Pharmaceutical Dosage Form - Gums

• Medicated gum is a pliable dosage form that is designed to be chewed rather than swallowed.
• Medicated gums release the drug substance(s) into the saliva.
• Medicated gums can deliver therapeutic agents for local action in the mouth or for systemic absorption via the buccal or gastrointestinal routes (e.g., nicotine or aspirin).
• Most gums are manufactured using the conventional melting process derived from the confectionary industry or alternatively may be directly compressed from gum powder.
• Medicated gums are formulated from insoluble synthetic gum bases such as polyisoprene, polyisobutylene, isobutylene isoprene copolymer, styrene-butadiene rubber, polyvinyl acetate, polyethylene, ester gums, or polyterpenes.
• Plasticizers and softeners such as propylene glycol, glycerin, oleic acid, or processed vegetable oils are added to keep the gum base pliable and to aid in the incorporation of the drug substance(s), sweeteners, and flavoring agents.
• Sugars as well as artificial sweeteners and flavorings are incorporated to improve taste, and dyes may be used to enhance appearance.
• Some medicated gums are coated with magnesium stearate to reduce tackiness and improve handling during packaging.
• A preservative may be added.

Preparation#

**Melted gum:** 

• The gum base is melted at a temperature of about 115° C until it has the viscosity of thick syrup and, at that point, is filtered through a fine-mesh screen.

• This molten gum base is transferred to mixing tanks where the sweeteners, plasticizers, and typically the drug substance are added and mixed.

• Colorings, flavorings, and preservatives are added and mixed while the melted gum is cooling.

• The cooled mixture is shaped by extrusion or rolling and cutting.

• Dosage units of the desired shape and potency are packaged individually.

• Additional coatings such as powder coatings to reduce tackiness or film or sugar coatings

• may be added to improve taste or facilitate bulk packaging.

  Directly compressed gum:

• The gum base is supplied in a free-flowing granular powder form.

• The powder gum base is then dry blended with sweeteners, flavors, the drug substance, and lubricant.

• The blend is then processed through a conventional tablet press and tableted into desired shapes.

• The resulting medicated gum tablets can be further coated with sugar or sugar-free excipients.

• These tablets can be packaged in blisters or bottles as needed.

Special Considerations#

• Medicated gums are typically dispensed in unit-dose packaging.
• The patient instructions also may include a caution to avoid excessive heat.