Yahagi R, Onishi H, Machida Y. Preparation and evaluation of double-phased mucoadhesive suppositories of lidocaine utilizing Carbopol and white beeswax.
J Control Release 1999;
61:1-8. [PMID:
10469898 DOI:
10.1016/s0168-3659(99)00111-x]
[Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In an attempt to restrict drug absorption from suppositories to only the lower rectum, mucoadhesive lidocaine (LID) suppositories were prepared using Witepsol H-15 as a base, and Carbopol 934P (CP) and white beeswax (WAX) as additives. CP has a mucoadhesive property and WAX gives the suppositories stiffness. The suppositories containing 10% CP and 20% WAX stayed in the lower recta of rats for at least 2 h. Double-phased suppositories consisting of a front layer containing 10% CP and 20% WAX and a terminal layer containing LID and various amounts of CP were prepared. In vitro release profiles of LID from double-phased suppositories were similar to conventional single-phased suppositories containing CP alone. Values of AUC(0-6 h) and MRT of LID after administration of double-phased suppositories to rabbits were larger than those for single-phased suppositories with or without CP. On the other hand, the initial plasma metabolites concentrations after administration of double-phased suppositories were significantly lower and tended to exhibit delayed T(max) compared to single-phased suppositories. These results suggest that the double-phased mucoadhesive suppositories suppress initial metabolism of LID, and may be useful for improving bioavailabilities of drugs, like LID, which accept first-pass effect considerably.
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