Mouth Washes : Formulation and Manufacturing

Formulation of Mouthwashes:

Mouth washes are formulated with the aqueous or alcoholic solutions of flavouring oils. These mouth washes removes the bad odours and gives a refreshing feeling in the mouth. They may or may not contain a soap or detergent. These mouth washes contain ingredients such as alcohol, water, flavouring oil and sodium lauryl sulphate.

The above mouth washes are not very popular. Therapeutic agents like anti-bacterials, astringents are added to manufacture them as drugs. Some of the anti-bacterial agents which are added are

• Chlorinated phenol – para-chloro meta-cresol, para-chloro meta-xylenol
• Thymol
• Quaternary ammonium compounds – benzalkonium chloride
• Chlorhexidine
• Peroxides – Hydrogen peroxide

Essential oils which are used in anti-bacterial mouth washes shows anti-bacterial activity along with imparting flavour, thus they show synergistic anti-bacterial effect.

Some of the essential oils are

• Cinnamon oil
• Clove oil
• Eucalyptus oil
• Peppermint oil
• Anise oil
• Winter-green oil

The constituents of these oils like menthol, thymol, eucalyptol, anethole, methyl salicylate are used. Thymol is chemically isopropyl meta-cresol and it has anti-bacterial action. It is sparingly soluble in water, to enhance its solubility it is mixed with borax or suitable alcohols.

Astringent Mouthwash:

Astringent mouth washes are prepared by using metallic compounds. The most commonly used metallic compounds are zinc and aluminium compounds like

• Zinc chloride
• Zinc acetate
• Aluminium potassium sulphate

These compounds are used in the concentrations of 0.05 to 0.2 %. Zinc phenol sulphonate can be used in the concentration of 0.1 to 0.3 %. Copper salts are not used for the formulation as they show emetic effects. Salts of iron and manganese are not used as they may stain the teeth. Some other substances which can be used for formulation are

• Tannic acid and its derivatives
• Citric acid
• Lactic acid
• Acetic acid

Alkaline Mouthwash:

Alkaline mouthwashes are formulated by using sodium bicarbonate.

Anti-enzyme Mouthwash:

Anti-enzyme mouthwashes are formulated by using sodium N-lauroyl sarcosnate in the concentration of 0.1%. Mouth Fresheners are also prepared in the form of aerosols. They are solutions of antiseptic material in alcohol containing some amount of water. A container charge may contain 30-35 of mouthfreshner base and the rest is filled by propellent.

Manufacture of Mouthwashes:

The most suitable mixing vessels for manufacturing of all types of mouth washes are stainless steel vessels of grade SS 316, the mixing vessels are glass-lined and they should have refrigerant chilling coils, this is because if the solubility of the formulation is low, they can be chilled before filtration. Alternatively, clean ice can be used instead of water in the formulation. Before filling, all mouthwashes should be filtered. For the filtration filter aids like fuller’s earth, pure talc etc can be used. Pressure filters are the suitable filtering machines. After filtration, they are then filled into suitable containers. The most suitable containers are glass containers. Mouth washes are generally manufactured in concentrated form. Directions for use like dilution should be clearly indicated on the label. Warnings and cautions, if any should also be indicated on the label.