标题：In Vivo Release of Water-Soluble Drugs from Stabilized Water-in-Oil-in-Water (W/O/W) Type Multiple Emulsions Following Intravenous Administrations Using Rats
摘要：The in vivo release of four water-soluble drugs, cefadroxil, cephradine, antipyrine and 4-aminoantipyrine, from a stabilizing water-in-oil-in-water (W/O/W) type multiple emulsion was studied using rats. The W/O/W type multiple emulsion used in this study could be stabilized for 30 d after preparation at room temperature and also for 24 h in pH 7.4 isotonic phosphate buffer or in rat plasma at 37°C. The cefadroxil and cephradine concentrations in rat plasma following intravenous administrations of their W/O/W type multiple emulsions containing drugs were considerably prolonged compared with those of respective aqueous solutions. Sustained-releasing properties of cefadroxil and cephradine from W/O/W type multiple emulsions could be explained by the mechanism underlying the long residence time of W/O/W type multiple emulsions and delay-release of drugs from the W/O/W type multiple emulsions circulated with rat blood stream. However, antipyrine and 4-aminoantipyrine decreased rapidly following W/O/W type multiple emulsions and these plasma profiles coincided precisely with those following intravenous administration of the aqueous solutions of drugs. These in vivo releasing data correlated with in vitro drug release observation stated in the previous papers [W. Zhang et al., Yakugaku Zasshi, 112, 73 (1992); S. Goto et al., ibid., 111, 702 (1991)].
关键词：sustained-releasing;W/O/W type multiple emulsion glyceryl tricaprylate;polyoxyethylene hydrogenated castor oil;cephradine;cefadroxi
