rectal and vaginal delivery routes Flashcards
formulation of suppositories
what are rectal preparations intended for?
-rectal use in order to obtain a systemic or local effect or they may be intended for diagnostic purposes
what are vaginal preparations intended for?
-they are liquid, semisolid or solid preparations intended for administration to the vagina in order to obtain a local effect
-they contain 1 or more active substances in a suitable basis
what are suppositories?
-solid,single dose preparations, the shape, volume and consistency of suppositories are suitable for rectal administration
how many active substances do suppositories contain?
-one or more and they are dispersed or dissolved in a suitable basis
what excipients can be added to suppositories?
-if necessary and authorised by the competent authority, recipients such as diluents, adsorbents,surface active agents, lubricant,antimicrobial preservatives and colouring matter may be added
what are pessaries?
-solid,single dose preparations that have various shapes, they are usually ovoid with a volume and consistency suitable for insertion into the vagina
how many active substances can pessaries have?
-1 or more, they are dispersed or dissolved in a suitable basses that may be soluble or dispersible in water or may melt at body temp
what excipients can be added to pessaries?
-if necessary and authorised by the competent authority, excipients such as diluents, adsorbents,surface active agents, lubricant,antimicrobial preservatives and colouring matter may be added
how are suppositories prepared?
-compression or moulding
-sometimes the active substances are ground and sieved through a suitable sieve
-the medicated mass is sufficiently liquified by heating and is poured into the suitable mould
-the suppository solidifies on cooling
what excipients are available for the process of the production of suppositories?
-hard fat
-macrogols
-cocoa butter
-gelatinous mixtures consisting of gelatine,water and glycerol
what are the 4 main steps of formulating and compounding?
-mould preparation
-base preparation(DV calcs)
-prep of the active drug
-mixing and pouring
what happens in mould preparation?
-the mould must be clean and dry
-Lubrication may be needed-glycerin (inc fatty acids) and mineral oil (inc hydrophilic bases)
-mould needs to be equilibrated at room temp 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
what happens in base preparation?
-the temperature of melting must be controlled depending on the base used
-the amount of base needed will depend on the amount of drug included-displacement value calculation
what happens during the preparation of the active drug?
-the drug ideally needs to be included as a powder as liquids occupy too much volume
-inclusion of liquids might require the use of emulsifiers to form an emulsion
-Powders are included by:direct mixing when soluble in the base,trituration when insoluble in the base
why is it important to reduce the particle size of the powder during the pre of the active drug?
-to improve the dispersion in the base
what happens during the mixing and pouring step?
-enough mixing time needs to be allowed in order to have a homogeneously dispersed drug
-continuous mixing needs to happen until there is an increase in viscosity which indicates that the base is about to set (congealing point)
-base needs to be poured into the first cavity of the mould
-the cavity of the mould needs to be overfilled to allow for shrinkage
