Evaluation of aminophylline suppositories prepared in a hospital pharmacy

Physical and chemical stability of suppositories containing aminophylline and various bases prepared in our hospital pharmacy was investigated. Ethylenediamine in aminophylline decreased, the melting points of the suppositories rose, and the disintegration and liquefaction times were prolonged in suppositories with Witepsol base when stored at room temperature. Thin-layer chromatography produced evidence supporting the assumption that ethylenediamine may react with Witepsol constituents to form an acid amide linkage. However, the suppositories were stable at lower temperatures. Suppositories prepared with PEG base were found to be satisfactorily stable at room temperature.