Excipients and Vehicles in EP

• Excipients


  Substances added to a dosage form to aid formulation and manufacture, e.g. give it a good taste or flavour
• Diluents (fillers)


  Add enough bulk for compression and make the tablet easier to handle during manufacturing, e.g. lactose
• Disintegrants


  Encourage tablet to break into smaller particles after ingestion, e.g. modified starch
• Lubricants, glidants, anti-adherents


  Essential for flow of the tablet material into tablet die and to prevent sticking of the compressed tablet onto the punch and die, e.g. magnesium stearate
• Flavouring agents


  Make medicine more acceptable to take, especially if drug has an unpleasant taste, by giving them a more tolerable, nicer taste
• Flavouring agents


  • Must be non-toxic and soluble
  • Must be stable and compatible with the preparation so they don't interact with the drug or other ingredients
• Sweetening agents


  Oral liquid preparations are sweetened with sugars including glucose and sucrose; sucrose also increases the viscosity of liquids
• Sugar-free preparations


  Preparations containing hydrogenated glucose syrup, mannitol, maltitol, sorbitol or xylitol
• Colouring agents


  Added to pharmaceutical preparations to enhance appearance, increase acceptability to patient, prepare products of consistent colour, aid identification
• Colouring agents


  • Should be non-toxic and free of any therapeutic activity
  • Natural colourants derived from plant and animals are preferred
  • Synthetic organic dyes/colouring agent, e.g. azo compounds, sometimes used
• Stabilisers


  Added to prevent or reduce oxidation, e.g. ascorbic acid, citric acid, sodium metabisulfite, sodium sulfite
• Viscosity-enhancing agents


  E.g. syrup may be added to increase the viscosity of an oral solution, improve palatability and physical stability of emulsions and suspension, and facilitate pourability
• Preservatives


  Added to reduce or prevent microbial growth, e.g. chloroform, benzoic acid, ethyl alcohol, sorbic acid, butylhydroxybenzoate, chlorocresol, glycerol, chlorhexidine, chlorbutol
• Vehicle


  The medium which contains the ingredient of a medicine, determines the physical form of the final formulation
• Water as a vehicle


  Widely available, cheap, palatable, non-toxic for oral use, non-irritant for external use, good solvent
• Potable water


  Drinking water drawn freshly from a mains supply, palatable and safe for drinking, may include mineral impurities which could react with drugs
• Purified water


  Prepared from suitable potable water by either distillation or de-ionisation, supports rapid growth of microbiological organisms on standing
• Water for preparations


  Either freshly drawn potable water or freshly boiled and cooled purified water, can be used for oral or external preparations, not intended to be sterile
• Water for injections


  Distilled, pyrogen-free and sterilised, used for parenteral products
• Aromatic waters


  Saturated aqueous solutions of volatile oils or other aromatic substances in water, often used as vehicle in oral solutions, add flavour, have mild carminative effect