------------------------------
Example VII
Ingredients Parts
__________________________________________________________________________
Malic acid 8.77 Succinic anhydride 5.00 Na H CO.sub.3 22.88 KH
SO.sub.5 28.00 Na BO.sub.2 H.sub.2 O.sub.2 15.00 Sodium salt of
dodecyl benzene sulfonate 0.8 Soap chips 0.2
__________________________________________________________________________
The malic acid, succinic anhydride, Na H CO.sub.3, KH SO.sub.5 and
Na BO.sub.2 H.sub.2 O.sub.2 are thoroughly blended. The sulfonate
and the soap chips are added to and mixed with the above
composition for 1 minute and then fed to the tablet press. The
tablets do not stick to the machine.
---------------------------------------------------------------------------
Example VIII
Ingredients %
__________________________________________________________________________
Malic Acid 19.27 Boric anhydride 5.00 Na H CO.sub.3 45.00 KH
SO.sub.5 18.67 Na BO.sub.2 H.sub.2 O.sub.2 10.00 Methyl napthalene
sodium sulfonate 1.60 Alkylphenoxypoly(ethyleneoxy)ethanol 0.20
Acid Red -14-0.01%-Flavor oils-0.25%
__________________________________________________________________________
The ingredients may either be mixed and made into a slug for
tableting purposes or may be prepared into a wet granulation and
then subjected to compression molding in a tableting device.
Example IX
Maleic anhydride is substituted for the boric anhydride of Example
VIII. The formulation is adequately lubricated to eliminate
sticking in the tableting device.
Example X
0.01% of Acid Red -14 dye is preblended with 7.73% malic acid and
12.26% Na H CO.sub.3 and thoroughly blended with the formulation in
Example VIII along with 0.25% flavor oils. The mixture is subjected
to normal pressure in a tableting device yielding improved tablets
in accordance with this invention.
Although the present invention has been described with reference to
particular embodiments and examples, it will be apparent to those
skilled in the art that variations and modifications of this
invention can be made and that equivalents can be substituted
therefor without departing from the principles and true spirit of
the invention.
* * * * *