DESC:Field of the Invention
The present invention relates to a pharmaceutical formulation comprising of fluoride compounds in the form of oral composition. More particularly, the invention relates to a stable oral formulation comprising of fluoride ion containing compound for prevention and/or treatment of dental caries and also to manufacturing processes thereof.
Background
Dental caries, which is also referred to as tooth decay or cavities is the most prevalent oral disease and considered as a major public health problem and is also one of the most preventable diseases. It is defined as a localized, post-eruptive, pathological process of external origin involving softening of the hard tooth tissue and proceeding to the formation of a cavity. Dental caries has been the most common oral health problem in the world. Untreated dental caries can affect the quality of life as a result of pain or discomfort, tooth loss, impaired oral functioning.
Dental caries is caused by the action of acids on the enamel surface. The acid is produced when sugars (mainly sucrose) in foods or drinks react with bacteria present in the dental biofilm (plaque) on the tooth surface. The acid produced leads to a loss of calcium and phosphate from the enamel; this process is called demineralization.
Saliva acts to dilute and neutralize the acid which causes demineralization and is an important natural defense against caries. Aside from buffering plaque acids and halting the demineralization of enamel, saliva provides a reservoir of minerals adjacent to the enamel from which it can remineralize and “heal” once the acids have been neutralized. The enamel demineralizes and remineralizes many times during the course of a day. It is when this balance is upset and demineralization exceeds remineralization that caries progresses. When demineralization occurs frequently and exceeds remineralization over many months, there is a breakdown of the enamel surface leading to a cavity. Cavities, even in children who do not yet have their permanent teeth, can have serious and lasting complications such as pain, tooth abscess, tooth loss, broken teeth, chewing problems and serious infection. To repair a cavity, the decayed part of the teeth must be removed and replaced with a manmade substance.
Common treatments available for dental caries are as follows:
Fluoride: For cavities in the early stages of decay, a fluoride treatment can help restore the enamel (or outer coating) of the tooth. Dentist may apply a fluoride gel, varnish or paste to the area. Fluoride helps to protect teeth by strengthening the enamel, making teeth more resistant to the acids from plaque that can cause tooth decay.
Fillings: A dentist uses a drill to remove the decayed material from a tooth. He then fills the tooth with a substance, such as silver, gold, or composite resin. The material is used to fill in the hole left by the cavity. Fillings do not last forever and may need to be re-filled in the future.
Crowns: A crown is similar to a filling but instead of filling the hole in a decayed tooth, a custom-fit covering is made that is placed over the top of the tooth. A crown requires the decayed portion of the tooth to first be drilled out. Like fillings, crowns do not last forever.
Root Canals: When tooth decay causes the death of the nerves, root canal is performed to save the tooth. The dentist removes the nerve tissue, blood vessel tissues, and any decayed areas of a tooth. The dentist then checks for infections and applies medication to the roots as needed. The tooth is then filled and a crown is placed on it.
Tooth Removal: A tooth that is damaged beyond repair will need to be removed. The gap that is left by an extracted tooth is often filled with an implant or bridge.
A hydroxyapatite is a main component of an enamel, and an uptake of a fluoride ion into a crystal lattice of hydroxyapatite is easily performed and the fluoride ion enhances crystallinity thereof. As a result, the tooth is reinforced, the enamel becomes more resistant to decalcification by the organic acid formed by the microorganism present in the oral cavity, and thus caries may be prevented. It is also believed that the uptake of the fluoride ion is more easily effected into a lesion of incipient caries (wherein some decalcification proceeds) than into a sound enamel, and thus enhances recalcification and inhibits the progress of caries.
However dental caries can be prevented by brushing the teeth with a fluoride toothpaste. It works mainly by slowing down the process of demineralization, whereby the enamel loses calcium and phosphate when exposed to acid following ingestion of food and drinks which contain sugars. It also helps to “heal” (remineralize) surfaces which show early signs of calcium or phosphate loss, such as an opaque appearance.
U.S. Patent No. 4,078,053 discloses a method for the prevention of caries in newly erupted teeth using from 500-3000 ppm of ammonium fluoride.
U.S. Patent No. 3,711,604 discloses a transparent dentifrice formulation in which a fluorine containing ingredient, preferably stannous fluoride is incorporated in aesthetically pleasing speckles that are uniformly dispersed throughout the clear dentifrice.
U.S. Patent No. 6,251,369 discloses a foamable dental fluoride composition for forming dental foams containing about 0.5 to about 10 percent by weight available dental fluoride;
U.S. Patent No. 5,188,821 discloses method of preparing an oral composition, mouthwash or liquid dentifrice wherein delivery and retention of a plaque-inhibiting antibacterial agent is enhanced by attaching, adhering or bonding to oral tooth and gum surfaces comprising an aqueous vehicle, an effective amount in the range of about 0.15-5% by weight of substantially water insoluble noncationic antibacterial agent.
U.S. Patent No. 5,820,852 discloses an oral composition comprising a soluble fluoride ion source, tetrasodium pyrophosphate, calcium peroxide, and one or more aqueous carriers, wherein the oral composition has a neat pH ranging from about 9.0 to about 10.5 and a total water content ranging from about 9.1% to about 20%.
U.S. Patent No. 4,363,794 discloses an oral composition comprising a stannous salt such as stannous fluoride, a water-soluble fluoride salt such as sodium fluoride and an orally acceptable acid such as L-ascorbic acid, lactic acid, malonic acid, tartaric acid, citric acid, hydrochloric acid and pyrophosphoric acid, the molar ratio of fluoride ion to stannous ion being in the range of 3.2 to 7:1, preferably 3.5-6:1, in an aqueous condition and the pH of the composition being in the range of from 2 to 4. The composition exhibits excellent effects on the inhibition of dental caries.
Claudio Sicca (J Clin Exp Dent, 8(5): e604–e610, Dec 2016) et al discloses a review on effective treatment available for prevention of dental caries. There are some commercial products marketed in USA but are not reviewed and approved by the USFDA such as 5% Sodium Fluoride Varnish which contains 22,600 ppm fluoride and Colgate® PreviDent® 5000 Plus Rx only incorporated herein as reference.
The prior art references do not provide a toothpaste composition with higher concentration of fluoride ions. The currently available compositions with higher fluoride ion concentration have a limitation of application to teeth i.e can be applied only by dental professionals and would require the patient to visit to his clinic either once a month or once in a span of two to three months depending upon the severity. Therefore, there is a need to develop a toothpaste composition having higher fluoride concentration which is safe and efficacious and would allow more fluoride ion concentration to be available at the tooth enamel surface. Such a tooth paste composition can be easily applied daily in the comfort of home for either prevention and or treatment of dental caries.
Summary of the Invention
Accordingly, the present invention relates to a pharmaceutical composition comprising:
(a) a fluoride compound or its pharmaceutically acceptable salt, ester, prodrug thereof; and
(b) one or more with pharmaceutically acceptable excipients.
The present invention relates to an oral composition. More particularly, the present invention relates to an oral dentifrice composition which can considerably enhance a preventive effect and facilitate the treatment for caries of the teeth in comparison to a conventional oral treatment and/or composition.
A fluoride ion is reported to be used to prevent caries. Thus, in the present invention a fluoride compound such as sodium fluoride, sodium mono-fluorophosphate, or stannous fluoride has hitherto been added to tap water, or to a dentifrice, and topically applied to the tooth surface.
Objective of the Invention
The primary object of the present invention is to provide oral dentifrice composition.
It is another object of the present invention to provide for compositions and methods for the prevention and/ or treatment of dental caries.
It is another object of the present invention to provide oral composition for treatment of caries.
Yet another object of the present invention is to provide oral composition for prevention of caries.
Yet another object of the present invention is to provide oral composition for prophylaxis of caries.
Yet another object of the present invention is to provide a safe and effective means for the oral administration of fluoride.
Yet another object of the present invention is to provide a dental paste to treat dental caries.
Yet another object of the present invention is to provide a method of treating dental caries.
Yet another object of the present invention is to provide a method of preventing formation of dental caries.
Yet another object of the present invention is to provide a method of making a dental paste to prevent and treat dental caries.
Brief description of the drawings
Figure 1: Percent inhibition of bacterial adhesion at various concentration of the tooth paste formulations
Figure 2: Percent inhibition of bacterial bio-film at various concentration of the tooth paste formulations
Figure 3: Confocal Laser Microscopy Images
Figure 4: Percent survival rate at varying concentrations of tooth paste formulations
Figure 5: pH cycle model; S- Seconds, Min-Minutes, TP-Toothpaste, RM-Remineralization.
AC- Acid challenge, ONS-Overnight Saliva

Detailed Description of the Invention
Before describing the present invention in detail, it is to be understood that this invention is not limited to specific pharmacologically active carriers, formulation types, treatments, so forth, and as such may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.
The present invention relates to a pharmaceutical composition comprising:
(a) a fluoride compound or its pharmaceutically acceptable salt, ester, prodrug thereof; and
(b) one or more with pharmaceutically acceptable excipients.
Further, the present invention relates to an oral composition for prevention and treatment of dental caries.
In one embodiment, the fluoride compound is a compound containing fluorine which is prevailingly present in the biological field. The fluoride compounds include but are not limited to an inorganic fluoride, such as an alkali metal fluoride such as sodium fluoride, potassium fluoride, lithium fluoride, or cesium fluoride; zirconium fluoride, ammonium fluoride, stannous fluoride; alkali metal monofluorophosphate such as sodium monofluorophosphate, or potassium monofluorophosphate; or alkali metal titanium fluoride such as sodium titanium fluoride or potassium titanium fluoride; and an organic fluoride compound such as a monoalkylamine hydrofluoride such as hexylamine hydrofluoride, laurylamine hydrofluoride, or cetylamine hydrofluoride; amino acid hydrofluoride such as glycine hydrofluoride, lysine hydrofluoride, or alanine hydrofluoride; or fluorosilane.
In another embodiment, the fluoride compounds are used singly or in combination thereof.
In a preferred embodiment, the fluoride compounds are selected from the group consisting of sodium fluoride, potassium fluoride, ammonium fluoride, stannous fluoride, sodium monofluorophosphate or potassium monofluorophosphate, or combinations thereof.
In an embodiment, the pharmaceutical composition of the present invention is in the form of a topical composition, preferably an oral composition.
In a preferred embodiment, the topical dosage form is in the form of solution, cream, gel, paste, powder and tincture.
In a preferred embodiment, the fluoride compound is incorporated in the oral composition in an amount ranging from about 100-20,000 ppm, as a total fluorine concentration in the composition. If the amount is less than 100 ppm, a desired reinforcement action cannot be obtained. Although the fluoride compound may be used in an amount of more than 20,000 ppm, the desired effect does not increase as the amount increases beyond 20,000 ppm, and thus it is not economical.
In a further embodiment, the present invention relates to the topical use of sodium fluoride or its pharmaceutically acceptable inorganic salt in the toothpaste, especially for the treatment and prevention of dental caries.
In yet another embodiment, the pharmaceutical composition of the present invention contains a fluoride compound with an antiseptic, wherein the antiseptic is selected fromChlorhexidine and pharmaceutically acceptable salts thereof.
In yet another embodiment, the pharmaceutical composition of the present invention contains various other additives. The kinds of the additives depend on the types of oral composition. Examples of the pharmaceutical additives include but are not limited to polishing agents, humectants, wetting agents, thickening agents, anionic surface active agents, oils, sweeteners, essential oils, flavouring agents, colourants, anti-tartar agents, opacifying agents, an antimold agents, antioxidants, and water.
Polishing agents or abrasives include but are not limited to calcium phosphate (dibasic) dihydrate or anhydrate thereof, calcium phosphate (monobasic), calcium phosphate (tribasic), calcium carbonate, calcium pyrophosphate, titanium dioxide, aluminum hydroxide, aluminum oxide, silica polishing agent (e.g., amorphous silica, crystalline silica, complex of alkali metal silicic anhydride), aluminum silicate, insoluble sodium metaphosphate, insoluble potassium metaphosphate, insoluble calcium polyphosphate, magnesium phosphate (tribasic), magnesium carbonate, magnesium sulfate, calcium sulfate, methyl polymethacrylate, bentonite, zirconium silicate, hydroxyapatite or synthetic polymer.
Humectants include but are not limited to sorbitol liquid, glycerine, glycerol, polyethylene glycol 600, alpha hydroxy acids, panthenol, carboxylic acid, sorbitol, sodium hyaluronate, sodium and ammonium lactate, sodium pyrrolidine, urea, propylene glycol, gelatin, and honey.
Wetting agents include but are not limited to glycerol, sorbitol, liquid sorbitol, propylene glycol, polyethylene glycol, polyethylene glycol 600, ethylene glycol, 1,3-butylene glycol, xylitol, maltitol, or lactitol.
Thickening agents include but are not limited to such as carboxymethyl cellulose, sodium methyl cellulose, hydroxyethyl cellulose, hydroxy propyl methyl cellulose, hydroxy propyl cellulose, sodium carboxy methyl cellulose, sodium alginate, carrageenan, sodium polyacrylate, gum arabic, xanthan gum, tragacanth gum, karaya gum, polyvinyl alcohol, carboxyvinyl polymer, or polyvinyl pyrrolidone, dental type Silica such as precipitated Silica-MFIL-P, precipitated Silica-ABSIL 100-(C)].
Anionic surface active agents include but are not limited to water soluble salts of C8-18 alkyl sulfate sodium lauryl sulfate, sodium myristyl sulfate, Cocamidopropyl betaine (Tegobetaine), soluble higher fatty acid monoglyceride sulfate wherein the fatty acid has 10-18 carbon atoms (e.g., sodium lauryl monoglyceride sulfate, sodium coconut oil fatty acid monoglyceride sulfate, sodium higher fatty acid monoglyceride sulfate), a-olefin sulfate, paraffin sulfate, sodium salt of N-methyl-N-palmitoyl tauride, sodium N-lauryl sarcosinate sodium salt of N-lauroyl-ß-alanine; a nonionic surface active agent such as fatty acid alkanol amide (e.g., lauric acid diethylamide), sucrose fatty acid ester (e.g., sucrose mono- or dilaurate), polyoxyethylene sorbitan fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene hardened castor oil derivative, lactose fatty acid ester, maltitol fatty acid ester, or polyoxyethylene polyoxypropylene block copolymer; a cationic or amphoteric surface active agent.
Oils include but are not limited to as higher alcohol or wax; a lower alcohol.
Sweeteners include but are not limited to saccharin sodium, stevioside, neohesperidin, dihydrochalcone, glycyrrhizin, perillartine, p-methoxycinnamic aldehyde.
Essential oils include but are not limited to peppermint, spearmint, or fennel.
Perfumes or flavouring agents include but are not limited to 1-menthol, carvone, eugenol, anethol or other perfume base, clove, ginger mint, bubblegum, cinnamon, lavender, neem, ginger, vanilla, lemon, orange, pine, apricot, peach, chocolate, coffee, honey, coca cola, blueberry, watermelon and strawberry.
Colorants include but are not limited to US FDA approved colours, Unicert blue, orange, red, pink, green, brown, white, black, yellow.
Anti-tartar agents include but are not limited to polycarboxylates derived from acrylic or methacrylic acid, particularly copolymers of maleic anhydride with methyl vinyl ether (GANTREX®), potassium pyrophosphate, sodium pyrophosphate, azacycloheptane-2-2-diphosphonic acid (AHP), AMP (azacycloheptane-2,2-diphosphonic acid), PPTA (phosphonopropane tricarboxylic acid), PBTA (phosphonobutane-1,2,4-tricarboxylic acid and EHDP (ethanehydroxy diphosphonic acid);
Opacifying agents include but are not limited to titanium dioxide, amaranth carmine.
Preservatives include but are not limited to sodium benzoate.
In a further embodiment, oral composition of the present invention contains ingredients that are usually incorporated in an oral composition. For example, dextranase, protease, lytic enzyme, mutase, mutastein, sorbic acid, alexin, ß-glycyrrhetinic acid, hinokitiol, dihydrocholesterol, epidihydrocholesterol, alkyl glycine, alkyldiaminoethylglycine salt, allantoin, e-aminocaproic acid, tranexamic acid, azulene, other vitamins, water soluble salt of phosphoric acid (mono- or dibasic), quaternary ammonium compound (e.g., cetylpyridinium chloride), sodium chloride, active components (e.g., crude drug extracts), Tetra Potassium Pyro Phosphate, or the like; polymers such as Vinyl Polymers like Polymethacrylates, Polyvinyl Alcohol, Polyvinylpyrrolidone, Polyacrylic acid; Cellulose Ethers like Methylcellulose, Ethylcellulose, Hydroxypropylcellulose, Hydroxyethylcellulose, Hydroxypropylmethylcellulose, Hydroxyethylmethylcellulose, Sodium Carboxymethylcellulose; Polyesters like Poly(lactide) and Related Copolymers, Poly(e-caprolactone) and Miscellaneous Polymers like Gelatin, Polyanhydrides, Polyethylene Glycols, Polyethylene Oxide; solvents such as alcohols, ketones, amide, ethers, amine, nitriles, esters, aromatic hydrocarbon, hydrogenated solvents, sulphur containing solvents and water.
Sodium fluoride acts systemically before tooth eruption and topically afterward by increasing tooth resistance to acid dissolution, by promoting remineralization, and by inhibiting the cariogenic microbial process. Acidulation provides greater topical fluoride uptake by dental enamel than neutral solutions. When topical fluoride is applied to hypersensitive exposed dentin, the formation of insoluble materials within the dentinal tubules blocks transmission of painful stimuli.
Sodium fluoride is a colorless crystalline solid or white powder, or the solid dissolved in a liquid. It is soluble in water which is used to fluorinate water supplies to prevent formation of dental caries and has melting point of 993 °C. The structure of Sodium Fluoride is as depicted below

The term “prevention” as disclosed in this specification meaning action taken to decrease the chance of getting a dental disease or condition.
The term “treatment” as disclosed in this specification meaning the management and care of a patient to combat disease or disorder.
The term “prophylaxis” as disclosed in this specification meaning a measure taken to maintain health and prevent the spread of disease.
The terms prevention and prophylaxis are commonly interchanged.
The present invention can also be used in combination with antibiotics.
The present invention can also be used in combination with antifungal agents.
The present invention can also be used in combination with topical anesthetics.
The present invention can also be used in combination with antiseptics and germicides.
The present invention can also be used in combination with flavonoids.
The present invention can also be used in combination with non-steroidal anti-inflammatory drugs.
In an embodiment, present invention provides a dental paste comprising Sodium Fluoride, Chlorhexidine digluconate, Liquid sorbitol, Polyethylene glycol 600, Saccharin Sodium, Xanthan Gum, Glycerol, Carmellose sodium, Dental type Silica (A), Dental type Silica (B), Tetra Potassium Pyro Phosphate, Sodium Benzoate, Surfactant(s), Colour(s) , Titanium dioxide, flavour(s), Polymer, Purified water.
In another embodiment, oral composition of the present invention is produced in any dosage form, for example, a dentifrice (e.g., paste dentifrice, powdery dentifrice, wet tooth powder, or liquid tooth powder), an oral detergent (e.g., mouth wash), a topical application, an oral refrigerant, or a collutory (e.g., chewing gum, candy, dental floss, troche).
In a preferred embodiment, the pH of oral composition of the present invention is 3-10, more preferably 4-9, most preferably 5-8.
Examples
Example 1: Anti-adhesion assay (Crystal violet assay)
Sodium Fluoride (NaF) compositions of present invention were evaluated for its anti-adhesion activity and compared to reference product and placebo. 6 hour old cultures of Streptococcus mutans grown in Trypticase soy broth (TSB) was taken and the bacterial culture was adjusted to 0.1 McFarland’s Standard (1 x108 CFU/ml). Anti-adhesion ability of the 23 toothpaste formulations (test, reference product and placebo) with 3 different test concentrations (100mg/mL, 200mg/mL and 300mg/mL) were tested. 100µl of the adjusted culture was seeded on the 96-well plate along with 80µl TSB media and incubated for an hour at 37°C. After incubation, 20µl of test formulations were added and the total volume was made up to 200µl. For the negative control group instead of the paste formulation, 20µl of MilliQ was added. 96-well plate was incubated at 37°C for 24 hours and the anti-adhesion ability was quantified using crystal violet assay. The planktonic cells were removed and thereafter, 200µl of 0.1% crystal violet solution was added to stain the adhered cells. The plate was incubated for 20 min at room temperature and washed in distilled water to remove excess stain. The adhered cell stain was solubilized with 150µl of 30% glacial acetic acid for 10 minutes at room temperature and the ability of anti-adhesion was quantified by measuring Optical Density (OD) at 540nm. The percentage inhibition was expressed as mean percent inhibition ± SD using equation as given below.
Equation 1.

Observation: The percent inhibition of adhesion of S. mutans at 100, 200 and 300mg/mL concentration is represented in the figure 1. The percent inhibition of bacterial adhesion was found directly proportional to the concentration of the formulations in all the groups.
Result: The formulations POC-0118/14 showed statistically better anti-adhesion property at higher concentrations like 200 mg/ml and 300 mg/ml, POC-0118/19 also showed statistically better anti-adhesion property at higher concentrations like 200 mg/ml and 300 mg/ml, POC-0118/23 and POC-0118/28 showed better activity only at 300 mg/ml and POC-0118/29 demonstrated statistically better anti-adhesion property at all tested concentrations than the reference products. Thus the anti-adhesion property as exhibited can be shown comparatively as below:
POC-0118/29 > POC-0118/19 > POC-0118/14
Example 2: Anti-biofilm assay
A) Assay by Colour Staining: The compositions of present invention were evaluated for anti-biofilm formation. 6 hour old cultures of Streptococcus mutans grown in Trypticase soy broth (TSB) was taken and the bacterial culture was adjusted to 0.1 McFarland’s Standard (1 x 108 CFU/ml). Biofilm disruption ability of the 23 toothpaste formulations (test, reference product and placebo) with 3 different test concentrations (100mg/mL, 200mg/mL and 300mg/mL) were tested. A 100 µl of the adjusted culture was seeded on the 96 well plate along with 80µl media and allowed to form biofilm by incubating for 24 hours at 37°C. Following the incubation, 20 µl of paste formulation to be tested was added and the final volume was made up to 200 µl. For the control group instead of the toothpaste formulation, 20µl of MilliQ was added. 96-well plate was incubated at 37°C for 6 hours and the biofilm was quantified using crystal violet assay. The planktonic cells were removed and thereafter, 200µl of 0.1% crystal violet solution was added to stain the biofilm. The plate was incubated for 20 min at room temperature and washed in distilled water to remove excess stain. The stained biofilm was solubilized with 150µl of 30% glacial acetic acid for 10 minutes at room temperature and the amount of biofilm formed was quantified by measuring OD at 540nm. Percent inhibition of bio?lm formation was determined by Eq. (1) presented in example 1. The results were expressed as mean percent inhibition ± SD.
Observation: All the formulations displayed less anti-biofilm activity compared to anti-adhesion activity, which could be attributed to the minimal ability of the formulations to penetrate into the already formed biofilm and disrupt the same. The result of anti-biofilm activity evaluated against S. mutans is depicted in figure 2.
Result: The formulations, POC-0118/28 at concentration of 300 mg/ml, POC-0118/29 at concentrations of 100 mg/ml and 300 mg/ml and POC-0118/11 and POC-0118/24 at 100mg/ml demonstrated anti-biofilm activity close to that of PREVIDENT 5000 at respective concentrations. Whereas, formulations, POC-0118/18 at 300 mg/ml, POC-0118/22 and POC-0118/24 at concentration of 100 mg/ml and 300 mg/ml demonstrated anti-biofilm activity close to that of DURAPHAT 2800 at respective concentrations. It can be stated that the anti-biofilm activity is directly proportional to the concentration of the fluoride levels.
B) Assay by confocal laser microscopic: In this method mid log phase culture of S. mutans grown in Brain Heart Infusion broth was adjusted to 0.1 McFarland’s standard to get a uniform cell density. 3ml of the adjusted cell suspension was seeded to each of the 6 well plate along with autoclaved cover slip and allowed to form biofilm by incubating for 24 hours. Biofilm grown coverslip was transferred into the fresh 6 well plate containing 2.7 ml of fresh BHI broth along with 300µl of toothpaste dissolved in distilled water at different concentration (100, 200, 300 mg/ml). The plate was incubated at 37 °C for 6 hours. The coverslips were removed from the media and one side of it was wiped with 70% ethanol to remove the biofilm formed. The coverslips were fixed with 4% paraformaldehyde at room temperature for 30 minutes, washed and stained with BacLight bacterial live/dead stain (SYT09-PI) by adding 3 µl of both the stain in 1ml of distilled water and incubated in dark for 20 minutes at room temperature. The excess stain was removed, and the stained coverslip was mounted on a glass slide with Mowiol for 6 hours in dark. The mounted coverslip was observed using a 100x lens with the excitation/ emission maxima of 480/500nm for SYTO9 and 490/635nm for Propidium Iodide (PI). BacLight bacterial live/dead staining (SYT09-PI)), is based on the rationale that SYTO9 penetrates into the live bacterial cells and stain them green, and Propidium iodide is unable to penetrate healthy live cells, but it can enter cells whose cellular integrity is lost or dead and stain them red. Overall, based on the proportion of red and green stain, it is possible to derive at a conclusion whether the formulation possess better antimicrobial potential or not. The activity was evaluated at three different concentrations (100, 200, 300mg/mL).
Observation: The antimicrobial potential of each formulation was visualized and images were captured under confocal laser microscope. Majority of the formulations showed higher red staining suggesting antimicrobial potential in a dose dependent manner. However, at 300 mg/mL majority of the formulations neither demonstrated red nor green stain, which could be attributed to the fact that because of higher concentration of the drug, bacterial cells may have got killed at the initial stage and have got removed during the washing process in the experiment. The red and green staining were furthermore quantified to derive at percent of remaining live and dead cells for all the formulations at the concentration 200mg/mL; since the concentration 300mg/mL was too high and 100mg/mL was very low to validate the results in a percentage form, and the same is represented in the table 1.
Table 1: Quantification of live and dead cells for all the formulations at 200mg/mL concentration
Sr. No. Formulations Percent live bacterial cells Percent dead bacterial cells inhibition at
1 DURAPHAT 2800 23.5 76.49
2 PREVIDENT 5000 PLUS 9.57 90.43
3 POC-0118/08 0 100
4 POC-0118/10 0.54 99.45
5 POC-0118/11 0.64 99.35
6 POC-0118/13 0.22 99.77
7 POC-0118/14 0.23 99.76
8 POC-0118/15 0.25 99.74
9 POC-0118/16 0.2 99.79
10 POC-0118/17 0 100
11 POC-0118/18 0.66 99.33
12 POC-0118/19 0 100
13 POC-0118/20 1.9 98.09
14 POC-0118/21 0.38 99.61
15 POC-0118/22 0 100
16 POC-0118/23 0 100
17 POC-0118/24 0 100
18 POC-0118/25 0 100
19 POC-0118/26 0.22 99.77
20 POC-0118/27 4 96
21 POC-0118/28 0.79 99.2
22 POC-0118/29 5 95
23 POC-0118/30 5.68 94.31
Result: The formulations POC-0118/08, POC-0118/17, POC-0118/19, POC-0118/22, POC-0118/23, POC-0118/24 and POC-0118/25 demonstrated 100% dead cells at 200mg/mL concentration and was depicted in figure 3.
Example 3: Cyto-compatibility assay
The compositions of present invention were assessed for its biocompatibility against gingival fibroblast cell lines (L929) isolated from primary culture. Under strict aseptic condition viable fibroblasts cell suspension (50 µl) with density 1 × 104 cells/ml concentration as determined by trypan blue exclusion method using neubauer chamber were seeded into each well in a flat bottom 96 well plate followed by addition of test sample (100 µl). The cells were incubated for 16-24 hours at 37 °C in a CO2 incubator for the cells to attach to the culture vessel. After incubation, add 100 µl ulbecco modified Eagle Medium media containing various concentration (1mg/L, 5 mg/L, 10 mg/L, 25 mg/L, 50 mg/L, 100 mg/L, 200 mg/L, 300 mg/L) of drug in all the wells. For each of these drug concentration blank was prepared that contained no gingival fibroblast cell. The negative control contained gingival fibroblast cell along with ulbecco modified Eagle Medium media. Incubate it for 48 hours for the drug to act on the cells (depends on the type of drug). After 48 hours MTT, 20 µl (5.0mg/ml) to each well was added and incubated it for 4 hours in CO2 incubator at 37 °C for the development of formazon crystals. After 4 hours of incubation, the plate was centrifuged at a speed of 3000 rpm for 10 minutes to spin down formazon. The supernatant was aspirated. DMSO was added to lyse the cells and to solubilize the formazon crystals. The reading was taken at 570:630 dual wavelength using ELISA plate reader (Lisa plus, India) and percent cell viability was calculated using formula mentioned below.
Equation 2.
The Percent cell viability=(Mean absorbance of test compound)/(Mean absorbance at control (untreated cells))×100
The Cyto-compatibility/ cyto-toxic behaviour of all the tooth paste formulations at eight different concentrations were evaluated using colorimetric MTT assay. A formulation is considered to be biocompatible when it favours cell proliferation more than 95%.
Observation: Due to viscous nature of the formulations, some of the formulations were evaluated from 1 to 200 mg/mL, whereas others were evaluated from 5 to 300 mg/mL.
The percent survival of gingival fibroblasts on exposure to varying concentration of tooth paste formulations of all the formulations are demonstrated in figure 4. However, in the present study although some formulations (POC-0118/08, POC-0118/16, POC-0118/20, POC-0118/21, POC-0118/23 and POC-0118/24) demonstrated more than 95% cell survival at the concentration between 1-5mg/mL, majority of the formulations
Result: The results were compared with the positive controls; PREVIDENT 5000 PLUS and DURAPHAT 2800 demonstrated reduced cellular viability at concentration = 25mg/mL. The study indicates that all the formulations are safe to be used in local application to teeth in suitable dosage forms (toothpaste).
Example 4: Demineralization (DM) and re-mineralization (RM) study
The compositions of present invention were studied on sound non carious permanent teeth extracted for orthodontic or periodontal reasons to evaluate remineralization in said teeth. Teeth with wasting diseases, visible carious defects and hypo/hyper mineralized lesion were excluded. An enamel window of 4 mm X 4 mm was identified on the buccal surface in the middle one-third of the crown. Windows were prepared on the buccal and lingual surfaces of incisors, canines, premolars and molars. The surfaces were assessed using Diagnodent for any changes and the teeth meeting a set range of value between 0 and 7 on the digital display were included in the study. The baseline values of the same were recorded.
After the preliminary screening and selection of samples were done, each sample was subjected to Surface Micro Hardness (SMH) test which was evaluated with three indentations using a Vickers hardness indenter (MMT-X, LECO) at a load of 200 g for 15 seconds. An average of the three indentations was calculated per sample and was recorded as baseline value. The samples were scanned using Scanning electron microscopy -Energy Dispersive X-Ray (SEM-EDX) to check the baseline calcium and fluoride and phosphorous contents. Following the baseline evaluation of Diagnodent values, surface micro-hardness and elemental analysis using SEM-EDS all the samples were then immersed into a glass container containing demineralizing solution for a period of 96 h at 37 °C using an incubator. After 96 h of incubation in the demineralizing solution, the teeth samples were washed with deionized water, dried with the help of an air syringe. The teeth samples were evaluated with Diagnodent and the samples showing a set value increase on the digital display were taken for further evaluation. This value indicates the presence of a subsurface lesion on the tooth surface. The surface micro-hardness and calcium, fluoride and phosphorous levels were tested using Vickers hardness tester and SEM-EDX analysis respectively.
The percentage SMH (% SMH-RM) is the total gain of SMH after RM. It implies the capacity of the formulation to increase or decrease the SMH after RM and is calculated as below,
% SMH-RM=( R-SMH – D-SMH )/(B-SMH – D-SMH)×100
The Ca/P ratio determines the major content of hydroxyapatite. The presence of Fluoride prevents the Demineralization activity. Thus, the current study also evaluated change in Ca/P ratio. The net percent gain of Ca/ P after re-mineralization is calculate as,
Net Ca/P RM=( RM ratio - Baseline ratio )/(Baseline ratio )×100
The teeth samples were randomly divided into twenty-three groups, (n=10 - 20 test formulations, 2 positive control and 1 placebo).
The teeth samples were brushed using tooth paste slurry (5g in 10ml) using a commercially available powered tooth brush and the samples were then subjected to pH cycle model as demonstrated in the figure 5. The demineralized samples were subjected to a daily treatment regimen consisting of exposure to toothpaste brushing for one minute and rinsing in water for 5 secs. After the brushing, the teeth samples were stored in artificial saliva for 2 hours for re mineralization process to occur. This was followed by rinsing with water for 5 seconds and immersing the sample in an acid buffer (50 mM acetate; 2.25 mM CaCl2•2H2O; 1.35 mM KH2PO4; 130 mM KCl at pH 5.0) for 4-hours to mimic the oral condition (where, due to food intake the pH in the oral cavity becomes more acidic). Following this, the samples were rinsed again with water for 5 seconds and placed in artificial saliva for 2 hours for the remineralization (Expecting the oral cavity situation, where the pH is brought back to neutral or slightly basic due to buffering capacity of the human saliva).Further the samples were rinsed with water for 5 seconds and the brushing with tooth paste slurry was repeated for 1 minute. The samples were rinsed again with water for 5 seconds and stored overnight in artificial saliva. This procedure was followed daily for up-to 14 days with the replenishment of the artificial saliva every 24 hours.
After 14 days, the samples were subjected to SEM-EDX analysis to check the post remineralization uptake of Calcium, Fluoride and Phosphorous, followed by the determination of SMH and Diagnodent values. The baseline, post demineralization and post pH cycle values were compared and the data was analyzed statistically.
The intragroup comparison was done using paired t-test whereas the intergroup was done using Student’s t- test. The value was considered statistically significant when the p-value was < 0.05.
A decrease in the Diagnodent value is suggestive of healthier tooth structure whereas an increase in the SMH indicates better resistance against abrasion. The level of calcium, fluoride and phosphorus determines the formation of hydroxyapatite or fluorapatite which is responsible for further caries prevention.
Observation: All the formulations that were tested for Diagnodent value, showed significant decrease in diagnodent value; when compared between after DM and after pH cycle. All the formulations also showed increased in SMH values post DM. The study also indicated, there was overall reduction in Calcium/ Phosphate post DM. The table 2 tabulates the observations of RM DM study.

Table 2: Mean Diagnodent Values (DV), Surface Micro Hardness (SMH), and weight percentage values of the elements (Ca-Calcium, F-Fluoride, P-Phosphorous).

Sr. No Formulation Pre-treatment After-Deminerization After pH Cycle
DV SMH Ca F P DV SMH Ca F P DV SMH Ca F P
1 DURAPHAT 2800 2.9 238.44 57.63 10.71 31.86 4.3 227.49 57.29 9.39 32.46 3.5 229.73 63.57 6.03 30.40
2 PREVIDENT 5000 PLUS 3.1 243.23 61.57 8.5 30.47 4.6 236.34 59.26 8.85 32.46 3.5 239 59.58 8.23 32.08
3 POC-0118/08 2.9 231.56 63.22 3.60 33.18 3.9 228.83 56.80 11.76 31.40 3.2 232.3 56.60 10.96 32.68
4 POC-0118/10 3.0 235.02 60.46 8.38 30.16 3.9 230.58 54.39 13.42 31.98 2.9 235.64 56.85 12.34 31.27
5 POC-0118/11 3.6 242.28 56.94 10.67 32.37 4.8 238.28 58.14 10.61 31.23 3.4 241.98 57.83 10.22 32.0
6 POC-0118/13 3.0 241.4 63.25 4.46 31.62 4.1 235.88 60.53 9.34 30.12 3.2 242.19 56.81 11.62 31.54
7 POC-0118/14 3.4 249.51 63.52 2.62 33.09 4.7 244.04 58.69 9.18 30.89 3.6 250.28 57.56 11.14 31.23
8 POC-0118/15 2.3 234.84 63.85 3.3 32.86 3.8 227.58 58.23 10.48 31.09 2.9 234.44 55.75 12.83 31.56
9 POC-0118/16 3.6 234.02 62.13 4.53 33.34 4.4 231.76 57.37 10.40 32.53 3.4 234.96 56.57 11.73 31.64
10 POC-0118/17 4.5 238.82 58.57 9.50 31.92 5.3 236.55 56.73 11.07 32.22 4.3 239.80 58.38 9.60 31.97
11 POC-0118/18 3.4 220.68 59.47 11.21 28.93 4.3 217.57 56.81 11.49 31.68 3.4 218.16 59.42 7.43 33.13
12 POC-0118/19 3.1 229.56 60.57 9.38 30.05 4.9 225.61 59.58 7.81 32.71 3.2 228.97 58.67 9.97 31.36
13 POC-0118/20 4.3 237.65 61.61 3.86 34.54 5.4 235.41 54.74 11.67 33.45 4.6 239.58 58.05 11.46 30.66
14 POC-0118/21 2.4 233.74 62.58 3.79 33.66 3.4 230.48 55.02 12.58 32.36 2.7 235.91 57.18 12.18 30.70
15 POC-0118/22 2.9 245.20 59.92 8.8 31.29 4.4 238.19 57.84 9.58 32.62 3.1 251.53 56.68 11.72 30.84
16 POC-0118/23 3.0 226.55 61.24 6.68 32.03 4.4 221.44 57.08 7.12 33.11 3.1 232.09 60.40 8.47 31.59
17 POC-0118/24 3.0 225.06 60.51 7.0 32.48 4.5 215.30 58.77 9.97 31.26 3.1 226.16 60.63 8.66 30.64
18 POC-0118/25 3.3 238.08 62.62 4.51 32.87 5.1 222.87 58.81 10.39 30.83 3.8 243.76 59.38 8.91 31.72
19 POC-0118/26 2.9 228.68 61.22 4.19 34.22 4.7 223.52 55.79 11.64 37.91 3.1 230.99 56.91 11.05 32.34
20 POC-0118/27 3.0 244.43 61.18 6.81 31.01 4.3 241.62 55.71 12.40 31.31 3.2 244.27 58.07 10.02 31.90
21 POC-0118/28 3.2 223.53 57.20 9.98 32.49 4.4 220.12 56.44 10.33 32.16 3.2 225.48 58.09 10.66 31.20
22 POC-0118/29 3.2 247.34 58.36 8.7 32.84 4 244.51 58.02 10.81 29.73 3.0 249.64 58.98 9.01 31.96
23 POC-0118/30 2.3 251.27 62.53 2.94 34.52 3.9 245.39 61.22 4.55 33.73 3.1 248.34 60.43 5.04 34.53
The placebo (POC-0118/30) batch did not show any gain in Ca/P RM or net Ca/ RM value however, there appeared to be significant increase in Fluoride post DM but not post RM indicating that the Fluoride was able to bring the structural modification of apatite crystal and restricting partial OH group replacement by Fluoride ion. The table 3 provides data for SMH after RM and net gain of Ca/P ratio.

Table 3: percentage of SMH after RM and Net gain of Ca/P ratio
Sr. No. Formulation % SMH-RM Ca/P ratio
1 DURAPHAT 2800 20.45662 17.20
2 PREVIDENT 5000 PLUS 38.60668 -8.80
3 POC-0118/08 108.4765 -9.73
4 POC-0118/10 1.351351 -10.57
5 POC-0118/11 92.08443 2.95
6 POC-0118/13 114.3116 -9.55
7 POC-0118/14 114.0768 -3.51
8 POC-0118/15 94.49036 -9.23
9 POC-0118/16 141.5929 -4.08
10 POC-0118/17 143.1718 0.0016
11 POC-0118/18 18.97106 -14.71
12 POC-0118/19 85.06329 -8.48
13 POC-0118/20 186.1607 6.28
14 POC-0118/21 169.0184 0.33
15 POC-0118/22 190.2996 -4.00
16 POC-0118/23 208.4149 -0.15
17 POC-0118/24 111.2705 6.68
18 POC-0118/25 137.3439 -1.68
19 POC-0118/26 144.7674 -2.41
20 POC-0118/27 94.30605 -8.23
21 POC-0118/28 157.1848 6.19
22 POC-0118/29 181.2721 3.73
23 POC-0118/30 50.17007 -3.44
Results: The formulations no. POC-0118/17 and POC-0118/29 showed significant decrease in Diagnodent values when compared with post DM values and also from pre-treatment DM value but not statistically significant. The formulations no. POC-0118/18 and POC-0118/28 showed significant decrease in Diagnodent values when compared with post DM values but has same values as that of pre-treatment DM value. The formulations no. POC-0118/11 and POC-0118/16 showed significant decrease in Diagnodent values when compared with post DM values and also from pre-treatment DM value but not statistically significant.
Thus, formulations POC-0118/11, POC-0118/16, POC-0118/17, POC-0118/18, POC-0118/28 and POC-0118/29 showed equivalent or decreased DM values as compared to pre-treatment.
There was overall reduction in SMH when these samples were put into DM solution. The increase in SMH after 14 days of RM process through pH cycle was seen due to redeposition of lost mineral content through DM. The formulations POC-0118/25, POC-0118/24, POC-0118/23, POC-0118/15, POC-0118/14, POC-0118/13, POC-0118/10, POC-0118/26, POC-0118/29, POC-0118/19, POC-0118/17, POC-0118/11, POC-0118/21, POC-0118/20, POC-0118/16 and POC-0118/08 showed statistically significant increase in SMH values. Overall in terms of SMH formulation POC-0118/16, POC-0118/17, POC-0118/29 showed better result.
The formulations POC-0118/20, POC-0118/21, POC-0118/24, POC-0118/28 and POC-0118/29 showed net increase in Ca/P RM values as well as Fluoride levels. The formulation POC-0118/11 showed gain in net Ca/P RM value however, Fluoride levels were found reduced.
Example 5: Minimal inhibitory concentration (MIC) & Minimal bactericidal concentration (MBC) assay
Mid log phase culture of the bacterial colony grown in Brain Heart Infusion broth (BHI) was adjusted to 0.1 McFarland’s standard to get a uniform cell density. 100µl of the adjusted cell suspension was seeded to each well of the 96-well microtiter plate. The MIC value for Streptococcus mutans against the 23 toothpaste formulations at 8 different concentrations (300, 200, 100, 50, 25, 10, 5 and 1 mg/ml) were tested. 20µl of the paste dissolved in distilled water at different concentrations were added to the cell suspension in the well and mixed thoroughly. The final volume was made up to 200µl in each well by adding BHI broth to get the final concentration as given above. The experiment was performed in triplicates. The plate was incubated at 37°C for 16 hours. 5µl of the cell suspension was taken from one well of each concentration and added to 4995µl of distilled water (1:1000 dilution) and mixed well. 25µl of this diluted suspension was taken and spread on a Brain Heart Infusion agar plate to determine MBC. 5µl of cells were removed from the other wells also to maintain the volume. Spectrophotometric readings of the microtiter plate at 600nm was taken to analyze the growth of cells in various concentrations of toothpaste and graph was plotted with X axis having concentration of the drug and the percent inhibition on Y axis. IC-50 and IC-90 values were calculated using graph-pad prism version 5. Concentration that showed minimal visible bacterial growth or turbidity was considered as MIC and the concentration which showed zero colony in agar plate was considered as MBC.
Observation: The results were compared with placebo (POC-0118/30) and the positive controls (PREVIDENT 5000 PLUS and DURAPHAT 2800). The experiments demonstrated only MIC for all formulations; as the many formulations were extremely viscous, evaluating the antimicrobial activity at concentration higher than 300mg/mL was not favourable due to the practical difficulties in pipetting. MIC and MBC values as per the number of colony forming units on streaking on the Brain heart infusion agar and IC50/IC90 values are represented in the table 4.
Table 4: Antimicrobial activities representation in the form of IC50, IC90, MIC and MBC
Sr. No. Formulations IC50(in mg/mL) IC90 (in mg/mL) MIC (in mg/mL) MBC (in mg/mL)
1 DURAPHAT 2800 33.08 100 DE* DE
2 PREVIDENT 5000 PLUS 94.18 300 DE DE
3 POC-0118/08 11.43 DE 300 DE
4 POC-0118/10 34.49 100 DE DE
5 POC-0118/11 22.07 200 DE DE
6 POC-0118/13 7 75 DE DE
7 POC-0118/14 5.05 150 DE DE
8 POC-0118/15 7.18 200 DE DE
9 POC-0118/16 99.6 DE DE DE
10 POC-0118/17 14.27 DE DE DE
11 POC-0118/18 11.43 DE DE DE
12 POC-0118/19 38.19 200 DE DE
13 POC-0118/20 46.14 DE DE DE
14 POC-0118/21 9.23 DE 300 DE
15 POC-0118/22 23.07 100 300 DE
16 POC-0118/23 13.4 50 300 DE
17 POC-0118/24 9.28 25 300 DE
18 POC-0118/25 79.85 150 300 DE
19 POC-0118/26 27.3 DE DE DE
20 POC-0118/27 49.06 DE DE DE
21 POC-0118/28 91.68 300 300 DE
22 POC-0118/29 17.14 50 200 300
23 POC-0118/30 5.94 DE DE DE
*DE: Difficult to Evaluate
Further it was noticed that the antimicrobial potential was evident at specific concentration/formulations; the potential reduced as the concentration of fluoride ion was increased.
Result: The formulations with respect to MIC and MBC values, the POC-0118/24, POC-0118/23, POC-0118/22 and POC-0118/29 demonstrated comparatively better antimicrobial activity than other formulations. Further, formulation POC-0118/29 is the only formulation to demonstrate MBC which caused complete bacterial killing at the concentration of 300mg/mL. The IC90 values play a key role because as 90% of bacterial killing evident. In this regard, POC-0118/24, POC-0118/23, POC-0118/29, POC-0118/13 and POC-0118/22 showed a significantly better antimicrobial activity than placebo and the positive control.
The following examples serve to provide further appreciation of the invention, but are not, in any way, to be considered restrictive of the effective scope of the invention
Example 1: Paste Composition containing Sodium fluoride
Table 5: Paste Composition containing sodium fluoride
Ingredients % Concentration
Sodium Fluoride 0.62 - 2.21*
Liquid sorbitol 10.0-50.0
Polyethylene glycol 600 1.0-5.0
Saccharin Sodium 0.01-1.0
Xanthan Gum 0.1-5.0
Surfactant 1.0-5.0
Dental type Silica (A) 1.0-6.0
Dental type Silica (B) 10.0-30.0
Tetra Potassium Pyro Phosphate 0.1-2.0
Sodium Benzoate 0.1-2.5
Colour 0.001- 0.01
Flavour 0.1-1.5
Purified water Q. S.to 100%
* Sodium Fluoride concentration equivalent to 2800-10,000 ppm of Fluoride ion
Manufacturing Process:
Step 1: Gum Dispersion Phase: Purified water was heated in a mixing vessel at 60 - 65°C, followed by addition of saccharin sodium and stirred at 1000 ± 200 rpm until a clear solution was obtained. Xanthan gum was added under stirring at 1000 ± 200 rpm to the said solution so obtained and stirred for 30 min. The content of the vessel was allowed to soak for 45 min. Liquid sorbitol was added under stirring and stirring was continued for 10 min. Polyethylene glycol 600 was added under stirring and stirring was continued for 10 min.
Step 2: Preparation of Drug Phase: The purified water was heated in a stainless steel (SS) vessel at 60 - 65°C, followed by addition of sodium fluoride, sodium benzoate and tetra potassium pyrophosphate in this order under stirring at 1000 ± 200 rpm until a clear solution was obtained.
Step 3: Preparation of Surfactant Phase: The purified water was heated into SS vessel at 60 - 65°C followed by addition of surfactant in container under stirring at low speed (200 - 300 rpm) to avoid foaming, until a clear solution was obtained.
Step 4: Preparation of Colour Solution: The weighed amount of colour was added to purified water into SS vessel under stirring until uniform coloured solution was obtained.
Step 5: Mixing: The solution of step 2 was transferred into mixing vessel containing the gum dispersion phase maintained at 60-65°C under stirring at 1000 ± 200 rpm. The container was rinsed twice with purified water and said rinses were added into the said mixing vessel. The content of mixing vessel was stirred for 15 minutes at 1000 ± 200 rpm. The temperature of the bulk was maintained at 60-65°C. The content of mixing vessel was soaked for 60 minutes with intermittent mixing (1 minute every 10 minutes at 1000 ± 200 rpm). The content of the vessel was homogenised for 10 minutes at 3500-4000 rpm. The weighed quantity of precipitated Silica (A) was added into mixing vessel under homogenization at 3500-4000 rpm with intermittent manual stirring on need basis and continue homogenization for 15 minutes maintaining temperature of bulk at 60-65°C. The Precipitated Silica (B) was dispersed into the mixing vessel under homogenization speed at 3500-4000 rpm and with intermittent manual stirring on need basis and continue homogenization for 45 minutes. The content of the vessel was stirred using anchor stirrer at 1000 ± 200 rpm for 15 minutes maintaining the temperature of bulk at 60-65°C until paste is formed. The solution of step 4 was transferred to the paste under stirring at 500-700 rpm and the container was rinsed with purified water and the rinses were added to the mixing vessel and stirring was continued for 10 minutes. The surfactant solution from Step 3 was transferred to the above bulk paste under stirring at 200-400 rpm and stirring was continued for 10 minutes. After 10 minutes cooling cycle for bulk paste was initiated while stirring at 1000±200 rpm by circulating chilled water till temperature reaches to 44 - 46°C. The flavour was added into the mixing vessel at 44 - 46°C with stirring at speed of 1000 ± 200 rpm and stirring was continued for 10-15 minutes.
Example 2: Paste Composition Sodium fluoride and Chlorhexidine Digluconate
Table 6: Paste Composition Sodium fluoride and Chlorhexidine Digluconate
Ingredients % Concentration
Sodium Fluoride 0.62 - 2.21*
Chlorhexidine digluconate 0.12
Liquid sorbitol 10.0 - 50.0
Polyethylene glycol 600 1.0 - 5.0
Saccharin Sodium 0.01 - 1.0
Xanthan Gum 0.1 - 5.0
Surfactant 1.0 - 5.0
Dental type Silica (A) 1.0 - 6.0
Dental type Silica (B) 10.0 - 30.0
Tetra Potassium Pyro Phosphate 0.1 - 2.0
Sodium Benzoate 0.1 - 2.5
Colour 0.001 - 0.01
Flavour 0.1 - 1.5
Purified water Q. S. to 100 %
* Sodium Fluoride concentration equivalent to 2800-10,000 ppm of Fluoride ion
Manufacturing Process:
The fluoride toothpaste bulk was prepared using the process given in example 5, in addition chlorhexidine digluconate solution was added to said bulk paste at 25-30°C under stirring at 1000 ± 200 rpm. The container of chlorhexidine digluconate solution was rinsed with purified water and the said rinsate was added under stirring to bulk paste, stirring was continued for 15 minutes.
Example 3: Paste Composition Sodium fluoride with Polymers
Table 7: Paste Composition Sodium fluoride with Polymers
Ingredients % Concentration
Sodium Fluoride 0.62 - 2.21*
Liquid sorbitol 10.0 – 50.0
Polyethylene glycol 600 1.0 - 5.0
Saccharin Sodium 0.01 - 1.0
Xanthan Gum 0.1 - 5.0
Surfactant 1.0 - 5.0
Dental type Silica (A) 1.0 - 6.0
Dental type Silica (B) 10.0 – 30.0
Tetra Potassium Pyro Phosphate 0.1 - 2.0
Sodium Benzoate 0.1 - 2.5
Colour 0.001 - 0.01
Flavour 0.1 - 1.5
Polymers
0.2 - 5.0
Purified water Q. S. to 100 %
* Sodium Fluoride concentration equivalent to 2800-10,000 ppm of Fluoride ion
Manufacturing Process: The process of preparation of composition comprising polymer was same as that of process covered under example 5, except the polymer was added in step 1 along with sweetener and gum.
Example 4: Paste Composition Sodium fluoride and Chlorhexidine digluconate with Polymers
Table 8: Paste Composition Sodium fluoride and Chlorhexidine digluconate with Polymers
Ingredients % Concentration
Sodium Fluoride 0.62 - 2.21*
Chlorhexidine digluconate 0.12
Liquid sorbitol 10.0 – 50.0
Polyethylene glycol 600 1.0 - 5.0
Saccharin Sodium 0.01 - 1.0
Xanthan Gum 0.1 - 5.0
Surfactant 1.0 – 5.0
Dental type Silica (A) 1.0 - 6.0
Dental type Silica (B) 10.0 – 30.0
Tetra Potassium Pyro Phosphate 0.1 - 2.0
Sodium Benzoate 0.1 - 2.5
Colour 0.001 - 0.01
Flavour 0.1 - 1.5
Polymers
0.2 - 5.0
Purified water Q. S. to 100 %
* Sodium Fluoride concentration equivalent to 2800-10,000 ppm of Fluoride ion
Manufacturing process: The manufacturing process of composition of example 8 was similar to process covered under example 6 except in addition to other excipient polymer was added in gum dispersion phase
Example 5: Paste Composition
0.62% of Sodium Fluoride Paste
Table 9: 0.62% of sodium fluoride Paste
Sr. No. Ingredients POC-0118/08 POC-0118/10 POC-0118/11 POC-0118/22 POC-0118/26 POC-0118/28
1 Sodium fluoride 0.62 0.62 0.62 0.62 0.62 0.62
2 Chlorhexidine digluconate - - - 0.12 0.12 0.12
3 Liquid sorbitol 21 21 21 21 21 21
4 polyethylene glycol 600 2 2 2 2 2 2
5 Saccharin sodium 0.3 0.3 0.3 0.3 0.3 0.3
6 Xanthan gum 1.1 1.1 1.1 1.1 1.1 1.1
7 Sodium lauryl sulfate 1.25 1.25 1.25 1.25 1.25 1.25
8 Dental type Silica (Precipitated Silica-MFIL-P) 4.5 4.5 4.5 4.5 4.5 4.5
9 Dental type Silica [Precipitated Silica-ABSIL 100-(C)] 15 15 15 15 15 15
10 Tetra Potassium Pyro Phosphate 0.3 0.3 0.3 0.3 0.3 0.3
11 Sodium Benzoate (E211) 0.5 0.5 0.5 0.5 0.5 0.5
12 Unicert blue 05601-J 0.0035 0.0035 0.0035 0.0035 0.0035 0.0035
13 Spearmint flavour 1 1 1 1 1 1
14 Hydroxypropyl cellulose 0.55 - - - - 0.55
15 Sodium Carboxy Methyl Cellulose - - 0.55 - 0.55 -
16 Purified water 51.876 52.426 51.876 52.306 51.756 51.756
1.1% of Sodium Fluoride Paste
Table 10: 1.1% of Sodium Fluoride Paste
Sr. No. Ingredients POC-0118/13 POC-0118/16 POC-0118/17 POC-0118/23
1 Sodium fluoride 1.1 1.1 1.1 1.1
2 Chlorhexidine digluconate - - - 0.12
3 Liquid sorbitol 21 21 21 21
4 Polyethylene glycol 600 2 2 2 2
5 Saccharin sodium 0.3 0.3 0.3 0.3
6 Xanthan gum 1.1 1.1 1.1 1.1
7 Sodium lauryl sulphate 1.25 1.25 1.25 1.25
8 Dental type Silica (Precipitated Silica-MFIL-P) 4.5 4.5 4.5 4.5
9 Dental type Silica [Precipitated Silica-ABSIL 100-(C)] 15 15 15 15
10 Tetra Potassium Pyro Phosphate 0.3 0.3 0.3 0.3
11 Sodium Benzoate (E211) 0.5 0.5 0.5 0.5
12 Unicert blue 05601-J 0.0035 0.0035 0.0035 0.0035
13 Spearmint flavour 1 1 1 1
14 Hydroxypropyl cellulose - 0.55 - -
15 Sodium Carboxy Methyl Cellulose - - 0.55 -
16 Purified water 51.946 51.396 51.396 51.826
1.32% of Sodium Fluoride Paste
Table 11: 1.32% of Sodium Fluoride Paste
Sr. No. Ingredients POC-0118/14 POC-0118/18 POC-0118/20 POC-0118/24
1 Sodium fluoride 1.32 1.32 1.32 1.32
2 Chlorhexidine digluconate - - - 0.12
3 Liquid sorbitol 21 21 21 21
4 Polyethylene glycol 600 2 2 2 2
5 Saccharin sodium 0.3 0.3 0.3 0.3
6 Xanthan gum 1.1 1.1 1.1 1.1
7 Sodium lauryl sulphate 1.25 1.25 1.25 1.25
8 Dental type Silica (Precipitated Silica-MFIL-P) 4.5 4.5 4.5 4.5
9 Dental type Silica [Precipitated Silica-ABSIL 100-(C)] 15 15 15 15
10 Tetra Potassium Pyro Phosphate 0.3 0.3 0.3 0.3
11 Sodium Benzoate (E211) 0.5 0.5 0.5 0.5
12 Unicert blue 05601-J 0.0035 0.0035 0.0035 0.0035
13 Spearmint flavour 1 1 1 1
14 Hydroxypropyl cellulose - - 0.55 -
15 Sodium Carboxy Methyl Cellulose - 0.55 - -
16 Purified water 51.726 51.176 51.176 51.606
2.2% of Sodium Fluoride Paste
Table 12: 2.2% of Sodium Fluoride Paste
Sr. No. Ingredients POC-0118/15 POC-0118/19 POC-0118/21
1 Sodium fluoride 2.2 2.2 2.2
2 Chlorhexidine digluconate - - -
3 Liquid sorbitol 21 21 21
4 Polyethylene glycol 600 2 2 2
5 Saccharin sodium 0.3 0.3 0.3
6 Xanthan gum 1.1 1.1 1.1
7 Sodium lauryl sulphate 1.25 1.25 1.25
8 Dental type Silica (Precipitated Silica-MFIL-P) 4.5 4.5 4.5
9 Dental type Silica [Precipitated Silica-ABSIL 100-(C)] 15 15 15
10 Tetra Potassium Pyro Phosphate 0.3 0.3 0.3
11 Sodium Benzoate (E211) 0.5 0.5 0.5
12 Unicert blue 05601-J 0.0035 0.0035 0.0035
13 Spearmint flavour 1 1 1
14 Hydroxypropyl cellulose - - 0.55
15 Sodium Carboxy Methyl Cellulose - 0.55 -
16 Purified water 50.846 50.296 50.296
2.21% of Sodium Fluoride Paste
Table 13: 2.21% of Sodium Fluoride Paste
Sr. No. Ingredients POC-0118/25 POC-0118/27 POC-0118/29
1 Sodium fluoride 2.21 2.21 2.21
2 Chlorhexidine digluconate 0.12 0.12 0.12
3 Liquid sorbitol 21 21 21
4 Polyethylene glycol 600 2 2 2
5 Saccharin sodium 0.3 0.3 0.3
6 Xanthan gum 1.1 1.1 1.1
7 Sodium lauryl sulfate 1.25 1.25 1.25
8 Dental type Silica (Precipitated Silica-MFIL-P) 4.5 4.5 4.5
9 Dental type Silica [Precipitated Silica-ABSIL 100-(C)] 15 15 15
10 Tetra Potassium Pyro Phosphate 0.3 0.3 0.3
11 Sodium Benzoate (E211) 0.5 0.5 0.5
12 Unicert blue 05601-J 0.0035 0.0035 0.0035
13 Spearmint flavour 1 1 1
14 Hydroxypropyl cellulose - - 0.55
15 Sodium Carboxy Methyl Cellulose - 0.55 -
16 Purified water 50.716 50.166 50.166
Placebo Paste composition
Table 14: Placebo Paste composition
Sr. No. Ingredients POC-0118/30
1 Sodium fluoride -
2 Chlorhexidine digluconate -
3 Liquid sorbitol 21
4 Polyethylene glycol 600 2
5 Saccharin sodium 0.3
6 Xanthan gum 1.1
7 Sodium lauryl sulfate 1.25
8 Dental type Silica (Precipitated Silica-MFIL-P) 4.5
9 Dental type Silica [Precipitated Silica-ABSIL 100-(C)] 15
10 Tetra Potassium Pyro Phosphate 0.3
11 Sodium Benzoate (E211) 0.5
12 Unicert blue 05601-J 0.0035
13 Spearmint flavour 1
14 Hydroxypropyl cellulose -
15 Sodium Carboxy Methyl Cellulose -
16 Purified water 53.546

Example 6: The stability and physicochemical evaluation
The stability and physicochemical evaluation of some of the above formulations which showed better results in all the studies are depicted in the following table.
Table 15: The stability and physicochemical evaluation
Sr. No Parameters Initial 25°C/60%RH 40°C/75%
Conditions 3 Month 6 Month 9 Month 3 Month 6 Month
1 POC-0118/08
Viscosity 34760 46520 48680 44360 43800 50960
Rheology [(tau)(pa)] 12.94 25.81 36.01 33.25 12.68 19.79
Assay of fluoride 94.8 93.8 94.9 93.2 92.4 92.8
2 POC-0118/11
Viscosity 92080 120880 108240 133360 114440 115000
Assay of fluoride 96.6 100.2 98.5 94.8 100.7 94.6
3 POC-0118/13
Viscosity 42280 50640 53920 55840 57720 58800
Assay of fluoride 100 94.7 100.2 95.8 93.9 100.5
4 POC-0118/14
Viscosity 52120 46760 50760 50280 52800 57560
Assay of fluoride 99.5 99.4 100.7 97.6 99.9 100.1
5 POC-0118/16
Viscosity 43880 54960 59600 65320 63560 77040
Assay of fluoride 103 96.1 101.8 95.4 96.5 102.6
6 POC-0118/17
Viscosity 110440 138680 150960 127240 142040 141400
Assay of fluoride 98.1 96.8 99.3 94.6 97.1 100.6
7 POC-0118/19
Viscosity 135120 147560 154000 144880 150960 140240
Assay of fluoride 99.8 100 96.2 93.1 103.2 99.8

,CLAIMS:We claim,
1. A pharmaceutical composition comprising:
(a) a fluoride compound or its pharmaceutically acceptable salt, ester, prodrug thereof; and
(b) one or more pharmaceutically acceptable excipients.
2. The pharmaceutical composition as claimed in claim 1, wherein the composition is a topical dosage form.
3. The pharmaceutical composition as claimed in claim 2, wherein the topical dosage form is in the form of solution, cream, gel, paste, powder and tincture.
4. The pharmaceutical composition as claimed in claim 1, wherein the fluoride compound is selected from the group comprising of an alkali metal fluoride such as sodium fluoride, potassium fluoride, lithium fluoride, or cesium fluoride; zirconium fluoride, ammonium fluoride, stannous fluoride; alkali metal monofluorophosphate such as sodium monofluorophosphate, or potassium monofluorophosphate; or alkali metal titanium fluoride such as sodium titanium fluoride or potassium titanium fluoride; and an organic fluoride compound such as a monoalkylamine hydrofluoride such as hexylamine hydrofluoride, laurylamine hydrofluoride, or cetylamine hydrofluoride; amino acid hydrofluoride such as glycine hydrofluoride, lysine hydrofluoride, or alanine hydrofluoride; or fluorosilane and mixtures thereof.
5. The pharmaceutical composition as claimed in claim 4, wherein the fluoride compound is sodium fluoride.
6. The pharmaceutical composition as claimed in claim 5, wherein sodium fluoride is present in an amount of from 0.62 to 2.21 wt %.
7. The pharmaceutical composition as claimed in claims 1-4, wherein the composition further comprises a humectant, a sweetener, a thickening agent, a surfactant, an abrasive agent, an anti-tartar agent, a preservative, colouring agent and opacifying agent, flavouring agent, polymer, and a solvent.
8. A composition for treating dental caries comprises sodium fluoride, a humectant, a Sweetener, a thickening agent, a surfactant, an abrasive agent, an anti-tartar agent, a preservative, colouring agent and opacifying agent, flavouring agent, polymer, and a solvent.
9. The pharmaceutical composition as claimed in any of claims 1-8, wherein the composition optionally comprises an additional active.