Buccal and Sublingual Tablets Overview

Buccal / Sublingual Tablets

• Held in the mouth, either between the cheek and teeth or under the tongue
• Usually small and flat
• Release drug content for direct absorption through the oral mucosa
• Require good absorption through the mucosa for systemic effect
• Use tasteless excipients to avoid stimulating salivation
• Should dissolve slowly, over 15 to 30 minutes
• Offer advantages over swallowed tablets, including avoiding first-pass metabolism and rapid onset
• Limitations include the inability to use bitter or foul-tasting drugs

Troches and Lozenges

• Used for local effects in the mouth and throat, such as treating sore throat or controlling cough
• Designed to dissolve slowly, over 30 minutes or less
• Lozenges consist of drug incorporated into a flavored hard candy sugar base
• Troches are formed by compression

Dental Cones

• Small tablets placed in the empty socket remaining after tooth extraction
• Prevent bacterial multiplication by releasing an antibacterial agent or reducing bleeding using an astringent or coagulant
• Common vehicles for these tablets include NaHCO3, NaCl, and amino acids
• Dissolve or erode slowly, over 20 to 40 minutes

Implantation Tablets / Depot Tablets

• Subcutaneously implanted to provide prolonged drug effect, lasting from one month to one year
• Usually small, cylindrical or rosette-shaped
• Limitation includes requiring surgical technology to discontinue therapy and potential tissue toxicity in the implantation area

Vaginal Tablets

• Ovoid or pear-shaped tablets designed for slow distribution and drug release in the vaginal cavity
• Used to treat infections with antibacterials, antiseptics, astringents, or release steroids for systemic absorption

Effervescent Tablets

• Rapidly soluble tablets that release CO₂ within one minute or less
• Produce a clear solution and a carbonated drink
• Require water-soluble excipients
• Advantages include accurate dosing and taste masking
• Limitations include difficulty in producing chemically stable products due to moisture sensitivity and requiring special packaging to protect from moisture

Dispensing Tablets (DT)

• Intended to be added to a given volume of water
• Commonly incorporated materials include bichloride of mercury and germicidal solutions
• Utilize completely soluble components in the formulation
• May contain buffering or isotonicity-creating excipients
• Less commonly used as water quality is unknown and some components are extremely hazardous if swallowed accidentally

Hypodermic Tablets (HT)

• Readily water-soluble tablets added to sterile water or water for injection
• No longer in common use, previously used in rural areas by physicians

Tablet Triturates (TT)

• Small, cylindrical tablets containing potent drugs
• Soft and fragile tablets, leading to potential drug loss

Formulation of Tablets:

• Compressed tablets are typically composed of active ingredients mixed with excipients, including:
  • Diluents
  • Binders
  • Disintegrating agents
  • Lubricants
  • Coloring agents
  • Flavoring agents
  • Sweetening agents

Manufacturing processes for tablets:

• Direct compression
• Dry granulation (slugging or roller compaction)
• Wet granulation
• Fluid bed granulation

Fluid Bed Granulation

• Performs preblending, granulation, and drying in a single piece of equipment

Direct Compression:

• A process that obviates the need for granulation
• Suitable for materials with good flow and cohesive properties
• Requires premilling of components, mixing, and compression of the powder mix

Dry Granulation:

• Granulation is formed by compacting large masses of the mixture, followed by crushing and sizing

Wet Granulation:

• Involves mixing the drug and diluent, adding a binder, wet massing, wet sizing/milling, drying, dry screening, lubrication, and tabletting
• Advantages include reduced segregation, suitability for low-concentration therapeutic agents, and amenability to post-processing
• Disadvantages include multiple processing steps, potential for drug degradation, and possible changes in polymorphic form due to drying

Tableting:

• The final stage of tablet formation where the tablet is produced by compressing the formulation in a tablet press
• Basic components of a tablet compression machine include:
  • Hoppers for holding and feeding the granulation
  • Dies that define the tablet size and shape
  • Punches for compressing the granulation
  • Cam tracks for guiding punch movements