A method for stabilizing an oral, liquid medicament on the basis of imipramine and an ion exchange resin

摘要

1,176,194. Pharmaceutical preparations containing imipramines. GEIGY (U.K.) Ltd. 9 Aug., 1968 [12 Aug., 1967], No. 37136/67. Heading A5B. [Also in Division C3] A pharmaceutical preparation (providing immediate and rapid release of the therapeutic agent for oral administration) comprises a suspension or dispersion, in a carrier liquid which is substantially free of ions or ionisable material, of a solid compound formed from imipramine, chlorimipramine, 10-keto-imipramine, desimipramine or opipramol base and a cation-exchange resin in the form of a methacrylate polymer containing carboxyl groups and having a degree of cross-linkage from 1 to 10%. The base is combined with the resin by agitating the resin with a solution of the base, e.g. in an acetone/water or isopropanol/water mixture, in the proportion of base to resin from 10 to 50% on a dry weight to weight basis. The resin may be a polymethacrylic acid or a copolymer of methacrylic acid and divinyl benzene, preferably having a particle size in the range of from 1 to 150 microns. The base may be used in the form of a pharmaceutical grade free base or it may be set free from the corresponding salt, preferably the hydrochloride, by solvent extraction after making alkaline, or by passing through an anion-exchange resin column, e.g. a polystyrene type polymer containing quaternary ammonium groups and cross-linked with divinyl benzene. The carrier liquid medium may comprise water and may also contain one or more sweeteners, flavours, colloid thickening agents, colours and preservatives.