[The dynamics of the drug release from suppositories. Part 5: Liberation of chlorpromazine from suppository bases (author's transl)].

The authors determined the liberation of chlorpromazine hydrochloride from suppositories prepared with the polyethylene glycols PEG 1000, 1500, 2000, 4000, 6000 and their mixtures as well as with the lipophil bases cocoa butter, Witepsol W35 and Witepsol H15. The determinations were made with the apparatus described by Kerckhoffs and Huinziga using a phosphate buffer (pH = 7.4). It was found that the liberation was most rapid from hydrophilic polyethylene glycol bases; and the release rates decreased in the following order: PGE 4000 (75%) + PEG (25%) leads to PEG 4000 (75%) + glycerol (25%) leads to PEG 2000 leads to PEG 1500 (70%( + PEG 6000 (30%) leads to PEG 4000 leads to PEG 6000. The release from lipophil bases was poor.