Tooth Pastes - Industrial pharmacy - I B. Pharma 5th Semester PDF Notes
Tooth Pastes
Contents
• Tooth paste
• Formulation aspects
• Manufacturing of tooth paste
• Packaging and evaluation of dentifrices
Learning objectives
• At the end of this lecture, student will be able to:
– Explain the formulation of tooth paste
– Explain the manufacturing of tooth paste
– Discuss on packaging and evaluation of dentifrices
Dentifrices
• The tooth is composed of calcium, phosphorus, and other mineral salts
• The hard, shiny and outermost layer visible is called the enamel
• Dentifrices are hygienic preparations intended to cleanse the teeth, keep them shiny and to preserve the health of teeth
• Though the primary function of a dentifrice is the cleaning of the accessible surfaces of the teeth, some other functions include:
– Prevention of formation of dental plaque
– Prevention of formation of calculus
– Polishing of tooth
– Removal of stains
– Reduction of periodontal disease
Parts of tooth
Types of Dentifrices
• Tooth powder
• Tooth paste
Ideal properties of good dentifrices
• It must adequately clean teeth of stain, food, debris and plaque
• It must remove bad odour of mouth cavity and should leave sensation of cleanliness and freshness in mouth sensation of cleanliness and freshness in mouth
• It should be non-toxic
• It should be pleasant and provide good flavour in oral cavity as an after effect
• It must be easy to use
• It must reduce the teeth decay
• It should not damage tooth enamel because of its abrasiveness
• It should be economic
Tooth paste
• Tooth pastes contain several ingredients such as
– Abrasives and polishing materials
– Detergents and foaming materials
– Humectants
– Binding agents
– Sweetening materials
– Flavors
– Preservatives
– Miscellaneous or special ingredients such as
Anti caries agents
Anti-bacterial agent
Desensitizing agent
Whitening agent etc.
Abrasives and polishing materials
• Abrasiveness depends on the inherent hardness of abrasive, size, and shape of abrasive particle
• Other factors that may affect abrasiveness are:
– Brushing technique,
– The pressure on the toothbrush,
– The hardness of the bristles,
– Direction and number of strokes
• Excess abrasion may cause damage to tooth surface tooth enamel erosion
Detergents and foaming materials
• The cleansing action of the detergents is due to their lowering of surface tension
• They help in wetting the teeth which aids in removal of debris
• Sodium lauryl sulphate is one of them most widely used
• Others are magnesium lauryl sulphates, sodium lauryl sarcosinate, and diethyl sodium lauryl sulphosuccinate
Sweetening agents
• Sweetening agent is an essential ingredient
• Sodium Saccharine and xylitol is a widely used sweetening agent
• It is used in 0.05 to 0.31%
Flavouring agents
• Flavours are incorporated to provide a good flavour and to have a long term effect in the mouth
• Commonly used are peppermint oil, spearmint oil, anise oil, Clove oil, winter green oil
Humectants
• Humectants are added to maintain moisture and impart some plasticity character to the toothpaste
• They prevent drying out of toothpaste
• Usually added in concentration of 10-30%
• They aid in subsequent hardening of the product upon exposure to air
• Sugar and honey were used previously.
• Commonly used are Saccharin, sorbitol, xylitol, mannitol, propylene glycol and Glycerin
• Sorbitol – also known as glucitol, is commonly used in modern cosmetics as a humectant and thickener
• Transparent gel can be made using sorbitol
• Xyitol – also called as wood sugar, is a naturally occurring sweetening agent found in the fibers of many fruits and vegetables including berries, corn, husks, oats and mushrooms
• They aid in repairing minor cavities caused by dental caries
Binding agents
• Various hydrocolloids are used in tooth pastes to improve and maintain the consistency
• These hydrocolloids are used in 2-5%.
• Initially starch, liquid glucose and simple syrup were used
• But slowly they were replaced by mucilages, karaya gum, gum arabic, gum acacia, tragacanth, and sodium alginate
Preservatives
• Preservatives are added to prevent bacterial growth
• Commonly used are methyl and para parahydroxy benzoate (parabens) in range of 0.15%-0.02%
Colouring agents
• FD & C approved colours and opacifiers like titanium dioxide, zinc oxide are used
Miscellaneous or special ingredients
• Anti caries agents
• Anti-bacterial agent
• Desentizing agent
• Whitening agent
Miscellaneous or special ingredients
| Anti-Caries / Cavity Protection | Sodium fluoride sodium monofluorophosphate | contain fluoride to stop tooth enamel decalcification and protect teeth from tooth decay and cavities | Eg. Colgate cavity protection |
| Anti-bacterial (Plaque & Gingivitis Prevention) | Sodium Lauryl Sulphate, Triclosane, Zinc and Stannous ions | Antibacterial and prevent the formation of dental plaque. | Eg. Crest-pro- health clinical gum protection |
| Desentizing | Potassium nitrate, sodium chloride | Reduces the sentivity of teeth to hot and cold | Eg: Sensodyne |
| Tooth Whitening | Papain, Dimethicone Charcoal | Have either higher abrasion value than normal toothpastes to mechanically remove food, smoking and other stains from teeth. | Eg. Colgate Optical White and Colgate Pro-clinical White. |
Manufacturing of Tooth Paste
First method
• Binder is wetted by humectant it’s then dispersed in liquid portion containing saccharine and preservative
• Its allowed to swell untill a homogeous mass or gel is obtained
• Flavours an detergents are added and mixed well
• The paste is then milled, cleavated and tubed
Second method
• Binder is premixed with solid abrasive
• Its then dispersed in liquid portion containing humectant, saccharine and preservative
• Its allowed to swell untill a homogeous mass or gel is obtained
• Flavours an detergents are added and mixed well
• The paste is then milled, cleavated and tubed
Packaging of dentifrices
• Tin coated lead tubes were used
• Aluminium tubes being light and strong are used commonly
• Corrosion of aluminium tubes is minimized by internally waxing or lacquering the tubes
• Inhibitors of corrosion such as sodium silicate is added
• Paste containing stannous fluoride should not be packed in aluminium tubes
• Polyolefins collapsible tubes are also used
Evaluation of Dentifrices
• Dentifrices are evaluated
– Abrasiveness
– Particle size
– Cleaning property
– Foaming property
– pH
– Consistency
Determination of abrasive particles
• The paste was extruded about 15 to 20 cm length from collapsible tube of each sample on a butter paper
• Then all the samples were tested by pressing it along its entire length by a finger for the presence of hard and sharp edged abrasive particles for all samples
Determination of spread ability
• About 1 gm of each sample was weighed and placed at the centre of the glass plate (10X10 cm) and another glass plate was placed over it carefully
• Above the glass plates 2 kilogram weight was placed at the centre of the plate avoid sliding of the plate
• The diameter of the paste in centimeters was measured, after 30 minutes for all samples
• The experiment was repeated three times and the averages were reported for all samples
Determination of fineness
• 10gm of each sample was accurately weighed and placed in a 100ml beaker
• To this 50ml of water was added and allowed to stand for 30 mins with occasional stirring until the toothpaste was completely dispersed
• This solution was passed through to 150 micron Indian Standard sieve
• Then the sieve was washed with running tap water
• Washing should be continued until all the matters passed by through the sieve
• After washing the residue remains on sieves were collected and dried in an oven at 105°C
Determination of pH
• 5 gm of all samples was accurately weighed and placed in a 150 ml beaker
• To this 45 ml of freshly boiled and cooled water was added at 27°C
• It was stirred well to make a thorough suspension
• The pH was determined for all samples within 5 minutes by using pH meter
Determination of foaming power
• About 5gm of each sample was weighed and placed in a 100ml glass beaker
• To this 10ml of water was added and the beaker was covered with a watch glass and allowed to stand for 30 minutes, this operation was carried out to disperse the toothpaste in water
• The contents of the beaker were stirred with a glass rod and the slurry was transferred to a 250ml graduated measuring cylinder, during this transfer ensure that no foam was produced and no lump paste went into the measuring cylinder
Summary
| Constituent | Purpose |
| Abrasive | Cleaning/stain removal |
| Water | Solvent for ingredients |
| Humectants | Provide creamy texture |
| Detergent | Surfactant/foam builder |
| Thickening agent | Controls viscosity |
| Flavoring agent, | Enhances flavour |
| Sweetening agent | Improves taste |
| Colouring agent | Imparts colour |
| Therapeutic agent(s) | Active ingredient(s) |
| Preservative | Inhibits microbial growth |
| Binder | Holds ingredients together |
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