suppositories

• Rectal delivery route


  Intended to obtain a systemic or local effect, or for diagnostic purposes
• Vaginal delivery route


  Intended to obtain a local effect
• Rectal and vaginal preparations of the BP contain one or more active substances in a suitable basis
• Suppositories


  Solid, single-dose preparations suitable for rectal administration, containing one or more active substances dispersed or dissolved in a suitable basis
• Pessaries


  Solid, single-dose preparations suitable for vaginal administration, containing one or more active substances dispersed or dissolved in a suitable basis
• Suppository production


  1. Preparation of the mould

  2. Base preparation (displacement value calculation)

  3. Preparation of the active drug

  4. Mixing and pouring
• Mould preparation


  • The mould must be clean and dry
  • Lubrication may be needed
  • Equilibrate the mould at room temperature before use
  • Each mould has a specific capacity
  • Moulds are filled by volume so not all moulds and all bases give 1g suppositories
  • Each mould needs to be calibrated
• Base preparation


  • Temperature of melting must be controlled depending on base used
  • The amount of base needed will depend on the amount of drug included
• Preparation of the active drug

  • Drug is ideally included as a powder
  • Inclusion of liquids might require the use of emulsifiers to form an emulsion
  • Powders are included by direct mixing when soluble in the base or trituration when insoluble in the base
  • Reduce particle size of the powder to improve the dispersion in the base
• Mixing and pouring


  • Allow enough mixing time in order to have an homogeneously dispersed drug
  • Mix continuously until you notice an increase in viscosity that indicates that the base is about to set (congealing point)
  • Start pouring into the first cavity of the mould
  • Overfill the cavity of the mould to allow for shrinkage
  • Move to the following cavity without stopping pouring to avoid formation of layers
  • Trim excess when it has solidified
  • Allow to cool
• Characteristics of suppositories and pessaries

  • Single dose dosage form
  • Solid dosage form
  • The drug can be dissolved or dispersed
  • They are administered to obtain both a local and a systemic effect
  • They are formulated with bases that are soluble or dispersible in water or melt at body temperature
• Steps of suppositories compounding

  1. Prepare the mould

  2. Weigh the excipients and drug

  3. Melt the base

  4. Mix the drug with the base

  5. Pour in the mould

  6. Mix until congealing point

  7. Trim the excess

  8. Remove suppositories and wrap individually
• The molten base is poured at congealing point to avoid formation of layers
• If the molten base is poured before congealing point the suspended drug might precipitate before the suppository solidifies
• If the molten base is poured after congealing point the base might solidify too quickly and give malformed suppositories
• The base must be poured continuously to avoid the formation of layers
• Each cavity must be overfilled to allow for the shrinkage of the base on cooling