EFFECT OF SUBSTANCES INSOLUBLE IN LIPOPHILIC EXCIPIENTS ON DRUG RELEASE FROM SUPPOSITORIES

The dispersion in a lipophilic excipient for suppositories of an insoluble powder produces an increase in viscosity which is proportional to the concentration. The nature and the amount of the powder have shown to greatly influence the release rate of a drug from suppositories. Hydrosoluble substances, such as mannitol or lactose, have failed to influence the availability of a drug such as paracetamol, although the viscosity of suppositories was high. On the contrary, water insoluble powders have caused a considerable decrease in drug release rate.