Deposits from Creams Containing 20% (w/w) Urea and Suppression of Crystallization (Part 2): Novel Analytical Methods of Urea Accumulated in the Stratum Corneum by Tape stripping and Colorimetry

• Goto Norio

  Honjo Reserch Section Drug Development Technology Center, Customer Joy Department Eisai Japan, Eisai Co., Ltd.

• Morita Yutaka

  Reserch & Development Div., Elmed Eisai Co., Ltd.

• Terada Katsuhide

  Faculty of Pharmaceutical Sciences, Toho University

抄録

The transfer of urea from a urea formulation to the stratum corneum varies with the formulation base and form, and impacts the formulation’s therapeutic effect. Consequently, determining the amount of urea transferred is essential for developing efficient formulations. This study assessed a simple method for measuring the amount of urea accumulated in the stratum corneum. Conventional methods rely on labeling urea used in the formulation with radiocarbon (¹⁴C) or other radioactive isotopes (RIs), retrieving the transferred urea from the stratum corneum by tape stripping, then quantitating the urea. The handling and use of RIs, however, is subject to legal regulation and can only be performed in sanctioned facilities, so methods employing RIs are neither simple nor convenient. We therefore developed a non-radiolabel method “tape stripping-colorimetry (T-C)” that combines tape stripping with colorimetry (urease–glutamate dehydrogenase (GLDH)) for the quantitative measurement of urea. Urea in the stratum corneum is collected by tape stripping and measured using urease-GLDH, which is commonly used to measure urea nitrogen in blood tests. The results indicate that accurate urea measurement by the T-C method requires the application of 1400 mg (on hairless rats) of a 20% urea solution on a 50 cm² (5×10 cm) area. Further, we determined the amount of urea accumulated in the stratum corneum using formulations with different urea concentrations, and the time course of urea accumulation from formulations differing in the rate of urea crystallization. We demonstrate that the T-C method is simple and convenient, with no need for ¹⁴C or other RIs.

収録刊行物

• ＣＨＥＭＩＣＡＬ　＆　ＰＨＡＲＭＡＣＥＵＴＩＣＡＬ　ＢＵＬＬＥＴＩＮ

  ＣＨＥＭＩＣＡＬ　＆　ＰＨＡＲＭＡＣＥＵＴＩＣＡＬ　ＢＵＬＬＥＴＩＮ 64 (8), 1092-1098, 2016

  公益社団法人 日本薬学会

キーワード

• urea
• tape-stripping
• colorimetry
• urease
• accumulation
• stratum corneum

詳細情報

• CRID: 1390001204176575616
• NII論文ID: 130005253971
• NII書誌ID: AA00602100
• DOI: 10.1248/cpb.c15-00784
• ISSN: 13475223
• ISSN: 00092363
• NDL書誌ID: 027522787
• PubMed: 27477646
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I027522787
• Web Site: https://www.jstage.jst.go.jp/article/cpb/64/8/64_c15-00784/_pdf
• Web Site: https://search.jamas.or.jp/link/ui/2017306839
• 本文言語コード: en
• データソース種別:
  • JaLC
  • NDL
  • Crossref
  • PubMed
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可