Influence of the dissolution medium on the release of dehydroepiandrosterone from lipophilic suppositories

Suppositories with cocoa butter containing dehydroepiandrosterone (DHEA) without and with the addition of Span 80 and Tween 80 as surfactants with low and high HLB values were prepared. The physical properties and the drug content of all prepared suppositories were in accordance with the pharmacopoeial requirements. The release study tests in three dissolution media such as water, lactic acid solution at pH 4.2 and phosphate buffer at pH 7.4 were carried out. In acidic and alkalic media only about 10% and 27% of DHEA were released, respectively. The addition of Span 80 to the suppository mass did not improve the release process, but the addition of Tween 80 caused the increase in the amount of DHEA released in the acidic medium to about 35%. The data showed that rectal administration of suppositories with DHEA based on cocoa butter caused about 30% availability and after vaginal administration, only topical activity can be expected. By the addition of Tween 80 to the suppository mass availability of DHEA of about 35% from vaginal suppositories can be achieved.