Pharmaceutical Excipients: Binders and Fillers

Binders

• Definition: Substances that hold the active pharmaceutical ingredient (API) together to form a solid dosage form
• Function: Improve the strength and cohesion of tablets or granules
• Examples:
  • Natural binders: starch, cellulose, gelatin
  • Synthetic binders: polyvinylpyrrolidone (PVP), polyethylene glycol (PEG)

Fillers

• Definition: Inert substances that add bulk to the formulation to make it easier to manufacture and handle
• Function: Increase the weight and volume of the final product
• Examples:
  • Inorganic fillers: calcium phosphate, silica
  • Organic fillers: lactose, starch, cellulose

Lubricants

• Definition: Substances that reduce the friction between the API and the machinery during manufacturing
• Function: Prevent sticking and wear on equipment, and improve the flow of powder during tableting
• Examples:
  • Hydrophobic lubricants: magnesium stearate, calcium stearate
  • Hydrophilic lubricants: sodium lauryl sulfate, sodium stearyl fumarate

Preservatives

• Definition: Substances that prevent the growth of microorganisms in the formulation
• Function: Protect the product from contamination and spoilage
• Examples:
  • Antimicrobial preservatives: parabens, phenol, cresol
  • Antioxidant preservatives: vitamin E, vitamin C, beta-carotene

Coatings

• Definition: Outer layers applied to tablets or capsules to control the release of the API
• Function: Modify the release of the API, improve stability, and enhance appearance
• Examples:
  • Film coatings: hydroxypropyl methylcellulose (HPMC), polyvinyl acetate phthalate (PVAP)
  • Sugar coatings: sucrose, corn syrup
  • Enteric coatings: cellulose acetate phthalate (CAP), hydroxypropyl methylcellulose acetate succinate (HPMCAS)

Binders

• Hold the active pharmaceutical ingredient (API) together to form a solid dosage form
• Improve the strength and cohesion of tablets or granules
• Examples of natural binders: starch, cellulose, gelatin
• Examples of synthetic binders: polyvinylpyrrolidone (PVP), polyethylene glycol (PEG)

Fillers

• Add bulk to the formulation to make it easier to manufacture and handle
• Increase the weight and volume of the final product
• Examples of inorganic fillers: calcium phosphate, silica
• Examples of organic fillers: lactose, starch, cellulose

Lubricants

• Reduce the friction between the API and the machinery during manufacturing
• Prevent sticking and wear on equipment, and improve the flow of powder during tableting
• Examples of hydrophobic lubricants: magnesium stearate, calcium stearate
• Examples of hydrophilic lubricants: sodium lauryl sulfate, sodium stearyl fumarate

Preservatives

• Prevent the growth of microorganisms in the formulation
• Protect the product from contamination and spoilage
• Examples of antimicrobial preservatives: parabens, phenol, cresol
• Examples of antioxidant preservatives: vitamin E, vitamin C, beta-carotene

Coatings

• Modify the release of the API, improve stability, and enhance appearance
• Examples of film coatings: hydroxypropyl methylcellulose (HPMC), polyvinyl acetate phthalate (PVAP)
• Examples of sugar coatings: sucrose, corn syrup
• Examples of enteric coatings: cellulose acetate phthalate (CAP), hydroxypropyl methylcellulose acetate succinate (HPMCAS)